ARL 150 a bit flat

[richiek]

I've recently picked up a 2003 GT Tdi 150 for a nice run around. It has 113k on the clock with good service history and drives quite well but seems flat for a 150 and only returns about 30mpg around town whereas all my other 130's and 150's have returned at least 40.
It doesn't smoke or miss and while changing the rocker gasket (as it had a slight oil leak) at my mate's local garage they checked the camshaft for wear and it all looked fine. They also checked for boost leaks and there doesn't appear to be any.

Yesterday I took the MAF sensor off and it appears to be the right one (Bosch) which I was thinking could have been a problem. I cleaned it and also the plug pins with some electrical contact cleaner and it did seem to make a slight difference so I'm guessing it could be on the way out. I also noticed that the plastic mesh in the MAF housing has very small gauge holes compared to the usual Bosh or Peirberg units especially on the ones which are fitted to the ARL/ASZ engines.

Due to the cost of the genuine Bosch/Peirberg units I'm loath to buy one which would be a gamble especially if that didn't cure the problem. I'm wondering if there's anyone out there in the Plymouth area with a perfectly running ARL/ASZ that could meet up and lend me their MAF for a few minutes to eliminate this as the cause.

The other thing I'm thinking it could be is the timing being very slightly out. The guy I bought it off did the cambelt kit himself a few months back with the aid of his brother who is a garage mechanic but not a VW specialist so I'm thinking they may not have set the timing up exactly right. I think I need to find someone around here with VCDS but not sure there are too many TBH.

Has anyone else on here had similar problems and if so what did you do to cure it? Also, if there is anyone in the Plymouth/East Cornwall area with VCDS who could do a quick scan for me for some beer money I would be very grateful.

Many thanks

[zollaf]

to see the timing you would need to obtain the lock tool for the crank, time it up and see if the cam is in the right place. other than that a code read, looking at the maf values in live data and any other codes or anomolies.

[richiek]

It's not coming up with any codes on my hand held VAG scanner or on my mates £8k Snap On machine.

Can't you read the timing values on VCDS? I'm sure I read somewhere that you can.

The air filter looks a bit dirty and I will replace it tomorrow but I can't see it making that much difference in all honesty. I may take the egr off aswell and give that a good clean.

My money is on the timing being slightly out.

[Darrenh321]

I would agree about the timing being a possible issue.
I would also say that I had similar issues with regards to loss of power, a VW specialist checked for boost leaks and found none, but it became apparent after a while that my "pancake" pipe was not fitting snug and was causing an issue.

[richiek]

Thanks Darren.

What do you refer to as the 'pancake pipe?' My top intercooler hose that goes into the EGR wasn't fitting snugly when I first got the car but I tensioned the spring clip a bit and it was much better.

Did you solve your power loss problem?

[Darrenh321]

Yes eventually the power loss problem was solved, but I do not know if it was the timing or the pancake pipe that was causing it as they were both rectified at the same time.

I would try your timing first though as my replacement pancake pipe was over £100. This pipe is located at the front left of the engine bay, but right at the bottom of the engine, which makes it easier to get to. The VW dealership (which is the only place you can get them from) referred to it as a pancake pipe. It is metal/aluminium in construction, and is a round at both ends and almost flat in the middle.

Difficult to explain really, but if you google it you will see pictures of it, and other peoples comments with regards to boost leak from there.

[richiek]

Thanks Darren, how did you get your timing checked as I've been told to check it properly is about 5 hours labour which even at mates rates is going to cost me more than a pancake pipe I would suggest? There must be easier ways like with Vagcom surely?

[zollaf]

5 hours, utter tosh, you take the crank pulley off, and the top belt cover off. you line up the marks, insert the crank locking pin, then see if the cam lines up. about 1.5 hours , 2 tops to check it.

[zollaf]

the pipe you refer to, the pancake pipe, breaks at the ends. its a poor design really, needs to be thicker. i have fixed one today funnily enough, just took it all off , drilled some holes and used self tappers to hold it together. vast improvement.

[richiek]

Thanks Zollaf, can the timing not be checked using VCDs then?

It has actually been noticeably better since I put a bottle of Forte diesel treatment in at the start of the week and have been driving it quite hard so it may be just a bit gummed up. Still hasn't got the fierce torque the ARL's usually have though.