Coolant Light Woes

[robw09]

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

[VW BUSH]

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

[robw09]

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

[gazareth]

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.

[VW BUSH]

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

[oakgreener]

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.

[robw09]

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

[robw09]

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.....

[robw09]

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

[SimonG]

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.