Over heating

darkangylgem77 · rice boy Joined: 22 Jul 2003 Posts: 20

I've been reading this site for awhile now but havent found any messages that relate to my problem with my Gem. Ever since I bought it its had this problem that if I take it on a long drive, even for like 30mins, at a high speed it (like 100 clicks) the temperature gage just shoots up. I have thought about changing the radiator to something bigger, to see if that will make any difference but thought I would ask some advice from here first. If anyone can help out it would be much appreciated.

-Gena

MR_GEMI · Posted: Tue Jul 22, 2003 3:18 pm Post subject: Re: Over heating

firstly you need to figure out why its overheating, have you tried having your cooling system completely flushed and checked for blockages in the water channels, maybe the guage is dodgy?? check thermostat?? try all those before spending up on a bigger radiator.

cheers,
Kevo
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FLYINLoW · backyard mechanic Joined: 08 Oct 2001 Posts: 924

you may have a blown a head gasket
or your radiator is shot, but if your radiator does not leak and is still circulating the water then it may also be your thermostat that has gone.

best option is to make sure your radiator has no leaks and is full then take it for a drive if its still overheating then you have a more serious problem

darkangylgem77 · rice boy Joined: 22 Jul 2003 Posts: 20

Well i dont believe there is any blockages as its been flushed out a few times but how do you check if the gauge is dodgy or the thermostat for that matter? Im only learning all this stuff as i go along so sorry if i come across as some kind of dunce.

-Gena

darkangylgem77 · rice boy Joined: 22 Jul 2003 Posts: 20

Well its not the head gasket. I blew that months ago and its been replaced and the radiator seems fine, no leaks from what I can see and im running cooliant so im sure they would show up.

Anything else?

-Gena

maDGeMvAN · tinkerer Joined: 06 Oct 2001 Posts: 452

If you blew your headgasket and didn't replace the thermostat, there is a good chance that is stuffed.

Are you losing water/coolant from your radiator?

darkangylgem77 · rice boy Joined: 22 Jul 2003 Posts: 20

Nope.

TGemi1 · tinkerer Joined: 23 Mar 2003 Posts: 456

i bought a gem with the same problem, there was a blockage in the water gallery in the inlet manifold.

chris...

peanut buttered · tinkerer Joined: 11 May 2003 Posts: 74

If worst comes to worst, put your heater on full blast and it should help cool down the engine. Check your thermo fan is working, if it is, flush the whole system again. Take off the water pipe going into the engine, stick a hose inside wrapped around a towel to stop the air escaping from the gaps, and try and dislodge the blockage. If no blockages and it is still overheating, get another thermostat as it might be closed permanently shut, therefore not allowing water to flow around your engine.

hope it helps
peanut man

DrIFtA · tinkerer Joined: 13 Mar 2003 Posts: 246

My roomies gem had the EXACT same symptoms as your car - i mean ALL your symptoms and signs.
I was scratching my head after changing the thermostat and giving it a thorough high pressure clean reverse flush and normal flush. Radiator looked A1, reasonably new hoses were already fitted. It had a new head gasket fitted not long before as there were slight bubbles in the radiator, but not enough to seem like a blown gasket - but it was changed to be on the safe side. Turns out the gasket was fine, it also copped a new radiator cap for something to do.
Aaaaaanyhoo, i had just finished an engineering course that covered cooling systems among other things, and i remember learning about cavitation from water pumps (causes, effects, etc.).
So i thought, the pump bearings must be ok as the wear indicator leak hole was dry as a nuns - unless it was somehow blocked. But for a measely $20 odd clams from a wrecker + 2 goldies for a gasket, i changed it for interests sake.
It ended up being the culprit, first drive the temp sat beautifully and my roomie couldn't be happier. We took it out on the highway to really test it under the conditions it normally skyrocketed in temp - it didn't even blink an eyelid after 20 kays of 100kph.
After close inspection, the bearings were fine but the impellor was badly corroded and had very uneven facings due to cavitation.

So give it a burl and see what you come up with, for a total outlay of no more than $35 odd bucks it's worth a shot.

sime · tinkerer Joined: 27 Oct 2001 Posts: 352

Have you tried radiator flush? The stuff you put in the radiator to unblock any potential blockages? If you have and still no luck it could be a faulty guage if its not that then its probably a faulty thermostat. If its not any of those then maybe its a faulty temprature sender unit?

Good luck I hope you find a fix to the problem.