si-vtec

Hey guys, hope somebody can help me cos its starting to get on my wick now. I have an 02 Focus 1.8tdci. Last week the temp gauge started playing silly buggers and every time you let off the throttle the heaters started to blow colder air out, So i messed about with coolant system, dropped all the water out was horrible rusty brown, so started pulling each pipe and flushing them out, have done the radiator and the heater matrix aswell, today I changed the water pump and flushed the rad through and the matrix again, the thermostat was tested and worked correctly. Put it all back together spent over an hour trying to get it up to temp, the temp gauge reads normal, the top rad hose gets quite hot, the bottom hose was cold, the heaters are just the same, cold till you drive it soon as you let off the gas back to luke warm/cold. Please help as it is driving me round the bend

uruk hai

I know you've already drained and refilled the system but it does sound like a problem related to air in the system or perhaps an air lock.

How was the thermastat tested ? That would be my next port of call as it sounds as though the stat simply isn't opening ?

si-vtec

The t/stat was tested in a pan on the stove, heated the water up and the stat opened normally. the stat was only fitted in november so isnt very old. the car doesnt over heat at all. I did notice today when starting from cold and driving to work it didnt take half as long for the temp gauge to get to halfway as it did before I changed the pump.

RichieST

iTrader: (2)

I had a knackered 'stat on my old st170, lukewarm air through the heaters and not getting fully up to temperature. Took the stat out and tested it in boiling water and it still opened, but put a new one in and it was fine.

I'd suggest putting in another genuine ford thermostat, if it doesn't sort it then i'd be looking at the water pump.

si-vtec

Thanks richie, Ill get a new stat on way home tonight, I changed the water pump yesterday!! Wasnt a bad job really. 1st time I have worked on a Ford in a long long time.

si-vtec

Well, couldnt get a stat tonight, so have to wait till tomorrow for 1, so, in my wisdom I butchered the stat I have now, cut the cage off and removed the moving parts so i ended up with just the disc and the seal, i fitted it, topped up with water and went for a drive, and guess what.............it is exactly the same as it was with a working stat in it. I think next step is heater matrix? anybody else want to throw some ideas at me I am more than welcome. I have got somebody wanting to buy the car now aswell but I wont sell it as it is

uruk hai

If its the same as when the stat was in it then it would seem to point to that part being shafted ?

si-vtec

Well, I have made some progress tonight, I got a new stat and got it fitted, took an age to bleed the system up, anyway after about an hour or 2 i decided it was time for a wee test drive to try help things along, so off up my private stretch of road to give it a good rinse out, temp gauge read normal and i had some very nice hot air out of the blowers, untill I eased off the gas then it went to luke warm again, got back on the drive and checked all the water pipes I could get my hand into, they are all at the point where you can only hold them for a second or 2, and I even have hot water in the header tank (which I have never had since owning the car) would it be feasible to say that possibly the aux belt that drives the water pump is worn? thus only pumping the water when driven hard? thats my next theory anyway, new belt tomorrow night. Now I know why I went away from Fords about 15 years ago when my XR2 shat itself.

uruk hai

Could be that mate and I think the old "replace the cheapest first" approach never hurts or failing that you could try reverse flushing the matrix to see if its a bit gunked up ?