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Model specific boards => Golf mk2 => Topic started by: kappatango on 02 August 2006, 08:42

Title: Coolant light and Temp
Post by: kappatango on 02 August 2006, 08:42
HI,

Last night I turned ignition on on my MK2 8v and ther coolant light started flashing.  I topped up with water to get home.

Where does the coolant go - in the header tank to the right of the engine??

I also noticed some sh!tty white stuff on the undersider of the radiator tank screw cap.....

This morning the engine did seem to run a little hotter than usual and the fan was running.....

I fear the worst....any ideas
Title: Re: Coolant light and Temp
Post by: ...joe on 02 August 2006, 08:59
sh!tty white stuff on the oil cap normally means head gasket, on the coolant cap it could mean oil cooler? they have a habit of corroding and oil seeping into the coolant.

yeah you fill up the radiator through the expansion tank and i assume thats the cap that the sh!tty white stuff is on?
Title: Re: Coolant light and Temp
Post by: kappatango on 02 August 2006, 09:05
I assume that the coolant goes into the same header tank as the radiator water....?? or is there a separate tank....

Sorry to be dumb - I am new to older cars and mechanics and desparate to learn.....

thanks
Title: Re: Coolant light and Temp
Post by: ...joe on 02 August 2006, 09:12
yeah it all goes in the same hole!
Title: Re: Coolant light and Temp
Post by: kappatango on 02 August 2006, 11:14
ok just been down to the car and the coolant light is still flashing.......but I have not lost any water on my 30 min drive to work.  Is there a way of draining some of the radiator header tank so I can add more coolant.  last night I topped up with water, befrore i realised it was a coolant problem ( :laugh:) so that would have made the mix ratio worse......

Is there a bleeder on the Rad header tank??

Thanks

Karl
Title: Re: Coolant light and Temp
Post by: rubjonny on 05 August 2006, 21:57
Right, the flashing light is just to tell you the level is low, it wont tell you if the mixture is incorrect.  The sender is inside the tank where you've been topping up the coolant, if the light is still flashing when the level is up to max then it means the sender or the wiring to it is shafted.

First thing to do is remove the electrical plug from the tank and bridge the 2 pins then turn on the engine, if the coolant light is still flashing then your problem lies elsewhere.  If the light goes out then you know there is a problem with the coolant sensor, or your coolant level is low ;)

If you have the older squareish shaped tank, then you can unscrew the sender from the top and check the pins, if they're filthy give em a good clean and see if that helps.  If its the newer ball shaped tank then the sender is part of the tank and cannot be replaced.

If you have some nasty white oily stuff on the bottom of the header tank then I suspect your oil cooler has gone, and this has gunked up the contacts on the level sender.  1st thing to do is either replace the oil cooler or bypass it for now, then clean out the coolant system.

Completly drain the coolant system, unhook as many pipes as you can and flush them through with a hose pipe till the water runs clear. Then refill the system with plain water and then chuck a cupfull of bio washing powder in the tank, then run the car for 5 mins.  While its running squeeze all the pipes & rev the engine now & again, then leave it to cool.  Drain the system, flush it all out again & repeat till you are satisfied all the oil is gone from the system.  Then fill the system with a 50/50 mix of water and antifreeze.  I always use G12 from VW or GSF, but the pink halfords stuff should be ok.

If the header tank is really dirty, try leaving it in a bucket of water with some bleach in it overnight. Then flush it all out with a hosepipe.  If that doesn't clean it up, you'll probably have to buy a new one!
Title: Re: Coolant light and Temp
Post by: kappatango on 07 August 2006, 08:30
HI Thanks for this - I have just moved house so havent got internet at home at mo  :cry:

I think it may be a sensor issue as sometimes the light does not come on - normally if I turn the ignition, wait 1-2 secs then turn over.

does this make sense??

Thanks
Title: Re: Coolant light and Temp
Post by: rubjonny on 07 August 2006, 09:01
lookin at your sig its an 'E' reg, so should be the earlier tank. I think you need a 24mm socket to remove the sensor if memory serves, handily this is also the same size as the nut holding on the steering wheel, so quite handy to have one this size in your toolbox :)

Keep an eye on your coolant, if you keep getting white oily gunk on the bottom of the cap then its almost definitly a dead oil cooler!
Title: Re: Coolant light and Temp
Post by: kappatango on 07 August 2006, 10:07
Being a newb.....is it easy to replace the oil cooler...and where do I get one from....I hate being new....   :sad:
Title: Re: Coolant light and Temp
Post by: rubjonny on 07 August 2006, 10:20
http://www.gsfcarparts.com sell the coolers.

Its sandwiched between the oil filter & oil filter housing on the front of the block, it has 2 water hoses going to it :)
Title: Re: Coolant light and Temp
Post by: ...joe on 07 August 2006, 13:07
there is a 'gsf' in worthing tango, opposite sainsbury's at lyons farm, you'll be using it a fair bit in the future i'd imagine!
Title: Re: Coolant light and Temp
Post by: kappatango on 07 August 2006, 13:21
cool cheers joe....the wierd thing with this light is that it is intermittent.  Not the flashing (on, off, on, off....lol ) but sometimes, maybe 50% of the time, it doesnt happen.  This makes me wonder whether it is the fault sensor - I may bridge it and see what happens.....
Title: Re: Coolant light and Temp
Post by: Gambit on 07 August 2006, 13:47
also, if your getting a new oil cooler make sure you get a new oil cooler gasket also.
Title: Re: Coolant light and Temp
Post by: kappatango on 07 August 2006, 14:35
cool thanks guys - how long do you rekon this should take to change cooler and gasket - and do I need any special tools...... I am so new to this but want to learn  :smiley:
Title: Re: Coolant light and Temp
Post by: rubjonny on 07 August 2006, 14:45
A big adjustible spanner and patience, ideally you should take the rad out otherwise its a right sod for clearance!

If the cooler has indeed gone then you'll be flushing out the coolant anyway ;)  I'd also bung a new thermostat & seal in while you're there :)
Title: Re: Coolant light and Temp
Post by: kappatango on 07 August 2006, 15:13
cool..a busy weekend ahead then.....

Dont know if this makes any sense or sheds any light but :

When you start cold the light seems to flash.  If I then drive a short distance, switch off and restart it doesnt flash anymore.....

I am not trying to shy away but as I have not done the engine work before, I guess I want to make sure I really need to strip all this out and flush it before getting stuck in.  Having said that, the job sounds a good learning experience anyway and cant do any harm...

So my shopping list is :

oil cooler
Gasket
thermostat and seal
coolant
patience
no injury to fingers to alllow typing on forum for help....bearing in mind this is my daily drive.....

| :smiley:
Title: Re: Coolant light and Temp
Post by: rubjonny on 07 August 2006, 15:38
Well the first thing I'd do is clean the sender, and remove any white gunk from the cap.  Leave it a fortnight or so, and if it comes back I'd suspect its the oil cooler.  Is it defo oil on the cap, or just dirt from a filthy coolant system ;)
Title: Re: Coolant light and Temp
Post by: kappatango on 07 August 2006, 15:50
cheers Jonny thats good advice - I will clean the gunk off the cap and clean the two pins on the sensor.  If it continues then I will arrange to do this weekend - I am supposed to be driving 200 mile round trip fri/sat so need th cr to be ok....so would rather get the prob identified before deciding whether to go or not....
Title: Re: Coolant light and Temp
Post by: ...joe on 07 August 2006, 17:08
remember oil and filter as well!! you might  as well change the filter as you'll be draining the oil to remove the cooler. i'd help you out this weekend if you got stuck but i'm away at a show.

the reason the light flashes when cold and not hot is because the coolant level rises as the temperature increases. so if its below level when its cold, it'll be above level when hot.
Title: Re: Coolant light and Temp
Post by: kappatango on 08 August 2006, 07:47
JOe thats makes sense but I cant get any more water/coolant in the header tank - even when I check before a cold start.  Thats what concerns me slightly.  Also what temp should the oil be running at when warm on the MFA....??
Title: Re: Coolant light and Temp
Post by: rubjonny on 08 August 2006, 09:56
Around 100 degrees depending on how hot it is outside :)
I don't think its a level problem, I recon the sensor is just dirty or its buggered :grin:
Title: Re: Coolant light and Temp
Post by: kappatango on 08 August 2006, 10:06
yeah thats what i think - oil temp was 94 this morning and water temp was in the middle, just over in traffic jam.......  dont want to got ripping out the oil cooler and rad if not necessary.  I pulled the plug of the top of the header tank for the rad so maybe will give it a clean tonight.....just worried about damaging engine if there is a problem.....I wish I understood engines more, red lights scare me  :wink: .... and i didnt think that the light above the rad temp showed oile temp as well as water.....  confused .....gotta start somewhere though
Title: Re: Coolant light and Temp
Post by: bungy on 08 August 2006, 10:14
hi,

exactly the same symptoms as my 87 16v. not entirely sure why it doesnt do it all the time but i just replaced the sensor.

takes about 2 mins, costs less than £5 and no more red lights. it is only a level sensor though, so if you are happy that it is full then no problem.

good advice though to do the filter, oil, cooler stat seals etc in one hit, but if your temps are holding ok then you have time to collect the parts you need before taking it apart.

got my sensor from:

http://www.vwspares.co.uk/

but im sure europarts and gsf do it...or go to vag if your feeling rich.!
Title: Re: Coolant light and Temp
Post by: kappatango on 08 August 2006, 11:07
will replace the sensor and go from there...... thanks :smiley:
Title: Re: Coolant light and Temp
Post by: rubjonny on 08 August 2006, 13:06
theres a seperate oil pressure light, when that & the buzzer starts sounding then you should worry ;)
Title: Re: Coolant light and Temp
Post by: kappatango on 08 August 2006, 13:55
OMG there's buzzer as well...... that would scare the sh** out of me.... Man i need to learn
Title: Re: Coolant light and Temp
Post by: kappatango on 10 August 2006, 08:33
OK I am going to GSF today to get the sensor......Is it obvious how to replace it?? 
Title: Re: Coolant light and Temp
Post by: rubjonny on 10 August 2006, 09:00
clean it first ;)
Its screwed into the top of the tank, you need a big socket to remove it.  I think its 24mm, perhaps bigger!
Title: Re: Coolant light and Temp
Post by: kappatango on 10 August 2006, 10:27
Will ask a GSF if they do the socket for it as my toolbox is non existant as a newb- i have a socket set but dont think it has a 24mm.....  Do you think try cleaning the old one first - the new sensor is only 3 quid....
Title: Re: Coolant light and Temp
Post by: rubjonny on 10 August 2006, 10:34
Well it depends how tight you are, since I'm a northerner I'm very tight indeed  :grin:
Title: Re: Coolant light and Temp
Post by: kappatango on 10 August 2006, 10:39
I am gonna need a decent toolkit built up so I may as well start now
Title: Re: Coolant light and Temp
Post by: rubjonny on 10 August 2006, 16:32
problem with tools is you can never have enough!
Title: Re: Coolant light and Temp
Post by: kappatango on 10 August 2006, 16:51
yeah - one day, one day........ I need knowledge first  :grin:
Title: Re: Coolant light and Temp
Post by: kappatango on 11 August 2006, 08:59
Is it normal that when you have bought the part you need - the problem goes away, without actually changing anything??  :rolleyes: ....lol.....oh well at least I have a spare part for next time......
Title: Re: Coolant light and Temp
Post by: rubjonny on 11 August 2006, 09:07
heh yeah happens a lot :grin:
I'm guessing the contacts have cleaned up a bit since you put some fresh coolant in or summat!  Keep an eye on it ;)
Title: Re: Coolant light and Temp
Post by: kappatango on 11 August 2006, 09:53
thats the plan, gotta spare now, my first spare part  :smiley: - thanks everyone for your help :)
Title: Re: Coolant light and Temp
Post by: rubjonny on 11 August 2006, 09:56
thats it!  Slippery slope from here.  Soon any available space will be stacked to the roof with VW bits that 'might be handy one day'  :grin:
Title: Re: Coolant light and Temp
Post by: kappatango on 11 August 2006, 10:49
just moved into a new house last thurs with a big shed and a garage...... wife thinks would make a good playhouse for the kids but I have grander ideas...  :wink:
Title: Re: Coolant light and Temp
Post by: bungy on 11 August 2006, 11:20
lol..glad it has sorted itself out..
playroom for the kids....that a good one.. :grin:
numerous times i have threatened my car with a spare part and it has decided to work, and i swear she goes better after having a wash...... :wink:
Title: Re: Coolant light and Temp
Post by: kappatango on 11 August 2006, 11:43
strange - I washed her Wed night as well......must be the lovin  :grin:
Title: Re: Coolant light and Temp
Post by: kappatango on 15 April 2007, 12:06
I like closure.

History : I opened this thread 9 months ago, bought a new level sensor but the light stopped gflashing before I replaced.

Well it started again - I went to th shed, dug out the replacement I had bought and Bobs your uncle.

No more flashing light :)

Thanks for all your help with this one guys.   I know its been a while but life has been in the fast lane recently.

Just wanted to finish this post.  I hate unanswered threads!!