15 replies to this topic

[gsms]

For about 3 weeks my Cooper has been overheating for the entire journey (temp reaches maximum after a couple of minutes of driving). This isn't driving in high revs or anything, it just always does it, even cruising along the motorway.

The fan is working (it spins anyway), and there's nothing on the grille obstructing the cold air intake, so what could it be?

Any help appreciated. Cheers. Guido.

[Dan]

Check the thermostat isn't seized shut, and check soon as if it is you'll blow the head gasket in not very long at all.

[Dom]

i had the same problem with mine... in the end i got a new radiator fitted and the chap fitting it checked the rest of the engine to check for blockages in the water pumps, which there were'nt.

[chocolate jazz]

check you havent got a air block, drain the water out and refill back up leave the cap of and start the engine and squeeze the pipes. do what dan said to

chocolate jazz

[Alburglar]

most likely be a knackered temp sender or theromstat. drop it in a pint glass of boiling water and see if it opens. If not then it's an airlock

[Boab]

Could also be a knackered voltage regulator

[Alburglar]

yep. that would send it straight to hot.
However, I sorted everything mentioned so far in this thread no sender/thermo/voltage faults and my 1380 was still overheating. A trip to the rollers sorted everyithing out.

[miniman5]

i would cheack the thermostat and flush therad and the engine. when did you last check your water? you might have a leak and have not noticed and you might not have any water in it what so ever!

[Dan]

If there's no water the temperature gauge reads cold, since it's measuring the temperature of the coolant.

[gsms]

Wow, thanks for so many replies in such a short time everyone!!

I'm gonna go out now and check everything that was mentioned here.

Cheers. Guido.

[maph2]

if you've got a 92 cooper, then it might be time for a new rad - it is probably sludged up with rust and limescale which has concreted prob the bottom 1/3 of the rad.

check all the obvious stuff like do a rad flush, airlocks,water pump, themostat, fuelling etc, then get a new 4 core rad.

if that doesn't work then your head gasket could be going - I had no mayo or bubbles in the rad but gas was escaping the cylinders and pressurising the water jacket enough just to boil the coolant. put a new gasket on - cured over heating

[Mini Man Sam]

How hot does the engine and rad FEEL after a journey. My gauge reads nearly max after only a few mins but even after a 10 - 15 minute journey I can remove the rad cap with no pressure hiss or anything, dipped the water with a meat thermometer and read only 75 ish. So whilst the gauge is saying you had better stop, everything else seems to be ok. Am going to chage sender unit at weekend to see if that changes anything, will let you know.

[gsms]

How hot does the engine and rad FEEL after a journey. My gauge reads nearly max after only a few mins but even after a 10 - 15 minute journey I can remove the rad cap with no pressure hiss or anything, dipped the water with a meat thermometer and read only 75 ish. So whilst the gauge is saying you had better stop, everything else seems to be ok. Am going to chage sender unit at weekend to see if that changes anything, will let you know.

Yeah, i suspected this may be the case too, until I drove for 20 mins this morning, when I got home smoke was POURING out from the engine!!


I've had no mayo either, but I may replace the h gasket too to see if it does the trick!

Cheers!

[Mini Man Sam]

Well I replaced the sender with with a nice new shiny one from Motor Factors in Standard Way, Fareham (£5.55) and now it only reads just over 1/4 after an 15 min run and about 10 mins of stationery tickover. So unless I have bought a U/S sender hopefully my days of high temp readings are over.

[Cir-clipalot]

If there's no water the temperature gauge reads cold, since it's measuring the temperature of the coolant.

As i once learnt in my old chevette, going along the M40, "cool, the gauge is reading cold, the overheating problem has disappeared!". Along with it all my coolant. I was young and foolish. Carried on for a couple of miles tho!! Ended up replacing the engine in a cinema car park in high wycombe a few days later...