2000 Focus help diagnosing issue with fan on
 

Hi,

Trying to workout what the real cause of this before ordering parts.

At the end of the summer I had a slow coolant leak so I put some k seal coolant stop leak into the coolant with summer coolant.

All seemed ok till a month or so later. When I noticed that the car was blowing cold air after the engine had warmed up (with blasts of hot air intermittently). The temp gauge was dropping slightly to begin with but now seems to have settled in the middle. The A/C is not on double checked that this morning. Also the car fan seems to be on a lot sometimes near enough straight away. I've been driving around for a few months like this, probably should have got it sorted a lot sooner.

My gut feeling is it may be the thermostat casing/thermostat from what ive read, however i'm not a mechanic so wanted someone to check above before getting the parts from, unipart. The thermostat casing was replaced about 4 years ago not long after I brought the car.

Any ideas?

Thanks,
Chris

Hello! Did you ever find the source of the leak that you had in summer? Now would be a good time to open the system up, do a complete flush. I have a suspicion that the stop leak has found its way into the heater core. You say fan is on almost right away? Are you running in defrost? If car is equipped with a/c, compressor will run, and fan may come on? even with heat called for.
1. Try to find leak, so it can be repaired properly.
2. Drain and flush everything thouroghly.
3. I would replace thermostat since system is open.
Good luck! This should give you a good starting point.

Afraid not, id suspect it was the thermostat casing but didnt have a car lift to check it and couldnt afford to have it in at the time hence the diy approach (even if it has caused more problems now!).

The fan is on pritty much all the time, car is not on defrost assuming you mean windscreen defrost. I'll double check the hoses make sure there ok but just done some research and some valvoline radiator flush + distilled water isnt too bad so if i flush the existing coolant, add distilled water and radiator flush keep car running for a good 15minute plus then drain then replace thermostat and casing then finally new coolant ~ £40 in parts plus my time so worth a punt.

My wife's dad is a mechanic but doesnt have a lift and works mainly on robin reliant's so he can make sure I do the thermostat bit properly to get a garage todo it will cost good few hours labour....

Still not had chance to look at this. In the recent snow thermostat has being going up to into danger red (been slowing down to counter the measure).

Checked this morning not much coolant certain not at the correct min level. Also looked by the thermostat for the first time, I think what i can see bear in mind im not a mechcanic is leaking coolant which confirms my problem? Can someone check this is correct before I order the parts?

http://i.imgur.com/bqK9WSg.jpg

Thanks,
Chris

My other question is does it make a difference which radiator flush I use ie. valvoline or wynn's?

Looks to me you have a valve cover gasket leaking on to your thermostat housing, and then your thermostat housing is also leaking. Unless I see the picture wrong. Common on these. I would replace both. as to the flush, I really don't have an opinion either way, I have not used either. I believe last time I did one I used prestone. Good luck!

Great thanks - there's a preassembled kit with gaskets and new thermostat on ebay for around £40+p&p so i'll probably get that ordered for the sake of a few quid now would rather its sorted.

Would you do the flush with the old components on that's the only question left really for me.

Thanks,
Chris

Sorry forgot to say that the valve cover gasket was changed roughly 6 months ago the mess is probably from that as it was pressure washed a few weeks before the change etc.

Sure, it would do no harm at all to flush with the old components on. Then you won't be sending crud through the new parts.

Right flushed everything the weekend that went well, however ended up having to put it back together.

All three thermostat housing bolts are ceised up completly meaning I cant get them off. Any ideas how to get them off with sheering off the bolts?