39 replies to this topic

[purplesuit1]

So the problem i am having is my Mini is overheating rather quickly. From the time i start it up it only takes about 4 or 5 minutes of driving before its all the way at the top of the red on the temp gauge. The water is coming out of the overflow port after driving so i am pretty certain it is not a gauge problem. The water pump, thermostat, and temp sending unit are all relatively new and the engine seems to be running ok so i dont think its a head gasket problem. Any ideas?

Thanks

Edited by purplesuit1, 21 March 2013 - 12:40 PM.

[ProfMattMec]

Is there an air lock in the system? If water is not getting somewhere due to an airlock, that could cause it to overheat.

What is the color of the oil?

[purplesuit1]

Oil is ok color and how do i find an airlock? Just flush the cooling system?

[Woreign]

Could your timing be too advanced? Or carburetor too lean?

[mini*mad]

also check your in car rad (heater matrix)
if thats failed or blocked it will heat up fast
have you got coolant in it?
and hows the rad condition?

[purplesuit1]

I have been tuning the carb but the spark plugs are brown and seem where it needs to be. just replaced the heater matrix a bit ago with a used one and the heater heats up fine and and doesnt leak so i dont think its that. Raddiator seems to be in good shape. No rust or corrosion anywhere and for coolant i am just using water. It is a bit dirty from the inside of the engine but i dont think that makes much of a difference.

[ProfMattMec]

When did this overheating start? Is it a recent thing, or has it been going on since you changed something.

[Archa]

Run the car up to temperature on the drive with the rad cap off, give it a few revs off the throttle, this should help to move any airlocks in the system, the same happened to me just before winter when I replaced the coolant with a fresh batch with antifreeze.

[purplesuit1]

I cant say exactly when the over heating started. My temp sending unit wasnt working and i ordered a new one with a bunch of parts and took the engine out. I put on all the new parts including the new temp sending units, did some work on the engine( changing oil pump, gaskets, fitting stage 1 kit servicing the carb) i put the engine back in and now its showing over heating. I am at work right now so i cannot try and force any air bubbles out but i will once i am off work and will update you guys.

Edited by purplesuit1, 21 March 2013 - 02:33 PM.

[Dan]

I would imagine the thermostat is either stuck or fitted upside-down. Either that or the pump has failed.

Edited by Dan, 21 March 2013 - 02:56 PM.

[purplesuit1]

I tested the thermostat in hot water and it opened just fine. i fit it so the opening piece is down towards the head and the dome like piece is up towards the housing. the pump is only about 500 miles old.

[Dan]

Not sure which way up you mean, the spring and the brass barrel should be at the bottom.

[purplesuit1]

yes, thats how i have it set up.

[Dan]

It's almost impossible to trap air anywhere that matters while filling up, the cooling layout isn't exactly complicated. And an air locked or blocked hater won't cause this. When it's overheating is the top hose hot?

[purplesuit1]

By top hose do you mean the hose between the rad and thermostat? If so then yes it is hot.

Edited by purplesuit1, 21 March 2013 - 04:15 PM.