mk1 focus broken down help

[the snooper]

Might be worth doing, should inform you why it threw the light in the first place and also live data would verify the gauge reading.

wont show anything if it didn't illuminate the engine management light, and certainly not if a blockage caused it, the only thing that will be useful is live data to show if the gauge shows the same temp as the reader

 

[the snooper]

Well, I was assuming that as:



that was the opening to the thread, it might be handy

dash lights up I would take as, the usual lights alternator, oil pressure etc

 

[steveo3002]

was overheat light and check engine light

 

[the snooper]

was overheat light and check engine light

so it threw the eml because it detected too much heat in the engine or the fact the excessive heat started to cause the various sensors to act erratically, I doubt very much it will give you any clue as to why, just the results of what it caused

 

[octo0072000]

has this got one of the stupid plastic water pump impellers that slip when hot so not pumping enough water

 

[delta9]

check heater control valve and thermostat housing?

I did one before that was losing coolant (hariline crack where hoses connects, oddly enough both thermostat housing and heater control valve suffered same failure).

 

[steveo3002]

has this got one of the stupid plastic water pump impellers that slip when hot so not pumping enough water

checked and its metal and fine...real xxxx to take off too

 

[steveo3002]

right update if anyones still looking in

driven the car alot and keep stopping , at no point does the hoses /rad feel too hot

gauge still shoots from normal to hot and back again in around 10 seconds , seems to happen mostly when going from 70 ish and backing off to 50 , i think its too fast to be a genuine overheat

fan comes on randomly even at speed

i got the machine hooked up and cylinder temp is showing 114 after a long run , hoses felt normal , no fan on , im told fan should come on at 105

does it sound like a duff cylinder head temp sender??

basicly its thinking its hot and its not?

 

[octo0072000]

change senser for what they cost
if it still does it could be head gasket going
bubbles in header tank excess pressure in header tank etc

this sounds like it's either boiling or air locking

gauge still shoots from normal to hot and back again in around 10 seconds , seems to happen mostly when going from 70 ish and backing off to 50 , i think its too fast to be a genuine overheat

 

[the snooper]

If it was just the gauge I would say sensor but the fan sensor I separate from temp sensor so you have other problems, as said could be air locks but without doubt there is more to it then sensors

 

[steveo3002]

i *think* said sensor tells ecu its too hot and that then tells the fan to come on...it doesnt have a rad fan switch like older cars used to

 

[Cobbler]

I know you are talking about a gauge sensor, but I had an odd fault with a BMW I had. It would run for about 21/2 to 3 miles & cut out. Open the bonnet looking for a fault, could not find anything wrong, this carried on for ages unable to sort what it was. One day I was getting it ready for an Mot test & borrowed a gas analyser to set the mixture. Watching the meter the reading suddenly shot across to very rich just as the temperature came up. I realised that if I took the rad cap off & released the pressure it went back to normal. What had happened was the sensor had gone pressure sensitive & as the pressure went up, it told the ECU it wa cold, ECU enrichened the mixture & the engine cut. Once it had done it, release the pressure, it all seemed to back to normal & ran perfectly. Changed the sensor & never had a problem after. I've never heard of a sensor going pressure sensitive since, but this one had. Could this be similar to your guage fault?

 

[the snooper]

i *think* said sensor tells ecu its too hot and that then tells the fan to come on...it doesnt have a rad fan switch like older cars used to

Hmm not sure, it's a while since I messed with a mk1 focus or that age of zetec engine it needs live data running on it to see what's happening try a new sensor if they are cheap

 

[steveo3002]

got a sensor on its way

managed to narrow down when the gauge sweeps into the red , it will only do it if it runs at 70 or more for a few mins then back off to 50 , gauge will sweep over and its repeatable over and over , will drive for hours on slower roads or idle for ages and not hiccup at all

 

[Wallace]

I seem to remember Ford having problems with bleeding the air out on the 1.6 engine and made mods to the pipework, vacuum bleeding was another thing I had to do on one to get the cooling system stable. You can stick the dash in test mode and get the LCD to display true engine temperature and watch the temperature swing about and the gauge stays at 90°.

 

[steveo3002]

tried a used ecu today...no change

dash test mode swings about same as the gauge , can change 10-15 in a flash

 

[octo0072000]

is that bleed pipe that was blocked still clear should have a constant flow back to header tank
sounds like a hot spot in the head causing it to boil hence asking if it still has a constant flow back to header tank

 

[steveo3002]

checked it again yes its flowing .....you see some movement in the tank when revved , not loads

if you ignore the lights on the dash it will sit there and heat all the hoses up and the fan comes after a bit of revving like you would expect it to

 

[octo0072000]

have you had it sniff tested for head gasket failure
see link for DIY kit cheaper than taking it to the garage
just trying to cover all is that return to the header tank fully clear could still be an air lock but do the sniff test could also be head gasket leaking into a water way when it's getting hot
all the best


http://www.ebay.co.uk/itm/BT-1-COMB...007336?hash=item3f74a67ba8:g:vA8AAOSw4DJYi63f

 

[steveo3002]

wondering if i should try a rad in it

airlocks...yeah sounds possible , theres no way to tell its done right though is there? its done a good 100 miles or so over the weeks ive been messing and the level hasnt dropped