Lumpy / surging Cupra especially when cold

ChrisG

Full Member
Apr 22, 2002
426
1
Hants
Hi All

In the past few weeks my car has developed an intemittent fault which I hope some of you may be able to point me in the right direction with.

Sometimes when starting the car from cold, the engine sounds like its running on 3 cylinders and so shakes like mad rattling the exhaust etc in the process, but at the same time its trying to idle at about 12-1300 rpm, higher than usual. When I then pull away its quite irratic at low revs / light throttle and when coming to traffic lights etc it tries to stall on occasions, but if you rev it more it generally picks up OK, and the fault if present clears itself within 5-10 minutes running, and only does it maybe once or twice per week, not every cold start.

Today for the first time it seemed to hesitate when I accelerated coming off a roundabout onto a dual carriageway even though it was warmed up, and again started feeling lumpy and hesistant on a light throttle particularly but I was within 5 minutes of the end of my journey so couldnt check if it continued, but when starting back up to come home it was lumpy again for a few minutes until its warmed up as its done previously.

Ive put VAG COM on it and it mentioned an intermittent signal from the coolant temp sensor, but Im inclined to think that may be a red herring and it may be something like a coil pack actually causing the problems? When they fail do they gradually break down and cause these kind of symptoms, or do they just die immediately? Any other ideas?

thanks

Chris
 

Saul

<b>SCN Admin</b>
May 21, 2001
4,194
0
coolant temp sensor can cause those issues, 5 min job to replace (about £15 from gsf i think)
 

Cupra2505

Guest
I've had similar problems and the coolant temperature sensor did indeed help. It was a lot better this morning. I'd post the link to my thread but I'm not sure how to do it. Have a search through my posts and I'm sure you'll find it. There's even a web link from someone showing where the sensor lives.

Hope it helps.
Mark
 

ChrisG

Full Member
Apr 22, 2002
426
1
Hants
Cheers, yep will clear the error codes with VAG COM again.

Mark, this one? http://www.seatcupra.net/forums/showthread.php?t=137324

Yep I spotted the link etc in that so will have a look at lunchtime to see if I still have the black sender.

Out of interest are these same faulty senders installed in Leon TDi's of a similar age (2001), because my missus's Leon also has a similar VAG COM error but it doesn't seem to affect it adversely, although I have noticed a couple of times the temp guage on the dash deviates from the de facto VAG standard of 90c (come rain, shine, snow etc :D). Is the dash gauge also linked to this sender, or does it have a seperate one?
 

Saul

<b>SCN Admin</b>
May 21, 2001
4,194
0
sender for dash temp is in the res, sender in the pipe is for the ecu read
 
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