LCR 3000RPM brief boost flutter hesitation

[PSX]

Hi all,

There are a couple of symptoms for me that need looking at as the weather picks up.

First - on WOT from 2000RPM, the turbo winds itself up to what must be near full boost, hits 3000RPM, has a faint dip of boost for a moment and then resumes full boost to redline. It's just a single flutter. Is it more likely to be DV (stock) or N75 (stock)? It is a gentle cut, no fault lights, so I don't think this is ignition.

Second - on initial cold startup the revs climb to 2000RPM and tail off in the last week. The first time the car tries to climb up the rev range on partial throttle, I can hear a wheeze from the engine bay as though a vacuum valve is open. Acceleration is rough and uneven until it passes above 3500RPM once. Sounds like the lower T-piece valve in PCV system? Replace this and PCV 'hockey puck' together? As soon as vacuum is restored, i.e. within the first 90 seconds of driving from cold, the problem goes away.

Clues on whether these issues are related? My thinking is not, because that vacuum valve should be open on closed throttle, and shut on WOT - so when the system is pressurised, the vacuum system is all tight anyway.


Cheers,

Alex

 

[ibizacupra]

I will sound like a broken record next

Get it smoke tested for leaks.. So many of these have split pipes which result in all manner of random things occuring..

 

[PSX]

Thanks Bill, I will get under the inlet manifold, clean up the pipes and check for leaks when I service it this month and reply back

Alex

 

[PSX]

Well, I had a check of the PCV pipework and as I did so, one of the pipes split badly. Should've taped the pipe there and then but couldn't find tape - end result - car loses a lot of power and the pipe breaks in half in two places when I do try to tape it. Recovered home by breakdown. Plenty to do Monday/Tuesday now..

 

[PSX]

This diagram (not of BAM 225 engine) shows last night's offending items. Photographs are of my BAM 225 engine.

2 - the torn pipe - this is 06A103213AF (06A103213AK on my car)
11 - T-piece plugging into the PCV valve (number 8)
8 - PCV valve
5 - crankcase breather pipe (different shape on BAM engine)

06A103213AF (piece #2):

The lower arrow points to piece #2, the upper points to an 'intake breather pipe' connecting the 'hockey puck' PRV valve to the turbo intake pipe (TIP):

This was very soft and looking ready to tear as well, so I'm also replacing this. I will be replacing the PCV now and the PRV and crank case breather Y-pipe later on when funds allow.

Above the lower arrow you can see the connection into piece 5, crankcase breather pipe.

Creations Motorsport sell an item that replaces parts 2 and 11 in the diagram:
http://www.creationsmotorsport.com/product-detail.php?pid=15

..Forge and Creations both sell a replacement for the PRV intake breather:
http://www.creationsmotorsport.com/product-detail.php?pid=574

And another excellent reference point: http://www.ttforum.co.uk/forum/viewtopic.php?f=2&t=210189

So here's hoping I can replace these bits without breaking anything else on the lower system...


Alex

 

[PSX]

80% of the VW clips came off with gentle twisting of a screwdriver at the end of the band to coax it up over the 'peg'. The clip attached over the PCV valve (piece #8) was very hard to reach - the BAM engine pipework includes more complex pipework higher up from the PCV and I was worried about tearing this while working on the stubborn clip. (See the TT forum link).

All the pipework held... the dipstick tube however, didn't - smashed this in two places and a replacement from the main dealer is in two parts, upper and lower, that should be a push-fit down into the top of the sump. £14 for the lot.

The elbow pipe into the top of the oil filter housing (piece #1) also broke at its edges - there is enough in place to hold a seal against the O-ring but it is knackered. Part #06A103213F - £13 at Ebay for a pattern part (£45 at a dealer). With the dipstick gone and the elbow pipe moved, I had enough access for the difficult clip, and the whole lower of the system is disassembled.

Crank case breather pipe is knackered - the rubber inside is very rough and tearable - cleaned it as best I could until it can be replaced.


Alex