Th expansion cap can cause issues especially as it might as old as the car, I changed mine and the header tank for new ones but still get overheating, I didn’t bleed the engine and the on baulkhead bleed no water came out so will have to try bleeding again. Good luck, hopefully we will both get it sorted!

 

I have noticed a bit of moisture around the cap, I'll replace that too, Thanks

 

Could be a stuck thermostat......they do not last forever unfortunately in any car.

 

Hi Julian I'm sort of pinning my hopes on it being a stuck thermostat especially as the car has had so little use in the last few years.

 

First off, you need to get the system bled properly from all THREE points.

 

I managed to open the 3rd bleed screw, so I rebled the system from rad to bulkhead then engine bay. No air came out of any as far as I could tell. I did notice that it had lost a bit of fluid ( about 20mm down from the level before I went for a run yesterday). When I got back as I mentioned there was moisture around the reservoir cap. As the car was running very hot I'm assuming it escaped through the cap. I can't see any leeks or signs of leakage and the oil has no water in it. I'm going to change the timing belt, thermostat and waterpump and replace the under car coolant pipes on the weekend, so hopefully if there are any hidden leaks I should spot them. Would the coolant look oily if I had a HG failure and would there be any other signs?

 

Are you loosing coolant ?

 

No it doesn't appear to be loosing any at all

 

Does the fan come on? If not check for a blown fuse in the fusebox, geez what was the number again. Happened to my F was fine normally but in slow traffic managed to overhead as no working rad fan. You can also confirm if the pipes into the radiator are warm / hot, if cold when the engine is getting too hot prob thermostat as above.

 

O.P has already said that both fans are working.

 

More info on rad fan here : Fan fuse alarm- How to fit.

 

If you are not LOSING coolant try taking the cap off the radiator at the front right. Mine is plast and very easy to remove. Let any air escape.

 

My money would be on a ‘lazy’ thermostat.

 

As I said earlier in your thread, my bet is on the thermostat. Like my 1998 MGF, your car has been little used over the last 20 years. I never thought it would have been the thermostat but then I realised that overheating (and not losing coolant), was either the radiator fan or the thermostat. The thermostat failed in the closed position hence the cause of my overheating.

Lack of use is really not good for cars (mainly on the mechanical elements).

You can check by feeling the temp of the front radiator pipe (from memory the one on the left - the other will be 'cold'). It should be hot if the thermostat is opening.

 

Thanks Julian, I'll try the pipes and see. I'm a bit gutted,UPS have let me down on my parts delivery today so I'll have to wait until next week to replace the waterpump and thermostat etc. At least it'll give me time to take it apart in preparation.

 

How are you getting on Dough in the shed? Best of luck. Hope mine is a cap or thermostat also 🤞

 

No progress, yet. I'm waiting for the parts to arrive from rimmer bros. UPD have failed to deliver. Next day delivery has turned into hopefully next week! Good luck I hope yours is an easy fix👍

 

How are you getting on Dougy?

 

Hi Will., I think its sorted (fingers are firmly crossed). Ive just come back from a 45 minute drive and the gauge stayed just below the half way mark. When I got the old stat out it was properly gunged up with cooling system crusty's . I popped it into some kettle boiled water (Apparently Mrs D's sauce pans are not for thermostats ), it failed to open. after a bit of a cleaning it would just creep open about 1mm. I replaced that the same time as the timing belt, water pump, tensioner and the under car metal pipes. After getting it back together yesterday I had a massive water leak from the stat housing O rings. Although I replaced them I'd managed to roll both of them out of their grooves, that'll teach me trying to change the stat without removing the inlet manifold. So today it was off with the inlet manifold and in with some new O rings. One good thing to come out of my ineptitude was a flush of the cooling system which revealed some lovely lumps of rust and crud that came out of the old decaying metal pipes. I plan on fitting a low water level alarm next weekend so I'll drain and replace the coolant again and hopefully that'll be the end of my over heating. How are you getting on, is yours sorted?

 

I'm in need of further guidance I'm afraid 😞. Fitted a B & G low coolant alarm (nicely put together kit), emptied refilled and bled the coolant. I went for a 130 mile drive, mostly A and B road and the temp didn't budge off one spot below half way. The last 40 miles was motorway, after a few minutes at about 70 ish the temp went up to on spot above half. Dropped to 70 ish and it dropped back down but was erratic going up and down. When I got home the level in the res level was about an inch up. Checked this morning and the fluid was still up. Opened the cap there was a suck of air in and the level went to normal. Is this an air lock or somthing else?

 

Hi Douggy, how have you been getting on? Sorry to learn of your further woes..