I have a 05 1.9 vw t5, i have had it chipped the

You put it in park and turn off and it resets. You turn it on and it runs awhile and zeros out. Try looking at the parking sensors and the on board computer.

check the turbo relief valve for overbost

you may have a bad turbo it is common on the vw. with engine off take off big black tube and see if filled up with oil. if has alot of oil it in it will need to be replaced.
did the cam code come back on or was this a old code stored in memory?

sounds like the turbo bearings are siezing and when really hot it releases.

Turbo failure is never normally intermittant so I doubt it is a turbo fault.

The wastegate relys on a signal from the ECU via the MAFS.

Mass Air Flow Sensors are very common to fail on VW TDi and this also fits in with your symptoms.

Kind regards

Lloyd

did you try a blow off if its overboasting with the blow off is it easyer for the turbo to blow the overpressure out and it dont whistle's a suggestion

Hi nick. I have a T5 04 model and recently had the same problem. i was told it was a blown turbo so i had a friend look at it and turbo was fine. got vw to run a diagnostics and it had a broken wire running from the charge pressure meter. replaced for 9 euro. 3 weeks later same problem and it turned out to be a loose plug on the air mass meter. now its perfect again. apparently what happens is that if the engin management is getting a wrong reading from the pressure meter it limits the van to 40 horse power for fear of blowing the engine. whenever i switched the van off and back on the problem would fix itself but as time went on it got worse until complete failure. the wire is located under the coolant resivoir. dont know exactly where though. email me on [email protected] if you need to know more. if it does turn out to be the turbo (which i doubt) then there is a website called CRTurbos that seem to be the cheapest around. but i seen another forum where the turbos were replaced and the problem remained. I suggest first look at the charge pressure meter.

here is what i remember ... there was a class action law suit against VW about the high failure rate of the coils especially for the 4 cyl cars with turbo ... VW lost and agreed to install heat shields around the coils ... not sure what years are involved but you might check with a VW dealer to see if you come under that agreement .. as i recall VW charged a fortune for the replacement coils and labor.. a few years ago you could expect a second coil to go bad and even a third or all eventually .. VW would only change one coil at at time when in warranty .... the replacement coil did not appear to be an improved version .. .. it looks like VW is obligated to install the heat shields on models included in the suit ..

My best advice to you would be to check www.passatworld.com Look into the forums and use the search function. There is an unbelievable amount of information with just a little bit of searching. And there may be some turbos for sale on there as well. If you can't find anything in your price range, check out a chip... slightly cheaper and just as much power gain as you would from a larger turbo. You will have to chip it if you drop in a larger turbo anyhow. Hope this helps!

I had the same problem with my wife's 2006 passat turbo. We lost 2.5 quarts in 3000 miles and the warning light came on. They put us on a 1000 mile oil test and I lost 1.8 more quarts of oil. They finally agreed to replace the rings. Service tech told me that the factory rings are defective, they begin to lead after about 25,000.