Was driving home tonight (about half an hour ago) when a few miles from home something changed very suddenly with the engine (vw 1.9tdi 115pd chipped to 140ish by previous owner 70k ago) may have heard sudden noise to coincide but I was driving quite spiritedly and the stereo was up at the time.
Egine suddenly lost power - this has happened a couple of times before where an engine sensor has failed and ecu has gone into 'get home' mode. Normally stopping and restarting the engine solves it - it didn't this time. The way the engine is behaving feels very different, doesn't appear to be holding boost, the turbo is spinning as I can hear the whining in the background. The engine revs fine when stopped/with clutch in but does not pull at all, very intermittantly it feels like the turbo makes boost and it pulls but only for a fraciton of a second and then it goes again -very lumpy/stuttery especially in 1st/2nd

Had a quick look under the engine (plastic) cover with a torch, no signs of any leakages so I was thinking turbo's gone poop, boost hose gone awol, head gasket (can't really see much in the filler cap but no mulch that I could see) or some wierd engine sensor fault.

Anyone any experience of anything similar or any ideas? Had the day off so need to decide whether it's ok to drive (limp) to work in the morning (25 miles each way) and don't want to do any (more?) damage.

any help appreciated...

Ned.

[Edited on 5/12/06 by ned]

Had similar loss of boost in the Mk4 TDI and it turned out to be the wastegate stuck open. Was on a motorway journey. No definate signs of failure. Just found the car seemed down to about half power. Not noticeable around town. Still ran 'normaly'. Just gutless

Sounds like your N75 valve or a related issue... very common problem with the TDI engines. Basically it controls the variable nozzle geometry in the exhaust turbine. Also check the vacuum lines going in and out of the N75 valve for any leaks. Better to check these as they're much less expensive than the valve itself. If there's a problem with it, the car goes into limp mode and feels sluggish. You're aware of other potential problems, but sounds like you've ruled them out.

[Edited on 5/12/06 by akrallysport]

Brake light SWITCH failure can have some interesting effects on the engine.

I used to have a 130bhp TDI Passat as a company car.

Similar thing happened to me, twice! First time booting it out of a hairpin on the Hartside Pass. Engine pulling hard then whoosh back to driving an asmatic 1.1 litre Polo. Limped home, took it to the main dealer and they found the pipe from the turbo to the manifold had split.

They replaced it and it lasted another 30,000 miles, but it went again. Replaced it again and all was fine.

HTH

Mike

as the concencus on here seems to match my opinion that it's something mechanically/boost related I don't think I can do any damage so am off to work (slowly), will report back later if it goes pear shaped

Well,

got here ok, max speed attained was 63mph anything over 1500rpm was a no-no as the intermittant spinning up of the turbo made for far too jerky a ride in any gear. Any sign of a hill and plumes of black smoke came out of the rear of the car - my guess is unburnt fuel as trying to use low gears and no torque from engine - 40mph in 5th up a hill isn't pleasant.

Had another quick look under the bonnet when I got to work (pee'ing with rain) and still no visible leaks of any sort.
When i did manage to get upto 50mph+ on motorway it was very regular in the gain and loss of boost, as if it were getting upto a certain boost and then a split pipe was opening, either that or a fault with the waste gate imho.

cheers for help so far..

Ned.

local vw dealer couldn't fit it in until 20th december!!

booked it in nearer work (and g/f's) and they can look at it tomorrow!

I would look at it myself but it's too wet, not enough light in the day, need car for work and might still struggle to get parts etc etc etc.

cheers all,

Ned.

my 3l dti vectra blows intercooler hoses every 10k, i keep a apare in now

I'm more concerned it's a boost controller valve/waste gate and is gonna cost in parts and labour

if it's just a hose I'll be happy.

Ned.

ebay if your friend

God you guys are good: boost pipe had come off at intercooler apparantly.

Shame I couldn't see it/repair it myself but at least the dealer did a good job of the vallet and was quite amusing when they 'found' £800 worth of other work that I wouldn't authorise them to do (passed mot less than 2 months ago and just been serviced locally) but it was nice to see what they picked up for future reference and the parts are much cheaper from German, Swedish and French

cheers all,

Ned.

Agreed about GSF prices- often fantastic compared to Veedub. I generally phone Veedub first then I feel good about the GSF price!

But be a little careful about the quality of what's on sale from them. It's not all OEM stuff- lots of pattern parts and the like and an awful lot is visibly lower quality. The thermostat I bought the other day was pretty cheap looking compared to the VW one I also bought. And the price was only a quid or 2 more at VW. So it's not worth the saving for 'mission critical' parts.

Oh, and some bits are cheaper at VW too! So keep both their nmbers on Speed dial!

Cheers,
James



[Edited on 7/12/06 by James]

quote:

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Originally posted by graememk
my 3l dti vectra blows intercooler hoses every 10k, i keep a apare in now

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quote:

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Originally posted by James
Oh, and some bits are cheaper at VW too! So keep both their nmbers on Speed dial!

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Ned, i think you're out of order!

You know its only £100 per hour. The other £5 is for the vallet. Vallet's don't grow on trees you know :p

Mike,

The invoice says £90 for 1 hours labour + £15.75 vat

they diagnosed (i'd already told them where the fault would be albeit not specifically what) the fault was, fixed it and diagnosed some other issues (downpipe, engine mount and rear seatbelt clip which had been priced at £800 in total) and managed to vallet the car inside and out - did a nice job on the wheels so I'm not too bothered - sh*t happens!