Low Mileage Issue List. Suggestions Appreciated!

[ninetytwo]

Some of you might have seen my introduction post a month or so ago, if not, I have a '93 400E with 36k miles. It has very clearly not been driven much at all and even less in the last five years. Unsurprisingly the more I drive it, the happier things are but I do want to take care of these details. My shop is good and familiar with this series but examples they work on are few and far between.

I have been doing extensive research but some things I cannot find or don't quite fit my situation. I appreciate any knowledge, direction, links, etc. I am very excited to finally have a 124 yet my time to solve these problems is limited and I want to make sure I have enough background knowledge before talking with my shop.

-Shifting into D or R is hard. Highway shifts are smooth. ATF is clean. Idling in gear is smooth and level at 600RPM. Have not tested cruise control yet.

-Running rich? The exhaust while idling has a slight unburnt smell- not nearly as clean smelling as I would expect. Likewise fuel economy is lousy.

-ASR/ABS: all four related lights come on from time to time or don't show up at all. I do not have a limp condition. The battery appears strong. Ignition harness is the updated version in like-new condition. Lower harness is flaking. Because its NLA, I will have to have it rebuilt. Stored codes: 007 Ignition System & 096 Started lock-out backup lamp switch S16/3.

-External temp inaccurate and occasionally blinks off and on. Probe behind plate looks like its had water intrusion.

-Bang from dashboard center when key is in Pos.II Has a vacuum-esque sound to it.

-Oil pressure gauge: sometimes while cruising it will indicate '2' or stay at full pressure while idling in Park.

 

[gsxr]

Has the ATF & filter been changed since you bought it? If so, what fluid was used? What is idle speed in Park, before you put it in D or R?

Fuel economy - has the oxygen sensor been replaced? Fuel pressure tested, and/or fuel pressure regulator replaced? LH module adaptation values pegged rich or lean? (Need digital scanner to view adaptation values.)

Stored code 007 Ignition System, what module is that code stored on? Code 096 indicates your starter lockout switch likely needs to be replaced, or at least adjusted. Plan on replacement.

External temp sensor, behind front license plate, probably needs to be replaced. You can splice in a good used one, at least for a test, new aren't cheap.

Dash vacuum noise may be normal, but hard to say without a video clip.

Oil pressure - replace the sender below oil filter housing, OE/OEM Hella/VDO only. This *may* also be related to the lower harness if badly degraded.

 

[gerryvz]

Shifting into D or R is hard. Highway shifts are smooth. ATF is clean. Idling in gear is smooth and level at 600RPM. Have not tested cruise control yet.

Generally this is because of an idle issue, or no/bad vacuum at the modulator from the intake manifold. If it's idling at 600, then it sounds like it's at the right place. There is a vacuum line that runs down along the inner firewall behind the engine that goes to the modulator. Check that line and replace it + the connectors.

-Running rich? The exhaust while idling has a slight unburnt smell- not nearly as clean smelling as I would expect. Likewise fuel economy is lousy.

As GSXR says, very well could be the O2 sensor being incorrect and sending a bad signal back to the computer. Could also be an issue with the cats. Is the engine firing on all cylinders, and idling smoothly at the 600 rpm? Both coils are good? One bad cylinder will cause this issue, with unburnt gas moving through the engine and into the exhaust.

-ASR/ABS: all four related lights come on from time to time or don't show up at all. I do not have a limp condition. The battery appears strong. Ignition harness is the updated version in like-new condition. Lower harness is flaking. Because its NLA, I will have to have it rebuilt. Stored codes: 007 Ignition System & 096 Started lock-out backup lamp switch S16/3.

Before doing ANYTHING else, I recommend that you have your shop do a complete scan using an HHT/Star C3 after you eliminate all of the codes and see what comes back.

The starter lock-out/backup lamp switch (which is the reverse switch on the side of the transmission) is a common one to throw codes, that are sometimes not always the issue. I'm not convinced that this switch is a problem -- I've seen this code thrown plenty of times with the switch not really being the problem. Definitely replace your lower harness, as a matter of course (with the rebuild) - talk to jhodgc5k as he has them rebuilt/rebuilds them in his shop.

Given that you have the lights coming on (which lights are they, exactly?) or staying off, I think it's another issue. Are the lights illuminating when you turn the key to position 1 ("ACC") before you keep turning it to start the car? That should be a self-test to ensure the bulbs are working in the instrument cluster.

-External temp inaccurate and occasionally blinks off and on. Probe behind plate looks like its had water intrusion.

There's not a lot that goes too wrong with the temp probe itself -- it's designed to be exposed to the elements. I'd start with a replacement temp display at the bottom of the instrument cluster before attacking the probe itself. The temp display is available used/cheaply, and is fairly easy (two Philips head screws and a plug) to replace when you remove the instrument cluster.

-Bang from dashboard center when key is in Pos.II Has a vacuum-esque sound to it.

Hard to say on this one. Sounds like it could be a flap door that is closing or opening with no foam cushioning to silence it. Does it do this when the ACC system is in OFF ("O") mode? Or only when in Economy or A/C mode? Sounds like more diagnosis is needed here to determine WHEN this sound is happening, not just when the key is turned.

-Oil pressure gauge: sometimes while cruising it will indicate '2' or stay at full pressure while idling in Park.

This is almost definitely the oil pressure switch sender. There's a HOW-TO on the forum to replace this. A quality replacement is available for around $50 new, and oil change is an excellent time to do this. It's pretty accessible from underneath the car. 10-minute job.

Cheers,
Gerry

 

[Allgonquin]

I think the bang inside the dash is relatively normal, a flap opening or closing. I had this on my '95 diesel for years, and it eventually stopped, because (I think) the vac pod actuator got weak and failed - I had issues with air flow out the vents after that.

 

[ninetytwo]

My word, thank you all for your replies! I sincerely appreciate it. It was a bit scary to think I might be on my own in maintaining this car.

Gsxr: No, the ATF & filter have not been changed under my ownership. My shop said the fluid looked healthy although I am not opposed to a flush and filter replacement to get it to my own known baseline.

To the best of my knowledge, no engine management sensors have been replaced. I will have to ask the shop more details about the codes. The screen shot of those to codes say:

DM Quick Test Result DTC Memory 007 ->DI1

EA Quick Test Result DTC Memory

I think my next purchase is a digital scanner. The starter lockout switch…could that affect ASR?

Gerryvz: Thank you- I will take a look at that vacuum line. Now that you mention it, I remember hearing Kent at Mercedes Source talking bout the modulator and hard shifts. Should the vacuum line be soft?

There is a rattle from one of the cats. Its very subtle but clearly part of the honeycomb structure has come off. So far the engine sounds/feels incredible smooth. I have to imagine that its firing on all 8. The correct German-made Bosch plugs are on order. I suspect the currently installed ones are probably pretty old.

I will have to check the coils or as the shop how if they looked at them. I will also ask them to use the HHT/Star C3 scan. I assume that’s a standard issue tool any reputable MB shop would have?

ASR: The lights that come on are: Snow Chair switch light, speedo warning triangle, ABS & ASR warning lights. Every startup is different. Now that its getting more use, it will at times start with with only the self-test lights. Other times they will come on and stay on or go on/off multiple times as I’m driving. So far I can’t detect any pattern. I was hoping it was related to road bumps and maybe a loose connection but there doesn’t seem to be a correlation.

Dashboard Bang: I always turn off the ACC before turning of the car, so it starts with the system off. As soon as Pos II is reached it bangs. I will test it again and this time turn the system on.

Temp Probe: That is good to know. I have been reading posts that seem to vary on which end of the system is the cause of the problem. So much of this car is untouched that I’m worried about my ability to properly remove the cluster. On that note, does any part of the mechanical odometer require lubrication? Its smooth but I worry about it stopping and me not noticing.

Allgonquin: I will take a look at map of where the vacuum pods are- this might be exactly that.

 

[gsxr]

With shifting issues, I'd start with fluid & filter. No "flush" required, the converter has a drain plug so there is no need for a flushing machine or special procedures. Search the forum for info on the process.

The DM code is probably a ghost code, I'd ignore it unless it keeps coming back after being cleared. The E-GAS 096 code, as mentioned earlier, should be cured with a new NSS.

The vacuum line from engine to transmission is Tecalan (plastic) with rubber fittings at each end.

Cat rattle... uh-oh. Last I heard, the OE/dealer cats are NLA, and the Magnaflow direct-fits might be as well. I'd try to find a good used catalyst pipe before welding in aftermarket stuff, but that's just me.

All the lights on (ASR, snow chain, ABS+ASR) indicate a major fault with the ASR/ABS system. Further diagnostics will be required, not enough info available currently to diagnose via keyboard.

Dashboard bang is almost certainly because you are turning off ACC before starting the car. Why are you doing this? The "off" position closes the main air flaps to seal off all air entering the passenger compartment. I leave our cars in "EC" (economy) mode all the time, unless I want the air conditioning on. Only time I press "O" is when there's a skunk perfuming up the area I'm driving through.

The odometer generally does not need any lube, but if it stops working, the gears may have turned to mush... see the forum thread on gear replacement.

 

[TerryA]

Your car has not been driven much but is still 25 years old. You should REPLACE all of the FUSES in the fuse box with new copper or brass ones. (NO ALUMINUM FUSES) Clean all of the contact points before installing the new fuses. There are other bar fuses outside of the fusebox on firewall (for the aux fans) that should be cleaned or replaced. There may be more that I’m not familiar with. If so others will know.

Some of your gremlins might just disappear.

At one time I bought a 300E w/30K miles on it. Minor problems crop up w/ lack of use also. Electrical, oil leaks ect; but on the whole the car is far from worn out especially a Mercedes. Once you overcome your niggling issues you will have many miles of trouble free driving. Dave and Gerry as well as others here give great advise. Most of us have experienced similar issues over the years.

Good Luck w/ you new ride!

 

[skikrazey]

If the lower harness is bad, what is the condition of the upper harness? Has it been replaced. If not, replace it or rebuild it. Talk to Jono as Gerry said to do. Good luck and enjoy your 400E!

 

[ninetytwo]

gsxr:

I’ve become too accustomed to saying, “flush” when thinking about the fluids. Yes you’re right, a drain and fill will be just fine.

Cat rattle - Oh yes I am bummed to find so many NLA parts now. Every 500/400 I have looked had something rattling in the cat. Does yours have it as well? That will be a problem for another day. The good news that my state doesn’t require emissions for a vehicle this old so if worse comes to worse……out it comes.

ASR - a major fault? Its very odd. There are days when it doesn’t come on at all. My shop isn’t very enthusiastic about tracking it down, which is frustrating. Is there any other information I can provide to assist?

I feel fortunate to not have had any limp conditions. When the car arrived via carrier, it had been driven about 3,000 miles in four years. The more I have a been driving it, the less frequently (or not at all) these lights come on. But it is always Triangle, ABS, ASR, Snow Chain.

Dashboard Bang- I leave the system off as in 0 mode almost all the time. Its warm out so the windows/sunroof are open. I apologize if I made it seem that ACC is on when the car is shut off.

One new issue - engine is running cold. While driving it suddenly wouldn’t even clear 60C, only moving just below 80C while idling in the driveway. Add this to the awful gassy smell from the exhaust. Even the engine oil doesn’t smell right. Parts to replace: fuel pressure regulator, thermostat, spark plugs. Any others?

TerryA: Thank you! That is a good point about the fuses. As far as I can tell they are all original. I will inspect them tonight. Wouldn’t that be nice if some of these problems originate from there!

Skikrazey: The upper harness looks very nice. My mechanic says it looks like the updated design. Everything seems as it should. Thank you for the suggestions for the rebuilding the lower harness.

 

[gsxr]

I've never had a catalytic converter break apart and rattle on any 124 that I've owned. Strange that you have seen several with this issue. Make sure the rattle is not from the external heat shield, which might make noise if it's starting to come loose. If the cat rattle is not annoying from the driver seat, and not causing a power loss, I'd ignore it.

ASR limp mode usually just turns on the ASR idiot light, not the ABS light, and not the triangle (not sure about snow chain, never paid attention). If you are seeing all of those, something is weird. I'd start by checking the simple things - clean all fuse ends, clean & tighten battery terminals, and the small wires that attach to the positive battery terminal. I'd remove all 4 modules from the CAN box and re-seat them as well, after confirming there is nothing odd visible at the connectors. Really need the error codes to try and further diagnose this, specifically the exact codes which appear after the 4 lights turn on.

When you have the HVAC system in "O" mode, all air is blocked through the vents, and the blower motor is completely off as well. I'd want to exercise the blower motor to keep the bearings/bushings moving, so you may want to spend at least some time with it in EC mode, even if you have the windows / sunroof open. [Edit: Same applies to the AC compressor, it should be run periodically, even if it's not warm outside.]

Engine running cold is almost guaranteed to be a defective thermostat. Replace with new OE or OEM Behr. Details here. Make sure you don't accidentally buy the late style that was phased in mid-1995 production, see photo in post #46 of that thread.


If the engine is running very cold, it could be stuck in "warmup" phase, which is not good. FPR, etc may not help much... sounds like a fuel mixture issue that may require live data from the LH module to further chase down, if not cured with the new t-stat and 80C+ temps.

 

[bill420e]

The temp light on dash is probably the display in the cluster. I just fixed mine by replacing the capacitor in the unit. Pretty easy to have done or do. That is probably the cause.

 

[ninetytwo]

Gsxr: Thank you again for your continued detailed help. I’m learning a great deal about these cars!

Catalytic Converter: With the car(s) up on the lift, tapping the cat produces the rattle. Its more like a tiny “tink” in this one. The 500E I looked at a few months ago had quite a bit of debris vibrating on the bottom of the cat housing. I cannot hear it from inside at all and so far I do not think it is causing any flow issues.

ASR: Could you tell me more about the CAN box and modules? I am not familiar with this module or its location.

I did check the fuses in the primary box. I did not pull all of them but select aluminum and brass units. It looks shiny and new. I didn’t see any obvious corrosion but I have looked at the all-brass upgrade kit from Mercedes Source.

The battery does not have date code on it that I can find. Its an AC Delco. The terminals were cleaned but I’l recheck the smaller wires on the + terminal. Those caused all sorts of woes in my C107 when the retaining bolt loosened.

I’m waiting for my shop appointment and will report the codes here then.

HVAC: That is a good idea about blower motor exercise. I haven’t driven the car since the running rich/cold symptoms as I wait for my appointment. Thank you for the link to the correct thermostat. Does the FPR have service life determined by time as well? If the diaphragm or spring is weak, perhaps that is another factor?

I hope it won’t require a life data session to chase down. I knew the car would need some TLC from lack of use but I am certainly itching to get it out on the road (without making anything worse).

Bill420e: Thank you. A faulty capacitor sounds in line with the flashing LCD. Are the originals electrolytic?

 

[gsxr]

ASR: Could you tell me more about the CAN box and modules? I am not familiar with this module or its location.

The CAN box (aka Module Box, F23) is located near the windshield on the passenger side, under the hood. It contains 4 of the primary engine computers (LH/fuel, ASR/brake, E-GAS/throttle, and BM/power-supply). Click here and see PDF page 59 (of 76) for details, you may want to read the entire PDF to learn more about the car.

I did check the fuses in the primary box. I did not pull all of them but select aluminum and brass units. It looks shiny and new. I didn’t see any obvious corrosion but I have looked at the all-brass upgrade kit from Mercedes Source.

If all the fuses are clean and intact, they are probably fine. If you buy replacements, make sure they have ceramic bodies, not plastic.

Does the FPR have service life determined by time as well? If the diaphragm or spring is weak, perhaps that is another factor?

The FPR can last a very long time, and is tested by connecting a fuel pressure gauge to the rail, and observing pressure with & without the vacuum hose attached. At ~$40 or so for a new Bosch is usually easier to just replace it proactively, but don't expect anything to change if the old one was ok.

 

[ninetytwo]

I opened up the CAN box. Oddly I found two compressed rubber hoses (like small diameter coolant lines) under the cover resting along the modules, presumably to keep them seated. Is that standard practice? They don't feel loose at all. No jiggling, all at the same height, no dust/dirt, or any other signs of intrusion. The first module has several fuses along the top and all look good. The white tags with the bar codes are all clean and shiny except for the EGAS unit.

Additional oddity - the brake pedal in town and stop-go driving creaks very noticeably when depressed. I see no signs of anything leaking anywhere save for what looks like a fuzzy dried leak on the plastic pan to the right front of the engine. Hopefully the shop will have an opening next week.

 

[gsxr]

There should not be any hoses between the modules and the cover... sounds like someone was getting creative, possibly related to the 4-light-syndrome you're experiencing. Strange.

The brake pedal squeak is an occasional "feature" of the 124. There are a couple of threads discussing this topic and how to remedy it, but the easiest method is to turn up the radio, assuming it's the usual noise and not something more sinister.

 

[ninetytwo]

Turning up the radio it is then! Or at least until I fix the 4-light-sydrome and have some time to relax.

That was my impression about the lights & "compression" solution in the box. The odd thing is, nothing is loose or otherwise unsecured. When the car left Shirley Temple's estate, it might have wound up with someone who thought they could make a larger profit than the Barrett Jackson sale. Maybe during that time this issue arose, and not wanting to spend perceived big bucks on a repair, tried to some workarounds. This is all pure speculation but I can't imagine a MB shop or reputable indie putting those hoses in the box.

I don't have the removal tool but I'll ask my shop to try re-seating them. The large connection cable outside the box, are there any known issues there?

 

[gerryvz]

A medium or large flat-blade screwdriver works just fine as s removal tool to wedge the computers out of the CAN box, and a rubber mallet can ensure they are well seated.

I’ve never heard of issues with the wiring going into/out of the box.

Obviously you know of the issues with the disintegrating wiring of upper and lower wiring harnesses, and with the ETA.

 

[ninetytwo]

There is something darkly funny about removing a sturdy metal cover and inspecting computer modules...then ensuring their connection with a rubber mallet.

The ETA, I have not done much research on that that yet. I assumed that if it was malfunctioning it would be noticeable with poor driving characteristics. Are there distinct signs of a problem there?

 

[gerryvz]

ETAs have eco-wiring, and they can and do go bad. Generally they indeed will cause running issues, particularly if an ETA's wiring cable is disturbed in the course of doing other work (if it's an original ETA and hasn't been replaced). Not as bad as the upper harness, but they can and do go bad both from wiring and sometimes with age/mileage, the potentiometer and wiring inside go bad too.

I wouldn't smack the computers hard with the rubber mallet; just enough to ensure they are well seated in their slots. That is after cleaning and inspecting the female slots in the connectors, and inspecting the male prongs on the bottom of the CAN computer modules.

 

[gsxr]

The ETA, I have not done much research on that that yet. I assumed that if it was malfunctioning it would be noticeable with poor driving characteristics. Are there distinct signs of a problem there?

A flaky ETA typically causes limp mode, which usually turns on the ASR light only, an causes the first half of accelerator pedal travel to have no effect (i.e., you have to push the throttle way down to make the engine rev above idle).

If you want to experience limp mode on purpose, start the engine, pop the hood, and pull the throttle cable by hand (located behind the airbox). At first, this may rev the engine, but if you do it a couple times it will stop working. You have now entered limp mode, and should see the ASR light on the dash. Drive the car and enjoy the experience. Now shut off the engine and re-start to clear limp mode. This will also store a couple of codes on the modules, btw.

 

[ninetytwo]

I'm not sure the ETA wiring harness was inspected along with the others. All these harnesses- this car is becoming more of a project than I had anticipated.

That sounds like an interesting experiment- causing a limp condition. It sounds down right awful and certainly something that I have no experienced yet with this car by its own accord. I have an appointment at last next week so hopefully I will have some more to report.

 

[a777fan]

I'm not sure the ETA wiring harness was inspected along with the others. All these harnesses- this car is becoming more of a project than I had anticipated.

That sounds like an interesting experiment- causing a limp condition. It sounds down right awful and certainly something that I have no experienced yet with this car by its own accord. I have an appointment at last next week so hopefully I will have some more to report.

Yep. Gerry's 5-10k estimate is also applicable to the 400E/E420. Ask me how I know!

 

[gerryvz]

If the ETA isn't causing problems, then I'd just leave it alone. The upper wiring harness (and the lower one is important too) are the more critical ones to be replaced. Many bad running characteristics have been caused by bad upper harnesses. There is a sticky HOW-TO on determining the age of one's wiring harness -- recommend that you read it. Same for the ETA date.

Limp mode sucks, and there are a number of things that can cause it.

Low mileage is never a guarantee that everything is hunky-dory. These cars can suffer problems as much from NOT being driven as BEING driven. There's an old adage, "Garages Kill" that applies to these cars. They're meant to be driven, and driven vigorously !!!

The other adage is the one that Triple-Trouble just referred to: ALL E500Es (as well as 400E/E420s) out there carry AT LEAST $5,000 of deferred maintenance. All cars with more than 100K miles on the clock carry at least $10K of deferred maintenance.

I made this adage up some years back, and it's only been proven "NOT TRUE" in one instance .... the car belonging to 600Eric, but that car went through a two-year, rotisserie restoration with all new parts. Oh yeah, and then there's GSXR's cars. None of them carry any deferred maintenance, because GSXR meticulously maintains them in his Idaho batcave.

 

[gsxr]

...Oh yeah, and then there's GSXR's cars. None of them carry any deferred maintenance, because GSXR meticulously maintains them in his Idaho batcave.

Nah, all mine have at least SOME deferred maintenance... but I'd cautiously claim it's substantially less than average. I'm referring to mechanical items only, not cosmetic. All my cars are less-than-stellar cosmetically, but I'd have no qualms driving one cross-country. I prefer it that way, rather than having a show-quality beauty queen that I wouldn't trust to drive across town. Function over form for GSXR!

 

[ninetytwo]

"Rotisserie restoration," I like that! Although I hope that's not my fate here. Thank you for the info on the wiring harness sticky; I will give it a read. I knew going in that low miles wouldn't mean a get out of repairs free card, but I had hoped that the needed repairs would be more straightforward to find.

My first Mercedes was (still is) a January '73 build 450 SLC that had been in the family since new. I kept that going for 14 years and a hefty chunk of change at reputable shops (like Hatch in Massachusetts when they still did repairs) and there was always something failing. It eventually came down to time vs. recurring disappointment at not being able to drive the car. Two years ago I gave up, parked her nicely in the garage, and say hello every morning. My second is a 2001 SL500 that I found in 2010 with 24k miles. What a dream. Beyond regular maintenance, a dirty MAF threw a CEL and the windshield washer pump failed- that's all. I bought the 400E partly because I've always loved them and partly because I realized I detest the direction cars have gone today and if I wanted a good 124 example, now was the time.

I'm happy when I know my cars don't need anything mechanically and happiest when they don't need anything mechanically and cosmetically. Perfectionism by any other name..

The car is finally in the shop and a previous post in this thread came back to memory- my condition, with all four lights on (ASR, ABS, triangle, snow chain switch), if that's not the normal failure mode would that seem to imply that maybe the CAN module is faulty?

In any event, we should have some codes by end of business on Monday (I hope...)

 

[ninetytwo]

The summer is bustling along far too quickly and I realized its been a while since I've given an update. Since my last post there have been some positive changes:

-Replaced plugs with German-made Bosch
-Replaced thermostat & coolant

Coolant gets to 80C quite quickly (compared to before) and fuel economy has greatly improved. Temperature tends to move between a touch above 80 and the next hotter tick mark. I have become very accustomed to temp gauges that barely move. Is it normal for the M119 to show actual movement with driving/environmental conditions?

The old plugs were Russian-made Bosch units and while they weren't rounded they were quite black and ugly. My thinking is no one noticed the coolant temp prior to my ownership and therefore drove it rich for a while. Does that sound plausible? The engine is super-smooth for me (no misfires) and I don't detect oil consumption. It does, however, have a slight "hydrocarbon" smell to it. That is to say, my M113 R129 has no exhaust smell at all but my 400E does have an odor to it. Normal for an older engine/catalyst system?

-A/C is functioning very well and the dashboard "thunk" is much softer now.
-Oil pressure sender is failing. I assume if at 50MPH the oil pressure was barely above 1, the light would come on?
-ASR/ABS light show has minimized. The four lights rarely come on and when they do its usually from braking over road bumps or a bump in general.

Now that I have addressed the immediate mechanical needs, I'm looking at aesthetics...wheels mainly.

 

[gsxr]

It is 100% normal for the engine temp gauge to show actual movement with driving/environmental conditions. After reaching operating temp (80C) the normal range is 80-100C, where the unmarked line between 80 and 120 is 100C. (This may seem obvious, but it's been the subject of much debate on other forums, believe it or not.) On a hot day with AC on, and/or climbing a grade, or sitting in traffic, you may see temps of ~105C or so. When you see 110C or higher, that's generally an indicator something is awry. Temp gauges that never move tend to be by design for non-German vehicles, to keep drivers happy, rather than inform them of actual temperature.

Change the oil pressure sender ASAP, with OE/OEM Hella/VDO only. There is no low oil pressure warning light! Only a low oil level light, that comes on 60 seconds after it registers low level.

For the exhaust smell, I'll quote Klink from a different thread earlier today:

Talking here only about cars WITHOUT running faults, I have noted over the years that when these cars sit for a long time, I find that the exhaust absolutely reeks, and that they can do this for a long period of time, as in, it can take daily use for a number of days before it diminishes. I have measured fuel system, ignition, etc. while this goes on, certain that I was going to find an overly rich mixture, etc., and found nothing wrong. I don't know what brings this about...

 

[ninetytwo]

Once again, thank you! When thinking about the logic that went into engine design at MB in that period, I was comfortable with the idea that the gauges were actually used for a function. The (German) cars over the past ten years or so that have omitted a physical temp gauge, frightening! Then again, that is why we love these cars; an honest machine, not a machine trying to masquerade itself as a smartphone motivated my a magic plastic box under the hood. Well, now I've shown my hand....

I appreciate the quote. It is spot on- I have just turned 37,000mi (so about 600 miles of driving) and it still stinks. Clearly I need more highway time!

Oil Sender: I just finished reading Gerry's post about replacement and found the genuine part at Pelican. Perfect use of the internet! Problem->Community Help-> Part Look Up->Hello UPS.