Turbo issues (late spooling)

[james306]

I have a 2000 HDI 110 which I bought from a friend in January as a cheap runaround, when I first got it there was an issue with the turbo occasionally not spooling until around 2800rpm, I wasn't overly concerned about this for what I paid for the car, however since then it has been gradually getting worse to the point that it wouldn't spool in any gear until just over 3000rpm.

I'm fairly sure it's an issue with wastegate actuation, sometimes when it kicks in you can feel the turbo snapping in, as though the wastegate is slamming shut. you can hear the turbo begin to spook straight away but it only spools a small amount then drops off and sits at one speed until the wastegate finally shuts. Then it spools up fully and there's plenty of power!

So far I have tried changing the vacuum pipe from the solenoid on the bulkhead to the wastegate, looked over the other vacuum hoses and not found any obvious leaks, swapped the solenoid for the EGR over with solenoid that actuates the wastegate but none of these have made a difference.

There is a reasonable vacuum being drawn into the lines (although having not worked a lot with brake control systems etc I'm not sure how strong it should be) I assume that I could get hold of a vacuum gauge to test how strong the vacuum is.

I also have a breaking fault warning up, although I believe this to be an ABS sensor but wondered if it could be related to insufficient vacuum, also had an anti-pollution fault briefly thrown up which once again I think could be related to insufficient vacuum to actuate EGR perhaps?

So, any thoughts/suggestions on what to look for/where to go from here?

Also if there is anyone in either the Northampton or Southampton area who may have the PP2000 diagnostic kit and wouldn't mind helping out a fellow pug owner to diagnose these issues?

Thanks in advance

[Doggy]

James, there have been a lot of similar posts recently, so worth doing a search.
(Others are more familiar with this issue on a 110, so hopefully someone else will contribute).
The checks you've made so far are sensible. It could be a MAF issue, (may be worth trying it with the MAF unplugged).

I have PP2000 and could have a look for you, (NN17). PM me if interested.

[james306]

I shall try unplugging the MAF shortly and see what happens!

I've done some searching already and a lot of people think it may be related to the vacuum pump, however I have yet to find a thread where the issue has been solved! Certainly does appear to be a relatively common issue though so hopefully someone will have a good idea on what's causing it!

[GingerMagic]

I am in Bournemouth but can pop up your way if you need me.

If you get chance you can squirt WD40 into the air intake when the engine is running ( after the MAF - I use the breather pipe as access ) to free off any sticking vanes, try sucking on the turbo vac pipe at the same time to open/close the vanes.

I thought my EV was working okay but when I swapped it with a known good one my car now spools all the way through the revs.....

Maybe the EGR is also sticking, affecting the air flow to the turbo..?

[james306]

So I unplugged the MAF sensor and happy days, works fine! I have a feeling I have a spare complete air housing in the shed from the DW10TD from my old 306 which I'm hoping has the same MAF sensor, failing that pick one up off Fleabay! Happy days!

Cheers for the suggestion Doggy!

[fattail95]

DO NOT get a MAF sensor off eBay. My original MAF sensor was playing up, and I replaced it with a £40 eBay special. The car still performed poorly, and once plugging it in found it was faulty right out of the box. Do yourself a favour and pick up a brand new OEM siemens part.

[GingerMagic]

A fellow on the coupe forum bought one from Europarts and the readout on planet is very good - it seems a quality item and was around £40.
Ebay ones are a lucky dip, stick with genuine if you can or LMF if money is a bit tight.

[runner1]

I have had this issue on an intermittent basis for a while now and it has gradually got worse to the point I was not getting much turbo action at all!
I disconnected my MAF connector and sprayed with Silicon, jiggled the connector a few times... Damn it has made such a huge difference! The car now feels quite light and not like the engine is trying to pull a tank, and that nice turbo sound is back once again!
The results are a lot better than when I cleaned the crap off the three sensors that the MAF contains too!

So please try this first!