Urgent, thermostat location

[ianeire]

Need the location of the thermostat plaease lads, car suddenly not blowing hot air through the blower into the car, leaking some sort of coolant into the footwell and the engine temp is in the red....


help help help

[Andy335Touring]

Which engine ?

[ianeire]

m20 325is. found location in tech article. Would some sort of coolant leak into the car if the therm was stuck or knackered?

Leaking down onto the clutch pedal

[Andy335Touring]

It could be leaking where the heater pipes come through the bulk head or the heater matrix could be leaking. I'm not to sure as i've been lucky not to have any leaks in that area before.

How low on water has it got ?

If it's been really low then you could have an air lock.

[Brianmoooore]

M20 325s don't tolerate temperature gauges in the red very well at all!
Overheating and no heater output is a symptom of an airlock in the head or a failed water pump.
Is your car RH or LH drive?
Does your coolant pressure cap have a yellow or a black disc on its bottom end?
Thermostat stuck shut would cause overheating, but the heater would work exceptionally well (for a while).
Thermostat stuck open would give poor heater outbut, but certainly no overheating.

[ianeire]

Car is RHD. ive had the thermo out and it seems knackered so thats the first thing to change tomorrow. Cant remember the color of the coolant pressure cap, car is outside a buddies house... from memory I'm thinkin yellow.

I got hot air out for a period and then cold only. What I thought was the window after fogging up was in fact some sort of residue blown out through the blower..

Thermostat or pump.... how would an airlock have gotten into the head?

[Brianmoooore]

we're getting some weird faults today!!
Airlock shouldn't get into the head, unless it's pressure leaking in from a cylinder.
Sure it's coolant by the clutch and not rainwater? Coolant on that side, must be a leaking matrix - often blown by the old type black bottomed coolant cap.
Put the new stat in and see what happens, but have the heater set to full hot when you start the engine and watch the temp gauge carefully.
Check that the heater starts to blow warm air after a minute or so.

[ianeire]

Changed the stat and the problem persists. Didnt have the fan set at full hot when I started the engine, and didnt see your reply untill now Engine warmed slowly, took it for a short spin, temperature settled at about halfway. Stopped and waited for a minute to see if it would progress any higher and it did, up it crept slowly.

As the temperature began to rise the blower once again began to blow cool air even though it was still set on full hot and had been blowing hot air all along.

Next port of call is the pump I presume.... into the gargae it'll go for that tomorrow, OTTO has them in stock.

[ianeire]

Air lock, problem solved

[Brianmoooore]

Air lock, problem solved

OP says heater suddenly stopped working and a coolant leak.
Airlocks don't suddenly appear if no ones been messing about, and what happened to the leak.

[ianeire]

Leak has stopped leaking, mechanic that bled the system told me it might have been the airlock putting pressure on the inner fan causing it to leak some coolant....?

Couldnt have seen how it was an airlock personally but... thats what I was told and now its running sweet again. Even starts, idles and pulls away from very cold smoothly, something which it had not done for a while.

Airlock or not, thats what I was told, now its fixed, cost me only a few squids for labour so happy chappy!!

Especially seeing as I have now also just taken a deposit on it!