Hello all,

I have a 1998 Bonnie SSEi and I've got a head scratcher of an engine noise. Last fall I did the LIM and UIM gaskets and replaced all with GM parts. This car had a slight lifter tick when I took it apart so I decided to install a new set of aftermarket lifters supplied by a local engine shop. the sound in this video: http://www.youtube.com/watch?v=6KOy_LYBFTg has slowly been getting worse to the point you hear in the vid. Now I didn't replace the rocker bolts as some have recommended on this site however everythings torqued to spec. I checked the harmonic balancer, and while its original (134K) it seems to be OK. (unable to rotate outer hub)I removed the belts and the same noise was there. In the video I show the engine running without any of the belts installed. This sound is worse in the extreme cold, but now we're back into the 20 C weather so its a little quieter. This sound is driving me nuts because I've already got a day'* labour into it just to do the intake gaskets, I really don't want to have to take it all apart again to replace a defective lifter.

Any help would be welcomed.


1998 Bonneville SSEi Supercharged
134000 km
clean oil
clean coolant
no leaks
infuriating rattle[/url]

that sounds like Rod Knock

Sounds like a rod to me too.

You could check your rockers, as the old bolts would have already been stretched when you reused them. Maybe they aren't torqued properly anymore.

Aside from that, the knocking noise seems to be something that sounds too big to be rockers or valvetrain. Still, I would exhaust all your options before you determine the engine is done. I'm afraid it could be rod knock, but do some checking first.

thanx for the speedy responses. As soon as i find a way to get my toolbox here and i'll tear into it again.


Thanks again

Jason

take a big screwdriver put it on the block put your ear at the end of the screwdrive im about sure that come from the lower end = rod knock

Jason.. If it'* rod knock. You probably can check it by the oil pressure gauge. What does the gauge read when the car is warmed up at idle?

Thanx Bill,

cars undergoing a minor body resto but i'll see if I can roll 'er out and run it to answer your question. I'm going to make another vid of it after its been running for 20 minutes or so...


J

Take another vid from under the car too, that might help narrow it down.

Here'* another video of the engine running after 20 mins. The sound is a lot quieter, and when you rev 'er up to about 2 grand, the noise goes away. I poked it a bit with a stethoscope, and it seems to be coming from down in the lifter valley. I poked the oil pan too and the sound seems to be coming from higher up inside the engine.

Here'* a link to the vid
http://www.youtube.com/watch?v=Sn7qnWs17A4

Here'* the oil pressure at idle, after warmup http://www.pxa.ca/oilgauge.jpg

Remember this is after it'* warmed up. The first video is when it'* stone cold.

Bill, I can't really get the camera under the car, but that noise really seems to be coming from the top end.