Need a little advice here:

Have a '92 400E w/102K miles. The timing chain was rattling at start-up, but as soon as oil pressure jumped to "3" it quieted down to normal. Ran fine...

I took it in and had them replace the timing chain, tensioner, upper rails, etc...
Took it home with a big $800 smile thinking I was good for another 100K.

Next morning, SAME NOISE! Tested the smog pump clutch (unplugged), not that... Same symptom, after the car sits a hour or so, start it and it sounds like a diesel (sorry "D" fans) for the first second or two until the oil pressure jumps to "3" then quiet...

Once started, it will start quiet for hours, but once left to sit for a few hours or over night, the noise returns at startup.

Took it back, and of course, THEY didn't hear a thing. They took the valve cover off to check things out and all appeared to be OK. Picked the car up (and it didn't make the noise, making me look a little sheepish), go home, let it sit and ...YEP same thing....

HELP
Tks
BOBB

I had the same problem on my 300SEL 89 a couple of weeks ago. I had a post but did not receive any reply. The problem was for first 2-3 secs the car would sound like a diesel only after a overnight start.

Guess what changed the oil and switched to 91 octane fuel and I have not heard that again. Just my experience.

Sounds like the tensioner is bleeding off the oil pressure over night. (I know, thanks for stating the obvious.) Is there a check valve to hold the oil in it? I am not so familiar with the 400E, although it may be like a tensioner for the other MB V-8's. Try a search on this forum for tensioner and rattle. I wish you good luck!

Timing chain noise
 

Funny you should mention that. I did the same one time
and it worked for about a week. This time they changed
out the chain, tensioner, rails etc AND did an oil change,
but the startup noise is still there (and loud too, this is no little rattle)! The 400 is the 4.2L V8 and the tnsioner does have a pressure check valve (so I'm told), but will drain out after a long sit...

BOBB

The following is a generic answer but it applies to any car that has hydraulic valve lifters. I do not know if your car does but if it does then the following applies:
It is normal for any hudraulic valve lifter to be noisy at startup especially if the car has been sitting for too long, such as overnight or more. The reason is that the oil inside the lifter gets bleed out by the pressure of the valve spring, and until it gets filled up again the excesive valve clearance will result in some increased noise. The weight of the oil may also contribute to this effect.

I may be way off base here, but I have read elsewhere that noisy lifters on other models, especially older diesels, can be substantially reduced by a switch to synthetic oil, like Mobil 1. IF your noise is in fact lifter-related as suggested above, might be worth a try.

I switched over at 80,000 miles on my 400E. . .

[Edited by 400E on 06-16-2001 at 08:44 PM]

Lifter noise?
 

Man, I don't think this is lifter noise. Lifter noise shouldn't be THAT LOUD! This sounds like a jar full of marbles for about three seconds. The mechanic agreeded that it sounded like the standard 100K+ timing chain & tensioner on these 4.2L V8's. Now he's stumped and wants me to leave the car with him for a couple of weeks!!!

WHAT TO DO???

You should do a search on this< I have covered it over and over.

On the 119, there was a check valve that often went faulty inside the oil filter housing. IT allows oil to flow out of the top of the engine and the result happens when cold. The oil pump will have to re-prime the whole engine with oil, hence the rattle.

I would have the oil filter housing removed and the check valve replaced. There is a Service Information Bulletin on this.

It may not cure the problem but is a first step.

When the chain was replaced, the upper rails should have been done too.

[Edited by Benzmac on 07-05-2001 at 08:00 PM]

Noise
 

Thanks Benzmac,

Would this be the same on a 400? 4.2L V8? It has the
canister oil filter with replaceable element.

I did have all the upper rails replaced as well....

I will talk to the mechanic about this oil filter valve.

Thanks
BOBB

Back to Silver Star Motors!
 

Back to John this morning....

THE FIX!
 

:mad: Well after $1K :eek: the $13 valve "O" ring on the oil pump valve seat. I recorded the noise so there wasn't any doubt!

First visit - $750.00
parts replaced:
Timing chain
Upper rails
Chain tensioner

Second visit - $0.00
Re-check tensioner

Third visit - $250.00 (10 days later)
replace:
Oil pressure relief valve ($67)
Oil pump valve seat ($13)

Gee, he even tightned the oil pan gasket that was leaking for FREE! (and it still leaks)!:eek:

Oh Well :o guess it's good for another 100K miles:confused:
Anyone ever replace the lower oil pan gasket ($21) on a 4.3LV8?
Tks > BOBB

I replaced the gasket on my M119 (5.0 liter) and still have a small drip forming. I can tell you the gaskets will tear very easily if you just go in there and give it a turn or two.

You probably have the same situation I had/have, the areas around the bolt holes are deformed from mechanics and such giving that little extra turn I just mentioned.

The solution- remove again (another $21 if you tore it or damaged it) and hammer the pan mating surface completely flat. I did this and still had slight leak, but several of the holes are hard to straighten in the corners, I still haven't had the time to go in there and correct the leak.

One more thing, you might try and very thin coating of gasket sealer on both sides of the gasket when and if you decide to correct/straighten the pan.

Good Luck!

...might be worth purchasing a new pan?

SEE Timing Chain Noise Fix Thread
 

SEE "Timing Chain Noise Fix" thread for Fix and pictures

http://www.peachparts.com/shopforum/showthread.php?threadid=21525

What were the part numbers of the relief valve & valve seat? Please let us know:)