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Halfway through a lap today the turbo stopped boosting. The boost gauge read zero. No plus or minus figures. No overheating so it wasn't the ECU saying no more fun. No mechanical noises or signs of anything wrong mechanically apart from the valvegear noise still present 5,000kms after the rebuild. The car drove 3 hours home sort of okish with the turbo audibly spooling up. At the same time the cruise control has either stopped working or only works randomly.

Thoughts?

Sounds like a vacuum leak.

Wastegate actuator not shutting properly ?

Boost gauge hose has come off?


If down on power, intercooler pipe come off, or split, leaking air under boost.

Is it boosting or isn't it? Have you lost half your power, or just getting a zero reading on the gauge with normal power levels?

If so, my money is on an intake-side plumbing leak, like a blown intercooler pipe or something.

May sound silly, Fuse? Otherwise look where the cruise control connects to the throttle just in case the two issues are related.

as cruise uses vac and that is playing up you have a vac leak.
i recently had similar on my turboed car .
i lost boost but car still ran ok and i checked under the bonnet and all looked ok.
i continued my trip but it started running worse and worse until it wouldn't idle.
further look under the bonnet found a hose completely off its connector.
the first symptoms (like yours)where from the hose just being loose and near off but when the hose eventually coming right off it wouldnt run.
i would check all of your hoses while the motor is running...wiggle joins and push on pipes here and there trying to get an idle response.
it can be hard to track down a leak.
some guys recommend spraying carby cleaner over your hoses and your idle will rise at your leak but i cannot say ive done that...that stuff is flammable.

Reckon pezchops is the winner. Thanks also for all the other suggestions.

There was no boost on the gauge because the pipe to the gauge was off.

There were also at least two pipes on the intake side almost off and one completely off. Putting all of them back on restored the boost and the reading on the boost gauge. You can imagine my relief after the journey we've been through this last 18 months that it was this simple a fix.

Needless to say, all these pipes are now properly secured instead of just being pushed onto a couple of plastic barbs. Having discovered this I took a further look around the engine bay and found several other fixings that needed tightening, or even renewing in one case, as the nut and bolt had gone missing. Disappointing this.

Anyway, I'm not disappointed that Winton finished early because of my concern about the lack of boost, because I think I'd pretty much tired myself out by then anyway, especially taking into account the three hour drive home.

bartman and HKS where first on the leak idea ..i just rambled on more

Awesome news!


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pezchops wrote:bartman and HKS where first on the leak idea ..i just rambled on more

But it's how you rambled


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davekmoore wrote:You can imagine my relief after the journey we've been through this last 18 months that it was this simple a fix.

Dave, relieved to hear this was a simple fix.