I was out apartment hunting today when I started noticing problems.

One problem is that the oil pressure is rather low on longer idle (a few millimeters to the left of the '40' mark. It still is around 55 under load. Oil is full (Mobil 1 10W-30).

Another problem is that my mileage nosedived - this didnt occur today, but I only got 16mpg out of my last tank and I havent been driving my car hard.

The third weird thing was that twice when I hit the unlock button the car gave a short beep with the horn like it normally does when I lock it. No, I didn't hit the lock button. It unlocked on the second attempt.

The fourth thing (so far occurred only once) is, that the car made a weird high-pitched (not like a whistle but relatively high) modulated sound which stayed until I tapped the accelerator.

The fifth thing (probably unrelated and possibly simply measurement error) is that I only got 237hp on the last accelerometer tested WOT run. The car feels normal and if it really lost power it must have been so gradual that I didn't notice it. As I was doing the tests without assistance though, it can have been a simple operator error on my part. Last summer I got 304hp.

The car is a '00 SS Convertible with about 23000 miles. In case something is wrong with the engine - I have a GMPP Major Guard.

Any ideas what may be wrong?

Thanks

Chris

 

the only thing i can help w/ is the dyno #'s

some on this board say that your results can vary depending on which shop you go. are all dynomometers the same?

i hope you get help with the other stuff.

 

The number is from an accelerometer - so no chassis dyno. The conditions were similiar (actually the 237hp run was a bit cooler) and the accelerometer used was the same.

Maybe the pavement was different in grip, but at the top of 2nd traction shouldn't matter any more.

Thanks

Chris

 

That's normal for Mobil 10W30 once you get around 3k miles on that oil change...Mobil is a very thin oil so oil pressure will be a bit lower with it but it won't hurt anything. I would be worried if it was like 20...just under 40 won't hurt anything.


These 3 could be related...your belt could be slipping, that would explain the squel you heard, lower hp reading, and the lower gas mileage. Although I would never trust an accelerometer...there are too many variables(traction, weather, launch, setting up)


Sounds like your alarm was set off, probably somebody trying to break into the car. A lot of alarms are setup that way...if it beeps when you hit the unlock button that means somehow your alarm was setoff...and I mean completely went off, not doing that warning chirp.

 

About the oil pressure - I'm glad to hear that.

How does a slipping belt (I assume you mean the serpentine belt) affect the mileage and power reading? I'll check that out though.

And about the alarm: Sounds logical. There was no broken glass or anything but my alarm was fixed by the dealer a while ago and though I turned sensitivity down a bit already it's still too sensitive.

Concerning launch you are right, of course, so the quarter mile times I wouldn't trust. The power readings are on top of 2nd and 3rd, so traction shouldn't make a difference there. The curves looked smooth too, not jagged as if traction had broken and returned.

Thank you - the oil pressure really had me worried.

Chris

 

Update - ran a new test today - 309 rwhp ... looks like I did something wrong on my last run. The engine sounds and feels healthy too.

Also I switched the brand of gas back to Chevron. Maybe the gasoline was bad

Chris