Engine noise

[Greg1991Plus]

I've searched the forums and checked all the usual things...

I have a tapping sound on a 1991 Plus, on the top passenger side of the engine---and it gets softer as the engine is revved harder and goes to higher rpms.

Rod bearings are recent and rechecked, main bearings checked out OK, both belt tensioners are not it, removed vacuum line to secondaries, not it.
Changed injectors to another set and no change, checked valve adjustment, all good, noise not coming from chain tensioners either.

I'm baffled---noise is most pronounced when stethescope is on injector rails.

I thought it might be timing belt tensioner, not sure, belt is tight and normal.

Engine runs fine, it's just an annoying noise that I can't get rid of. Looking to sell soon so I'd like to get this figured out.

Any ideas?

Thanks!

Greg

 

[Sho_Freak]

could it be a sticky or about to go injector if most of the noise is from the rail?

 

[jmpSHO]

could it be a sticky or about to go injector if most of the noise is from the rail?

He tried another set of injectors with no change.

 

[Sho_Freak]

He tried another set of injectors with no change.

DUH! must have missed that part.........man, got some bafflers tonight! bearing goin bad on your timing belt tensioner?

 

[Greg1991Plus]

Thanks for the response

So a 3.0 timing belt tensioner could make this noise?

It's holdiing the tension fine on the belt.

 

[Sho_Freak]

I can't find the thread but he had a video on his that seems to be a noise like your describing and I'm pretty sure a new timing belt tensioner fixed it.

Edit: his was a bad atx tensioner... I'd still pull the top timing cover and start it up to see if it is more pronounced/louder.

 

[Greg1991Plus]

Put stethescope directly on tensioner and can hear the noise but I also can hear it at the same level through the water pump.

Tension on timing belt seems normal, could it still be the timing belt tensioner?

I can't think of any other source of this noise.

 

[jonheese]

Yes, it could still be the tensioner bearing. The tensioner still works to keep tension on the belt, but the bearing just makes noise as it goes bad.

The noise is not likely to be caused by the water pump, as they aren't known to fail in a noisy way (AFAIK).

 

[Greg1991Plus]

Thanks,
I've ordered a new tensioner.

Hope this takes care of it.

Greg