Suggestion on cleaning the 20 years of crud off underhood on my E-420.

[Ascension]

I normally would just bag the electronics and pressure wash but since this one still has the original upper and lower harness ( and they look for now to be in pristine shape) I am reluctant to do that and take the chance.
What chemicals would you recommend using to remove in particular the caked on crust off the front of the block and also the discoloration on the valve covers?

Here is how when looked when I got her it's better now but still not great.

.
For reference here is my Volvo V-90 under-hood with right at 200K and this is the goal on the E-420

 

[gsxr]

I pressure-wash the bottom half only (oil pan, steering box area, AC compressor, transmission, suspension control arms, etc) after soaking with engine cleaner, something like Gunk Engine Brite, preferably the citrus stuff which doesn't stink as bad as some of the other engine degreasers.

Don't spray anywhere near the top of the motor by the wiring. I always clean the top by hand... vacuum off the dry stuff, and then do the rest by hand with rags, mini wire brushes, toothbrushes, and your favorite solvent (degreaser, carb cleaner, brake cleaner, etc). Be careful with painted surfaces, some solvents will remove the paint.

 

[gerryvz]

Ditto GSXR. You can get the top end with some rags & brake cleaner and the polish the plastic & visible surfaces with bling polish.


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[Ascension]

I pressure-wash the bottom half only (oil pan, steering box area, AC compressor, transmission, suspension control arms, etc) after soaking with engine cleaner, something like Gunk Engine Brite, preferably the citrus stuff which doesn't stink as bad as some of the other engine degreasers.

Don't spray anywhere near the top of the motor by the wiring. I always clean the top by hand... vacuum off the dry stuff, and then do the rest by hand with rags, mini wire brushes, toothbrushes, and your favorite solvent (degreaser, carb cleaner, brake cleaner, etc). Be careful with painted surfaces, some solvents will remove the paint.

Bottom side is pretty clean. The worst area is the front of the block and the valve covers as the front of the block around and behind the water pump in particular is pretty crusted in 20 years of baked on gunk and the valve covers have that ugly yellow film on them. I have all the plastic and hoses looking pretty good now and the inner wells will clean up easily with something like the gunk foam and a light spray with a garden hose. It's hard to tell at this point if I have any drooling around the cams up front or not because of all the gunk + the filler cap is physically broken and has allowed a little leakage. I doubt the hood was ever raised on this car other than to do regular oil changes and such till now. Looks like it might be more dangerous to try and get into the area by hand to remove the more baked on gunk on the front of the heads /block than using a good degreaser to break the gunk down working what I can get to easily without disturbing the wiring then lightly spraying it down with a garden hose. I don't want to chance moving anything wiring wise around on that engine harness until I get the time/money to do that upper harness swap at this point.
Tried a little brake cleaner on the front of the block last night using the long tube but it didn't seem to phase the baked on gunk. I need to spray it down when cold with a good degreaser and let if soak to break that mess down I suspect. A pressure washer would take it all off in seconds but----.
Want to get it cleaned up a little before I start doing much to her right now. We are about to get socked in with rain for a few days here in the South East and being that I only have an open carport to work in that will put a damper on what I can do for a few days here.

 

[clarkz71]

I'm betting besides the P/S hose, your cam advance magnets are leaking.

I would clean the front of the engine while you have it apart for that repair.

The fan/shroud will be off so access will be at a premium.

 

[gsxr]

The yellow film is the factory protective coating when the cars were shipped across the pond. You don't need to remove it. Gotta clean the oil & grime off by hand to pinpoint leaks, no easy way around it. Meaning scrape the thick stuff with screwdrivers or a putty knife to start with. Spraying a gardeh hose on thick grime won't do anything but make a dark puddle under the car.

 

[gsxr]

I'm betting besides the P/S hose, your cam advance magnets are leaking.

I would clean the front of the engine while you have it apart for that repair.

Same here. PS reservoir feed hose was leaking on almost every single M119 that I've ever purchased. Cam magnets is a close second place along with the pump front seal, and ATF cooler hoses...

 

[Ascension]

I pressure-wash the bottom half only (oil pan, steering box area, AC compressor, transmission, suspension control arms, etc) after soaking with engine cleaner, something like Gunk Engine Brite, preferably the citrus stuff which doesn't stink as bad as some of the other engine degreasers.

Don't spray anywhere near the top of the motor by the wiring. I always clean the top by hand... vacuum off the dry stuff, and then do the rest by hand with rags, mini wire brushes, toothbrushes, and your favorite solvent (degreaser, carb cleaner, brake cleaner, etc). Be careful with painted surfaces, some solvents will remove the paint.

Bottom side is pretty clean. The worst area is the front of the block and the valve covers as the front of the block is pretty crusted in gunk and the valve covers have that ugly yellow film on them. I have all the plastic and hoses looking pretty good now and the inner wells will clean up easily . It's hard to tell at this point if I have any drooling around the cams up front because of all the gunk + the filler cap is physically broken and has allowed a little leakage. Looks like it might be more dangerous to try and get into the area and hand removing the more baked on gunk on the front of the heads /block than using a cleaner then lightly spraying it. I don't want to chance moving anything wiring wise around on that engine harness until I get the time/money to do that upper harness swap at this point.
Tried a little brake cleaner on the front of the block using the long tube but it didn't seem to phase the backed on gunk. I need to spray it down when cold with a good degreaser and let if soak to break that mess down I suspect.

 

[Ascension]

I'm betting besides the P/S hose, your cam advance magnets are leaking.

I would clean the front of the engine while you have it apart for that repair.

The fan/shroud will be off so access will be at a premium.

Yes there is a slight drool underneath around the PS system from somewhere hard to tell exactly where but it's there.
Keep in mind that I am completely clueless on these engine designs so what the heck is a cam advance magnet?? Never heard of such an animal before so enlighten me here on what it is and more importantly where is it????
And while I'm at this what the heck is up on what looks to be fuel being run through a cooler on the driver side in the AC system on these? Flow would have to be high enough that it could not do much cooling at WOT for performance so???

 

[gerryvz]

Cam advance magnet is what advances the intake cam timing (variable valve timing) under certain loads and RPM. One per cylinder head.

There's a current thread on rebuilding them in the M119 sub-forum (not a common item to have to do). But the cam advance magnet is a common oil leak/weep point on the front of the engine, as is the power steering pump (tandem pump on the 500E) and associated hoses.

 

[gsxr]

And while I'm at this what the heck is up on what looks to be fuel being run through a cooler on the driver side in the AC system on these? Flow would have to be high enough that it could not do much cooling at WOT for performance so???

Yep, that is a fuel cooler. It's not designed for WOT performance, it is designed to avoid vapor lock at extreme temperatures. Typical MB over-engineering. Neat stuff, IMO.

 

[clarkz71]

Keep in mind that I am completely clueless on these engine designs so what the heck is a cam advance magnet?? Never heard of such an animal before so enlighten me here on what it is and more importantly where is it????

Image courtesy of 124 Performance (gsxr)

Red circles, cam advance magnets

 

[gsxr]

And that is how clean an M119 should be.

 

[clarkz71]

And that is how clean an M119 should be.

I knew I should have used someone else's image...............

 

[Ascension]

Yep, that is a fuel cooler. It's not designed for WOT performance, it is designed to avoid vapor lock at extreme temperatures. Typical MB over-engineering. Neat stuff, IMO.

Yes it is. That was was what I first thought that cooler could be when I saw it. I knew there was no way it was large enough in area to affect temp at WOT so I could only think of one other reason for it being there and you nailed it.

 

[Ascension]

Cam advance magnet is what advances the intake cam timing (variable valve timing) under certain loads and RPM. One per cylinder head.

There's a current thread on rebuilding them in the M119 sub-forum (not a common item to have to do). But the cam advance magnet is a common oil leak/weep point on the front of the engine, as is the power steering pump (tandem pump on the 500E) and associated hoses.

Got it now and a slight weep I can deal with just need to know where and why so I can watch it.
While we are talking oil leaks and such what is the crankcase vent system on this one?? I have a flame trap service I am about to have to do on the Volvo (and it 's a PITA!!) , anything I need to know on maintaining this M-119 system?
The entire 2 distributor system is what's strange to me here with a crank trigger, the variable cam timing I understand just didn't know these had it. On the 2 distributors it just doesn't make and any logical sense to me to use this mechanical system instead of a coil on plug with the crank trigger. What's the scoop on this??

 

[gsxr]

Wait until you see the twin fuel pumps, and all the drivetrain parts designed to handle 450hp without failing.

Oh, and through the early 90's, MB had a rear pump on the transmission, to allow tow-starting! That went way around 92 or 93 as a cost-reduction item. Darn bean counters.

 

[gsxr]

got it. The entire 2 distributor system is what's strange to me here with a crank trigger the variable cam timing i understand just didn't know these had it. On the 2 distributors it just doesn't make and any logical sense to me to use this mechanical system instead of a coil on plug with the crank trigger. What's the scoop on this??

Coil on plug came along in 1996 with the newer Bosch ME injection system. The distributor system may be a little old-school, but it's smart enough to pull timing on individual cylinders when detonation is sensed. Crazy advanced stuff for the early 90's.

 

[Ascension]

Image courtesy of 124 Performance (gsxr)

Red circles, cam advance magnets

Thanks nice to see this one stripped from the front to get my bearings on how it's layed out.

 

[gerryvz]

There were three iterations of the M119 ... the first being old-skool CIS-E mechanical injection (never used on the W124, but rather in the first couple of years of the 500SL and 500SE/SEL sedans) in the 1991-1992 time frame; the second being our LH electronic injection (used on the 400E and 500E, 500SL, 500SE/SEL sedans) from about 1991-1995; and the third being the coil-on-plug ME system that Dave mentions above from around 1995-1998 or so.

Then MB cheaped out a bit, and reverted back to the three-valve M113 engine in around the 1999 time frame. The 500E (introduced in 1991 in Europe) was the very first MB that ever used a CAN system to connect the car's computers. It's crude, and the diagnostic system is OBD-1, which doesn't give you all that much info, but at the time it was pretty cutting edge stuff.

MB did begin using coil-on-plug with the inline-six (3.2L) motors starting in model year 1993 in the US. That is the first time I'm aware of it being used by MB.

Cheers,
Gerry

 

[gsxr]

The 500E (introduced in 1991 in Europe) was the very first MB that ever used a CAN system to connect the car's computers. It's crude, and the diagnostic system is OBD-1, which doesn't give you all that much info, but at the time it was pretty cutting edge stuff.

The LH system is actually very, very good and has a lot of information available. However, you can't use a generic OBD-2 scanner to speak with it, you need an MB-specific scanner/software.

100+ live data elements is not what I'd refer to as crude... but that's just me. The HFM systems were a much cheaper solution, with maybe a third of the data available compared to LH. The ME systems were partly a cost-cutting thing as they combined fuel control and ignition control into a single module, instead of separate modules. The early ME (v1.0) systems are a bit more powerful than LH but it's not a quantum leap by any means. And, there are multiple drawbacks to the ME system. Other than getting coil packs with ME, there isn't much other advantage, IMO. Do a spark plug replacement on an M119.98x sometime and you'll be wishing it had distributors.

Live data available on that "crude" LH system:
http://www.w124performance.com/docs/mb/diagnostics/Snap-On/Mercedes_Live_Data.pdf

 

[clarkz71]

Gerry,

All W140 cars, and all W124 cars with the M119 are LH, 1992-1995

Only 1990 to 1992 R129 had CIS

ME injection came in 1996

 

[gerryvz]

Aah, thanks for the correction -- just happened to look that up after the fact to double-check my statement and saw your note. I stand corrected .. the CIS-E M119 was 500SL-only.

 

[gerryvz]

I'm comparing LH information to info that is available in today's cars, and/or what is available through OBD-2 systems, which is what most people are used to these days.

 

[gsxr]

I'm comparing LH information to info that is available in today's cars, and/or what is available through OBD-2 systems, which is what most people are used to these days.

LH is almost comparable to the info available in today's cars... but you are correct, you cannot access it as easily.

LH is a quantum leap over CIS-E though. Not even in the same ballpark.

 

[Ascension]

Gerry,

All W140 cars, and all W124 cars with the M119 are LH, 1992-1995

Only 1990 to 1992 R129 had CIS

ME injection came in 1996

Clark what will I need to look for in a scanner for the pre OBD II 95 420? An old Snap-On with the MB software maybe?
Also found the flash but how do I get instruction on to use it ?

 

[gerryvz]

Thanks for the yoink, another to add to my collection.

No doubt LH (or HFM) is a quantum leap over CIS-E, but you can access anything on CIS-E with a simple duty-cycle-capable multimeter & a blink-code reader. Score for accessibility !!

 

[Klink]

Coil on plug came along in 1996 with the newer Bosch ME injection system. The distributor system may be a little old-school, but it's smart enough to pull timing on individual cylinders when detonation is sensed. Crazy advanced stuff for the early 90's.

It even generates and stores individual antiknock timing maps for each individual cylinder, so that it is not constantly cycling in and out of a knocking range during the same conditions. At certain intervals that I've never seen disclosed anywhere, maybe it is constant for all I know, it will try to advance the timing out of one of those stored knock regulation ranges when it encounters the same load profile, so it won't leave the timing for any individual cylinder retarded if the original cause for the knocking is gone, let's say poor octane, carbon deposits, etc. in that sense it was far more advanced than any of the original Bosch Motronic systems. Once Motronic evolved and incorporated these features and some other features and functions it became "DME" which is "digital motor electronics". That's where the so-called "ME" came from on the 96 and later engines.

 

[gerryvz]

A table and instructions for the blink codes for the M119 are available on GSXR's site here, as a handy PDF:

http://www.w124performance.com/docs/mb/diagnostics/DTC_List_W124_M119.pdf

 

[gsxr]

Clark what will I need to look for in a scanner for the pre OBD II 95 420? An old Snap-On with the MB software maybe?

I'm not a Clark nor do I play one on TV, but yes, the Snap-On MT-2500 with a 2003 Mercedes cartridge plus appropriate cable/keys will work for many functions. It's not as comprehensive as the Chinese SDS but it will do MOST of what you need. A hand-held blink code reader is still required to use along side, the Snap-On will not replace the blinker box (but the SDS will).

Also found the flash but how do I get instruction on to use it ?

If you mean the blink code reader... please see the top posts in this forum section:
http://www.500eboard.com/forums/forumdisplay.php?23-De-Coding

 

[gerryvz]

All of this information about scanners and what works and doesn't work with the .034 and .036, and how to build a home-made blink-code reader, is all posted on this site and available through the search function.

 

[gerryvz]

I'm not a Clark nor do I play one on TV,

Yes, I think your new nickname should be ... Clark Kent !!!

 

[Ascension]

A table and instructions for the blink codes for the M119 are available on GSXR's site here, as a handy PDF:

http://www.w124performance.com/docs/mb/diagnostics/DTC_List_W124_M119.pdf

Just bookmarked that site Gerry thanks!

 

[Ascension]

Made a little progress but am a little "loopy" right now from all the fumes LOL.
What I though was baked on gunk is mostly the coating on the aluminum that has baked and turned into a very nasty looking wrinkled yellow skin on everything. A few cans of part/brake cleaner and some elbow grease + a little plastic dressing still worked wonders. Still a long way to get to where I want it but it's a good start.
Went from this


To this in a little over an hour.

 

[gsxr]

Yes, I think your new nickname should be ... Clark Kent !!!

I'm not sure there is any facepalm large enough to respond with.

 

[Ascension]

I'm not sure there is any facepalm large enough to respond with.

LOL!!

 

[clarkz71]

I'm not sure there is any facepalm large enough to respond with.

I feel a force choke coming.......

 

[clarkz71]

LOL!!

Tread lightly probie........

 

[clarkz71]

Yes, I think your new nickname should be ... Clark Kent !!!

No, more like Jimmy Olsen with all the picture he takes.....

 

[J-Sauce]

Just a quick word of warning: be careful with that degreaser near the electric clutch bearings on your ancillary pulleys. I suspect degreaser to have accelerated the demise of my smog pump (twice on my 500e and once on my 300e) AND my AC compressor. I didn't put two and two together until the last smog pump failed within a year. I've since paid extra attention not to degrease those bearings, and will occasionally spritz them with a little oil hoping it seeps down inside.

My theory is that the cheap degreaser I was using, which works great for taking off grease but smells terrible, was working a little too well and stripping all the grease out of the clutch bearings. All of the ancillaries mentioned still operated flawlessly, but the clutches either froze or began grinding while disengaged.

 

[Ascension]

Just a quick word of warning: be careful with that degreaser near the electric clutch bearings on your ancillary pulleys. I suspect degreaser to have accelerated the demise of my smog pump (twice on my 500e and once on my 300e) AND my AC compressor. I didn't put two and two together until the last smog pump failed within a year. I've since paid extra attention not to degrease those bearings, and will occasionally spritz them with a little oil hoping it seeps down inside.

My theory is that the cheap degreaser I was using, which works great for taking off grease but smells terrible, was working a little too well and stripping all the grease out of the clutch bearings. All of the ancillaries mentioned still operated flawlessly, but the clutches either froze or began grinding while disengaged.

I tried my best to direct everything to just where I was aiming the stream. Mostly the block and heads were the target until I figured out that the ugly yellow "skin" was the broken down factory coating not baked on gunk. Stuff looks absolutely NASTY on the valve covers heads and front of the block but it's at the least all clean now.

 

[Ascension]

The yellow film is the factory protective coating when the cars were shipped across the pond. You don't need to remove it.

That factory applied film now has yellowed, wrinkled up and makes the block and heads look absolutely NASTY it needs to be removed. Any suggestions here?