exhaust putting

[pontiac92gp]

If your exhaust is "putting" .. does that mean it is ignition related ? I have a timing light, but unsure whut Im doing ..

Its tha 3.4L TDC mated to a 284 .. and also, when Im hitting 3,000rpms or high, a rattle is occuring .. when I press in the clutch, the noise goes away .. I had the clutch done about 9months ago ..

Any input on any of these questions would be great .. Im about to put it away for winter, and a possibilty of rebuildin it in spring ..

Thanks

[jmgtp]

If the clutch is rattling and stops when you disengage it, its likely that the TO bearing is going bad. If the clutch was done 9 months ago I'd try and take it back and bitch, they might replace the TO bearing at the least.

Word of advice: dont sit at lights in gear (clutch disengaged for extended periods) that eats up TO bearings and gives the thrust bearing a beating too.

the "putput" could be a lot of things, even normal maybe or just the nature of your exhaust. Mine kinda "putputs" a bit after the modded cam timing but nothing really noticeable.

[BowtieKid79]

There was a TSB from GM about the 284 rattling while in neutral. This is actually normal. The gears have to have a certain backlash in them (clearance basically) so they will mesh correctly and not bind when they get hot and expand. This is most likely the rattling that you hear. If you put very slight pressure on the clutch pedal (not enough to disengage the clutch though) and the rattle goes away, then it could be a TO bearing. If it rattles until the clutch is disengaged and is not turning, then it is just the backlash in the gears. John has a good point... do not keep the clutch disengaged unless you are shifting or putting it in gear. The 284 uses a stiffer pressure plate than any other 60* 5 spd, yet the thrust bearing is the same size. This added force is hell on the thrust bearings.

As for the putting sound, this is also somewhat normal. A lot of the 3.4s don?t have the smoothest idle (especially the 5 spds). They tend to misfire from time to time at idle, which will cause the putting sound. I think it?s more noticeable with the stock exhaust because there is very little tone to cover up the putting sound. Also, since the 3.4 DOHC uses direct ignition, there is no way to set or check ignition timing. There is a mark on the front cover for TDC only. While a timing light will still flash, there are no reference marks on the front cover to check the timing. If the timing is retarded more than a couple degrees from stock, it can really kill the idle quality and the off-the-line performance. If the car is running like it should, I wouldn?t worry about it.

[5speedz34]

I have a rattle right when I start my car up from like 2500-3000, I'm thinking heat shielding ne ideas?

[pontiac92gp]

It doesnt make the sound in neutral .. its when Im in gear going about 3000rpms .. Im just gonna go throw a FOR SALE sign on this beast .. or am I ?

I was also pondering a heat shield .. Though, my noise occuired shortly after a pulley ripped a heat shield off and then the alternator blades were clashing into it .. what a disaster!

Thanks for the input .. Im just gonna garage the Prix til spring and have a rebuild .. too cold now to do it

[5speedz34]

Is the sound loud and then it cuts out for some reason. I think mine is heat shielding rattling, but I'll have to diagnose it some more. Maybe when you push it in it goes away cuz the rpm's drop?

later Tony

[BowtieKid79]

the rattling the occures from 2500-3000rpm is the exhaust resonance caused by the expansion of the exhaust gases. it usually only happens when its cold. the resonator after the cat (more like a bump in the pipe) is supposed to control that, but it's too small to do much. placing a 14" resonator directly after the cat will help a lot. the further back in the system the resonator is placed, the less effective it becomes at controlling that resonant frequency and the more raspy the exhaust will sound. The rattle is annoying as hell, but is normal. Some cars have weights hanging off the exhaust systems to add mass and help dontrol this problem.

[pontiac92gp]

Well .. after the whining of the power steering pump was fixed .. I could better hear the rattle .. it does appear to have the symptons of a bad throw out bearring .. Having a bad one, does this do any damage besides being annoying .. jus wanna make sure it doesnt cause the clutch to burn out quicker ..

[Anonymous]

Besides toasting your engine, it would be fine to leave a bad TO bearing in.

[grandprixgtp_91]

Having a bad TO bearing will definatly not damage your engine or clutch in any way shape or form. and a bad TO bearing will usually squeal not rattle.

[blk92z34getrag]

I have a sort of rattle in my tranny too, and it goes away when I press the clutch in completely, if I read correctly... someone said that that symptom would be the T/O bearing?

[BowtieKid79]

As i said before- the rattling that gues away when the clutch is pedal is pressed down is most often the gears i the transmission rattling. They have to have some slack in them so they will mesh correctly. The rattling is normal. and yes, a bad T/O bearing doesnt usually rattle, they sqeal.

[Cliff8928]

Ya, my 282s have rattled aswell... I've had 3

Cliff Scott
89 BerettaGT
89 Volvo740