PontiacBonnevilleClub.com

Ok so i rebuilt the top end from the head gaskets up. New head and intake gaskets, valve seals, injector seals, ETC.. the whole top end. i even did a quick valve grind just so i knew everything was sealing tight. got everything back together and drove it for roughly 500-600 miles no problems. the car was running better than ever before. On my way home from work one day i started to accellerate from a stop light and i heard knock, knock, knock, then it was gone?? however when i got it home i dug a little deeper and found a couple things. to me the knock sounds like a rod bearing. my oil pressure gauge was fluctuating a little. that and it doesn't knock all the time as a bad rod bearing should????? at idle it is ok but if i play with the throttle a little bit i can get the little knock to reveal itself.

my ideas on a diagnosis:
1. spun bearing (rod or main)
2. failing oil pump
3. or possibly something in the valve train.

any help would be appreciated as this is my primary transportation. that and i want my car back.

2000 Pontiac Bonneville SSEi

Why was the work done?

Is the sound coming from the top end, bottom, drivers side, etc? What is the location of the knock.
If you have to, put the car on ramps and locate it's location and if needed, get a cheap mechanic's stethascope or use a long screwdriver to your ear to listen and locate it.

Have you looked at your oil, to see if there is any excessive amount of metal?

the knocking is coming from the drivers side of the engine. and to me it sounds like a light rod knock. as far as metal in the engine oil, when i first heard the knock i changed the oil and didn't see any metal in it. i put Castrol Edge Syntec 10W-30 and a distance plus filter. i hoped this would have cured my issue. unfortunatly an oil change didn't do it.

other than that i replaced all this because my intake manifold gaskets blew. i went ahead and changed my valve seals and ground the valves because i was already down that far anyhow. and my car has 200k miles on it so i figure a top end refurbish was the best choice.

also like i said everything was running the best it ever had after i put the gaskets in.

little help please....if you all need anymore info on symptom just ask.

Did coolant make its way into your oil for any period of time, especially if it was running? I think you have bad bearings....

i would think if you changed all that and didnt change the oil when you did the work then possibly that could have damaged the bearings. that or they got damaged when you had the first issue.

is it high pitched or low pitched? (high usually= top end, low usually = bottom)
1: pull your valve covers, check all your rockers and pushrods. turn the motor over and make sure they are all moving correctly. (dont start the motor obviously) now watch to make sure the valves are all opening/closing all the way, and check valve springs... could be a bent valve or a broken spring. Now it may be as simple as adjusting the rockers or a bent/broken pushrod.


once you have done the above then you will have either found the problem or know its for sure bottom end internal and its time to drop the pan and inspect the crank/rod bearings.

S

There is no adjustment in the rockers. Did you use new head and rocker arm bolts when you assembled it?

00Beast wrote:There is no adjustment in the rockers. Did you use new head and rocker arm bolts when you assembled it?

correction-tight or lose. also did you use thread locker when you installed them?

New GM bolts would've come with thread locker on them, and the stock bolts are torque-to-yield, and to be thrown in the trash immediately upon removal or loosening. That's what's prompting my question.