My 87' roc is making a popping noise out the exhaust. It only happens when I accelerate. It doesn't matter how hard or soft I am accelerating, it happens no matter what. I checked the timing and it is fine. I did a tune up consisting of plugs,cap,rotor,and coil. I don't think it makes a difference, but I noticed the popping noise yesterday after I put my new catback on. It's a 2.5 dynomax. Please help me out. Thanks

back pressure read up on it make sure evey thing is welded up and hld togeter too

Sounds like a possible exhaust leak. Does it also do this when you are in neutral and rev it up pretty high ??

Nope, it only does it when in drive and accelerating.

Ok well that narrows it down, since it only does it when its under "load". Typically in my experience with exhaust leaks you can hear a popping and a ticking noise at idle also. Since yours only does it under "load" I would say its probobly not an exhaust leak. This a far off guess but maybe something is off with your fuel delivery and your getting too much.

How loud is the popping ?

What I have noticed recently is the car running real rich. Once in a while I will get a code 32 egr failure, but that only comes up about once every 3 weeks and it goes away within a few minutes. Within the past couple days the car has been hard to start. It takes a few seconds for it to turn over. Not to mention I have had kind of a misfire feeling in the car since I bought it. It runs real smooth, but it has a real slight mis. Could a fuel filter be the cause of these problems???

No, a fuel filter wouldnt cause you to have missfire or cause your car to be hard to start unless it was extremely clogged.

Well I think that your dealing with a fuel problem as I suspected. Part of EGR control is that when it is activated it advances timing. So if your EGR isnt operating properly you could have too much fuel and not enough timing possibly causing your popping.

Have your tried disconnecting the ESC and setting base timing ??

I would say change the fuel filter, because; 1 its easy enough to replace 2 you can now forget about it being a problem 3 its a good thing to do if you havent done it in a while just as good maintenace.

Well, I dis cinnected the set timing connector and set the timing 2 degrees advanced like most users do and the car ran really good. Now hopefully, it will continue to run good. You know these cars have a tendency to be a little tempermental... But if it continues to run good looks like the timing was the culprit. I just hope it continues to run good.

Good to hear that, that solved the problem. I mentioned setting timing because it sounded like you had too much fuel and not enough timing.
Glad to hear that you fixed it.

When I bring the rpms up to about 4000-5000, and then let off the gas, I get this wicked popping. I have about three exhaust leaks from a rusted out hole in the intermediate pipe right before the muffler, and some crappy welds that are temporary until I can get my hands on a new catback. It sounds pretty bitchin in my opinion, but it might be a bad thing for performance.






Do you other guys think an exhaust leak is detrimental for performance?

I had an exhaust leak in my old exhaust, same condition as yours guitarjunki, revv it up somewhere above 3500 and then you would get the ol' popping sound, I too thought it sounded pretty cool. But it only sounded good to me because it only did it in neutral for me when I revved it, on the street it didnt do it, or atleast it was low so that I didnt hear it.

sounds just like mine. I have a 2.5 dynomax also. Mine is the catalytic converter. Knock on a real solid part of it or the mount to the transmission and see if you hear rattling. Mine only does it underload and only from idle- 1300 rpms