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Model specific boards => Golf mk2 => Topic started by: ScottMk2Gti16v on 16 March 2008, 20:15
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Hi all, I've got a problem with the water light flashing randomly. The car isn't losing water, I mean I top it up now and again but nothing unusual and not often, but the water lights started flashing for random periods, usually 3 times in a row then it'll stop for a few mins then do it again. It also seems to come on when I put my foot down but goes out when I come off the gas and just cruise along. Sometimes it'll keep flashing for 5 mins, and other times it wont come on for 20 mins.
Also if you sit with the car just idling over the temp gauge rises right up to max - it'll take 5 mins but will go right up, but when you start driving it goes back to normal and stays there (between 1/4 and 1/2 way usually). The temp NEVER rises stupidly while actually driving.
A mechanic (who I don't rate greatly tbh) had a quick look and couldn't see anything obviously wrong and suggested maybe a faulty sensor in the water tank? Or maybe a blockage in the system?
Do you agree? Any ideas on what to check/replace?
Cheers
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That sounds very strange.
I think i'm right in saying that there is a coolant level sensor built into the expansion tank so you will need to buy the whole unit if the problem is due to this. However a faulty coolant level sensor won't explain why your temp guage goes to the max as this works from a reading from one of three sensors on the right hand side of the head near the dizzy.
I'd check for:
Coolant level sensor plug/wiring ok
Pressure test cap if you can or look for signs of boiling over
Check the wiring to the 3 sensors on the side of the head and the connections it makes
Then test each sensor using a multimeter and haynes manual. Should be about 22ohms resistance
Check your water pump is circulating or leaking from under the car
Changing the tank will be a good start tho as this should fix the random light. I'm sure ive read other people having the same symtoms. However the high temp problem is something new to me.
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Also, try the thermostat, and the thermo switch for the fan :smiley:
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Cheers for the pointers guys, I've got a new expansion tank with the level sensor built in, and I'm sticking it to a garage tomorrow to get that changed (amonst some other bits - wheel bearing and gear box mount) and will get them to have a proper look at what it may be. It's actually got a little worse in the last 2 days, temp gauge goes right up very quickly sometimes when your driving along, just for 20 seconds or so, then goes back down as rapidly as it went up. Just does this randomly every so often, usually when at slower speeds (30-40mph).
Is this likely to be a sympton of something getting worse? Or is it so bizarre that it's more likely to be something like a faulty thermostat?
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what condition is your rad in? when was it last changed. a new one will slove so many over heatin prblems
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Not sure to be honest, I'll get that checked to. I've not changed it in the 2 years ive had the car and dont think it was done any time soon before that - I'll dig out the old receipts and check but dont remember anything about it on them.
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As filthy said, check your fan is operating normally. My 16v regularly needs its fan in prolonged traffic. If your not losing water, then it must be electrical.
It could also be a weak water pump perhaps? To check, look inside the water tank, you should be able to see water coming out of the thin feeder pipe, and the flow should increase when the engine is revved.
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It could also be a weak water pump perhaps? To check, look inside the water tank, you should be able to see water coming out of the thin feeder pipe, and the flow should increase when the engine is revved.
Looks like you've got it bang on with that one. Car went to garage and I got the expansion tank changed, which hasn't solved the flashing water light problem - but I'm hoping it's all related to the fluctuating temp gauge which is still happening. Left the lights on for ages today and killed the battery so had to get the AA out, I told the guy about the problems and described the symptoms and he's certain it's the water pump. He checked as you described above and told me about the flow when revving (no life at all in my expansion tank when revving!). Quite handy to as I've just moved to a new town and wasn't sure where to put the car to next - he pointed me to a good small garage where the guy's a VW enthusiast. The AA had a VR6 himself he said.
How hard is it to change the water pump? AA guy thinks you have to take off the fan belt and replace that as part of the job? Would be handy knowing how many man hours I'm maybe looking at?
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shouldnt cost a great deal in labour as the alternator belt is a smooth one (ie no timing issues) and the water pump is easily accessible. new belts are about £5, id say job done in 1 - 1.5 hours at most!
unsure on water pump costs.
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The only major issues with changing the pump would be...
1) Are the hex bolts on the two big sprockets seized? These can be a pain to get off. Perhaps start spraying them occasionally with WD40 now.
2) My lower cam cover was a right pain to get off too.
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Cheers guys. Not expecting anything to be seized - all 3 belts were changed just a few months ago so I guess any problems would have been dealt with then?
Just ordered a new water pump and alternator belt, should pick up tomorrow and hopefully get fitted on friday. Watch this space...
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By the way, when they take off the old pump get them to check how many "fins" are still attached to the impeller, as the main reason they break apparently is the fins snapping off. If all loads of the fins are broken you can be fairly sure the pump was the problem!
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the light also warns of overheat, so it could be the engine is actually overheating. If you suspect the sensor. if its a 16v check on the side of the head, there are 3 sensors there and they're all the same. swap the red/yellow wire (dash gauge) to another sensor and see if symptoms persist!
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guy came into my work and had this also.. turned out to be the black sender for gauge and light on dash.
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The plot thickens...
Got the water pump changed and it didn't make any difference. If only I'd got my new mechanic to look at it first (I'd already got a water pump ready before going to him) I'd be ahead of where I am now!
It turns out we think the actual gauge itself is faulty (either the gauge and/or the printed circuit panel behind). And the radiator was full of sh!te, AND the cylnder head gasket needs done! Obviously with the radiator not working properly and the head gasket needing done, the temp will be high, but it's so random up and down and all over the place we think there's a problem with the gauge/circuit to it. Might also explain why my dash lights also don't work.
So a new radiator an head gasket are on the way and it's getting done in a couple of weeks. I'm also replace the circuit panel on the dash and maybe the temp gauge itself (with all other clocks if it has to be done together)....this is my problem now..I've got a spare mk2 gti 16v golf that I'm going to rob the bits I need for the dash-
I haven't had a chance to look yet, but how easy is it to get the dash off? Think I remember it as having to almost take the whole dash off by finding the various screws, etc but I've never been in about the clocks. Is there a guide anywhere to keep me right? Or any secret screws I need a tip off about?
Nightmare getting online just now to as I've moved and getting wireless soon, and my employer (local council!) has banned all forum use on it's network!!
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I had a similar problem, turned out it was the gauges fault. It was a loose wire or something, cos it starting flashing, then the fuel and temperature gauge died, then i would just give the clocks a little push into the dash and they would be up and running again. Havent had this for a while now. Have a look at the clocks mate.
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Hiya Mate,
I have been down a "similarish" route, and have tried absolutely everthing bar replacing the clocks and still have a flashing light!
Guess thats next on the list..
G
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anything new about the prob?
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Well that's the motor all sorted AT LAST! :smiley:
Picked it up yesterday after it has just had new (in addition to water pump and expansion tank in previous weeks):
- Cylinder head gasket
- Radiator
- Instrument cluster
Thankfully I managed to get the instrument cluster out my spare golf easy enough and it worked fine when connected up, for the first time in a while I've got a fully working cluster. My car has also just lost 32000 miles, going down from 175k to 143k! I've no intention of abusing this fact though, not least because I'm never selling the car.
Anyway so to summarise my problem:
Radiator and head gasket needed done - these problems alone will obviously cause problems with the temperature.
BUT
My temp gauge was faulty also - so while we knew the car was overheating, the reading was clearly false on the gauge - i.e. max temp INSTANTLY when stating car then up and down like a yo yo. Guy looking at it say's 100% it was gone and that's been proved now it's changed. Other one works perfect. No flashing red light, no dodgy temp and all is cool.
5 or 600 quid later + a lot of stress and I'm problem free again! For now.....
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just to add, this symptom can also be caused by a faulty temp sender, or the temp gauge wire earthing on something intermittantly :)