M119 chokes at 4250 rpm..? - MAS..replaced..EZL replaced..

[Benzer]

Re: M119 chokes at 4250 rpm..? - MAS..replaced..EZL replaced

The valve cover gaskets R&R is quite straight forward. Shouldn't take you more than a couple of hours. The hex bolts towards the firewall are a pain in the arse to get out if you don't have a swivel adapter to remove them. On the passenger side bank, towards the rear you will see rubber tubing, I think they are referred to as 'oil tubes'. If they look brittle and dried up, it will be a miracle if you can remove them without having them break so you can refit them. In general, be careful with all the rubber tubing going into the valve covers.They WILL break if they are old. So probably plan on adding those to the list as well.

A quick check that will bring having to replace the valve cover gasket from your top priority list, is going over the edge with a paper towel, if its leaking bad you will see it on the paper, (if you haven't by plain sight). So, unless the leak is bad enough to get into you caps and the camshaft sensor's I wouldn't panic. Next you want to remove your spark plugs one by one. Check the threads for any oil on them. If they have engine oil on them and specially around the lateral electrode, then the round seals on the valve cover gaskets are seeping into the plugs. Not fatal but a definite performance inhibitor and it will give you a misfire like symptom..

The slight tapping noise you hear are either your lifters and/or the camshaft oil lube tubes, all of which are accessible while replacing the valve cover gaskets. I think I mentioned it before..? Both are not that expensive $15-$25. Camshaft tubes easily replaced, lifters...not so much.. I did some in an Integra a while back and it was a pain..

The hydraulic system is an isolated system operating only on the principles of Force, Pressure and Area, (Pascals Law) and is independent of engine performance. Sure you will have a hard time steering if it goes, but thats about it.. What I found to be a common issue besides the seal rings leaking on the steering rack was the short, (about 2" long) high pressure return hose on the bottom of the Power Steering reservoir. No exceptional skills required to replace it but it takes some time and removing a lot things around it. Again, its just a leak and unless it's emptying your reservoir I wouldn't panic.

 

[Benzer]

Thought I would finish of my thread with this last post. I recently came back from some jobs and picked my car up at a shop where they removed the cats after performing a pressure test on the exhaust. Needless to say, they were plugged and toasted. The heat shield covering them was blackened by the heat.

So now, no more cats and its shifting right about 6100 rpms. I can finally feel the V8 in my Benz.!! In short the performance issue was caused by the previous owners neglect which led to:

1. New MAS.
2. New EZL and unplugging its vacuum line to the manifold.
3. New O2 sensor.
4. New IAT sensor.
5. Removal of catalytic converters.

Thanks for all the help on this thread guys..

 

[gerryvz]

Glad that it ended up as it did, and you found the cause. This is not an unheard-of problem, actually. If I remember correctly, Talbir also had this issue with one of his 036s ?!?

Cheers,
Gerry

 

[ivanned]

I am having the same experience now with my e500:

Here are my observations:

1. Not 3 months ago I got a blink code 4 and a CEL : Air injection code.

2. Never really had any drivability issues

3. A month ago after heavy driving session the car choked at about 4-4.500 prm when pressing the throttle relatively hard. Problem was not there if throttle was gradually pressed.

4. Problem did not appear with intermittent heavy driving: redlining it every once in a while, but if you drive hard for over 30 min.

My speculation was that something is failing under load.

I was thinking about changing the O2 sensor which I got at a great price thanks to J-Sauce and Dave.

EZL was changed at 2006, but if the coils are bad, they may have killed it as far as I can tell from the post.

Also the CATs are original.

And what about the knock sensors?

As I mentioned, the issues are not constant ...yet...just after heavy driving.

Any thoughts?


Thank you all

 

[Jelmer]

If it looks and feels the same as this movie I made, it could be cats (same issue as I had)
[youtube]VaB4Xswq-OQ[/youtube]

 

[samiam44]

Ivanned,

You need to pull codes and clear them. THen check again and see what re-appears. That's your best way to decide if you need knock sensors, NSS, etc.



Michael

 

[ivanned]

Thanks guys! I'll let you know what happens.

 

[ivanned]

Check this out

[youtube]-5welzdyXuo[/youtube]


Ps: the cel shows code 4 air injection

 

[ivanned]

Update:

1. Ruled out ASR/ABS as a problem
2. Ruled out Fuel pressure problem.
3. code 4 was due to a disconnected vac tube to the air pump nothing to do with the problem.
4. NO CODES at all!!!
5. Car intermittently loses power at more than 1/2 throttle particularly in 1 or 2 gear.

Next to check: ETA, E-GAS....any suggections?

 

[gerryvz]

Wiring harness been replaced?

 

[gsxr]

Complete wild guess shot in the dark:

Something fishy with the knock sensors, pulling timing. Or with the cam advance mechanism/solenoids. I'd expect codes though. Related possibility is ignition parts (cap, rotor, coils) which can also cause these symptoms. How old are the caps/rotors? Have you looked at the back of the insulator (behind the rotor) to make sure there is no trace of arcing?

Another faint possibility is loss of fuel pressure under load, but you would need to rig up a fuel pressure gauge that can be viewed while driving (~$125 in parts). I had this on my E420 and it turned out that one of the fuel pumps was bad, and fuel pressure would randomly drop, resulting in a significant power loss. Easy to see with the "live" gauge while driving.

 

[vexed]

Complete wild guess shot in the dark:

Something fishy with the knock sensors, pulling timing. Or with the cam advance mechanism/solenoids. I'd expect codes though. Related possibility is ignition parts (cap, rotor, coils) which can also cause these symptoms. How old are the caps/rotors? Have you looked at the back of the insulator (behind the rotor) to make sure there is no trace of arcing?

Another faint possibility is loss of fuel pressure under load, but you would need to rig up a fuel pressure gauge that can be viewed while driving (~$125 in parts). I had this on my E420 and it turned out that one of the fuel pumps was bad, and fuel pressure would randomly drop, resulting in a significant power loss. Easy to see with the "live" gauge while driving.

There is a seal ring that goes into the insulator that becomes brittle with age, I would look at that when you pull the rotors. And if it has not been mentioned check your plug wires in the dark. I had a bad plug connector which resulted in a intermittent power loss and no codes.

 

[ivanned]

The only thing I have not checked are the insulator rings and the seal rings. The wires are relatively new, so are the rotors and the caps. Plugs have about 20 K miles now.

Recently I got new ignition coils, ruled out the MAF and the fuel pressure as culprits.

Other things replaced are upper and lower harness - '02
ETA - '01 I think
recently the throttle body
as I mentioned EZL - '06 also LH module.
kickdown switch

symptoms are getting worse now

when car warms up it either severely cuts off during heavy acceleration or hits a that limiter like loss of power at high rpm.

idle can get quite rough and at one point engine almost stalled today while trying to park the car.

Again no codes of any kind.

questions: the seal rings if they become brittle should that affect the spark?

Could a real time diagnostic data pin point or at least narrow down the problem?

 

[ivanned]

http://www.youtube.com/watch?v=r0ms0rNRgcs

[youtube]r0ms0rNRgcs[/youtube]

 

[ivanned]

the former video does not fully represent the problem though. It's severe loss of power. Now somtimes the rpm would not even go up. Also sometimes it will accelerate fast but with intermittent cutting off.

 

[Jelmer]

Do you check codes with a blink reader or with the full fledged MB diagnostic devices? I'd say a proper MB mechanic could look at the live readings and tell quite a lot from that. "My guy" did exactly that - during the emissions tests he simply took his device and starting checking all kinds of values, and actually managed to make sense of them and convert that into suggestions.

Also: plugs that are in for 20k miles? That's kinda long, isn't it? We replace them every 20k km,and each time there's a noticeable difference.

You really need to stop throwing money into random bits of this car and get it fully checked out. Before you lose all hope and pleasure driving the car.

 

[gsxr]

Official interval in the FSM is 30kmi for spark plugs. I'd pull them for a visual inspection if you haven't done so.

This kinda sounds like ignition issues, but it's hard to say for sure. It would show up on the EZL live data via SDS if that is the case, or on a scope if it happens at idle.

How old are the fuel pumps, btw? If there is no misfire, but simply a loss of power, it could be the fuel pumps acting up under load. This is VERY difficult to diagnose, the only options are to replace both pumps (~$145), or buy a fuel pressure gauge+hose that can be viewed while driving (~$125 in parts). The fact that there are no codes makes me highly suspicious of the fuel pumps, even if the pressure tested ok in the parking lot. The pressure test is not helpful unless you can view the gauge while the "rough idle" occurs.

 

[ivanned]

Thanks guys I guess I will bring the car to the dealer for live diagnostics. I checked the plugs and they seem OK. I also checked the pressure while rough running is occurring and it is stable at 55 or so psi. I guess live date is what I will need to move forward.

So far I have been lucky that the only thing I have really invested in myself were the O2 sensor and the ignition coils both of which were in need of replacement anyhow. Jelmer you are right I hate throwing money away without a reason but this is what the previous owner was doing. I have $11,500.00 ticket that he paid in 2006 and he replaced a ton of stuff, which I guess is a good thing from where I stand

 

[ivanned]

Is that normal?

 

[gsxr]

Is that normal?

The black cabon-y areas on the brass terminals is completely normal. You can scrape them clean if you like but those look awfully good, pretty much what I'd expect for 5kmi.

 

[ivanned]

Officially, problem solved!! No more problems at all. I found out that the people that did my timing chain used some weird grease into the spark plug connectors. It turned into hardened pieces and it was all dried and cracked. After I cleaned it - voila - no more problems.

LESSON LEARNED: check the simple things first!

By the way is there a test for the MAF to check if it reads correctly?

 

[ivanned]

Another detail that I learned researching is that idle is controlled by the ECU through input from the camshaft and crankshaft position sensors and the ETA.

Is that the case?

 

[Jelmer]

Glad your problem is fixed after all this time!

Regarding the MAF, a simple check to see if it's doing anything at all is blowing in it with the engine running, it should stumble and shut off.

 

[ivanned]

yep and so it did. I still have an occasional millisecond misfire but it is not load dependent. It can happen at idle or WOT or anywhere in between. Happens maybe once every 2 days so its going to be hard to troubleshoot blindly. Again no codes.

 

[Jelmer]

There have been threads about this before, and I believe the general consensus is "just leave it". I also have the occasional hiccup, especially at idle (say, every 10-30 seconds when in gear), even after replacing nearly everything.

 

[emerydc8]

I am having the same issue with the ceiling of about 4250 RPM. The engine runs as smooth as glass at idle and on the way up to 4250 RPM. I checked the plug boots to see if any dried out lube was causing the problem like in ivanned's case and they are fine. The plugs are F8DC4 and were recently replaced. I swapped out the ignition module tonight (thanks to Gerry's killer deal on a spare) and it's still doing the same thing. My code reader is in my other car, which is at the airport parking lot right now, so I can't pull the codes until later this week.

When I accelerate from a stop it seems to hang there at 4250 RPM and eventually shifts. I did notice a few valve pings under heavy acceleration. So, I'm thinking maybe a knock sensor or bad coil. But wouldn't a bad coil cause it to run rough? Did we rule out the possibility that a bad transmission overload protection switch would limit RPM like this? Of the four times I've pulled the codes on this car, I have gotten a transmission overload protection every time.

If I drove this car and kept it under 3500 RPM, as I normally do, I'd probably never notice it. In fact, I don't know how long this has been like this. Any thoughts?

ISSUE RESOLVED: It turned out to be clogged catalytic converters. There is a separate post I started on that.

 

[Wdzman]

Re: M119 chokes at 4250 rpm..? - MAS..replaced..EZL replaced

 

[gsxr]

@Wdzman - your post was lost, can you re-type?

 

[Wdzman]

@Wdzman - your post was lost, can you re-type?

Sorry but I but did not make a post.

 

[Wdzman]

Sorry but I did not make a post.