Author Topic: Mk4 1.8t cutting out  (Read 5501 times)

Offline enyap

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Mk4 1.8t cutting out
« on: 22 January 2018, 19:20 »
Evening all,

I'm having problems with my car cutting out and trouble starting.

The problem is intermittent, which is making it difficult to diagnose. I had the AA look at it when I was left stranded, and it was apparently an electrical problem, with the coil packs not firing. Sometimes, it will cut out but will restart after prolonged cranking and then idle higher than normal. A subsequent switch off and restart and the idle will return to it's usual level. Other times, it will simply refuse to start again unless it is left for a few hours. Hesitations and miss fires are also common while driving.

I've changed all the coil packs, so that can be ruled out. I've also changed the crank sensor, checked wiring and cleaned up the related earth points to no avail.

Has anyone had any of these problems or could maybe give me some ideas as to what may be causing this? I won't take it out for long drives anymore in case it leaves me stranded   :undecided:

Offline Mr_Orange

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Re: Mk4 1.8t cutting out
« Reply #1 on: 22 January 2018, 22:40 »
Just a thought.  The harness for the coil packs can degrade and crack over time, due to heat from the engine. Get stuck into it and take a good look for damage to the insulation. Might be your culprit. If proven a problem you can buy a harness repair section  ;)


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Offline enyap

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Re: Mk4 1.8t cutting out
« Reply #2 on: 22 January 2018, 23:10 »
Hi mate, thanks for the response

I'll inspect those over the weekend. it just seems a little strange that it would stop all of the coil packs working

I was looking through the circuit diagrams and was wondering if the ecu relay could be a cause. I might order a new one and give that a try also

Offline enyap

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Re: Mk4 1.8t cutting out
« Reply #3 on: 24 January 2018, 15:55 »
£22 as quoted from the dealer. That's a lot of money for a relay  :angry:

Offline itavaltalainen

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Re: Mk4 1.8t cutting out
« Reply #4 on: 24 January 2018, 16:18 »
Fault codes at all?
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Offline enyap

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Re: Mk4 1.8t cutting out
« Reply #5 on: 24 January 2018, 19:52 »
Nothing coming up mate

Offline barrym381

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Re: Mk4 1.8t cutting out
« Reply #6 on: 24 January 2018, 20:42 »
Was it a genuine crank sensor

Offline enyap

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Re: Mk4 1.8t cutting out
« Reply #7 on: 24 January 2018, 21:33 »
It was a HAAS sensor from europarts

Offline barrym381

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Re: Mk4 1.8t cutting out
« Reply #8 on: 24 January 2018, 21:51 »
Try a genuine one

Offline enyap

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Re: Mk4 1.8t cutting out
« Reply #9 on: 26 January 2018, 20:49 »
just tried a new ECU relay - no different  :sad: