Hello, everyone.


Within the past two weeks, I finally managed to repair my 89 Iroc and get her back on the road where she belongs. Naturally, it's given me hell in every managable facet of its design, namely vacuum leaks and exhaust problems.


I've been driving the car (testing) throughout the final states of repair, and though all of the vacuum leaks have been found and dealt with at this point, I dare say that in order to run the car for the past week without stalling, I advanced the distributor in order to compensate for the many vacuum leaks. Within a few days of that, I noticed a very faint 'knocking' sound, which at first worried me that it may be a rod knock, (killer of my first engine) but doesn't seem to increase in volume with RPM. My guess is that I have a bad lifter, though, for a while, there seemed to be a correlation between the amount of fluid in the trans and the frequency/volume of the 'knock'. I've tried removing the fluid from and refillig my tranny, but to no avail, the knock persists, and in the past 5 days, it almost seems louder.


Just today I retarded the distributor into its correct position, and the car drives just fine. There doesn't seem to be a loss of power, and the knock doesn't seem to be affecting anything. (At the moment at least.) My friend thinks a bad exhaust manifold/Y-pipe is the problem, though I'd have to say the source of the sound is somewhere around the torque converter/engine area, and any attempt at tightening my exhaust has done little for the sound I'm getting. I guess the question I'm asking here is about the nature of running an engine a few degrees advanced for a week or so. Could it permanently harm the engine or the trans? I was told by my father that it causes similar damage as overheating, and could therefore warp several engine components, thus resulting in something like what I have. I spent a long time dropping this engine... it'd be too bad to have to do the whole damn thing over again because of a few days of bad judgement.

 

Persistent preignition under load can cause damage to piston tops, possibly crack rings or ring lands, and rarely but possibly damage heads. If the noise occurs even at idle or under no load, it is likely not related to incorrect timing. There is no way incorrect timing is going to affect a transmission mechanically.

 

^^^

Vaders got it, though you could probably also hammer out a couple bearings if its always detonating too.


Either way its no good!

 

Thanks the help, guys.


The car is still making the chatter, and I'm probably just as stumped now as I was before. I know that the engine timing couldn't effect the transmission, I wasn't implying that it did, I was just curious what COULD get effected by the timing, and in turn, possibly generate the noise that I've been hearing.


I still think that the transmission is at fault here, and I'll probably know for sure tomorrow after I test it. Thanks again for the useful information, I'll keep that in mind next time I decide to be dumb and drive a car with an advanced distributor.