Cooling system issue

[tune 0]

Hey all

ok heres something weird about the bema

I can drive it anywhere, anytime, anyplace

but sometimes (during a full car load or alot uphill climbing)

It will start to overheat (obviously i pullover and let it cool down as to not even risk blown the H/gasket)

then ill start it ten mins later and it will run sweet again for ages

diagnostics

when driving normal my engine temp is WELL under half way

then after a while it will goto half way temp then fluctuate between the two.

(i.e; stopping in traffic for ages makes it go up, then driving makes it go back down)

then if it starts going up i turn it off, and look under the bonnet

---the radiator hoses look astho they are going to pop, very tight and swolen.

the car never goes into the red temp zone, even if i keep driving.

any ideas?

Edited April 8, 2008 by tune

[QuickSilver 0]

It will be cooler when driving as there is cooler flowing through, and when sitting it will heat up because it is circulating warmer air etc,

Mine suddenly over heated a while back and turned out to be a stuck thermostat, a very common thing to happen, take it off and clean it, it could also be the temp sensor? I'd replace the hoses if your worried about them.

Edited April 8, 2008 by QuickSilver

[Mark 178]

Check your fusebox, it could be that the fuse for your auxillary fan has blown. I had similar symptoms to you and that turned out to be the problem.

[SIR E30 68]

What kind of fan is in there? If its a viscous the coupling could need replacing, quite a common problem. Just replaced mine as I had the same symptons and it worked a treat!

[Eagle 1535]

I have the same problem as you too, fluctuates in between 1\4 & 1\2 but never goes above 1\2

I replaced near everything bar hoses and aux fan sensor(thermostat, waterpump, viscous fan,radiator,coolant sensors dme and engine. instrument cluster even) while most of that needed doing.

But unlike you there are no signs to indicate the car is overheating & could be a dodgy ground on the sensor as much gauge acts a bit weird when cold.

I keep meaning to measure the temp coolant hoses near the sensors to get an idea if the gauge reading right or not.

Id be doing the thermostat first thou if it hasn't been done already.

[hotwire 352]

Problem certainly sounds like viscous fan not working correctly, but also could be a flow problem - partially blocked radiator or thermostat playing up.