no compression

**steve12** · 08-04-2009,08:07 PM

2.5tdi quattro been stood a while,just seemed one day had compression next it didn't.some people i've talked to seem to think its down to no oil in the hydraulic lifters can this be right.cheers

**Crasher** · 08-04-2009,08:48 PM

Have you measured this lack of compression or are you judging this from the way it turns over and will not start? Does this problem come and go?

**steve12** · 09-04-2009,07:36 PM

there permanantly you tell by the sound when turning it over off the ignition and when you turn over by hand theres no resistance all cams in one peice.can't work out how i've lost compression in all 6 pots.

**kenney** · 09-04-2009,08:05 PM

Hi I don't think it is the hydraulic lifters,that are the fault.Have a look at the intake manifold flap.

**steve12** · 09-04-2009,08:35 PM

are they easy to check over.thanks

**Crasher** · 09-04-2009,09:56 PM

I could have sworn I mentioned the manifold flap sticking shut, where it go! Must have been another post! It is on the boost pipe coming up on the left of the engine bay.

I had a wide angle V6 behave like this a few weeks ago. It was a 2.4 5v but they are similar to the TDI. It came in on a flat bed and when I cranked it over and my first thought was, ohh bugger the cam belt has gone. The reason for the “bugger” rather the “cool” or some other expression of pleasure was that about nine months previously I had done the said belt. I ripped the covers off in a state of frustration only to see the belt was perfect and when cranked, all looked fine. The inlet tract was clear, the throttle opened, everything was fine and no codes, most odd. I got my chap Matt to crank it over whilst I watched and for him to keep cranking, it just span over as if there was no compression. I was just about to say stop when it went “cough” and then cough, cough cough, at which point Matt let go of the key. When he picked himself up after being smacked over the head with a breaker bar, we tried again. After about 30 seconds it stated to cough again and then one by one a cylinder kicked into life and then it took over from the starter and after about a minute all six were running. We shut it down and tried again, perfect. Left it for a few hours, perfect. Left it over night and still perfect. Over the weekend, still starting no problem and now a month or so later, it is still fine and back with the owner. The longest part of the job was putting the belt covers back on. All I can think is that it suffered an extreme case of hydraulic tappet jacking due to excessive oil pressure, something we see on older 4 cylinder TDI Golf 3’s quite a lot and occasionally the VR6, but these recover in minutes.

**steve12** · 09-04-2009,10:05 PM

thanks i'll have a look asap hope its this could do without another bill on top of the injecter pump it already needs.thanks again

**Alan02** · 10-04-2009,07:16 PM

2.5 5cyl. commercials do this too.spin over,non start.same fault with the pump.

**steve12** · 10-04-2009,08:19 PM

can anyone describe abit better where this part is.i've already got the front of the car off ready to pull the injecter pump off but struggling to find this part.cheers