1.8 ADR Estate idle fails when hot

**pashathedog** · 10-06-2007,09:50 PM

My 1.8 SE (ADR petrol engine) after a long drive (i.e when the engine is hot) won't start unless I give it some revs. The car will start via the ignition and then the idle drops off and kills off the engine - after a second or so. This is becoming increasingly common after long drives (and at garages after refueling) and the engine is obviously warm/hot whilst all temperature 'warnings' and displays are normal. The car will start if I give it some revs with no other problems. Wifes just told me that it has also happened to her when the engine has been cold and not started for a couple of weeks!

Also, and this may be unrelated, there is an occasional and very slight drop in revs during reasonably hard acceleration (usually between 2-3k revs and usually in 3rd gear) but this may be unrelated?

Any advice would be appreciated.

**paasat_mark** · 12-06-2007,09:13 AM

I also have the same problem on my APU 1.8T Passat. (takes ages to start when hot) but I have have lack of power too, it feels like I am driving an old 1993 1.9D (90) Passat sometimes. My local dealer suggested it is the MAF that is faulty. Also since this fault has happened (not starting) the temp gauge has stopped working too. As soon as I told VW this the guy on the phone sounded like he had jumped out of his seat and said "oh. yes.......... its the temp sensor" and quoted me something like £95 to replace it, when I went back to the MAF unit he been talking about before he said "no no no, we will clear the faults on the ECU and it SHOULD be fixed" and in a 2nd breath "anyway if it is MAF they are ONLY £80 + labour"

As if I would use a main dealer to fix to simple problems my 5 year could do.

Do I replace both items? i.e the lack of power at 4,000RPM and poor MPG tells me it is the MAF unit. However would a temp sensor really stop the car from starting? Or are both faults linked? I

I have read loads of replies where lack of preformance is the MAF and once fitted disconnect the battery for an hour etc etc. Can you please

so I have the correct info and get my passat back up and running.

Thanks

**markbudd** · 15-06-2007,09:11 PM

I had the same fault not so long ago. I changed the Temp sensor and all is well again. DONT CHANGE IT WHEN IT IS HOT!!! And you will need some G12 to top up.

**ANGELO33** · 19-06-2007,08:41 PM

both MAF & coolant temperature sensors are link to ECU it means this sensors will vary your car performance. coolant temp. cost only £14 at eurocapartrs and its easy to fit the MAF is a little bit higher.

**pashathedog** · 19-06-2007,09:16 PM

Many thanks for the feedback. I will change the temp sensor first and see how it goes - especially as it's cheap. Got a horrible feeling that the MAF (car now on 76k) may be the real problem.