My Octy has been suffering from a lumpy idle during warm up - it was fine when cold, fine when hot but gently misfiring when the temp was between the two.

 

Its been getting worse of late, my local indy thought it was an injector issue - alarming given the cost of new injectors!

 

Anyway, I ran into a VW forum thread where a poster described the same symptoms and cured them by replacing the fuel temp sender.

 

Mine arrived from http://www.darksidedevelopments.co.uk/products/1-9-2-0-tdi-pd-fuel-temperature-sensor-sender.html yesterday and the car is transformed, the idle is silky smooth across the whole temp range.

 

A 5 minute job to change, unit is located in one of the fuel pipes on the right hand side just under the engine cover.

 

Result!

Very interesting that, mine has had a slightly lumpy idle when started from warm for years. For the price and ease of replacement I think I might give this a go.

For the cost I might look into this.

My symptoms are a 'rattling' from the engine on cold start most of the time.

VCDS shows a small misfire in cylinder 1 & less on 4.

Could be DMF (although pressing clutch doesn't usually stop the noise), tandem pump or injectors. All of which are expensive.

Could you post a link to the thread please?

Could you post a link to the thread please?

 

Sure: http://forums.tdiclub.com/showthread.php?t=390002 It's a useful link, the timing issue is interesting. My indy checked mine when they changed the cambelt.

 

Certainly the fuel temp sensor is worth a go before considering more expensive remedies. It's been one of those months - changed the MAF, cleaned out the EGR valve then I had an intermittent boost problem (i.e., none!) which was cured by changing the MAP sensor on the lower boost pipe.

 

It's never run better and it's very smooth now and feeling deceptively fast with the Shark map!

Edited 21 June, 201412 yr by Mike N

Thanks. I'll take a read.