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Author Topic: Low Boost and Timing Pull  (Read 5857 times)

Offline ruiadf

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Re: Low Boost and Timing Pull
« Reply #15 on: March 04, 2019, 03:35:18 pm »
Aha, well there you go then....a non genuine PCV is certainly a potential candidate for inconsistent boost!  You could also have leaking boost pipes.  Check for oily patches on your belly tray where the boost pipe connections are.

Do you think the non-genuine PCV is likely to be the culprit of the inconsistent boost, considering the specified boost is also low?
I thought the PCV & leaking boost pipes will be the ones to look for if there was a difference between the Specified and the Actual boost, which does not seem to be the case...

Offline pudding

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Re: Low Boost and Timing Pull
« Reply #16 on: March 04, 2019, 05:36:13 pm »
Possibly, if the one-way valve integrity isn't great, or if the rubber diaphragm has split.  If in doubt, I would replace it with a genuine one.  They're not expensive.

This is the thing with logging; it's not always cut and dry.  The turbo will keep on spinning to meet the target, regardless (unless it's completely knackered) so another thing to look for is how quickly the requested and actual values align.  Severe boost leaks are usually manifested as sluggishness to build boost.  Slight leaks generally aren't felt, but may show up in the logs as taking a few hundred rpm longer to align.

Best thing to do is go over everything and make sure the boost path is gas tight and everything is mechanically sound.  If there's still an issue, it's probably best to get it into a shop for smoke tests and deeper analysis.  How many miles on it?  Mine's on 130K and is nowhere near as punchy as it was at 75K when I bought it.  Turbo is probably on it's last legs.  Stuff just wears out.


2007 ED30 | 2009 TDI 140 | 2016 BMW 330D

Offline ruiadf

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Re: Low Boost and Timing Pull
« Reply #17 on: March 04, 2019, 05:59:26 pm »
Possibly, if the one-way valve integrity isn't great, or if the rubber diaphragm has split.  If in doubt, I would replace it with a genuine one.  They're not expensive.

This is the thing with logging; it's not always cut and dry.  The turbo will keep on spinning to meet the target, regardless (unless it's completely knackered) so another thing to look for is how quickly the requested and actual values align.  Severe boost leaks are usually manifested as sluggishness to build boost.  Slight leaks generally aren't felt, but may show up in the logs as taking a few hundred rpm longer to align.

Best thing to do is go over everything and make sure the boost path is gas tight and everything is mechanically sound.  If there's still an issue, it's probably best to get it into a shop for smoke tests and deeper analysis.  How many miles on it?  Mine's on 130K and is nowhere near as punchy as it was at 75K when I bought it.  Turbo is probably on it's last legs.  Stuff just wears out.

The car just turned 80k a few hundred miles ago.
I wouldn't expect the turbo the be on the way out considering the watergate log posted before, as in that log at 2.5krpm the wastegate seems to be 50% open and the turbo is still boosting 12psi, or I am reading it wrong?
The only annoying thing is that apart from the slight loss of power the car seems to be perfect no strange noises or other things...