AU Overheated on cold water.

Travisty FTT · 16-02-2010, 01:54 PM

Hi, just thought I'd post a quick question. I haven't had any problems with my 98 Model AU as of recently. This morning when I jumped into the car and started it, the temp bar went straight to Overheated and the little light for it came on.

I filled it up as it was about half way, and then started the car again, but unfortunately, the light didn't go away and the bar didn't go down. I was wondering if this is just a sensor malfuntion or something as I'm unsure of what else it could be.

Also, since this happened this morning, I can't put my car into "Economy" mode. I'm not sure if this is related, but it is also concerning as these two issues came up at the same time.

Could the over heating this be related to the termostat? Should I pull it off and cut the spring blocker thingy?

Should I avoid driving my car whilst it is like this?

Thanks for any help.

mac_man_luke · 16-02-2010, 01:56 PM

If you just start it from cold and goes straight to overheating then id say your temp sensor is dead

Travisty FTT · 16-02-2010, 01:59 PM

Quote:

Originally Posted by mac_man_luke

If you just start it from cold and goes straight to overheating then id say your temp sensor is dead

Where is the sensor located? Should I avoid driving my car for the moment?

Travisty FTT · 16-02-2010, 02:20 PM

Having a closer look into what the problem could be, I just inspected my thermo fans and unfortunately, they're not running. Could this be the source of the problem? Would it automatically register as overheated if they're not running even if the car has only been on for about 30 seconds?

sd1800 · 16-02-2010, 04:25 PM

Had the car been running for 10-15min++ by the time you inspected the thermo fans? They will only turn on when the engine reaches a certain temp.

I agree it must just be the sensor or a bad earth to the dash e.g. something electrical.

Travisty FTT · 16-02-2010, 04:33 PM

Quote:

Originally Posted by sd1800

Had the car been running for 10-15min++ by the time you inspected the thermo fans? They will only turn on when the engine reaches a certain temp.

I agree it must just be the sensor or a bad earth to the dash e.g. something electrical.

I'm hoping it is just the sensor. The car had been on for about 10 minutes rougly as I took it for a drive up the road and back to see how she went. I've also checked all fuses as well as I thought that a relay might have been dead, I'm not sure how to tell if a relay is gone though, I do know the fuses are all fine.

I might try and replace the thermo fans just to be on the safe side. I'd like to get second hand ones from the wreckers, but I'll have to go and get them from supercheap and work out how to put them on if they're not AU Ford specific.

Still has me stumped though.

GK · 16-02-2010, 05:21 PM

Quote:

Originally Posted by Teknoslasher

I might try and replace the thermo fans just to be on the safe side. I'd like to get second hand ones from the wreckers, but I'll have to go and get them from supercheap and work out how to put them on if they're not AU Ford specific.
Still has me stumped though.

Relays are under the bonnet. Pull the ones associated with the cooling system and inspect, just as you would a fuse. You should be able to see easily if one's cactus. The ones you are after are R6, R7, & R13.

Make sure you do this before going to the trouble of replacing thermos. Little, easy and least expensive things first!

GK

Travisty FTT · 16-02-2010, 06:03 PM

Quote:

Originally Posted by GK

Relays are under the bonnet. Pull the ones associated with the cooling system and inspect, just as you would a fuse. You should be able to see easily if one's cactus. The ones you are after are R6, R7, & R13.

Make sure you do this before going to the trouble of replacing thermos. Little, easy and least expensive things first!

GK

I wasn't too sure how to tell if the relays are fine or not, they all look very much the same as the other relays visually.

I have attached some pictures just to make sure though.

Travisty FTT · 16-02-2010, 06:05 PM

Sorry to have them be so big, I thought it would be best that way as you can see more detail on them like this.

svo supporter · 16-02-2010, 06:21 PM

Before going to all the trouble of relays, sensors etc, just check the sender wire is actually connected to the sender unit. It is quite possible it's fallen off and touching the block.

Travisty FTT · 16-02-2010, 06:32 PM

Quote:

Originally Posted by svo supporter

Before going to all the trouble of relays, sensors etc, just check the sender wire is actually connected to the sender unit. It is quite possible it's fallen off and touching the block.

Thanks, where would I find the sender unit?

Travisty FTT · 16-02-2010, 06:44 PM

I just tried to find the sender unit, I found something on the thermostat housing thought that I thought I should also ask about.

Should this little bit look like this, or should there be something on it?

The Monty · 16-02-2010, 06:59 PM

If you idled for 10 minutes, and your thermos arent working, your problem is the thermos, just replace them. Or make sure they are plugged in. Mine werent plugged in when I bought it and the temp shot straight up within 5 minutes.

illusivedreams · 16-02-2010, 10:30 PM

Electrical,

But im not sureifearthing you would get a hih readin instantly.
Aso des the AUavecylnder eactivatio hen overheaing? Im sure it does.

So does the engine deactvate cylinders..

Agin Im sure its eithereectrical connecion of fans

svo supporter · 17-02-2010, 12:32 AM

Unfortunately, I can't remember where the sender unit is located. Hopefully another member on here will be kind enough to point it out for you.

IMA. I'm no electrical guru, but from past experiences, it's quite often the little things, like a wire off a unit, that causes problems like this.

mik · 17-02-2010, 01:37 AM

Quote:

Originally Posted by illusivedreams

Electrical,

But im not sureifearthing you would get a hih readin instantly.
Aso des the AUavecylnder eactivatio hen overheaing? Im sure it does.

So does the engine deactvate cylinders..

Agin Im sure its eithereectrical connecion of fans

yes it does have cylander deactivation on overheating.

aufairmontghia · 17-02-2010, 12:10 PM

Temperature sender is located at the back of the head on the drivers side.
It's quite visible standing from side of engine bay...

Travisty FTT · 17-02-2010, 12:42 PM

Quote:

Originally Posted by aufairmontghia

Temperature sender is located at the back of the head on the drivers side.
It's quite visible standing from side of engine bay...

Thanks for letter me know where it is located.

Sadly, the sender is still plugged in firmly.

Having excluded the relays and sender now, would this problem solely be due to the thermo fans not running?

aufairmontghia · 17-02-2010, 12:55 PM

R u blowing any fuses??? I'm talking about the ones that sit below were the relays are... I think it's Fan 1 etc...

mik · 17-02-2010, 01:08 PM

i would be grabbing a bit of wire and unplugging the thermo`s and just wireing them up straight to the battery for a test , if they don`t run i`d be looking at the fans before anything else.

aufairmontghia · 17-02-2010, 01:12 PM

As per previous post.... Check the fuses again!!!!

Don't buy thermo fans unless you have to!!!!

Check the thermo fans???

Run the thermos straight to the battery with aligator clips. one side of the plug should be for the passenger side fan, the other for the drivers side.

If they work then...

Check with a multimeter or aligator clips with a globe at the plug before the thermos. That way you can check for current when the low speed thermos r suppose to kicks in... just above operating temperature, between n/o on temperature gauge.
When the a/c is turned on, the thermos should come on straight away.

Travisty FTT · 17-02-2010, 03:07 PM

Quote:

Originally Posted by aufairmontghia

As per previous post.... Check the fuses again!!!!

Don't buy thermo fans unless you have to!!!!

Check the thermo fans???

Run the thermos straight to the battery with aligator clips. one side of the plug should be for the passenger side fan, the other for the drivers side.

If they work then...

Check with a multimeter or aligator clips with a globe at the plug before the thermos. That way you can check for current when the low speed thermos r suppose to kicks in... just above operating temperature, between n/o on temperature gauge.
When the a/c is turned on, the thermos should come on straight away.

Good and bad news. The good news; the car is running fine now. The bad news, I have no idea what the problem was/is as I didn't (even though I should've) start the car every time I did something different.

I moved the sensor around a little bit, it didn't quite "move", but I did try and push the wires in. Then I unplugged the thermo fan and grabbed some wire from an old sub and tested the fans and they both worked. Then I read your post about the fuses and decided I'd give them another go, so I replaced the Fan 1 fuse with that of the A/C fuse of the same size and after all this I started the car.

I started the car after all of this and turned the air con on straight away and the thermos kicked in straight away as well.

I'm still unable to say what the problem was and I am hoping that it won't come back. To say the least, it has left me baffled.

To be honest, I'm considering selling the old girl now an downgrading to an EF or EL Ford again so my partner will have a little money to get herself something as well. I'm not sure if its worth the sacrifice though.

Thanks everyone for the help. I appreciate it very much.

GK · 17-02-2010, 05:57 PM

Wasn't there someone on here last year who had a similar sort of issue? He found it was corrosion in the fuse/relay box under the bonnet. He got another from the wreckers or something IIRC and fixed it up nicely.

Maybe pull all the relays and fuses from the box under the bonnet and check for the greenie coloured corosion.

It may have also been fixed by some spray or another. Not sure now exactly. Sorry.

GK

mik · 17-02-2010, 06:32 PM

if it was myself rather than go backwards to an older car, and worry about it happening again because you can`t find the fault i would perhaps think about wiring the thermo`s to another thermostat independant of the ecu , mr sparky could still wire them so they come on when the ac goes on, or have an extra switch on the dash so you can turn them on at your leisure.

jeno 09 · 17-02-2010, 07:14 PM

hey bud,
i had the exact same prob with my eb, i found the prob hiding under the overflow bottle, its a brown coloured relay, my money is on that relay bro

Travisty FTT · 17-02-2010, 08:46 PM

Quote:

Originally Posted by mik

if it was myself rather than go backwards to an older car, and worry about it happening again because you can`t find the fault i would perhaps think about wiring the thermo`s to another thermostat independant of the ecu , mr sparky could still wire them so they come on when the ac goes on, or have an extra switch on the dash so you can turn them on at your leisure.

I thought about doing it so I can manually flick a switch on from my dash to activate the thermos, but my father did that and left the car running. I'm sure I could get them wired so it only comes on when the ignition is on, but unfortunately I'm relatively new to wiring.

Travisty FTT · 17-02-2010, 08:51 PM

Quote:

Originally Posted by mik

if it was myself rather than go backwards to an older car, and worry about it happening again because you can`t find the fault i would perhaps think about wiring the thermo`s to another thermostat independant of the ecu , mr sparky could still wire them so they come on when the ac goes on, or have an extra switch on the dash so you can turn them on at your leisure.

I thought about doing it so I can manually flick a switch on from my dash to activate the thermos, but my father did that and left the car running. I'm sure I could get them wired so it only comes on when the ignition is on, but unfortunately I'm relatively new to wiring.

Travisty FTT · 18-02-2010, 01:54 AM

Quote:

Originally Posted by Teknoslasher

I just tried to find the sender unit, I found something on the thermostat housing thought that I thought I should also ask about.

Should this little bit look like this, or should there be something on it?

Sorry for the double post earlier; can't work out how to delete it.

I was just wondering, what the hell is the highlighted item in this picture meant to connect to? Is there anything at all or is it just there for decoration.

Bam · 18-02-2010, 06:07 AM

It's a Temperature Vacuum Switch. I'm not sure that it's supposed to be there. Recommend that you buy a workshop manual and check.

Regarding your original problems, they very likely all stemmed from a bad temperature sensor connection. The coolant temp signal goes to the ECU which in turn controls the fans and the transmission. I think that it fails 'high' when it's an open circuit.

aufairmontghia · 18-02-2010, 08:22 AM

I had major problems with my GHIA. My temperature on the gauge went from between n/o on the gauge to almost L overnight!!!!!! And it was cooking!!!!

My previous posts are a step by step process I took.....

It gave me the SSSHHHIII..........s

I too had no low speed thermo's but working with ac on....

Passenger side thermo wouldn't work at all....

Fuses blowing.... went through about 12 fuses in the process!!!

Car would get real hot & run really badly.... Transmission would go in LIMP HOME mode.... no low speed thermo while stationary.....

This happened intermittely for about 9 months i estimate.

About 4 weeks ago I replaced the water pump, thermostat, hoses, coolant, header tank, radiator last year, header tank cap....

Everything possible bar the temp. sender which was a bastard to get to.
This still didn't help anything... I replaced the relays & fuses which were related to the thermo's....

I had just about given up till I tested the thermo's & tried a new one to isolate any problems but it still did the same thing & kept blowing fuses...

I had a gut full & felt like pushing the ghia over a cliff!!!!!!

I pulled the new thermo's out as my thermo's proved fine when tested to the battery.

I pulled the battery out & started investigating around the fuse & relay box area..... The fuse box seemed fine!!!!

I kept looking around & discovered two earth wires coming off the main loom of the fuse box & earthed to the body was loose & floating in mid air underneath the battery tray...

The bolt securing the wires in front of the battery tray had completally corroded away...

I drilled out the bolt & fitted a new one with a nut as the hole was bigger now. Secured the bolt & wires........

Car is back to normal, auto changes great, thermo running great with no overheating whatsoever or isssues......

The car is running an absolute dream......

All for a 20 cent 10mm bolt, figure that one out!!!!!!!!!!!!!!!!!!!!!!!!