i have a 91 camaro rs tbi, runs well but high milage 152,000 miles. the valve seals are not fairing well and the car burns oil on start up only.

the problem im having is the car when driving or engine under load at low rpms sounds like its rattling. distintly sounds like pinging as if the timing were out. ive checked the timing and replaced the plugs and wires all done at a shop and the noise persists. i started thinking it was the belt tensioner so i replaced it today but the noise hasn't changed. it only makes the pinging at 1100-1600 rpm.

no engine lights have come on. the engine light does come on when driving on the highway 60-75 mph but im thinking that its the egr on that one, it goes out when getting on the gas or droping speed back to city roads.

 

anyone, have any ideas

 

Here is an idea. Remove the belt and start the car for a few seconds and listen to see if the rattle persists. If it is 150K my bet is on a worn timing chain. They make a horrible noise on startup or just above idle. Really irritating to find also. I swore it was coming from all different places.

 

my RS has been doing the exact same thing for months... have tried every thing... it happens at light loads with mine any more than 1/2 throttle and it is gone i am thinking it is just a worn timing chain

 

you know I actually never even considered that the timing chain would be worn, and now that you mentioned it i was triing to find this anoying noise on start-up - engine sounded like a sick supercharger. The closest i came to finding the noise before it went away (like it always does 10-15 sec after I start it) was around the water pump area but the water pump is brand new.

 

Pull a belt and check to see if its still there, if so then more than likely. My old timing chain (keeping in mind this motor was a crate replacement) was stock and it had a LOT of play in it, loose as hell. Even worse was putting the timing cover back on without dropping the oil pan. Since it was a one-piece seal, I got ticked off enough to cut off the lip on the timing chain cover and put a lot of black RTV silicone on it (most would consider it a hack job, but its my car, deal with it ) and it has yet to leak. Since it was done on a Sunday with no parts stores open, the double roller I bought brand new would not fit, they assured me it was the right one but to no avail, had to resort to using a used single roller from my crate 350 motor (for the 87 in build) so I have a car period. No noises and it worked like a charm.

 

I did the timing chain in my T.A, it was a PITA coz it was the first time i have done a timing chain on any car and going from a stock (3 teeth missing off the top gear and the chain was so loose it was hitting the cover) single roller setup to a RollMaster CS1000 Double Roller timing chain setup.
It said i had to drill a 1/8 hole in the block just over the cam behind the top pully (for extra lubrication of the chain :P).
It was fun since it was a every day driven car, i only had one weekend to do it with no help.
It ran 80% better after the swap.