a bit of background on my car first of all. It is a 97 el fairmont ghia. It has a tiny amount of seepage coming from the passenger side of the head (cyl 3 and 6) which has not gotten worse since i bought the car about 8 months ago. Apart from that there is no water in cylinders or other signs of the head blowing.

My problem is that in the past couple of weeks i have been having cooling issues, and because of the head being ready to blow at potentially any time, i am very careful of what the temp does. My temp usually sits just on the normal line and if it goes above that, it is uncommon.

I am finding that when i put the engine under strain for a prolonged period of time (going up a long hill , sitting or driving in traffic) the temp will rise very quickly getting up to the 'M' and unless i pull over to let it chill for a bit it will continue to rise.

At this point i have noticed that the fans are not kicking into full boar mode which leads me to think that it is a fan related issue. If i cycle the aircon on and off they kick in and the temp comes down quickly.

When i have inspected the overflow tank when it is heating up like this i have seen small bubbles in it which worries me, though i am pretty sure there is only water in the system atm does this mean its boiling? If i was to flush the system and put anti corrosion/freeze would that help the situation?

Another example i can think of is when i drove over cunninghams gap in QLD recently. I had to pull pver and cycle the aircon to get the fans to kick in to get the car to cool down. About an hr later traveling on flat groun behind a truck, the car started to heat up again. As soon as i was out from behind the truck the temp came down again. Ambient temp was about 30 degrees.

I am in hobart atm so its nice and cold and im not having these probs because of ambient temp, but when i get back to qld im going to have to have problems so i need to get this sorted.

Thanks,

Louie

Sounds like your radiator is partially blocked. It doesn't take much to remove it and reverse flush it>>>>>.

louie0408, having same prob with my 95 EF Wagon.

Had radiator removed and flushed by a radiator shop and a side tank replaced. Made a fitting for my air line nozzle and garden hose, and aggresively reverse flushed the block and heater. Reverse flushed the exterior of the AC condensor, and also degreased the auto trans cooler. I am satisfied there is no impedement to natural air flow. New thermoswitch, new waterpump (it had a leak), fresh castrol coolant concentrate mixed at 33:1 with demin water. Its still getting hot up the M in NORMAL and I haven't even tried towing yet (I plan to).

I have done some tests under different scenarios after the work and used a coolant thermometer :

Test A - genuine thermostat out, tap water in system
Test B - genuine thermostat in, tap water in system
Test C - genuine thermostat in, coolant mix in system
Test D - genuine thermostat in and modified, coolant mix in system
Test E - genuine thermostat in and heavily modified, coolant mix in system
Test F - genuine thermostat in and heavily modified, coolant mix in system, AC fans engaged at max speed via override

Results

Test A - slow to warm up (expected) and ended up with a fluctuating operating temp of 80-100c
Test B - way too fast to warm up to a scalding touch, ended up with a fluctuating operating temp of 80-100c
Test C - way too fast to warm up to a scalding touch, ended up with a fluctuating operating temp of 80-93c
Test D - faster warm up time but still quick to a scalding touch, ended up with a fluctuating operating temp of 80-93c
Test E - acceptable warm up time to a hot touch, ended up with a fluctuating operating temp of 80-93c
Test F - acceptable warm up time to a hot touch, ended up with a fluctuating operating temp of 80-85c, noticable drivability improvement

Discoveries

For some reason, the vehicle does not operate well with the genuine thermostat. Under most tests except F, the final operating temp is at its hottest 93-94c.
Further observation showed that the thermofans sporadically shut down from high speed operation, and exactly at this point the temp will rise from around the 80c mark to well over 90c.

I have an EL sedan that I have been comparing this with. The EL runs far cooler with a genuine thermostat and it also has a slight leak from the head gasket just behind the waterpump and I have no idea if the cooolant is fresh. It has never been scalding to touch the components under the bonnet but the EF is.

I also engaged the EF dash diagnostics and checked the temp reading there to compare with the actual coolant temp. They were +-2c.

So I have come to the conclusion that there is a combination of issues. That being that the EF motor is getting too hot too quickly and once too hot the fans are not reliable enough to keep it cool. I am fairly confident that once the fans cycle correctly the temp will be able to stabilise around the 80-85c mark. I still suspect the head gasket is the culprit but there are no symptoms. No Co2 in the system, no visible leaks, good compression, Cat Convertor in good nick as is exhaust, timing correct etc etc. I am going to do some more tests after I am 100% sure the fans are cycling correctly and hope to nail this sucker once and for all. I want this EF to have a stable temp so I can tow a medium weight trailer without too much concern.

I know this is a silly question, but did you remember to run the cars heater for a while to get all the coolant moving and the air bubbles out etc?

The opening temp of an EF 6cyl thermostat is 91c. an operating temp of 93-94 as you mentioned is normal. Running at 80-85 will have the ECU trying to trim in some fuel, IF this makes your car run better i would suggest you have other issues that need sorting.

I would also say that at some stage some one has fitted an incorrect thermostat to your EL.

its the fluctuations that concern me, not the actual temp. even under very light loads the fluctuations are too great. something just not quite right there. yes, all air expelled...Anyway, don't wanna highjack this thread....

louie0408, let me know when u return and how it goes in the heat

interesting stuff, seems like much the same problem i am having. At this stage i am going to try a new thermostat, change coolant and flush system and see if that gives me any joy, if that doesnt work i will start looking at the fans as when they do kick in, the car cools nicely and the temp stays stable.

yes, I have done some more work and found the following

Fans work at high speed so long as I turn AC on and interior fan to full prior to start up. If I do this and keep the AC/interior fan on full the car will maintain a stable temp in between the M and A of NORMAL. Just went to Mooloolaba and back, ran like a dream, hot day too. Got back to Brisbane, switched interior fan to low, up shot the temp to O.

I replaced all the relays down the front LH corner, no effect. I also had the ECU out yesterday having a gander. circuit board looks ok. Looks like it was serviced back in 2002 by some mob.

Also had a CO2 head check done.....no CO2 present.....

I am suspecting a broken head bolt causing the gasket to lose tension once it gets hot...will remove the rocker cover soon and have a look...still doesn't explain the thermo fan operation tho

i will also pressurise the cooling system when its hot, remove the plugs and see if any water pools into the cylinders overnight

Louie, any developments?

My car did thesame thing last summer just after the head got reco'd I took it to get flushed but I think the guy didnt do it, but this summer ive moved to a built up area and I drive 2 and from work in high traffic areas with alot of stopping and starting and ive had no problem this summer

got the system flushed and put new coolant in today. Also had a CO2 test done. Result is that head has not blown but am yet to see if the flush has made a difference. If the problem persists the next step is the thermostat and fans.

i found the solution to this problem so i thought i would update it for future searches.

I had my cooling system flushed a couple of months ago and my overheating problems persisted. This whole issue was really my own stupid fault in the end.

The cooling system was full before the flush but pretty dirty and clogged, but the mechanic who did it did not top up the system properly. I only found this a couple of weeks ago when i bothered to check my coolant, and i had to add over 3 litres to it...

In addition to this, there is also a small leak at the thermostat.

In summary, the old dirty and clogged system was impairing cooling performance, hence overheating. The system flush and refill fixed this, though because it was not refilled properly, the problem persisted.

Moral of story, check your water more often, and if its dirty, get it flushed.

Not trying to sound sarcastic, but you've only found what alot of people on here preach regularly. A well maintained cooling system will look after you well, wherever you want to go in this country.

Every 12 to 18 months my cars aways get a radiator flush and new coolant... Usually a new thermostat too. This was for my previous 2 EL Ghia's and now my BF s**t. People laugh at me for it.

But in my driving history I've never had a cooling system failure. Never a popped hose, leaky radiator or an overheat. Whether it be 45 deg outside, aircon on and I'm towing my boat with 5 people in the car or 2 degrees and freezing cold with the heater blasting, my EL's consistantly ran within a 92 to 96 degree water temp range when they were fully warmed up.



I know your posts were from a few months back, but your problem may be as simple as your ECU. I remeber back on FM1 there was discussions about the original "A" revisions of the EF ECU's had piss poor fan control mappings. They would rarely run on high fan speeds and the low speed would take too long to kick in.

Apparently this was fixed in later revisions of EF ECU's. So the answer might be as simple as trying a B or C revision ECU for your car.

yep, learned that lesson. And the one to check work done on your car.