[AndyPuma16]

Hi all, new puma owner. I drive a 1.6 with about
70k on the clock. When I was driving above 50, the temp gage started to go up and down. So stopped checked the engine and the coolant tank was hot but still ok to touch. Nothing out of the ordinary. Turned the engine back on and the needle went back to the middle, started driving at 60 and the temp went up to orange gradually so stopped, kept the engine going, opened it up and the fan was going but as before everything seemed ok. Got home with the temp cage going to the top line and then back a little again, this did seem to relate a little to speed/revs. Tested it by driving with the heater on, temp went up but when I stop quickly it goes back to normal. The fan seems to be coming on at the right time too, below 40 it's not a problem. Can't work out if the temp sensor has gone funny, if the pump isn't working properly (it is turning) or if the radiator has a block... No leaks and the system is overly pressured. Any ideas :/

[happy-kat]

welcome
I am not a mechanic so this is a guess, water pump but you write that it is turning, does it sound noisey the pump?.
The Wiki has a few srticles on the Puma heating system.

[AndyPuma16]

No, she ticks over nicly, felt the pipes going in and out the radiator and it appears coolant is circulating the engine. I've heard on some engines the propellor on the fan can become less effective... But without changing the pump it's hard to know... Thanks, I shall look at the web, may be a garage job, it's just frustrating

This post has been edited by AndyPuma16: 28 June 2014 - 08:14 PM

[happy-kat]

The common part of fail is the HCV but I don't know if your sysmptoms fit.
If you do change the HCV buy the Ford part, false economy buying an alternative on Ebay you will be replacing it.

[Greybeard]

If the gauge is not actually reading the temperature but giving random readings, you might consider looking at the wiring. The insulation inside the loom between the sensor and the gauge might have gone. On the other hand, it might be a problem with the gauge itself. Sudden fluctuations of the gauge are abnormal. I don't have access to a wiring diagram so I can't say if you can run wires from the sensor to the gauge directly to make a check - it would be nice if you could. Failing this, an auto electrician

The other possibility is cheap enough: get an ELM 327OBDII interface (get the Mini version) and the Torque App for your Android Mobile (which needs Bluetooth.) This gives a reading of the coolant temperature taken from the ECU rather than the gauge.

[happy-kat]

I use torque great app but had not realised it did that :-)

[AndyPuma16]

Thanks! Had some developments, took it out for a drive and the temp gauge seems to be behaving more consistently, increasing when the revs go above 3000 but then quickly decreasing when it's below and going back to normal when stpppped. Beginning to think the sensor may be accurate(?) but it doesn't explain why it would jump up and around orange when the car hasn't boiled over into oblivion. There is a slight coolant leak just above the themostat housing which I've been trying to seal and thought I had succeeded, I'm beginning to think that it might be that not behaving. I'm currently apple based but will look into apps etc... Spent so much getting the car on the road already I'm desperate not to have to buy lots of new tech

[AndyPuma16]

also Rac man plugged his lap top in but it didn't get a live coolant reading and, despite the temp going to red, no warnings. So perhaps it is the sensor giving odd readings, does that also control the fan?

[AndyPuma16]

Sorry HCV...

[Kidders]

Common problem on the 1.6. Is the radiator /bottom hose hot when the gauge indicates hot running? If it is, it needs the Focus TSB bypass mod.

[happy-kat]

^ something to check for.

The most common heating failure is the HCV and they should be replaced every 10 years tops as the pipes get brittle and then it can fail in one big mess.

[AndyPuma16]

I'm going to be really daft here, what's a HCV?

[happy-kat]

heater control valve

[AndyPuma16]

Thanks folks, problem solved! The pump had lost some blades, water was circulating but badly hense the over heating, new pump has it running very cool. Enjoying the car for the first time!

[Greybeard]

(Duplicate)

This post has been edited by Greybeard: 11 July 2014 - 09:31 PM

[Greybeard]

Good news! I've seen pictures of a water pump in the same condition - i.e. lacking blades: I don't know what causes it other, perhaps than low levels of antifreeze/protector..

[AndyPuma16]

Apparently for a short time they used plastic for the blades, the heat gradually weakens them and when one goes it kerflumps the others now got a bearing on the gearbox making a helicopter sound.. Awesome