AU 3 Overheating

daph2004 · 07-11-2007, 08:55 AM

OK had an overheating problem for to long and no "experts can fix it.

Spec: 2001 series 3 Fairmont I6, stock!

Replaced: Termostat (7 times (another story)
top hose, bottom hose, radiator, fans, pump, flushed system, changed temp pickup (that was a bugger to do)

Checked belt for slip, had computers reflashed to latest updateds.

Symptoms:

uphill driving 30+ seconds guage rockets into the red, climate control goes off and blows ambient air, then when coasting and the temp drops back to "nOrmal" in 25 seconds.

My next thoughts are trans issue or climate control issue

ANY thoughts?

FGII-XR6 · 07-11-2007, 09:31 AM

sounds like an electronic problem to me the changes are too extreme and quick to be real maybe something as "simple " as a bad earth

Fairlane · 07-11-2007, 10:16 AM

Water Pump?

Woops i saw that you checked pump. Got me stumped. Either electrics or some sort of blockage in the head

ronwest · 07-11-2007, 12:26 PM

Quote:

Originally Posted by daph2004

ANY thoughts?

Welcome to the forums.

As you've done, I'd be trying to exclude components.

Can you replicate the symptoms with the aircon off?

I'd also try it up a hill (or on the flat with your foot on the brake) in a lower gear at around the same rpm and see if you can get it to happen.

Don't AU's start shutting down cylinders when overheating occurs? Is that happening?

As as been said it sounds like an electrical/electronic problem (but I'm no expert).

peterban · 07-11-2007, 12:39 PM

Are the electric fans running when it starts to overheat?
If you unplug the temp sender the fans should run at full speed when you turn the ignition on regardless of temp.

Jokular · 07-11-2007, 12:53 PM

My wife had an appollo (camry) if you took it over 3000rpm it would overheat.
It was an auto.
flushed radiator (which was literally 1/2 full of gunk) changed 4 thermostats (it's said that they can come out of the box faulty). checked all pumps hoses etc.
nothing fixed it.
Anyway it ended up being the housing where the thermostat sits was too corroded to enable the thermostat to work properly.
I really hope you have some luck finding your problem because I put up with it for 9 months till i traded it in.

**Mechan1k** · 07-11-2007, 02:45 PM

Woo hoo ... I had this issue for the entire Summer last year ... it was hell.

Like you I replaced literally everything I could think of.

It came down to me pushing it too hard for work ... or so i thought.

In the end ... I put a twin core radiator in ... and did a relay mod so when i turn A/C on .. the thermos come on highspeed immediately.

Never had an issue since then ... well ... just need to wait till the really hot weather again and then test it.

I like you was seeing the temp spike on inclines with A/C on when unloaded ... back-off ... and it went straight back to normal. I even tested this on a dyno ... to really get the temps up ... and measured everything with an infra-red thermometer ... and the only thing that was getting hot was the Cylinder Head temp sensor in the back of the head on the driver's side ... also the surrounding area.

I replaced the CHT sensor ... and still had the same issue.

Had all my earthing checked out by my auto electrician ... nothing wrong there.

And I am running an external transmission cooler as well (I even removed it to see if that was the cause .. no difference).

daph2004 · 07-11-2007, 04:23 PM

Ok anyone know an "expert" who can diagnose the problem. To many dealers diagnose the problem with "we replaced this and it helped some and the bill is$"
I want a true mechanic who find problems not guesses

InfernoSR · 07-11-2007, 09:03 PM

Quote:

Originally Posted by daph2004

Ok anyone know an "expert" who can diagnose the problem. To many dealers diagnose the problem with "we replaced this and it helped some and the bill is$"
I want a true mechanic who find problems not guesses

Mate... i am actually a Specialist... dont bother with Mechanics... to many think they know everything there is to know about anything... if that was the case... why is there specialists in different fields like me.

First things first... can you give me more information about the radiator type? I need to know where you got it from to begin with, then we need to figure the type you have...

2nd thing nearly every AU has from factory is lack of air flow. We have been told to simply bend down the top tab of the Aircon core to allow some more air into the radiator.

Night · 07-11-2007, 09:11 PM

Just a wild stab at this but could it be related to a head issue, like head gasket or cracked head.

daph2004 · 08-11-2007, 09:03 AM

OK it is an AU series 3 Fairmont

Was over heating with the standard factory fitted Rad, was then replaced with a newly manufactured aftermarket aluminium unit.

The aircon condensor seems clean and clear of debris. I did have thoughts of airflow and saw considerable space air could route around the lhs of the rads.

Still scratching my head.

The Monty · 08-11-2007, 02:19 PM

Id be inclined to say its maybe electrical as well, it seems to go up very fast, and if its back to normal in 25secs, then it cant be much else.
When our old 4wd used to overheat, it would take half hour plus before you could drive it again.

AU2PWR · 08-11-2007, 02:24 PM

did you get it checked mate ?

InfernoSR · 08-11-2007, 06:37 PM

I highly think it is the Radiator TYPE. Factory are crap to start with... and there are a heap of aftermarket crap ones out there too... Aluminum should be avoided by the average user, as they cannot be repaired as successfully as copper/brass.

Do you have more information as to where you got it, and what brand/details you can give me. I'd like to rule it out if i believe it is sufficient.

daph2004 · 12-11-2007, 10:53 AM

I purchased on ebay and it is a SSS brand. Core was same thickness and looked same as original.

What I cant figure is the fact my AU is different to all the others and the dealer didnt know the problem. If it was as common as a crap radiator then it would be a known problem and it would be a general accepted path to fit a thick copper unit or sponge fill all external gaps surrounding rad.

Where to from here?

InfernoSR · 12-11-2007, 09:42 PM

Would you by any chance be able to get me a link to the same sort of radiator by the same company? I'd like to study the type and let you know the comparison against a known well performing radiator from a leading brand.

You also need to increase the air, not decrease the air.

AUXRVIII · 13-11-2007, 08:18 PM

Get your hands on a temp probe and measure the temp of the coolant coming out of the top radiator hose, the temp measurement on AU 6 cyl engines come from cyl head temp NOT the coolant temp. It may be possible the fault is in the PCM or CHT sensor.

mik · 13-11-2007, 08:53 PM

sounds like something is still amiss, i towed a van melb to brissy around the burbs up to noosa then back to melb some days 40c...... tempreture did not move from normal, cylander head cracks perhaps/gasget? if its been cooked already and you replaced everything else thats where i would be looking.

OzJavelin · 14-11-2007, 07:50 AM

Quote:

Originally Posted by BLUEPRINT

2nd thing nearly every AU has from factory is lack of air flow. We have been told to simply bend down the top tab of the Aircon core to allow some more air into the radiator.

I actually thought they were pretty good? At least they allow airflow thru the grille and under-bumper ..
My wife uses my AU V8 ute to tow a double horsefloat (2300kg hitch and loadleveler). She'll tow for many hours in the middle of a 40C day with A/C flat chat and temp never goes above normal. Only issue I've ever had was split header tank (and it still didn't overheat).
Good luck with the diagnosis. Hopefully you'll get it sorted soon 'cos it's probably going to be a stinker of a summer :(

InfernoSR · 14-11-2007, 09:57 PM

Quote:

Originally Posted by OzJavelin

I actually thought they were pretty good? At least they allow airflow thru the grille and under-bumper ..

It depeneds on the radiator too... if its built right, then the slight less airflow wont affect it...

Night · 14-11-2007, 10:10 PM

I still rekon to check your head, if it's a lack of air flow then it should have been overheating from new. Also if it you have to get more air into it to keep it cool then there has to be a fault somewhere else and all your doing is masking it with by forcing more air to keep it cool.

InfernoSR · 15-11-2007, 09:04 PM

Quote:

Originally Posted by Night

I still rekon to check your head, if it's a lack of air flow then it should have been overheating from new. Also if it you have to get more air into it to keep it cool then there has to be a fault somewhere else and all your doing is masking it with by forcing more air to keep it cool.

The information i supplied came from Tech bulletins direct from Ford to the dealers for repairs from new... it was a fault from factory that most were repaired in their warranty period...

That being said, i agree that it doesn't make sense as to why some are affected at a later date... the theory around the traps is another fault with minimal casting sand and an electrical fault somewhere... as i said, its only some theories :dr_Evil:

AUXRVIII · 16-11-2007, 10:43 PM

Quote:

Originally Posted by BLUEPRINT

2nd thing nearly every AU has from factory is lack of air flow. We have been told to simply bend down the top tab of the Aircon core to allow some more air into the radiator.

This issue was to reduce thermal shock to the radiator, had nothing to do with cooling/overheating issues. Bending down the top of the A/C condenser is a BS fix anyway, the second lip on the condenser sticking up wasn't touched, so no increase in airflow through the radiator occured.

InfernoSR · 17-11-2007, 01:09 AM

Quote:

Originally Posted by AUXRVIII

This issue was to reduce thermal shock to the radiator, had nothing to do with cooling/overheating issues. Bending down the top of the A/C condenser is a BS fix anyway, the second lip on the condenser sticking up wasn't touched, so no increase in airflow through the radiator occured.

Thermal shock is a cooling/overheating issue... its a rapid fluctuation in temperatures whilst under certain loads and conditions.

I also agree, the top tab being bent down was not a good solution at all. Aftermarket cores are by far superior compared to the factory.

Night · 17-11-2007, 10:12 PM

[QUOTE=BLUEPRINT]The information i supplied came from Tech bulletins direct from Ford to the dealers for repairs from new... it was a fault from factory that most were repaired in their warranty period...

If this car has done around 100,000 klms (I'm just guessing) and then started overheating then it doesn't look like it is a problem that came from the factory, thats why I say it looks like there's something else at fault here. I agree that there could be a design fault that makes an AU overheat but like I said if it has gone for say 6 years or longer without overheating, then something has gone a miss and getting more air into it to cool it down will just be a band aid solution. Who knows it might just get worse and worse until the extra airflow doesn't help anymore, but getting more airflow to the radiator is always a good thing whether it's overheating or not.

AUXRVIII · 18-11-2007, 01:53 PM

Quote:

Originally Posted by BLUEPRINT

Thermal shock is a cooling/overheating issue... its a rapid fluctuation in temperatures whilst under certain loads and conditions.

I also agree, the top tab being bent down was not a good solution at all. Aftermarket cores are by far superior compared to the factory.

The mod was to reduce the occurance of the radiators leaking caused by thermal shock when the thermostat opens, not to prevent overheating of the engine.

Brainspace · 14-05-2008, 08:32 PM

I feel for you!
I have a very similar problem, My car is an AU 1 that has done 160K
When everthing is OK the Temp gauge should sit before the N of
-- l l lNormal<> --
Mine is now sitting at the N to O and the motor feels like its missing until I get a clear run and it drops back to the N.
It is especially bad when I drive for 15 minutes then run into the shops as when I restart is misfires due to overheat
Nobody has been able to tell why?
Gas or petrol it makes no differance! When its cool it has all the power in the world !
otside air temp makes no differance!
It did once shoot up to nealy over heating Very fast but is back to heating up very quick and staying to warm.
I have replaced all 3 fan relays flushed the system 4 times
Even had the hose running in on idle & it still got to the high side of the N ????
Everything is Stock! Computer has been checked !
If it was a head gasket it wouldnt run so well when its cold! -- Would it?

Anyone Please....

Muzza · 14-05-2008, 10:09 PM

The Temp Gauge display is not directly connected to the Engine Coolant sender.
The Engine Coolant sender is actually connected to the ECU.
The ECU then sends data to the Cluster via a data link.
The Cluster processor then derives the reading from the data supplied by the ECU and drives the needle on the gauge.
This is same arrangement as in EF, EL and AU.

If the guage is showing spurious temperature readings, but the engine is not affected then the problem is either Eng Temp Sender, ECU, Cluster or wiring (not in any particular order).

If the engine is affected in conjunction with a higher gauge reading then it would be either of the Eng Temp Sender, ECU or wiring or could be an engine problem.

To provide a pointer as to what it could be -- wire a multimeter across the two wires going to the sender. Extend the wires into the cab so one can watch the volts readings.
I do not know what the actual volts will be (will be in the 0 to 5v range) but a bit of watching will identify the values to be expected:-
1. If the gauge goes up and the volts are steady, then no engine fault but the fault is in the ECU/Cluster/wiring.
2. If the gauge goes up and the volts also change accordingly then the engine temp is the problem.
3. If the volts fluctuate or don't track in a linear fashion the it could be wiring or faulty Temp sender.

I'd try the multimeter first to help point to the culprit (a needle type would be better in this case than a digital... but digital would do).
BTW, if this was an EF I'd immediately suspect the ECU...those are flakey and why Ford went back to EECIV for the EL.