2012 Leon fr cr170 cold start knocking. Any ideas?

stu1986

Active Member
Aug 19, 2010
102
0
redditch
Hi
I've got a 2012 Leon fr cr170 and recently it's started from cold start knocking (like a tappet noise) and I slight miss fire at low revs. But once the car warms up it's fine. It's done 85000 miles with full dearler service history. There are no codes showing. Any ideas would really help. I've been researching the problem on the internet and some people say maybe the egr valve is on its way out caused by the emission recall or an injector problem. Might have to bite the bullet and take it into Seat tomorrow.

Cheers Stu
 

ray

Active Member
Jan 7, 2016
591
190
Mine has been like this sometimes since I bought it, done 20odd k miles and it's still intermittent.

It has cut off a few times with the dreaded injector fault but I had a mess around with the wiring loom checking it's all ok and unplugged all the plugs and gave them a clean.

It ran spot on for about 6 months no issues even when cold but every so often it comes back.

I suspect it's the wiring loom because like you say once it's warm there's no issues. It's been mapped since too which of it was an injector on its way surely would have died by now.

I know it's not the done thing but just after you start give it a little squirt up the revs in first, that's when mine would give me the error code and shut down.

Your the first person I've seen with the same issue, welcome to the club. My car was on 80k when I got it, 105 now.


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stu1986

Active Member
Aug 19, 2010
102
0
redditch
I've just taken it out and put my foot down from cold trying to cause some sort of fault but still nothing. The car drives fine other than the low down rev hesitation and the tappety noise. Really annoying and I can imagine it's going to be difficult to diagnose.
 

ray

Active Member
Jan 7, 2016
591
190
Take off and give the injector plugs a wee blow out and check your wiring loom for anything dodgy looking, have a good feel around.

I think that's what my issue is as any time it does give me bother (and I've had the injector fault code) is that when it's cold if there's a dodgy connection or a Frey in a wire that once it's heated up wiring heats up and makes a more solid connection. That's my logic anyway, dealt with it for two years so not In a rush to buy a new loom.


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stu1986

Active Member
Aug 19, 2010
102
0
redditch
Has your car had the emmission recall done? A few people complaining about engine noise after the recall. I had mine done a few months ago.
 

ray

Active Member
Jan 7, 2016
591
190
No I never took it in, thought it was a load of bs tbh.


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ray

Active Member
Jan 7, 2016
591
190
At least you know it isn't to do with the map, the only other thing I can think of is the air flow sensor, might not be totally broke as you'd get a warning code but could be giving false readings?

Long shot though, I put through plenty injector cleaning too with no change. A new fuel filter did seem to help but it came back after a few months.


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