Guys, always had a bit of a problem with the temperature of my el 4 litre, I've just bought a rebuilt engine and its in and running fine, Im just curious as to what the normal running temperature of these engines is.. around town it sits at 93-98deg and 89-95 on the highway. Does that sound right, as far as I can tell and I have searched high and low, that is fine and the thermostat only begins to open at 94 anyhow.

Problem is, I live up quite a steep hill and its quite a climb, also being in Central Queensland its not the kindest climate. It seems that the fans are not coming on when they should and they seem to just come on randomly when they want to, coming up the driveway yesterday, it was 105 by the time I got to the house, I left it idleing and it took 10 minutes to go from 105 - 95. The fans came on for 2 seconds and then dropped again and didnt come on at all..

The highspeed on the fans is fine, as I can pull the sensor off the thermostat and they will go into HS mode, that also would mean the relays are fine?

Then today, I went down the street and it went from cold to 112 degress before the thermo's clicked into HS and it dropped from 112 to 94 in 10 seconds, but why did it get to 112 before the fans came on..?

Has anyone else had these issues, I've a mate is a mechanic and he said it will either be the computer or the sensor, he has given me another ecu to try so I will do that this week. Can the computer send irregular signals to the fans ?? Im Stumped!

sounds like a buggered sensor, thermostat should open at 91 i think. how olds the coolant? it can also loose its heat transfur properties overtime

Its a new engine, new radiator hoses, I did a home flush of the radiator while I had it out + it is only 6 months old, new waterpump, new thermostat etc. Coolant was brand new also. I've read airlocks can cause overheating and also read there are two breathers to release air from the cooling system on the inlet manifold, cant find them though... where do I look? And if the problem were an airlock, wouldnt it overheat constantly and not just sometimes..? I also had the old boy working the top radiator hose while I filled it up, which is suppose to help.

I guess at this stage all I can do is try this other computer and see how it goes.

theres two black pipes coming out of the top tank, one goes to the radiator, the other to the thermo housing these bleed off the air your talking of. fairly uncommon for that much air to stay in an i6 motor to cause such problems

only other place air can collect is the heater box. procedure for this is to run the heater at full for a few mins, but in fairness i really doubt its airlock. my money's on the sensor (or possibly connector / wire / feedback / earth)

Definitely get yourself a 180F (82/83C) thermostat!

What kind of radiator? A genuine Ford one with a decent brass core, or a dodgy wrecker/ebay special with an aluminium core.

The brand of radiator will make all the difference.

I know guys here swear on running a lower temp thermostat, but to me thats a s**t workaround for a poor cooling system. I've towed boats with a full carload with the aircon running on 40 deg days and never had my EL go over 96deg.

Also, how is the ignition timing? Are you sure its spot on?

Its a cheap aftermarket radiator. Ignition timing feels spot on, the workshop manual says 10degrees so I just went by that.

Well your radiator will be a problem. Cooling capabilities of a cheap aftermarket radiator are pretty s**t.

If have an EL, base timing (when set in base timing mode) is 0 deg, not 10. If it set wrong (as alot of people do, speak to fiftyone ) it can make a massive difference. Power loss, meaning making the engine work harder, hence making it run hotter. It is possible if its not set right, it will be a bit retarded, which also will make it run hotter.

I also noticed you say you have a new engine. Is it brand brand new, and what water pump did you use. Aftermarket or genuine. Aftermarkets will make the engine run hotter as their pump design is s**t in comparison to genuine.

I had 5/6 deg temp spikes like you are running an aftermarket pump when my original one failed. It lasted a month before I p****d it off for a genuine.

So an aftermarket pump and radiator I can easily see giving you these temp spikes/running overly hot you are getting. The water pump and radiator are 2 things Ford did design really well.

silly question, but is the thermostat new?

edit - actually read the first post lol i thought the thermostat might not be opening correctly...
but doesnt sound like the problem.
are you getting these temps from an aftermarket gauge?
if so, what is the gauge on the dash doing?

Last edited by misk_one on Tue Jan 26, 2010 12:16 am, edited 1 time in total.

hi guys ! i want to fit a 82 deg thermo/ to my au 4ltr ! for the amatuer what is involved in this ! do you just purchase a new gasket before hand ! and do you use some type of sealant as well. im sick of paying a mechanic $75 per hr to do something i could be doing

shouldnt need any gasket goo, just get a fresh gasket and thermostat and away you go

thanks bud !

Not to be seen to take that harshly, but the timing somehow slipped. And after three attempts by two mechanics, and checking it myself, the timing was set correctly by the marks. but for whatever reason it was still out. the marks are advanced to buggery now and runs like a dream.

but yes, a bit of retardation will warm things up conciderably

regardless of why its running hot (if it is indeed a mechanical issue) the fans should be coming on much earlier than they are.

i think this is either an ECU or the temp sender issue.
nothing else should/would influence when the fans come on

while the cars running, turn the AC on. the fans should come on straight away. could be a relay maybe?