18 replies to this topic

[clubman katie B.F]

Right i need to get this sorted as am at my wits end...so is minis84 and italianjob1275. have been having a overheating problem for a couple of weeks now. so far i have replaced all hoses, put a new rad in (3 core) two new thermostats (82 and 86 C) new heater valve, flushed the engine twice. checked timing several times, also recently just changed carb, ht's condenser, plugs, needles, coil and all that stuff. the head gasket went at drag wars. then my friend kindly COOKED my engine, by this i mean she drove it till the temp went above the red bit...i know i know!!! so last week i took the head off, cleaned out the mayonaisse from the rocker cover, removed the water from the pistons, took the head studs off and cleaned the block down, i got the head checked and it is still "true" very carefully rebuilt the top of the engine, making sure everything was scupulously clean, checked the tappets (0.015" on the metro 1275 lump) new gaskets all round, right coolan tmixture all that stuff, even changed the rad cap, and she still overheated really badly on the way to vineyards, we had a tinker at the show, but she was still just off the red bit on the temp guage even with the heater on in the car. nice and toasty. any ideas anyone, as it is doing my head in!!!!

[Woody]

Is it overheating or does the temp gauge just say its overheating ?, does it boil ?or blow the water out of the top of the rad ?

[vasi]

Did you get the head pressure tested or just checked with a straight edge? There may be a fracture.

[Guess-Works.com]

I'm with Woody....

Suspect the guage/sender

[Purple Tom]

we also changed the rad cap as the old one seemed knackered. There was visible steam coming out from under the bonnet as we pulled into the campsite on the night before Vineyards, we replaced the cap at the show, did the timing and richened the mixture ever so slightly, still made no difference.

[Dan]

Is your engine standard? I know you have probably told us all about it but I have a very poor memory. The standard rad can only just cope with the 1275 mill in the Mini anyway, which is why when Rover started putting it in again in the 90s they added a supplementary electric fan under the wing for the cooper versions. So the 1275 will always run slightly hotter than normal in a Mini with a three core rad than it would in the Metro, and any tuning will cook it up quick. Try a better radiator for starters, the best one being the two core rad from Minispares or an expensive aluminium version from somewhere. After that try a better standard fan like the six blade. It is louder and consumes a little more power than the 13 blade plastic one, but moves a hell of a lot of air. We used to run one of those but changed briefly to a really cool old stock tuning part. It was a fan with four sprung blades which flatten out at higher rpm, so at idle it moves loads of air and when cruising it consumes almost no power. Very cool. Then try an electric fan in the wing, with an automatic switch (buy the two core rad with the switch fitted to the bottom just in case you do want to use it in the future, it is only a couple of quid more)
Also, Rover used an expansion tank under the wing on the later 1275s, so that as the car heats up instead of loosing coolant the pressure is allowed to climb a little higher, raising the boiling point.
You could also try some Water Wetter or similar cooling additive.

I also agree that you should test the cooling gauge first, as they are pants.

[clubman katie B.F]

i think the guage is ok, as minis84 said, as we pulled into the campsite, she was blowing steam like a geyser

[clubman katie B.F]

engine standard metro lump apart from stage one kit......thinking of wrapping the manifold in that insulation stuff...good idea?

[Woody]

I am getting water loss from the rad , there doesent seem to be any leaks , the water pump is new , the temp gauge never gets to the normal let alone hot !
but after 50 miles she needs about a quart ('bout a litre for those under 35)to top up .strange

[clubman katie B.F]

check your compression woody......susprcted head gasket failure

[Woody]

the head gasget is new , I know that is no guarentee that it hasent blown ,as you say , i should check the compression , It only seend to do when i press on , if i was being followed by the fuzz it wouldent do it (or maybe not as much).

[willyj]

a good way to check if it's the head gasket is to take the thermostat out, turn the heater channel to open, take the radiator cap off and start the engine. If water blows out the top of the radiator or you see bubbles then it means air is coming through and your head gaskets gone. If its not this then you can be relieved but i cant offer any more advice, you've covered everything i can think of.

[clubman katie B.F]

or another way is run it a while then take out the spark plugs and turn over.....when i did that i got jets of water and steam out of the spark plug holes....mmmmmmm...nice

[Guess-Works.com]

Woody, a quart in 50 miles is a vast amount of water to loose, I'd strongly suggest getting the system pressure tested. Did this once when I had a suspected failure of the water pump, pressured the system and it was like a baby peeing out the bonnet ( those who've ever had to change a nappies !! ).

[clubman katie B.F]

just a little point......this is is katies question!!!!!