I've got a 97 bonnie with just over 100K miles that recently had the upper intake manifold replaced. In fact, just before I bought it. The first thing I like to do when I buy a car is go through and change all the filters, fluids, and other easily servicable items.

One thing I noticed was that the PCV valve was NOT THERE. I put one in and it didn't seem to make any difference. The car runs good, has good pickup and passing power. Get'* about 26.5 MPG on the highway at ~75MPH on mostly 100 mile trips. Not as good as I hoped, but acceptable.

This was about 2000 miles ago.

Over the last week or so, I've noticed a light squeeling noise, seemingly coming from the back of the engine. My first thought was power steering pump. Fluid looks fine, steers fine. Hmm Car still runs good.

The other day I took the oil fill cap off, and almost instantly the squeeling noise went away. I replaced the cap, and within a couple of seconds, the noise came back.

The other thing I noticed was that there was a decent amount of pressure blowing out of the oil fill hole when I took the cap off.

Also, I have started to get an EGR insufficent airflow (or something like that) code. I have an ELM based OBD2 interface, so I just clear the code and drive on. Comes back up after a couple hundred miles.

Last weekend, I took the EGR off and cleaned it. I let it soak in some old skool carb cleaner for a while, and ended up getting lots of carbon out of it. The code came back up yesterday.


SO, with all that said, anyone have any idea what might be going on with the car??
Specifically, the light squeeling noise.

edit* need to read better!

Most likely the squealing is the drivebelt system changing in RPM'* when removing the oil cap. Check your tensioners and idler pulleys, they may go out on ya at a bad time.

what'* a good method of checking them?

When I first got the car, I took the belt off and hand spun all the accessories on the belt (PS pump, water pump, alternator, compressor, ect) and they all spun with ease. Guess I'll check them again this weekend.

Thanks

Sounds like you're missing the O-ring for the PCV valve, and the crankcase pressure is causing the squeal. There should be a spring there, also. Here'* another thread on it.

http://www.bonnevilleclub.com/forum/...ic.php?t=24744

It is absolutely the PCV valve or missing o-ring. This is a typical problem given your symptoms.