Help figuring out this noise. (1 Viewer)

[monday]

Hi everyone. Long time lurker first time posting. I have a 1995 Cruiser with 251k miles. I've had it checked out and the best guess from the mechanic is the timing chain slipper/guide/dampener.

A little info about this noise. It doesn't always make it, and rarely as loud/pronounced as in the video. It only does it in drive and reverse, not park or neutral, but does it whether you're moving or not. It is worst around 1200-1400rpms. It only does it when the vehicle is hot. On my normal 10 mile 20 minute commute I don't hear it.

Does the diagnosis sound plausible? I know these are not supposed to have many issues with the timing chain. Any ideas would be greatly appreciated.

 

[Dave 2000]

Does sound like chain lash, you can normally see witness marks once the covers are pulled, yeh I know a pull down.

Regards

Dave

 

[SteveH]

You can do a Blackstone oil analysis and it it comes back with high aluminum numbers, then that's very likely the case. Sounds like the chain to me, especially given the conditions under which you hear the noise.

 

[monday]

Is it possible to replace the chain, tensioner slipper and damper without removing the head? I know I've heard of people removing the timing cover without removing the head, but don't know what else you're able to do without removing it.

 

[bajaphile]

I'd get a mechanics stethoscope or a long screwdriver and try and listen to see if it is pronounced towards the front of the motor.

 

[monday]

The techs did that and thought it was more pronounced towards the front, although said they could hear it everywhere.

 

[Red Merle]

OK, so it's either chain slap or there is something wrong with the bottom end. Listen to the head with the stethoscope. If it sounds very rhythmic and you can hear all the valves doing their thing, it's not that. You could change out the chain tensioner, but anything beyond that is going to require getting into the bottom end and that is just not going to be cheap, no matter how you slice it. Try switching to a lighter weight oil and see if that helps. Otherwise just run it. If you blow the engine, it will probably just be easier to get a used one and jam it in rather than rebuild anyway, unless you are about two tax brackets up from where I sit.

 

[monday]

Chain tensioner was replaced. It's made the same noise with 5w-30 and now with 15w-40.

 

[LS1FJ40]

Sounds like my 93!

I think it's the chain tensioner/guide thingy.

FWIW, I've put over 12k miles on mine since I first noticed it.

 

[Red Merle]

Chain tensioner was replaced. It's made the same noise with 5w-30 and now with 15w-40.

Could be the chain gear. Not as bad as some alternatives, but I am pretty sure you need to loosen the engine mounts and jack the front of the motor up to really get into that part of the motor. You might be able to use a bore scope to look in there if you took the valve cover off. Just getting to that point is a bit of a commitment.

 

[Rwhat]

Is it more pronounced on the drivers side?

 

[inkpot]

Could be the chain gear. Not as bad as some alternatives, but I am pretty sure you need to loosen the engine mounts and jack the front of the motor up to really get into that part of the motor. You might be able to use a bore scope to look in there if you took the valve cover off. Just getting to that point is a bit of a commitment.