I was just playing with some manual boost controllers. Was adjusting the pre-control and my boost went up to 12 psi.

I held it for a while, thought it was safe according to some other posts.

Right now it's just a streetported motor with no mods.

Anyways, after the run I pulled over and everything seemed ok. I then revved the engine in neutral to about 2500 rpm and it now fluctuates with a steady rhythm like 2500-2250-2500-2250 and so on. It does this at all levels of rpm above 2500 rpm.

Did I blow an apex seal or anything? My vacuum at idle is same as before 14 inhg. What's going on?!!? Help please...I'm so scared.

 

generally, if your engine is blown, it will idle very rough, the vac. will drop at idle (14 doesn't sound like a blown engine).

anyway, i'm not sure about your prob. but it doesn't sound like a blown engine.

 

Check the vacuum hose that goes to your MAP sensor. It's located on the firewall behind your throttle body. The hose plugs into the underside of the sensor.

Also, are you pulling 14 inches of mercury at an idle of 1000 rpms or 2500 rpms? Big difference. Does the Upper Intake Manifold shake violently at idle? At a constant engine rpm while at idle does your vacuum fluctuate? Give me some more info and I can help you out.

 

All good indicators of blown engine, if you have them. My UIM did shake violently, I had really low and unstable vacuum at idle (like 4-0 in hg). Sounds more like a hose issue than a blown Apex seal. 12 psi should be pretty safe.

 

WTF are you talking about?

 

My idle is at about 900 rpm still and I have about 14 inhg vacuum. I have misfire at idle but I always have and people said it was normal and probably more noticeable since I have a street port.

Anyways, everything seems normal until I rev the car to 2500 rpm and hold it there it will fluctuate 2500-2200-2500-2200 repeatedly at a steady rate and the vacuum will fluctuate respectively.

I checked the MAP sensor last night and its still on there pretty tight.

 

Just checked engine codes and I only have code 16 EGR which I had previously.

 

I always though 14 in. Hg was kinda on the low side. I know its not blown engine low, but I thought it was supposed to be 16-18.

 

Damn I knew that. Brain fart I guess. Thanks.

 

Quick, post again man! You have 666 posts, the Number of the Beast! Pretty kick *** Iron Maiden song if you ask me

Oh, and Mor: Are you holding the gas pedal steady but your rpms still fluctuate? How does the car drive otherwise? And if you're misfiring at idle that sure as **** *isn't* normal.....

 

 

Yup, I hold the pedal steady at 2500 rpm and it will automatically fluctuate from 2500 to 2200 and back. Also happens at rpms higher than this if I hold the pedal.

This also occurs with load if I hold the pedal really steady.