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Model specific boards => Golf mk2 => Topic started by: robw09 on 05 September 2015, 11:17
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Hi guys, over the past week I have had my coolant light come on intermittently after about 5 minutes driving. Oil temp looks ok, but coolant temp was a little left of centre. I ignored it the first couple of times, but then noticed the coolant level was lower than min. I topped it back up, however problem now seems worse. Light is on more often, but not straight away and it still comes and goes. Temp gauge of coolant is now unsettled going from first line on left to past centre when the light flashes. I also noticed the coolant level in the expansion tank after a drive is above max line....which has confused me. Also might be imagining things, but engine bay seems very hot. I took oil filler cap off and even that was giving off a touch of steam, but I have no idea whether that is normal giving normal operation temp levels. I checked all the hoses and they are all hot to touch. So I believe the coolant is going around the system. However, I am now worried about driving it and doing any damage :(
What should I be checking? If you need anything else let me know.
PB engine, coolant expansion tank has the level sensor in.
I thought about replacing the blue temp sender and seeing what happens....however as you can see I am flapping about this and highly confused.
Cheers
Rob
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Check your thermostat is opening/closing
Check fan comes on/off
Check your water pump/belt
Check you have no leaks (is the carpet wet in the footwells?)
Change fluid and bleed if you can so you know you have the correct amount in the engine.
Then start working through the temp senders and electrics if things persist
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Check your thermostat is opening/closing
Check fan comes on/off
Check your water pump/belt
Check you have no leaks (is the carpet wet in the footwells?)
Change fluid and bleed if you can so you know you have the correct amount in the engine.
Then start working through the temp senders and electrics if things persist
Just pretend I am thick for I moment.....
Thermostat & water pump belt....how do I check?
I will check the fan kicks in later today, no leaks that I can see and I replaced the matrix about 1 year ago.
Oh, on the way home the light cam on very briefly just twice during a 25 minute journey.
Cheers
Rob
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my other mk2 has an intermittent low coolant warning flashing randomly aswell. I just stripped down the clocks and put a small section of black tape over the led. not a repair that everyone agrees with but it was fine for me.
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my other mk2 has an intermittent low coolant warning flashing randomly aswell. I just stripped down the clocks and put a small section of black tape over the led. not a repair that everyone agrees with but it was fine for me.
I have done this too, so long as you know the fan cuts in and the stat works you can get away with it for ages.
I put in a new set of clocks once 3 months later bloody intermittent flashing light again :lipsrsealed:
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If it's a sensor problem it wont be the blue sensor, it will be the black one. Are you using water without visible leaks? Are you sure you have steam in the rocker cover? That sounds like head gasket.
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If it's a sensor problem it wont be the blue sensor, it will be the black one. Are you using water without visible leaks? Are you sure you have steam in the rocker cover? That sounds like head gasket.
I cannot see any leaks, but I was going to purchase a new silicon hose set. I may have to check again though as, as I said I had to top it up when it was below min this morning, but now it is reading slightly above max after running.
After running around for around for 20 odd minutes this morning I went to top up the oil and it was "steaming" ever so slightly like any other hot liquid would. It maybe just the actually heat of the oil and I am panicking. It was not like white clouds of steam coming out. Oil is clear, no smoke and expansion tank fluid looks fine.
Check your thermostat is opening/closing - Is this checking the hoses are warm/hot after running?
Check your water pump/belt - What am I doing here?
Cheers
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Gone through everything so far starting at the cheapest first.
No Leaks, but at least I have found where my oil leaks are from :)
New Black Sender
New Thermostat
It is now overheating pretty much all the time. So, it is currently having its water pump changed. If it ain't that I don't know what to do next as I have run out of ideas.....
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Right, so I have replaced the water pump. Car seems to run fine and i get no light. However, the water temp gaude is now at a level i have never seen before.
The gauge is sitting on just below the third line (with the 4th being the max and the 1st one being the line after the shaded area). This to me seems a little hot. I was expecting it to be dead centre???
Anyone know where it should sit and what I can do if it is not right as I have changed the thermostat, the black sender and the pump now!
Cheers
Rob
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It should sit somewhere around the middle in normal conditions and rise if you are not moving only to settle a bit once the fan kicks in. Sounds as though you may have some air in the system so try bleeding it again.
Generally the flashing light could mean an issue with the level sender in the expansion tank. Disconnect the plug and bridge the two terminals on the plug and drive it for a bit and see if the light continues to flash. If it does it could mean that the wiring may have an issue or a fault in the clocks themselves. If not it could be the sender in the expansion tank. It bloody annoying isn't it.
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Yeah it is bloody annoying! Thought it should sit in the middle, but it is a least stable and once up to temp it does not move.
It is certainly running better now with everything I have done to it.
I will try bleeding again. Running with expansion tank cap off and burping the pipes??
I get no lights now, so that is a good thing and I am happy it is not the head!
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These can be really tricky to bottom out and fix the flashing temp lights.
That's why when I used to have Mk2's with this fault I made sure the fan comes on, stat is working, level is correct, pump works and no leaks etc
You can drive the car if you know its all working and its just a light gremlin.
I even rigged a lamp to come on with the fan so I knew it was coming on properly.
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Yeah, i am pretty 100% sure all is good now. I will try burping and see whether it sorts where the gauge is reading.
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So after replacing just about everything I am still having issues. Waterpump, thermostat, temp sender, flushed system (twice), burped etc. The only thing I have not replaced is the coolant reservoir sensor.
Car comes up to temperature (water) as I have described. Drives fine and if I am moving I do not have a problem, but as soon as I am sat still for more than a minute or two the light starts flashing and the water temp moves on to the 3rd line, but not past it. Once I am moving the light goes off again and the gauge drops to just under the 3rd line. I know this is the wrong position, but I was going to ignore if I had no other issues. Oil temp is between 82-86 under normal driving and I have not seen it go above 88.
I really don't know where to start with this now. I am debating whether to replace the temp sender. I think the garage fitted a non genuine one. So, i was going to pop into my local dealer and get a genuine one.
However, can someone more knowledgeable than me number step through what I should check for by having the car just running on my drive. What hose should be cold/warm/hot & when etc.
If anyone is in Lincoln/Newark area and is handy and is prepared to help please let me know. I can travel out to you to make it easier.
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Change the tank sensor if its old or suspected to be duff.
It could be in the instrument cluster itself, good luck..
Temp sensors use two different metals to give different resistance and convert this to a temp signal.
If the wires break down or you get damp or a poor connection you get variable resistance giving you an iffy temp signal.
If you use the wrong sensor or connect the polarity the wrong way round you get all sorts of problems.
You need someone to go over your car with a fluke meter to check its all working correctly.
Start the car from cold and feel the pipes as they get warm, certain pipes will stay cold while others get hot.
Then you will feel the cold ones get hot pretty quickly as the stat opens
Then so long as the fan comes on and goes off and the oil temp remains normal/stable you are fine to drive.
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Sorry if I missed it but is the fan cutting in?
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So.
Ran the car on the drive and came up to temperature, but just under the 3rd line rather than the second. The bottom rad stayed cold as it ran up to temp.
After about another 3 or so minutes the coolant flashed and the reading was on the 3rd line, then the fan kicked in with the bottom hose now becoming warm/hot.
After about half a minute the coolant light stopped, the fan switched off and the temp line dropped just below the 3rd line.
Rinse and repeat there after. Oil temp never went above 88.
I am baffled. Firstly the temp reading is too high and i also don't get this repeated on off of the light.
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I wonder about the thermostat. Sounds like it's opening too late.
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Hmmm, this is the thing. I replaced the thermostat when I replaced the water pump. Do you think that is what is causing the water temp gauge to go the third line?
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Here's a good guide from rubjonny :smiley:
http://www.golfgtiforum.co.uk/index.php?topic=33252.0
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Hmmm, this is the thing. I replaced the thermostat when I replaced the water pump. Do you think that is what is causing the water temp gauge to go the third line?
Seems a possibility. If the temp sits stable at that point then maybe the stat is set for the wrong temp.
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I changed the black temp sender and will see if there is any difference.
The pump and thermostat was done by local garage.
I presume it is this one? For 6 quid I might just do it myself. It is by the water pump and I have to move the power steering pump out of way to get to it? Also noticed a small leak from the coolant flange going into the head. So, will have to get a O ring for that. Is that the second link?
https://www.vwheritage.com/shop/056121113D/thermostat-inc-gasket-mk1-2-golf-scirocco-corrado-1500-180/#esp_cf=years&esp_filter_ESP_Rational_vehicleAliases=MK2%20GOLF&esp_filter_years=1990&esp_pg=1
https://www.vwheritage.com/shop/037121687/o-ring-for-coolant-flange-t4-90-03-mk1-mk2-golf/
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Before doing anything please read and re read the guide by rubjonny that has been linked to earlier in this thread. The thing most people miss is resetting the ecu after changing the sender.
Your links look right to me.
From memory the stat is at the lower front left of the lump as you stand in front facing away from the car, I did one laying on the floor without jacks once.
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I did follow the guide, should have said that sorry. However, I could not see anything about resetting the ECU??
But do you mean for the blue sender or do you do this for black as well??
"Once the new sensor has been installed, start the engine and disconnect the blue coolant temperature sensor.
Rev the engine through 3,000 rpm three times, each time allowing the throttle to close completely.
This clears the Digifant ECM fault memory."
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ECM or ECU both mean the same.
Quite frankly I don't know as I haven't replaced the black one. I cant see it hurting though man.
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So, changed the black sender and reset the ECU. Guess what?!?
It seems to have worked. I suspect it now to have been a faulty (replacement) sender.
Temp comes up to just below 2nd line now (just under half way) and stays there under driving conditions. Bottom rad is still cold. I then left car ticking over on the drive and the temp rose to the line at which point the bottom hose got warm (presumably as the stat opened). I get no lights flashing. So, all appears ok now. Not had chance to check the fans spins up, but pretty confident it will as it was before hand.
Thanks everyone for helping. I am off to change the sump & do a service!
Balls. Spoke too soon. Temp fine, but light comes on after about 15 minutes driving and then pretty much stays on with it only occasionally going off. This is bloody frustrating as everything points to it being fine now. Gauge only goes between below the 2nd line and just on it.
Could it possibly be the sensor in header tank? Mine has the built in type so it would need the whole tank replacing.
Rob
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At this point I am out of ideas man.