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Discussion Starter · #1 ·
I have had a look through recent postings and I cant find anything similar, so wondered if someone could help me out with an idle problem on my Golf.

Basically I have two faults that are intermittent. They normally happen from cold, or if the car has been left for an hour or so.

Either the engine will just stall (ie you start up, drive off and then after a minute or so stop at lights with the clutch in and it just dies). Or, after driving off after a minute or so it holds really high revs and wont come down (eg anything from 2k up to 4k rpm).

Its a pig to start if it stalls, or if you switch off whilst its holding a high idle. Takes about 30 seconds of kranking.

I have tried spraying in carb cleaner in the throttle, and lubed up the throttle return spring but it doesnt seem to make any difference.

My thoughts are either a temp sensor or throttle position sensor, but I am after any help on how to track this one down.
 

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It's probably a temperature sensor that has failed - I had it on my Bora 1.6 a few years ago and is I believe a common problem.

Chris
 

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Mine's just bloody done that today! Manouevering in the car park and the engine just died with the clutch in. It wouldn't restart for about ten minutes.

It hasn't done it since last Winter but that time it left me blocking my road for ten minutes! It will always start from completely cold. It's just if it dies that restarting is a female dog.

Is this definitely a sensor problem?
 

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Discussion Starter · #4 ·
thanks Chris - at least I am not the only one to have seen the problem!

I guess the temp sensor makes most sense as the car is totally fine if it gets past the first few minutes of running and so accurate temp readings are probably less critical then.

anyone know where I can locate the sensor on the engine? Or how easy it is to change? Else I'll have a look at the Haynes manual tonight.

it would be great to get this one sorted - I hate it when you cant trust a car to behave itself - as jrsp says - it is a real pain when you are stuck at lights and you cant get going again!

Jeremy
 

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When I had mine, I found that suddenly I had lost engine braking whilst travelling along at 70 as the engine idle seemed to be anywhere between 2000-4000rpm. In the same journey I had to stop in slow moving traffic in the fast lane of the M4 whereupon the the revs continued to rise until I turned the ignition off, but of course then the traffic started moving and I couldn't get it restarted!!

I think the temp sensor basically causes the engine to think that it is cold and effectively overfuel (like a 'choke'). As you have probably found, this can be totally intermittent. I had mine fixed under warranty at the time, so I'm afraid I can't actually tell you any more about where the sensor is located or how easy it is to access.

Chris
 

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Discussion Starter · #6 ·
Chris - the fault you have described is so similar to the one I have got that I am pretty sure it must be the temp sensor.

I have been a bit more fortunate than you as the car has only tried racing away at relatively low speeds so far so I have been able to cope. It must have been pretty horrible at motorway speeds, and then to get stuck - ouch.

I think it may be off to the dealer or the garage round the corner to get the sensor changed as I imagine I'd have to bleed the coolant.

Appreciate the help.

Jeremy
 

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I think I'll get mine done at the service I'm having soon. Hopefully it won't take them too long if they're doing the timing belt anyway...

jezh, it might be worth getting your throttle body cleaned as well. That solved the rough idling I had but on the other hand it didn't rev quite as high as yours does!
 

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Discussion Starter · #8 ·
jrsp - I think I'll do as you say and give the throttle a clean, or at least another go with the carb cleaner as reading other threads it sounds like another common problem.

But the temp sensor is definitely getting replaced as well!

Hope it stops a recurrence of your stall as well.

Jeremy
 

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Cheers so do I!

Just been on the blower to the stealer, they reckon it'll cost ?35 for labour to change the sensor, even though they'll be in there doing the service anyway! I can't find instructions on here for changing it, have you got any?
 

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Discussion Starter · #10 ·
jrsp - just been looking at the Haynes manual

the only thing that is confusing me is that it seems like there are two sensors - one on the radiator and one on the coolant distributor housing, so I am not sure which one is going to be the one that needs changing!

according to Haynes its a "2 spanner job" so not too difficult. Once you have drained some coolant its a case of unscrewing the old one and screwing in a new one.

I guess if the dealer is replacing the coolant anyway it would make the job simpler.

Do you know which sensor you were quoted on?
 

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No idea sorry! This is where my limited knowledge comes to an end. I just spoke to the guy in services and said "I think I may need a new coolant temperature sensor" and he seemed to know what I was talking about.

Draining the coolant sounds a bit high tech for me, I don't really want to be d*cking around with that. Keep me posted as to how you get on and I might give it a go though.
 

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Discussion Starter · #12 ·
Just phoned the dealer.

The parts guy reckoned the temp sensor can be replaced without draining the coolant. Just have to make sure the engine is cold.

I now have the part and will give it a go to change it myself one as soon as I get the chance.

I'll let you know how it goes.

Jeremy
 

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dudes, which coolant temp sensor is it? does any one have a part number.

My wife just bought a 1.6s and the engine hunts when warm, and has just started to take its time starting.
 

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Discussion Starter · #16 ·
All

Well I changed the sensor last night. It was a doddle. It took longer to remove the plastic engine cover than to swap the sensor over.

Basic instructions if you are interested:

1. make sure the engine is cold

2. release any pressure in the coolant system by unscrewing the top of the expansion tank. Then replace.

3. remove the plastic engine cover (just the one the dipstick sticks through)

4. locate the sensor, its on the water pipe coming back from the radiator on the right hand side of the engine. There is one near the radiator (which I assume controls the fans) and the one for the ECU which is further down where the pipe has a number of other pipes joining it. The sensor on mine was blue.

5. remove the electrical connector from the top

6. then use a pair of pliers to pull out the retaining clip that holds the sensor in

7. the sensor then just slides out. You will get a little bit of coolant coming out, but its just dribble. Make sure you remove the o ring as well - it should come out with the sensor, as you may as well replace that as well.

8. pop in the new sensor with O ring

9. replace the clip and electrical connection. Then the engine cover.

Job done. I am not that great with this kind of thing but I found it really easy. ?35 for labour is really taking the p*ss if you ask me.

The old sensor had a part number: 078919501B

But the new one I got was: 059919501 (and the invoice even says that this is a replacement for the old part number)

My guess is that the new part is an "improved" or more reliable version!

The Oring part number is N90316802

Cost of both was ?25.19 inc the VAT

Its too early to say if its fixed the problem, so I have fingers crossed still!

Hope this helps.

Jeremy
 

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Thanks for posting that mate, should be a big help!

What engine have you got by the way? Just wondering if the part numbers are different for different sized engines.
 

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Discussion Starter · #19 ·
jrsp - no problem - pleased to help as I have been helped a lot by this forum!

As for the engine, I am not sure of the specific model number, but its an early 1.6 (its a '98 SE model). I am pretty sure its the 8v unit but I havent really paid that much attention to it.

I dont think the parts guy asked me when I phoned up, so I expect the temp sensor is pretty common.

And so far so good btw - no recurrence of the poor idle or stalling. Its a bit too early to say its fixed, but I am feeling more confident now!
 

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Sounds like you've got the same engine as me. I'm actually gonna get a local VW/Audi independent to do it when I have my new brake pads fitted. He says he'll do it for free - can't believe my main stealer wanted so much!
 
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