Timing Chain Rattle

[Grant V]

Ever since I got my car six months ago, it has had a timing chain rattle on start up. It only rattles for a second or two on start up when the car has stood for a few hours, both hot and cold.
The previous owner was upfront about the problem, so I know about it, but it's a problem that he couldn't cure.
The engine was removed twice, and the following parts were renewed, but without success:

Timing Chain
Tensioner
Timing Chain rails
Hydraulic Lifters
Vanos System
Oil Pump
Oil Filter Housing

The cylinder heads were never removed. Has anyone heard of this problem before? Any suggestions?

 

[gerryvz]

Welcome aboard.

How many miles does your car have on it? Timing chains do need to be replaced on the M119s, and around 125K miles is a good time to do it. A properly cared-for car wouldn't need a chain replacement before 100K miles.

This is intriguing given that your chain and tensioner have been replaced. Were both the upper and lower guide rails replaced? Do you know how much stretch was in the chain before it was replaced (in terms of degrees)? Have you inspected the condition of the chain's various sprockets?

The first thing that comes to mind is that the tensioner isn't correctly adjusted. I think the chain stretch for the new chain, and the tensioner operation, both need to be checked ASAP.

I hesitate to say this, but the only other thing I could think of (given that all of the critical chain-related parts have been replaced) is that you and the PO are mis-diagnosing the noise. Though indeed a worn/stretched chain would typically show up right at startup.

Our cars do have a variable intake valve adjustment system but it's not VANOS as BMW terms it. Hoping you're just using the VANOS term as a convenient acronym.

It may be worth taking the car into a competent dealer and having them check it out.

Keep us informed as to progress/diagnosis. Chain and tensioner will become an increasingly important maintenance item for many owners as their cars reach the mileage where these need to be proactively addressed.

Cheers,
Gerry

 

[gsxr]

Also - what brand / weight engine oil are you using? Normally I'd suspect the drainback valve in the oil filter housing, but the new housing should have taken care of that. The tensioner is self-adjusting on the M119.

You may want to read this very long thread on BenzWorld, it could have some useful information for you:
http://www.benzworld.org/forums/r129-sl ... cking.html


UPDATE: Video of rattle now available:
[video=youtube;SdCbWH-hYQU]https://www.youtube.com/watch?v=SdCbWH-hYQU[/video]

 

[Grant V]

Thanks guys.
All the replacements were done by a very competant Mercedes-Benz specialist, who is well known within the Merc Club, so his credentials are not in question. There's no way that I would take the car to the agents - they're useless on anything older than five years that doesn't require a computer to diagnose the problem - even if it's mechanical.
All the rails have been replaced, and someone did suggest the one way valve in the oil filter housing, but then I found out that that had been replaced as well. Could it be that some of these parts replaced were faulty new, so we actually think that that can't be the problem?
The oil question is interesting. I'm not sure what oil is used, but what oil SHOULD be used?
Colin, the Merc specialist, seems to think that there might be a hairline crack in an oil channel somewhere, which allows oil under pressure to escape once the car is standing. Sounds plausible, but I thought maybe someone might have encountered this problem before.

 

[sheward]

When working on my own cars over the years, everytime this situation arose where the likely part has already been replaced it has turned out that i got a bad replacement part. How difficult / expensive is it to replace the check valve mentioned?

drew

 

[Grant V]

I think the valve is the equivalent of $30 or $40, so it's worth a try.

 

[gsxr]

The oil question is interesting. I'm not sure what oil is used, but what oil SHOULD be used?

Per the early 90's spec sheet, you want to use xW-40 or xW-50 oils. However I would avoid 0W-40. Excessively thin oils are strictly for fuel economy and emissions, not engine protection or longevity.

I use 5W-40 or 15W-40 in my cars, and 10W-40 would also be fine. A good synthetic with Group IV/V base stocks is also helpful (Red Line, most Amsoil, some Mobil-1), especially if you don't like having to change dino oil every 3kmi. Avoid cheaper "fake" synthetics with Group III base stocks (Castrol, Pennzoil, QuakerState, Valvoline, and pretty much every other mainstream brand).

 

[Juho]

I use an old thread as the subject touches on so close…

Question for those who have themselves changed the timing chain.

How do I know with certainty that the timing chain is stretched or otherwise in need to change?

I just removed the valve covers and turn the crankshaft to 45 deg mark.

I tried to put the locking pins into the chain sprocket holes. The pin fits tightly only into the left exhaust cam sprocket where is shortest distance to the crankshaft. The intake cam of the same head was a bit more aside and the pin did not get in. On the right head the exhaust cams hole was about 1mm aside.

I'm going to change the chain, but in any case it would be fun to hear your opinions or your experience of how much chains are stretched up and on what kind of mileage?

Is all four cam shaft holes in line with a new chain or do I have to turn the cams slightly with the wrench to get all pins in easily?

 

[gsxr]

Juho, it sounds like your chain has very little stretch. What you can do is turn the engine past 45° until the left exhaust cam can be pinned easily, and read the number off the balancer (probably 44-42° or so). Now remove that pin, and turn the engine until you can easily slide in the pin for the right exhaust cam (probably 39-42°, approx). The right side will likely have about twice the delta to 45° as the left (i.e, if the left shows 2° off, the right will probably be 4° off).

While there is no factory spec, my '94 engine measured 3° off at the right cam (42° on the balancer). My spare engine showed double that amount (6° off at right cam, 39° at balancer). My opinion: Based on the right exhaust cam stretch measurements... 1-3° is probably normal, 4-6° is somewhat questionable, and if you measure more than 6° the chain should probably be replaced. While the valve covers are off, inspect the guides very carefully with a flashlight - make sure they are compeltely intact!

I'd recommend using the M119 chain tool shown at this link, as the factory method is a joke - you can't hold the chain on to the sprockets by hand. BT, DT.

 

[Christian_K]

Mercedes said that any deviation above 6° needs the chain or anything related to be replaced.

A friend of mine with his E420 has exactly the same Problem as described in the opening-posters post. He has that typical "rattle" only 1-5 Seconds after he hot-starts the car, means when the engine is warm or Hot and he stops it and the re-starts it, lets say within 30minutes after stop, then he gets that rattle.

Maybe that damn little thing inside the Oilfilter-Housing is really causing that Problem. As we talk, im about to replace it for my 500E revival, but i'm unable to get that old "Metal-Ring", securing the device, out.

 

[195910]

Hi guys, I have this as well, Though its only in the summer on Start-up.

The check valve in the oil filter housing did not solve it.
My conclusion is that its the Synthetic oil. I read a service bulletin about the R171 cars having the same issue when using Synth oil, the oil in the sprockets would drain out when warm. They have stated that their is no remedy and this should not effect the engine.

Regards

 

[gsxr]

Mercedes said that any deviation above 6° needs the chain or anything related to be replaced.

Christian, at which cam is that 6° deviation measured? Also, do you have any MB documentation that shows this spec for the M119 engine? I was never able to find anything in print, but I'd love to get a copy if it exists!