overheating on low revs

[LarsB]

 my murena has started overheating say below 1500rpm. Usually I will just change one gear down and the temprature will fall back to normal.

I am not shure what is causing this, but maybe waterpump?

any ideas?

[macaroni]

Or auxilliary drive belt, which runs the water pump?

[Anders Dinsen]

Now is the time of year where we start seeing cooling problems

Is the coolant level decreasing?
Are there any signs of coolant on the ground under the car when has been parked?
Check the water pump area carefully for signs of leaks.
Is the ignition correctly advanced? Is the vacuum advance working?

Water pumps usually start leaking around the drive shaft when the seal and bearing becomes worn. A leak will mean that pressure cannot be maintained in the engine causing local boiling and significantly lowered cooling effect.

If the coolant level increases rapidly in the header tank when the overheating starts, then the water is boiling in the engine and there's a pressure problem. If you run without the engine hood, it is possible to keep a constant view of the coolant level in the tank in the rear view mirror!

I don't think it would be the drive belt as if that was untensioned it would squeak and the charge light would be blinking.

- Anders

[Bart_Maztra]

Air in cooling circuit?
Radiator clogged? (using water instead of coolant?)

[krede]

Yahh... if you haven't done so recently, try flushing the cooling system... and check if the radiator has been clogged by dirt during the winter.
Is the cooling fan kicking in as it should?

[LarsB]

Well,I will have to admit to some poor maintenence, however I doubt it to be the reason for overheating.

Colant level is decreasing, just havnt had the time to check where it goes (I have a preassure pump wich I can fit to the expansion tank, that way I dont have to warm up the engine)

Ignition might or might not be an issue, at the time I am running the standrat camshaft with an S-type, distributor.

the electric fan is kicking in, but not until the needle has well passed the 90 mark.

I think I will order a new waterpump, and (thermostat?) (I have changed the head once, and the waterpump Is cheap compeard to that

[Anders Dinsen]

Colant level is decreasing, just havnt had the time to check where it goes (I have a preassure pump wich I can fit to the expansion tank, that way I dont have to warm up the engine)

Ok, there's a leak all right.

Ignition might or might not be an issue, at the time I am running the standrat camshaft with an S-type, distributor.

That shouldn't mean a lot - I was only concerned with the advance at low RPM (static advance) and the difference between the two distributors are very small. Roy has told me (here?) that the only reason the later S-models are fitted with Ducellier dizzys is that they were the same ones that went into the Tagoras. I.e. it has nothing to do with tuning.

the electric fan is kicking in, but not until the needle has well passed the 90 mark.

Sounds like normal, i.e. there's sufficient flow in the radiator.

I think I will order a new waterpump, and (thermostat?) (I have changed the head once, and the waterpump Is cheap compeard to that

There's a good chance the water pump is to blame as it is the most common cause for water leaks AFAIK.

- Anders