Timing chain sound

[4451533]

I was driving the car and suddenly It started… sound similar to fan touching the cover
Last time this sound caused due timing chain tooth jumping…

Any way, I removed the valves covers in both sides and the camshafts pinned in 45’ position.. so there is no tooth jumping…

Is it safe to turn on the engine and trying to locate the sound?

I replaced all upper and heads timing rails a few months ago so I dont think that they were broken…

Any suggestions?

Recently I had oil leaking from the oil housing gasket but I repaired it and the engine was working great

 

[TerryA]

It may be the chain tensioner. I’m not sure how you check it but I would get it checked before I attempted to drive it again.

@gsxr?

 

[4451533]

The tensioner replaced a few months ago

How can I check it?

 

[TerryA]

gsxr or someone else will have to help you with that. Was it a MB OE tensioner?

 

[4451533]

Someone else will have to help you with that. Was it a MB OE tensioner?

No, FEBI

 

[TerryA]

No, FEBI

That could be your problem. Most Febi parts are junk. You should only use an MB OE tensioner.

Check the Wiki on parts not to buy. There is a lot of bad Febi parts.

Sorry

 

[4451533]

but the timing chain tights and the camshafts pinned at the 45’ position

I will inspect the guide rail’s tomorrow (FEBI guide rails…)

 

[gsxr]

Can you confirm the noise is definitely inside the engine, and likely is the chain touching something internally? If so, there has to be something up with the rails or tensioner, since the cam timing checked OK. The tensioner uses oil pressure to maintain pressure on the chain, so if there is any restriction in the oil passages feeding the tensioner, that could cause a problem (no idea how to test this though).

FEBI is a crapshoot, most of the time they rebox no-name cheap junk, but sometimes they do rebox OEM parts. Be very careful when buying FEBI, if you are not 100% certain it's an OEM part, I'd avoid them for critical components. Get a flashlight on your tensioner and snap a photo. It could be OEM, in which case you're back to checking rails and oil feed issues...

 

[4451533]

Is there any chance that new rail guide will be broken? I will take some pics but it difficult to inspect the left inner guide rail..

 

[gerryvz]

If you used FEBI brand rails, there is a much higher chance that a rail is broken, than if you had used an MB factory part for the rails. I recommend replacing your rails, and tensioner, with factory MB parts.

As said, FEBI should NEVER be used for ANY critical part (such as tensioner and rails) and should ONLY be used when the part in the Febi box is a known OEM part (such as the SGF flex discs or SLS hydraulic fluid).

 

[4451533]

Now the timing chain is tight. Can be a chance that the tensioner failed and now it is maintain pressure?

 

[4451533]

Nothing wrong with the guide rails or tensioner

I have noticed that the oil is overfilled for approx 1 liter above maximum

any idea? Is it safe to start the engine and inspect whet is the sound source?

 

[gsxr]

Now the timing chain is tight. Can be a chance that the tensioner failed and now it is maintain pressure?

The tensioner has a spring inside so it will maintain some tension with the engine off / no oil pressure. But when running, it uses oil pressure to increase tension and keep the long curved rail pressing against the chain to eliminate slack. So it's normal for the chain to be tight when turning by hand.

If everything checks out OK, you can start the engine and see if you can pinpoint the location of the noise. It would help with diagnosis if you can determine where the noise is coming from.

 

[4451533]

Just wondered, overfill oil can cause such noise or tensioner issues? I drained more than 2 liters…

 

[gsxr]

Just wondered, overfill oil can cause such noise or tensioner issues? I drained more than 2 liters…

I have no idea. Did you adjust the oil level to halfway between MIN and MAX on the dipstick? If the oil level was not above the MAX mark it would have been fine.

 

[4451533]

No, I have adjusted it only now

 

[4451533]

Well. I started the engine.. there is a knocking from cylinder 4 erea

I disconnected the spark plug cable and the sound still there.. anyway it looks like a lifter. I check the metal oil tubes and they popped up a little bit. I pushed them back. Bit the sound still there

Is it safe to drive the car with this sound? I wand to upload short clip but it is too large. Any idea?

 

[gsxr]

Well. I started the engine.. there is a knocking from cylinder 4 erea

I disconnected the spark plug cable and the sound still there.. anyway it looks like a lifter. I check the metal oil tubes and they popped up a little bit. I pushed them back. Bit the sound still there

Is it safe to drive the car with this sound? I wand to upload short clip but it is too large. Any idea?

If the noise is definitely a lifter, yes it is safe to drive the car, although I wouldn't go on a long road trip like that. The oiler tubes are always slightly "loose", this is not the cause of the noise. Either there's an obstructed oil passage restricting oil flow to the affected lifters, or the lifters need replacement.

Instead of uploading the video directly to the forum, you can upload to YouTube and post a link here. Or, you may find other YouTube videos with identical knocking noises.