Engine Noise

[nahumm924]

My 98 GP GT has a terrible squeal that sounds like a belt slip or a pully bearing going after the engine warms up. I found that if I remove the oil cap the noise goes away. When I put the cap back on, the noise comes back. Anyone had this problem before?

[BNaylor]

Originally Posted by nahumm924

My 98 GP GT has a terrible squeal that sounds like a belt slip or a pully bearing going after the engine warms up. I found that if I remove the oil cap the noise goes away. When I put the cap back on, the noise comes back. Anyone had this problem before?

How many miles are on your GT? When was the last time you checked or changed the PCV valve. Another person had a similar problem whereby they complained of noise around the Upper Intake Manifold (UIM). We don't know the outcome of his problem. When you remove the oil cap, it may be associated posititve crankcase ventilation. Just my 2 cents.

[nahumm924]

It has 85000 miles and I replaced the PCV valve and it didn't help

[BNaylor]

Originally Posted by nahumm924

It has 85000 miles and I replaced the PCV valve and it didn't help

I found the post in the Grand Prix forum concerning noise which may or not be similar to your problem. Maybe the info will be helpful in pinpointing your problem. Good luck!


Re: Re: Re: Re: GM recall #03034 engine coolant leak (Post #7)

Quote:
--------------------------------------------------------------------------------
Originally Posted by Langning
I called GM about our 2001 Grand Prix GT and sadly our VIN didn't qualify for the recall. Since last Fall and car approached 40,000 miles, we have heard loud howling/blowing from the upper intake manifold whenever the engine is running (audible inside the car; sort of sound like the radiator fans are blowing at high speed except that the radiator fans are not making the sound but the UIM)...

BTW, I don't see any coolant leak or coolant loss on my car. But whatever wrong with my UIM, I want it replaced and I am thinking buying the aftermark UIM and do the replacement myself when I gather enough encouragement/skill to perform the task.
----------------------------------------------------------------------

[gulshome]

I have the same problem...81K miles on mine, anyone ever figure out what it could be?

[BNaylor]

Originally Posted by gulshome

I have the same problem...81K miles on mine, anyone ever figure out what it could be?

We have not received much feedback on this issue but there's a high probability that the sound is a vaccum leak or positive crankcase ventilation problem associated with the upper (UIM) and lower intake manifold. Even though you may have changed the PCV valve, etc, check to make sure the large orange oring and small black one on the PCV valve itself are present. Also make sure the MAP sensor is secured properly. Do you have the normally aspirated 3800 Series II engine?










Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[gulshome]

"Do you have the normally aspirated 3800 Series II engine?"

I do. I replaced the PCV last week, and that may be when it started. Think it could have been a defective part? Doesn't sound right to me - PCV is just a simple check valve, right? Maybe I will just buy another and try it out or put the old one back in (I always save old parts, maybe now I know why...).

I replaced the PCV because it has been 30 K since I changed it last, and I am trying to troubleshoot a hesitating engine so I was replacing suspect parts...

[gulshome]

Oh, another quick question: So, do you think this is something that could do further damage if it went for a week or two without replacement? I just moved a week ago, and I realized my tools are still in the basement of my old place - maybe this weekend I could get them - but it's only Monday :-(

[BNaylor]

Originally Posted by gulshome

"Do you have the normally aspirated 3800 Series II engine?"

I do. I replaced the PCV last week, and that may be when it started. Think it could have been a defective part? Doesn't sound right to me - PCV is just a simple check valve, right? Maybe I will just buy another and try it out or put the old one back in (I always save old parts, maybe now I know why...).

I replaced the PCV because it has been 30 K since I changed it last, and I am trying to troubleshoot a hesitating engine so I was replacing suspect parts...

Anything is possible but if the noise wasn't there before the troubleshooting it would be a good place to start. I use only the Fram or AC Delco pcv valve. Per the link below you should check to make sure all the parts are present including the orings and spring. Inspect the MAP sensor and make sure it's not cracked. All four prongs that hold the MAP sensor onto the PCV valve should be present and not broken.


http://macgp.clubgp.com/howto/engine/pcv/gt/pcv.html

Good luck and let us know how it turns out.






Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[gulshome]

Thanks much for the pics...
I don't recall the orange o-ring. Any suggestions on where I can get a replacement? Autozone or any parts store - or is it back to the dealer?

Thanks!
Gul

[BNaylor]

Originally Posted by gulshome

Thanks much for the pics...
I don't recall the orange o-ring. Any suggestions on where I can get a replacement? Autozone or any parts store - or is it back to the dealer?

Thanks!
Gul

The GM dealer has a complete repair kit for around $20. The orange o-ring is very important. Without it, it will make a noise sound like a motorboat and positive crankcase ventilation is affected. But you could check with Autozone and see if they have individual parts.

I'd check into it as soon as possible. Hard to say what will happen. The guy that posted the original problem had it for a while and was driving around.







Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[richtazz]

I agree with Bnaylor, that you should get this taken care of soon. The MAP sensor recieves it's vacuum signal from the PCV, so if one of the o-rings is missing, you may get a bad MAP sensor signal which can cause driveability issues, like the hesitation you are experiencing. The repair kit he refers to is part # 89017274. It includes the 2 o-rings, pcv valve, spring and top housing where the MAP clips in.