Hi,

Got another small problem with my S1, it never seems to get up to temperature, heaters are always cold too. Car has had new thermostat which has been tested ok, new radiator and coolant hoses. The hoses that go the heater matrix always stay cold, although the hoses that go the header tank and rad do warm up eventually if I let it idle for 15mins or so but as soon I start moving again it drops right back down. Gauge never goes over 1/4 of the way up and when moving drops back under the range.

I'm running cosworth managment and because the water temps are so cold the ECU is chucking in loads of fuel thinking its colder than it is, it's costing me loads in fuel and the back end is covered in soot from the unburnt fuel.

It used to be fine, then one day I topped it up with water now its doing this, any ideas?

Thanks

 

water pump?

 

Surely it would overheat if the pump is knackered?

 

eventually, My old audi had a duff water pump, giving all symptoms you describe

 

ok thanks, will check it over tomorrow

 

yeah sounds like water pump to me too

 

I dont understand how a duff water pump can overcool, it runs off the cam belt so only ever spins over a predetermined RPM range, and it's fins are only as big as they are? lol
Are your fans stuck on?

 

its hard to explain

 

Exactly what I thought too. Fans are off, but will come on if I leave it ldling long enough, once the temp drops then they switch off.

 

Air lock I would think.

Martin

 

I was thinking there might be one in the matrix, will check it and flush it out while I'm there.

 

Thing is if it's an air lock then your not really as cool as you think, because water is not circulating the engine, which is dangerous!
For the temp to read low it either has an airlock where the temp sensor is (so no water there), it really is that cold, your temp gauge is faulty, or you have no water in your cooling system like when the headgasket fails lol

 

I had exactly the same prob with my S1 turns out it was an air lock which i've now managed to clear, but even yesterday in the hot weather we had the car was still running just below the 1/4 mark on the gauge when driving along but as soon as i stopped the gauge went to the half way mark.
I've plumbed in the a kenlow temp adjuster switch which has enabled me to keep the car from overheating which works very very well.

My father in law works for Ford in R&D and he showed me the correct(Ford way) to clear air locks.

1) Top up header tank to MAX mark when cold
2) Leave header cap off and start car and keep revs at around 2.5k to 3k.

Keep a very very close eye on the water level in header(and cap in hand) as the car comes up to running temp the water level will drop if you have a air lock. if this does do this put a LITTLE more water in (make sure its not freezing cold water tho) at this point you should notice the water level start to rise above the max level DO NOT put the cap back on yet WAIT for the water level to get almost to the filler hole in the header then put the cap back on.

Leave the engine still ticking over at around 2.5k to 3k for about another 10 mins keeping a very close eye on the water level in the header.

After the 10 mins are up turn the car off and leave it till its completely cold, remove header cap again top up water if needed then take the car for a drive(or in father in laws words scream the nuts out of it) for at least half an hour.

Get back home and leave it again to go cold again, once cold the level should have returned back to the normal MAX level if not just top up with more water and keep repeating the process.

Hope this helps.