Rough idol

[TurboTer]

I used to have a quite quiet Grand National, but one day it started sounding rough, like "bom bom bom bom bom bom bom" when it's in park (or drive with your foot on the brake while you're at a light or something). Almost sounds like a 60's muscle car (but nowhere near that loud)! Could this be a cam problem, or some other problem? Also, the same time (or around the same time), my fuel pressure guage stopped working. How could this have hapened, I put it on myself in the Summer? Could this somehow be related?

 

[TurboTer]

Anyone?

 

[EMcNeice]

How did that sound go again??? LOL

 

[TurboTer]

Originally posted by EMcNeice
How did that sound go again??? LOL

Ya got me all excited thinking someone was finally responding to my problem, but I must admit, you made me laugh!

 

[TRBON8R]

So are you saying it's a high idle problem? If so have you checked for vacuum leaks?

 

[turbo buicks]

IF YOU HAVE A ROUGH "IDOL" MAYBE YOU CAN POLISH IT FOR BETR FLOW AHHAHAHAHAH

 

[TurboTer]

Originally posted by TRBON8R
So are you saying it's a high idle problem? If so have you checked for vacuum leaks?

Nah, the RPM's are normal at idle, it's just not quiet anymore. Sounds like a watered down 60's muscle car. Could it be the cam or cam sensor?

 

[TRBON8R]

I'd look at the exhaust system. You could have the famous header cracks or maybe a leak at the crossover. Does the car run ok?

 

[TurboTer]

Originally posted by TRBON8R
I'd look at the exhaust system. You could have the famous header cracks or maybe a leak at the crossover. Does the car run ok?

Well, I put both the exhaust and 3" downpipe on in July, so they are new still. I can tell tou that the exact same day I started hearing this noise, I found out the car car smokes under the hood a bit when I really get on the turbo, go up a hill, or especially if I do a burnout. I always thought this was the turbo, but I changed it the other day (and even the O2 sensor to be sure) and it still smokes.

 

[wlaukaitis]

Rough Idle

Does the motor shake a lot? Maybe you have a dead cylinder? You can get one of those spark plug wire pullers (plastic) and pull each plug wire off the coil while it is running, each wire pulled will kill a cylinder and make a huge difference in idle quality. The one that make the least difference is the worst "dead" cylinder.

You can also clean out the IAC port(s) with varb cleaner. The car wil be tough to start afterwards.

 

[Razor]

If you open the breather on the valve cover with the motor running, does it Puff Puff Puff smoke. Or is the smoke coming out of the breather minimal.

SP correct Idle not Idol like American Idol.

 

[EMcNeice]

A mis-aligned cam sensor can cause the car to do weird things. Check that with a cam sensor tools and i'd do a compression test if i were you. I bought my GN in 99 with 52k on it and found out it had a wiped out lobe on the stock camshaft. If thats the case, your car pop and miss at WOT.