Intermittent Turbo

[kenbert]

Took a trip to PA this weekend, 4 hour drive. After 2.5 hrs when climbing , the turbo boost started to kick out. With the pedal to the floor the boost would go to 12, down to 5 then up to 12 then down to 5. Kept doing this through entire climb, was normal on level grade.

Pulled into rest area for a while and finished trip with no problems.
Coming home after 4 hrs driving, started the same problem. This time even did it on level grade. Boost would not come on till shifted into 3rd gear, and did the same thing. Boost would not hold, kept falling off.

I am hoping someone here has had a similar problem and give some tips on what to look for. Thanks in advance.

[donn0128]

New turbo time is my guess. Possibly the turbo is sooted up, and if your handy you might be able to drop it out and clean it. What motor? What sort of emissions?

[wolfe10]

First question is this a gauge issue, or did HP drop off when this happened (meaning boost REALLY DID drop off)?

If you have an exhaust brake, confirm that it is moving freely and not sticking closed or partially closed.

Last easy/inexpensive issue is to make sure that there is no exhaust leak between engine and turbo (loose bolts holding the turbo on could allow the turbo to get good exhaust flow/then poor.

And, look at the plumbing on intake side from turbo through CAC and to the intake manifold.