Temperature gauge.

Hi Guys, the temperature gauge in my 83 Jetta 1.3 sits at 3/4 all the time, and the fan is regularly on when I come to park, and comes on after I've stopped for about 15 seconds too. I dont think its overheating, just wondered if this sounds normal lol.

The cooling system in small blocks are fairly crude - and lately mine has become prone to sitting above mid way.

This isn't normal - the needle on the gauge should point straight up in the middle. The cause of mine was ignition too far advanced, and my cam shaft was out by one tooth.

What you might want to try is bleeding the cooling system, when the car is cold, start it up with the radiator cap off, heater on full (pointed at screen) and let it get up to temperature. You could have an airlock in the system which is leading to the thermostat staying more closed than it should be.

X said

The cooling system in small blocks are fairly crude - and lately mine has become prone to sitting above mid way.

This isn't normal - the needle on the gauge should point straight up in the middle. The cause of mine was ignition too far advanced, and my cam shaft was out by one tooth.

What you might want to try is bleeding the cooling system, when the car is cold, start it up with the radiator cap off, heater on full (pointed at screen) and let it get up to temperature. You could have an airlock in the system which is leading to the thermostat staying more closed than it should be.

Sorry mate only just seen this!

Thanks for the advice, will have a try tomorrow and post results, I was thinking maybe it was just the gauge was worn as it only takes 5 minutes for it to get to 3/4 and yesterday it went up to about 5mm away from the end of the scale, the thermostat is doing its job though as all the pipes warm up. the fan kicks in when it should too, so I wasnt too worried. Admittedly I am more worried now!

I've the same problem on my 89 GTI - the temp gauge very quickly shoots up to at least three quaters with the warning light blinking. I've bled the system, replaced the radiator, thermostat, head gasket, had the head skimmed, rocker cover gasket, cam belt & tensioners, just about everything and still the engine is showing as hot.

Anything else I could try ?  My next idea was to replace the temp senders.

Its doing my nut in as I worried I'll damage the engine if I drive it as is, I'm not exactly too clever under the bonnet anyway so don't want to screw something up playing to fix the problem.  

RIGHT!

Done the old radiator cap off thing, as it was raining I got in the car and left the bonnet on the catch, the car got up to temperature, and then!! big puff of steam as it chucked a bit of coolant up.

I am no mechanic but i'm dying to learn, it wasnt boiling up or anything, I put the cap back on, as the bottom rad pipe had started warming up and the fan had kicked in.

Took her for a spin just round the block and it sat at 3/4 still, when i got back the top rad pipe was noticeably hotter than the bottom, but the bottom pipe was warm.

Any ideas?

Hi guys, little update.

I took the bottom rad pipe off yesterday and drained the coolant off and flushed the rad. I know not all of it comes out but a fair whack did. My main worry was not knowing how much antifreeze was in there. I put about 3 litres of 50-50 mix in and left the cap off to let it get to temperature again.

Pretty much the same thing happened to be honest. Right at the point where the thermostat opens the water gushed out of the top of the rad in 3 bursts. fan kicked in and thermostat opened, and I gave the pipes a squeeze to get any bubbles out. topped up the coolant, put the cap back on and this morning the temp gauge sits just over half way now!

Strange

My nextdoor neighbour has a Renault 5 turbo, and he said his ran a bit warm, it turned out to be the radiator not doing "as good a job" due to it being old.

Im pretty happy shes running a bit cooler anyway!