Help with Engine/Trans Sound

[Chris530]

I figure I'll give a quick hi out to all being a new member to the board. Now for the issue at hand:

As of late my '94 530 has been giving me some trouble and added to my stress. About 2 weeks ago when shifting to 2nd I would hear a noise kind of like moving one hand across the other w/a mild squeek. The sound only occurred shifting into 2nd.

Now fast forward to lastnight. I get about 20ft out of the parking lot (moving in 1st gear) and I hear a loud thud. Look around to see if I hit something but no signs of hitting anything. I drive the 2 miles back to my place.

I start my car up today and notice a small thud or scraping sound coming from the rear of the engine towards the firewall. I hear this "thud" twice (car was in neutral). I shut the car off to look around. Don't see anything so I fire it up again. I hear two thuds again and it goes away like before. It sounds like something hitting another part. I'm not sure what to make of the sound and am very concerned because I need to commute to school for the next two weeks and then 4hrs back home. Any ideas?

[Ross]

It would help to know if your car is automatic or stick.

[Chris530]

It would help to know if your car is automatic or stick.

Sorry forgot to put that. It's 5 spd and also has a little over 126,000 on the odometer. I am currently searching through my records as to the last clutch replacement.

ETA: After searching through all service records I don't see mention of a clutch.

[Ross]

You are looking in the right place. Sometimes a pressure plate will do strange stuff just before it goes. My guess is soon it won't disengage anymore.

[Chris530]

I started it up a couple nights ago and the sound reproduced much more this time. The determination was that it was actually predetonation and not a mechanical issue (somewhat relieved). I think I ended up having water in my gas when I filled up. The car also had some difficulty starting. However when I started it up I found one of the fuel lines was leaking terribly but I managed stop it. As for now though I have a consistent code 1221 claiming oxygen sensor 1.

My question for all after searching through the idle related articles are: what can cause the PCV plate to crack/fail and common areas besides the PCV for vacuum leaks?

Within a years time I have replaced the FPR, fuel sending unit, PCV plate, as well as some other mechanical parts. I have also looked through my records of the vehicle (rather extensive and I am 3rd owner). The records indicate on numerous occasions a rough idle and a code 1221. The O2's have been replaced around the 85K mark, 93K mark, and I have ordered a pair now to see if it helps (126K mark). I also had my mechanic check the fuel pressure on the return line and he said it was at 40bar a few months ago.

[632 Regal]

front plate can leak along with intake gaskets, very common when the weather changes to cold.

[Chris530]

front plate can leak along with intake gaskets, very common when the weather changes to cold.

Appreciate the response. Just checked the gasket b/t the throttle housing and the intake manifold and sure enough there is a leak. Now I think I have $130 worth of oxygen sensors I really don't need. :(