No boost (NOT Vac related)

[DennisG01]

I was driving last night, after picking my daughter up from gymnastics, and suddenly noticed that the boost gauge was at dead zero, not moving at all. I was in inner-city traffic, light acceleration so I'm not sure how long it was like that since I wouldn't be making that much boost to start with.

By the time I noticed, I was just about home and there were no cars behind me to check for black smoke in the mirror (using the other cars headlights). I could still hear the turbo whistling, but it did appear that the EGT's were climbing faster than normal (and it did appear to be down a bit on power). I didn't want to drive it anymore before checking it out so I pulled into the driveway and took another car to work this morning.

It'll be a few days till I get a chance to look at it, but one of the things I'll do (to eliminate variables) is blow a little compressed air into the boost gauge's feed line to make sure there are no cracks. I did look at the line when I got home and nothing was "obviously" wrong.

I'll also check over the intercooler system to see if there are any leaks. Last night, I was able to hear an unfamiliar sound when I pushed the throttle a little harder. BUT, it was not the typical "WHOOSH" sound that is made when a intercooler coupler pops off.

Any other thoughts?

The turbo I am currently using DOES NOT use the vacuum setup.

[Robyn]

Does the turbo have a wastegate ??? if so, how is it controlled ??
A failed, stuck wastegate would be my first thoughts.


Missy

[DennisG01]

It does. It's controlled by it's own pressure... does that help to answer the question? I'll have to look at the turbo when I get home to explain it better. Sorry, I know that's a little vague.

[sctrailrider]

Does sound like a leak somewhere on the charge side... if the line came off from the comp hsg to the actuator it might not build much boost..

[DennisG01]

Plans changed and I was able to get home early. Turns out it was just the silicone coupler between the intake manifold and the IC tubing:o. It was completely off, but resting close enough that, last night in the dark, it still looked like it was attached. Thanks!

[a5150nut]

Plans changed and I was able to get home early. Turns out it was just the silicone coupler between the intake manifold and the IC tubing:o. It was completely off, but resting close enough that, last night in the dark, it still looked like it was attached. Thanks!

Might try using a marker of some sort to put a line where the couplers are supposed to be seated to.

[sctrailrider]

Next time you have some time, take the tubes off and weld a couple of beads on the ends of the tubes and the couplers won't slide off anymore.

[DennisG01]

Thanks guys, those are good points and I actually do the marker thing and I have beads on the ends. The problem comes with how the IC tubing comes up. It doesn't match up perfectly to the intake so there's always a little tension on the IC tube to pull away. Coupled with the oil that gets mixed into the air from the CDR it looks like the tube just slowly worked it's way out - or maybe I just didn't tighten it down enough. I'm sure that 27psi of boost plays a role, too!

But, the beads aren't very big so maybe I can make them a bit bigger.