1.8T MK4 Golf - fan cutting in and out
Discussion
Hello All,
Got a problem with my MK4 Golf 1.8T Estate. It's totally std and done plenty of miles (100K). Recently it's started idling erratically and hesitating on a light throttle. Mid or full throttle openings seem OK. There's also a fan - (at least it sounds like some kind of fan) cutting in and out for about 5 secs each time - even when the car is pretty cold. Not sure if it's the thermostatic cooling fan or not.....
And before you mention - I've recently (5 months ago) changed the air mass meter and the temp sensor....
Any ideas very welcome.
Thanks
Got a problem with my MK4 Golf 1.8T Estate. It's totally std and done plenty of miles (100K). Recently it's started idling erratically and hesitating on a light throttle. Mid or full throttle openings seem OK. There's also a fan - (at least it sounds like some kind of fan) cutting in and out for about 5 secs each time - even when the car is pretty cold. Not sure if it's the thermostatic cooling fan or not.....
And before you mention - I've recently (5 months ago) changed the air mass meter and the temp sensor....
Any ideas very welcome.
Thanks
Hi mate, your erratic idling problem is caused by your MAF sensor failing. It's a crappy part on the Golf/A3 1.8T platform.
Your fans have a common fault with most MkIV's. check this thread for more details and how to fix.
http://uk-mkivs.net/forums/425656/Sho This is a list of the most common faults with MkIV's and their fixes. Beware though, you may find yourself fixing things you didn't know were broke!! Lol
DO NOT take it to the dealer. You'll get charged a handsome amount for "diagnostics" alone. When these faults are as common as they are, "diagnostics" takes as long as "Hello, I've got a problem with my MkIV..." "is it your fans and poor MPG/idle?"
Honestly this is sooooo common you won't believe!!
Hope this helps, and you get it all sorted.
Andy
Your fans have a common fault with most MkIV's. check this thread for more details and how to fix.
http://uk-mkivs.net/forums/425656/Sho This is a list of the most common faults with MkIV's and their fixes. Beware though, you may find yourself fixing things you didn't know were broke!! Lol
DO NOT take it to the dealer. You'll get charged a handsome amount for "diagnostics" alone. When these faults are as common as they are, "diagnostics" takes as long as "Hello, I've got a problem with my MkIV..." "is it your fans and poor MPG/idle?"
Honestly this is sooooo common you won't believe!!
Hope this helps, and you get it all sorted.
Andy
Thanks very much for all the replies and help. The car is 2001 on a 'Y' plate - interesting the comment about poor mpg as well. Even driving like my Dad, I only get 30-31 mpg. Any kind of enthusiastic use drops the figure well down from that. The other amusing trait is that some days (normally when ambient temp is cold) the performance is pretty good, with plenty of pull - but other days it's relatively sluggish. I'll have a stooge around the MKIV forum suggested as well
Cheers again.
Cheers again.
Phil C said:
The other amusing trait is that some days (normally when ambient temp is cold) the performance is pretty good, with plenty of pull - but other days it's relatively sluggish.
Colder air does make a difference but if it's a huge drop in power there's more likely to be a problem.
Mine's flying at the moment
The problem with your car is it needs the throttle housing cleaning out it then needs to be put on a vag diagnostic computer and have the throttle housing put back on to basic setting hence clicking fan noise,
The housing is part eletronic if its later type fully electronic (no throttle cable) this is a common problem and we hear all sorts of things that people say it could be but i'm 90% sure this is the cause i regulary have to do this to most of the vag cars that we look after the vag computer alters the flap inside the housing and resets it to where its supposed to be, other simptons are stalling and erractic idle
The housing is part eletronic if its later type fully electronic (no throttle cable) this is a common problem and we hear all sorts of things that people say it could be but i'm 90% sure this is the cause i regulary have to do this to most of the vag cars that we look after the vag computer alters the flap inside the housing and resets it to where its supposed to be, other simptons are stalling and erractic idle
dain bramaged said:
The problem with your car is it needs the throttle housing cleaning out it then needs to be put on a vag diagnostic computer and have the throttle housing put back on to basic setting hence clicking fan noise,
The housing is part eletronic if its later type fully electronic (no throttle cable) this is a common problem and we hear all sorts of things that people say it could be but i'm 90% sure this is the cause i regulary have to do this to most of the vag cars that we look after the vag computer alters the flap inside the housing and resets it to where its supposed to be, other simptons are stalling and erractic idle
The housing is part eletronic if its later type fully electronic (no throttle cable) this is a common problem and we hear all sorts of things that people say it could be but i'm 90% sure this is the cause i regulary have to do this to most of the vag cars that we look after the vag computer alters the flap inside the housing and resets it to where its supposed to be, other simptons are stalling and erractic idle
Hmmm
Sorry, I don't agree with that at all.
The throttle body can not cause the cooling fans to pulsate. The throttle body has no relation to cooling of the engine!
The Butterfly valve on DBW cars does need to be recalibrated for WOT and CT when it is removed from the car. The ECU alters the settings for WOT depending on how often you actually use WOT. Hence if you never do, it re-jigs WOT to 80-90% of true WOT (i.e. YOUR particular WOT). Throttle recalibrations are good, because the ECU re-learns that there is more to be had.
Erratic idle IS a symptom of a dirty throttle body, cos the valve can not move smoothly.
But, this is NOT a throttle body problem. The problem with the MkIV's fans, however, is VERY well documented.
[quote=LaSarthe&Back]Hmmm
Sorry, I don't agree with that at all.
The throttle body can not cause the cooling fans to pulsate. The throttle body has no relation to cooling of the engine!
The Butterfly valve on DBW cars does need to be recalibrated for WOT and CT when it is removed from the car. The ECU alters the settings for WOT depending on how often you actually use WOT. Hence if you never do, it re-jigs WOT to 80-90% of true WOT (i.e. YOUR particular WOT). Throttle recalibrations are good, because the ECU re-learns that there is more to be had.
Erratic idle IS a symptom of a dirty throttle body, cos the valve can not move smoothly.
But, this is NOT a throttle body problem. The problem with the MkIV's fans, however, is VERY well documented.[/quote]
no read what the original fault was hesitation and erractic idle and what sounds like a fan cutting in and out and where does it say i mentioned about the cooling fans i work on vw cars all day and this is the first thing we do before paying any money out on parts and does not cost a packet and nine times out of ten fixes the fault you need some one with a vag computer so you can use the cambus system and set the throttle housing back on to basic setting this is regaurdless if its removed or is the original one on the car thats all i was trying to say but its hard to diagnose a fault on a car with out even seeing the car to start with i've had 5 years of training at vw and this is a common problem and people are shocked when this was the only thing wrong after spending £300 on parts etc
Sorry, I don't agree with that at all.
The throttle body can not cause the cooling fans to pulsate. The throttle body has no relation to cooling of the engine!
The Butterfly valve on DBW cars does need to be recalibrated for WOT and CT when it is removed from the car. The ECU alters the settings for WOT depending on how often you actually use WOT. Hence if you never do, it re-jigs WOT to 80-90% of true WOT (i.e. YOUR particular WOT). Throttle recalibrations are good, because the ECU re-learns that there is more to be had.
Erratic idle IS a symptom of a dirty throttle body, cos the valve can not move smoothly.
But, this is NOT a throttle body problem. The problem with the MkIV's fans, however, is VERY well documented.[/quote]
no read what the original fault was hesitation and erractic idle and what sounds like a fan cutting in and out and where does it say i mentioned about the cooling fans i work on vw cars all day and this is the first thing we do before paying any money out on parts and does not cost a packet and nine times out of ten fixes the fault you need some one with a vag computer so you can use the cambus system and set the throttle housing back on to basic setting this is regaurdless if its removed or is the original one on the car thats all i was trying to say but its hard to diagnose a fault on a car with out even seeing the car to start with i've had 5 years of training at vw and this is a common problem and people are shocked when this was the only thing wrong after spending £300 on parts etc
Edited by dain bramaged on Sunday 11th February 16:37
Edited by dain bramaged on Sunday 11th February 16:39
Edited by dain bramaged on Sunday 11th February 16:45
Phil C said:
Hello All,
And before you mention - I've recently (5 months ago) changed the air mass meter and the temp sensor....
Any ideas very welcome.
Thanks
And before you mention - I've recently (5 months ago) changed the air mass meter and the temp sensor....
Any ideas very welcome.
Thanks
It looks like the sensor has already been eliminated, and I dealt with the MAF in my first post.
You didn't mention the fans at all!! the fix is quite cheap actually, all you need are a couple of power resistors, a heatsink, and a few other electronic components. This is discussed in the thread I linked, which you must have seen if you read it or already know. So the fans fix does not cost a packet anyway. Yes the the sensor is a cheap part, and yeah it causes a hell of alot problems for what it is, but what would the total charge for a job like that be? Example:-
Vag-Com diagnostic (and throttle reset) - £25
Temp switch - £18
Hour labour (I mean you gotta take the engine cover off and all!)- £85
Total + VAT = £150.40
Rough area do you think?
Now, that's pretty damn expensive if you ask me, for what is a 15 minute job for a pretty cheap part!!
What VW Garage do you work at? Just out of interest, it's not VW Warrington is it?
i work at one in cheltenham i know the early mk 4 golfs have a few problems with the components attached to the air filter box and the later ones go through air flow meters and temp senders a lot and some don't register a fault at all but yet they have a running problem like the one thats being talked about but if phil whips the air box pipe off after the air flow meter and has a look to see how dirty the housing is before modding anything it would be eliminated as a likely cause but as you say labour is dear at vw for a job that does not take too long but then again he could get charged a bit if he was to take it to a garage that didn't know how to fix the fault and started replacing stuff
Yeah the AGU engines have an ignition amplifier mounted on the airbox, the AUM's - which I think he has got, does not have one.
Pretty much all 1.8T's go through MAF's every 6-12 months or so, but temp sensors less so. If he takes the TIP off after the MAF (back right of engine bay), he will just be looking into the turbo, which a) is useless cos there'll be no light, and b) won't give him any indication to the state of the throttle body.
He needs to take the intercooler to throttle pipe off, just behind the left headlamp and peer in. The throttle body will no doubt be all gunked up, and is probably contributing to the problems. But I don't think this is the root of the problem.
If he took it to a specialist, AMD, Awesome, JabbaSport, QST anybody should be able to pinpoint the fault. Partly because of how involved these companies are with member forum's like this one and MkIV's.
Pretty much all 1.8T's go through MAF's every 6-12 months or so, but temp sensors less so. If he takes the TIP off after the MAF (back right of engine bay), he will just be looking into the turbo, which a) is useless cos there'll be no light, and b) won't give him any indication to the state of the throttle body.
He needs to take the intercooler to throttle pipe off, just behind the left headlamp and peer in. The throttle body will no doubt be all gunked up, and is probably contributing to the problems. But I don't think this is the root of the problem.
If he took it to a specialist, AMD, Awesome, JabbaSport, QST anybody should be able to pinpoint the fault. Partly because of how involved these companies are with member forum's like this one and MkIV's.
Hi again - wow - what a mine of information.....!!
Thanks. Must admit I'm struggling these days to find time to get my hands nice and dirty so I was going to take it to a specialist. I used AMD years ago but not been recently (also heard they've been taken over / moving). Any other recommendations for similar outfits in the Thames Valley / Surrey / Hants area?
Thanks once again......
Thanks. Must admit I'm struggling these days to find time to get my hands nice and dirty so I was going to take it to a specialist. I used AMD years ago but not been recently (also heard they've been taken over / moving). Any other recommendations for similar outfits in the Thames Valley / Surrey / Hants area?
Thanks once again......
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