gtp is sick =[

[PhunnyJesta]

Last week I put on a new-to-me 3800performance ported m90 s/c and it ran good but I still have this feeling of lack of power. I've had a P0420 from the high flow cat but to be honest have just been ignoring it since it doesn't really hurt anything. Just yesterday I changed the oil and saw a small group of bubbles formed in the bucket of my old oil I also noticed that something just doesn't sound/feel right about the way it drove. On my way home I was going downhill in 35mph and with my foot slightly on the brake pedal the car jerked forward twice and went up about 500 rpms each time. So far it hasn't done this at all when accelerating. When I shut off the car there was a short low pitched hiss. I don't have a scanner tool and its 12:30 in the morning so i couldn't really do much about this now anyways. I am taking a 1/2 day off work so in the morning Ill do a video of the noise and check the vacuum lines/spark plugs and what not. I've got this feeling in my gut though its not gonna be something small.



*edits*
list of mods in "my garage"
72k miles on the car

[BillBoost37]

The bubbles are likely just the way it drained.

[PhunnyJesta]

I've always heard that bubbles found in the oil was a sign of possible head gasket leak? Cant say i've seen them any other time i changed the oil

[BillBoost37]

Oil is dripping, drooling and hitting all sorts of things that can aerate it inside the motor. Pull the plug and let it drain at least a foot. What happens if you pour water from a foot, it aerates.

You have a higher probability of being attacked by a rabid ostrich dressed like a leprechaun than you do of having a bad head gasket.

If you told us your year etc, then I could guess at a little more. But in the meantime my initial diagnosis of your cars issues is the issue is between the steering wheel and seat. Say you have a year where the COT fueling etc effects things. That code could be causing issues. You don't give us a whole lot of info to go on.

[NegativeOne13]

You have a higher probability of being attacked by a rabid ostrich dressed like a leprechaun on Christmas day than you do of having a bad head gasket.

Fixed.

[PhunnyJesta]

well now that the bubbles in oil worry is out of the way, back to the noise I was hearing. If you notice in the video i just uploaded, when I hold down the bypass valve the sound gets a bit louder. Not much change when reving

YouTube - ‪gtp‬‏

[BillBoost37]

Can't see tube at current location.

WHY THE EFF ARE YOU HOLDING DOWN THE BYPASS VALVE?

[PhunnyJesta]

Can't see tube at current location.

WHY THE EFF ARE YOU HOLDING DOWN THE BYPASS VALVE?

why not?

[BillBoost37]

my initial diagnosis of your cars issues is the issue is between the steering wheel and seat.

I'm going to revert back to my original diagnosis.
Holding the bypass shut manually is forcing the engine to make boost at idle. Aka, asking for a motor swap soon.

[NegativeOne13]

I'm going to revert back to my original diagnosis.
Holding the bypass shut manually is forcing the engine to make boost at idle. Aka, getting something other than a supercharged Grand Prix or vehicle....

Think this is more suitable.

[PhunnyJesta]

congrats you've guys figured out I know nothing about cars! how in the world could of you known that -___- I was really hoping you guys could help out some1 with my lack of any knowledge, you know what people generally do on forums, but I guess Ill have to look elsewhere. thanks

[NegativeOne13]

How about instead of creating boost at idle.... did you look for any vac leaks after your swap? Maybe you trashed your bypass valve by manually engaging it?

[NegativeOne13]

And as for the bubbles... Bill is right. Water aerates like oil does. When you pour it at a distance it will create bubbles. Instance take a brand new quart of oil... shake it up... you'll have bubbles.

[BillBoost37]

What info did you supply? I asked you to give more. And yeah, sorry if I joke around when people say "my car doesn't sound right, what's wrong". Dude, I'm not there, you want free help, you gotta help us to figure it out.

Your hissing noise is likely the ac btw. Totally normal, you'd probably have heard it in the past if you were listening and being hyper sensitive to the car you picked up on it.

Your car hiccuped once from the sound of what you wrote. Dunno how we can diagnose that. It's not abnormal to have a "technical glitch" once in a while.

[NegativeOne13]

As for going downhill and you feel a jerk and RPM jump... could be your torque converter isn't locking up properly.

[PhunnyJesta]

I appreciate the feedback and I am sorry if I didn't provide much info at the start but to answer your question its a 2002. I've been looking for vacuum leaks since i swapped the s/c and using the brake fluid trick to try to isolate a leak but I havent found anything. The noise I am most concerned about though is the metal grinding noise that I think is coming from the supercharger.

[NegativeOne13]

I would go check out looking into buying a stethoscope. Few bucks, parts store usually carry them. And try isolating your grinding noise. Could be a pulley on the side of the engine, could be a bad bearing that they put in upon rebuilding, it's hard to tell unless you know for a fact its coming from the supercharger.

[PhunnyJesta]

coming back from autozone, same scenario as last time going downhill press on the brake, except this time the rpms were shooting down about 500 rpms but with no jerking although you can feel it when it drops down and comes back up. What exactly am I listening for with the stethoscope? On the snout to the right of the hole for the s/c oil I can hear on and off scratching/grinding

*edit*

Not just around the s/c oil hole, basically the whole right side of the snout

[BillBoost37]

One problem with a stethescope is since you've never listened to a good one, it's tough to know a bad one. Do you have any buddies in the are with the same type of car? That's a great way to narrow things down. Cause you can listen to both and compare.

Grinding hmm is this mostly at idle or do you hear it moving as well?

[PhunnyJesta]

Ill have to poke around more later, time for work. Unfortunately I have yet to see any other gtps around my town. There is a guy with a engine swapped fiero with the 3800 supercharged engine. I'll have to see if anyone knows him personally.