My Mk1 running warm

[GoLfMan]

My mk1 runs warm, like a 20% away from the red...
what can i do to solve this, is it just how it is? when i modify my 1600 the heat is only going to increase....
can i put in a bigger radiator?
solutions?? feedback???
cheers

[Golf Loon]

Change the thermostat. Or cut the middle out of the one you have there.
If that doesnt work, backflush the rad, hose up the wrong way
It should run at the middle of the guage, maybe a notch past it on a hot day.

[GoLfMan]

cheers i'll do that... workin full time has cut down car time
what does cutting the middle out of the one i have do...?

[brackie]

Thermostats are essential. They enable quick warmup and keep the engine running within it's optimum temperature range. If you look at a temp vs engine wear graph you'll understand why the thermostat should never be removed (if you want your engine to last and get optimum fuel economy and performance from it).
Chopping out the centre of the thermostat is an old trick that will increase water flow (slightly) while at the same time giving the restriction that's essential to allow the coolant to stay in the water galleries of the head for long enough to do its job.
If your temp gauge is reading high, then check the gauge's accuracy before you do anything. Use a thermometer in the top of the radiator or degassing tank (whichever) and monitor temp increase against time. This will also tell you if and when your thermostat's opening. If the thermometer confirms overheating with the thermostat open then the most probable cause (as Loon says) is a blocked radiator. Take it out and get it cleaned. While you're at it, put the thermostat in a pan of water on the stove and check its opening temperature.
With all overheating problems it's a process of elimination. Check the easy and cheap things first

[h100vw]

Have a look on ecstuning.com they sell lower temp stats. I am sure they must be available in Australia too. A rad with more capacity will help matters but ultimately VW state that the needle being anywhere on the gauge and the warning light being out is OK.

Gavin

[ausgolfer]

personally am not sure if any aussie mk1's (non gti's) had temp warning lights?? could be gravely mistaken though.

[jaffa]

Its probably not as hot as you think. One of my Mk1s sits in the middle of the gauge and the other one touches the red and even goes into the red on a hot day. I used to worry about it heaps, even changed the radiator, water pump, thermostat, but no change. I put a water pressure gauge on the system and it was sitting about 40kpa, well below cap pressure. That motor did 400,000k like that and never boiled.

[worm]

Jaffa: if ur guage is reading right and its in the red all the time ur motor is foobard.... so obviously the temp guage is wrong!

Run ur car without the thermo, works a treat until u can propely fix it. Mine used to run hot, then i figured out the thermo fan was wired wrong and was pushing warm air into the rad.... who ever did my conversion is a tard

[Water Boy]

With our Mk1 the best thing we ever did was install an oli cooler... I have been told 70% of cooling is done with an oil cooler... So my reconmendation is install an oil cooler espacilly if its a High Performance Engine...

Cheers James

[Peter Jones]

Ummm, Golfman. It is on the road now isn't it? It's going to get pretty hot if it's still sitting in the middle of the back lawn.!

Congrats if you've got it back on the road, that's pretty quick.

Pete