I bought this a week ago (1998 Passat Tdi 90hp):

http://rover.ebay.com/rover/0/e11003.m43.l1123/7?euid=7589fabaf9c741cfa62189fb701dbaf5&loc=http%3A%2F%2Fcgi.ebay.co.uk%2Fws%2FeBayISAPI.dll%3FView Item%26item%3D250855460383%26ssPageName%3DADME%3AB%3AEOIBSA%3AGB%3A1123


Picked it up today in Rugby, expecting it to run like crap (as promised in the ad), and it ran perfectly smooth..

Idles spot on forever, and driving it gently (low throttle) it didn't even so much as hiccup in about 20 miles.

As I got closer to home I tried to induce the stutter that the seller mentioned, and I succeeded:


As an initial observation, it appears to happen after giving it a good blast and then settling back, and varying throttle opening around the mid-point. Even then, I only managed to get the car to do it about 5-6 times.

It will stutter a little bit (pushing foot down doesn't cure it), but you can persevere through it and after a few seconds it goes away and returns back to normal.


Here's the kicker - whilst it's stuttering, it puffs out BLUE smoke out the back.


Any ideas what this could be? I thought turbo seals initially, but it doesn't smoke normally, at all, whether on idle or under throttle, so why should it only do it intermittently?

The seller seems to think that there is a timing issue with the IP or it's missed a tooth when they changed the cambelt, but to be honest it runs far too well 98% of the time for it to be ither of those as far as I can tell.


If it's something simple I can fix/check I'd like to do it as I want to keep it for a parts chaser. Otherwise I'll just take off some bits of trim and the rebuilt IP off and weigh it in.


Thanks,
Pavs

eBay Item

1998 VOLKSWAGEN PASSAT SE TDI SILVER 90BHP/65mpg ENGINE | eBay

Try the EGR valve they coke up and can cause all sorts of problems. Take it off and give it a good clean, I had to do it on a mondeo tdci with only 70 k on it.

EGR is a good call

Do you know if removing the EGR and blanking it on these engines will cause the ecu to go into limp home mode?

Thanks for correcting my link chaps.

Ta

Pavs

Probably worth checking the valve and pump timing as well if suspect but more likely to be EGR valve

http://www.myturbodiesel.com/1000q/egr-system-clogging-TDI.htm

Cleaning your EGR may help?

Thanks, definitely sounds like the EGR since it can weep oil into the intake at low/mid throttle..


Incidentally, that website is a really really good read!!

Pavel

Not sure if those suffer from the same fault as my A6 had (present model), but that was a poor oil seal on the fuel pump, so oil leaking into fuel. The fuel filter fills up and after a while it starts doing that sort of thing when under load.

The clue was oil in the fuel filter.

Thanks matt, I'll have a look in the filter

Although these pre-PD TDi engines will run quite happily on engine oil as fuel so shouldn't see such a dramatic stuttering if it did contaminate..

Deffo sounds like an egr valve to me. I had a Clio van that the egr valve that used to stick. I took it off cleaned and blew through with an airline which cured it. It was sometimes quite amusing though once I had discovered how to entice it. People in convertibles with the roof down on a mobile phone were always amusing when there super smooth image was destroyed by thick blue smoke!!!!!!