High Temperature on gauge

Not sure if this has been covered before so my apologies if it has.

My temperature gauge is reading very high.
I had an issue last week when I ran out of coolant on my way to the garage for other issues. The red light came on briefly, which is strange as there isn't a sensor in the expansion tank…

The water pump and thermostat has been replaced and there was a leak at the heater control valve, which was seized (no warm air in cabin). This has been resolved and there are no leaks. there was no pressure in expansion tank so the cap was replaced.
The fan kicks in and it doesn't appear to be losing any coolant yet the gauge still reads high.

Any clues please?

At a guess either there's an air lock in the system, sensor for gauge is faulty or the timing out.
Or the head gasket or head is warped from over heating….Are you lossing any more water/antifreeze?

Just re read your post these cars work from a pressureized system is the water pumping into the expansion tank when you run the engine? (Don't take the cap off when the car is hot, take cap off from cold and start the engine, see if water is being pumped in from the small hose, as the rev increase the water flow should increase)
Are all the water pipes getting hot?

Thanks for that.
It doesn't seem to be losing any more water. Water is pumping into the expansion tank and all the pipes are hot. There is hot air blowing into the cabin so there is no air lock by the looks of it. It has also had a new rad fitted recently as well as us fitting new water pump and thermostat.

Mine is doing this too, I've had new head gasket, new water pump, new thermostat, new radiator, timing done.

It still reads about 3/4 of the way across.

I've a similar problem but my dial usually reads almost max ocassionally with the light flashing, I've also changed, thermostat, radiator & head gasket.
I'm hoping to change the expansion tank and coolant level sensor on Saturday to see if this makes any difference (if the parts arrive on time anyway)

Glad it's not just me then having a similar problem. My expansion tank doesn't have a coolent level sensor so wondering how my red light came on? strange….

red light is also overheat warning! it may be the sensor is over-reading orwrong one. it should be a black collar. white is mfa oil temp and reads different.

http://www.vwgolfmk2.co.uk/viewtopic.php?f=37&t=14913

Thanks John, but my expansion tank doesn't have a sensor in the top as I have seen elsewhere. where the round recess is in the top, it is just part of the moulded plastic..

the sensor in the tank is low level warning only. overheat warning is handled internally by the clocks, based on the signal from the coolant temp sensor

That would make sense John, thanks for that. Should an 83 GTi have an expansion tank with Level sensor in it? Maybe I have the incorrect tank?
Hoping to replace the coolant temp sensor today.

most likely yes, have a look at the fusebox if you have a relay holder clipped to the top with a 42/43 in it then it should! if there is a relay holder but no relay check wire colours, coolant level sensor relay is as follows:
brown
red/blue
red/yellow (blue/yellow on some)
black or black/yellow

the coolant level sender is a 2 pin plug with rubber boot, brown and red/blue, looks the same as brake fluid warning switch plug

Coolant Temp sender replaced - still no difference
There certainly isn't a relay 42/43, not sure if there is a holder there. I will check later.
Is it looking like Head gasket or faulty gauge?,………..

try the gauge first, its much cheaper. I've had the head gasket changed and still having issues. I'm now trying one thing at a time starting with all of the potential sensors in the engine bay. So far I've changed the temp sender and will change the expansion tank and coolant level sensor hopefully this weekend (dependant on parts arriving in time) I've also fitted a new radiator and thermostat. After that I'll look at the clock switches but this means electrics and as mine are shot to pieces and I haven't a clue about these I'n trying to avoid the obvious !!

That's my next plan too, try swapping out the gauges. I know the Rev counter doesn't work and the fuel gauge needle moves around too (not just because i am using fuel ) so I am hoping this may be the problem.

Here we go again, I've now changed the expansion tank and coolant sensor. The warning light on the dash is now sorted !!
I left the engine to run for 30 mins with the expansion cap off to ensure that any air is expelled but after only five to tens mins the fan had alredy kicked in with the temp gauge sitting on 3/4 plus.
Water is flowing through the system back into the expansion tank as this can be seen clearly when the cap is off, also if you squeeze the pipes the water flow 'squirts' the top and bottom pipes are also warm to the touch.
For a bit of history, I've also changed, thermostat, radiator, head gasket.

Any ideas as to why I'm constantly running hot ?

I'm worried this will cause major issues if not sorted !!

it is normal for temp to get to 3/4 when sat, though generally the coolant will start to boil before the fan kicks in if you leave the cap off!

the rule of thumb when bleeding coolant is as soon as you see the level start to rise or coolant bubble, then switch the engien off and refit the cap. the problem is the coolant will boil before operating temp is reached which will then give you a load more airlocks and you'll have to start again. when the cap is on the system can pressurise, which raises the boiling point.

if the coolant did start to boil this may explain the odd fan running/temp?

it may be the timing is out though, this can cause the engien to run hotter than usual, or perhaps some of the radiator cores are blocked so its not cooling the system very well. if next time you try it the fan kicks in, feel all the way across the radiator. the whole thing should be hot to touch before the fan can kick in. if its mostly cold then that would tell you there is a blockage. have a feel around the rad fan switch as well, this area should be too hot to touch before the fan can kick in

That reading on the gauge is quite normal. It's funny how on older cars manufacturers gave the driver a lot more information or scale !!
You should take it for a drive and the gauge should drop quite quickly from the cooling air of moving - if it does not then you have an issue.

What is your oil temperature saying ?

Mk 83 GTI did not have the level sensor, the wires were there but the relay was not.

The oil temp seems to be OK - I've fitted a set of VDO gauges and the oil temp sits at a reasonable level taking a while to get there as well. If this also shot up I'd be more worried !

All is probably well then, the gauge will get to 3/4 when you're just sat, the fan should kick in and bring it back down to around half. when you're driving along there is airflow thru the rad so this should keep the temps to around 1/2.

frankly im surprised it didnt boil up and spout coolant all over the place if you left it for half an hour without the cap on it, so you're doing well