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        General >> Problems >> Overheating/weird autobox
        
(Message started by: Alf on Jul 22^nd, 2005, 5:45am)

Title: Overheating/weird autobox
Post by Alf on Jul 22^nd, 2005, 5:45am

Hi there,

The current problem is when I'm in a very hard traffic jam (it took about 1 hour yesterday), the engine overheats (gauge in the red area, fortunately no steam coming out, yet) and the autobox starts to operate weird. It seems that it chenges between 1st and 2nd at very low speed (about 10-20 km/h), and when stopping, it can't release from gear, and when accelerating, the engine revs up, but the car doesn't accelerates as well as it should. Like it is slipping, or something. After I was out from the jam, and on the highway again, the temperature dropped to normal, and the autobox was operating normal again.

For info: the fluid level in the autobox is OK, colour is red, the engine coolant is at normal level also. The car has the additional cooler for the autobox fliud. I don't know whether the O/D OFF light blinks or not, because the bulb in the dash is out or blown (as well as the speedo control's light).

I'm sure that the box and the engine have no problems basically, because at normal operating temperature they work great. I just have to stop the overheating before anything dies.

What should I check? Any information or idea is welcome!

Thanks in advance,
Alf

Title: Re: Overheating/weird autobox
Post by Octavian_P on Jul 22^nd, 2005, 9:31am

Hi there

You haven't mention if your cooling fans function. Just select AC and they should come on ( a quick check but not a verry good one).

Title: Re: Overheating/weird autobox
Post by Alf on Jul 22^nd, 2005, 9:49am

Thanks! I'll check in 10 minutes!

Title: Re: Overheating/weird autobox
Post by Alf on Jul 22^nd, 2005, 9:54am

Yes, both fans are running if I turn on the AC! What's next? :)

Title: Re: Overheating/weird autobox
Post by Snoopy on Jul 22^nd, 2005, 10:18am

Do the fans come on with the rise in temperature?

If not then I think you have a sender/sensor problem!

Title: Re: Overheating/weird autobox
Post by Alf on Jul 22^nd, 2005, 10:20am

Good question... is there any direct relation between the dash gauge and the fan switches, or there are two sensors (one for the gauge and one for the fans) ?

Either case, when they should come on?

Title: Re: Overheating/weird autobox
Post by Octavian_P on Jul 22^nd, 2005, 12:19pm

I think the fans should come one when the temperature gauge goes over half of it's scale. You can leave the car running on iddle, and wait for it to heat up. Also try a dashbord reset (hold the tripmeter button pressed about 10 seconds - it'll beep with the key on motor position).

Title: Re: Overheating/weird autobox
Post by Alf on Jul 22^nd, 2005, 12:23pm

Understand. This will be an easy job today, it's about 33oC outside :)

What's this dashboard reset for?? Never heard about it.

I'll keep posting the results from monday (I have no connection from home :( ).

Title: Re: Overheating/weird autobox
Post by Dave on Jul 22^nd, 2005, 1:20pm

Alf,

just to confirm what Octavian_P said, on our 1996 24v the cooling fan comes on when the gauge goes just over half way.

Cheers

Title: Re: Overheating/weird autobox
Post by Octavian_P on Jul 22^nd, 2005, 2:50pm

The dashboard reset is let's say a "calibration" just to be shore that the needels go all the way up.

Title: Re: Overheating/weird autobox
Post by oz_scorpio on Jul 23^rd, 2005, 7:41pm

I had a similar over-heating problem last week with my '95 2.0 DOHC - fans not activating - I replaced the temp sender unit and cured the problem.. 8)

see "Help - Auto 4th, Faulty PCM?? Solenoid?" thread below

CS

Title: Re: Overheating/weird autobox
Post by sardine on Jul 24^th, 2005, 2:28am

Hi
(24v 1995 estate)

I have had a similar problem. Last week the top hose split on the motorway - the car quickly steamed dry and I coasted the remaining 500yds home. I replaced the hose, filled it and changed the oil having let it cool naturally overnight.

It seemed at first to run fine but it changes rather hard at 10, 20 then 30mph - I'm sure it didn't before.

It also has a rather concerning ticking audible wiht the window open at low speed - in time with the revs

What else should I do to check for damage caused by overheating - should I change gear oil, check compressions or anything else?

Thanks
Darren

Title: Re: Overheating/weird autobox
Post by Alf on Jul 25^th, 2005, 5:38am

Dave,

Thanks, it seems that the fan is coming on, but I can't tell exactly when. It's sure, that it's somewhere over half way.

Octavian_P,

Thanks, I did the 'calibration', all the gauges work fine.

oz_scorpio,

Thanks, I've already read your thread, I wish my problem would be the same!

All,

Is that possible, that a non-existing thermostat causes cooling problems? I'm not sure the car has it or not, but it takes about 20 km of driving for the engine to warm up to normal operating temperature. And when the coolant was almost boiling, it was very hard to get it cooled down with running fan(s), I had to drive almost 30 km on the highway. My idea is without thermostat it's 'too late' for the fans to cool down the system from this high temperature. Am I right or stupid? ???

One more question: if the sender unit for the fans fails, then how does it work? It switches at a wrong temperature or it doesn't switch at all?

Title: Re: Overheating/weird autobox
Post by Octavian_P on Jul 25^th, 2005, 7:35am

Well not really, the thermostat does exactly the oposite, it opens after the engine gets warm, this helps the engine to get to it's optimum temperature faster. There's another thing with thermostats, because sitting in hot watter all their life, after sometime they get cloged, stuck etc. so in your case mabe it's halfway open all the time. This would explain for late warming of engine and bad cooling effect after (low water flow).

Title: Re: Overheating/weird autobox
Post by Alf on Jul 25^th, 2005, 7:57am

Hmmm... sounds logical.... although I've never seen a halfway open thermostat, only fully open or stucked. Thanks for the tip, will check that.

Title: Re: Overheating/weird autobox
Post by Alf on Jul 27^th, 2005, 4:46am

Update: If I run the car with climate control switched off, then it's not overheating so fastly. I don't understand the problem at all. ???

I'll buy a new thermostat and a new sensor for the cooling fans.

Does anyone have a picture about where's the thermostat and the sensor on the engine??

Title: Re: Overheating/weird autobox
Post by scorpio_man on Jul 27^th, 2005, 5:57am

http://www.fordscorpio.co.uk/replacestat.htm

Title: Re: Overheating/weird autobox
Post by Alf on Jul 27^th, 2005, 6:16am

Thanks.

One more question: what is that single-wire sensor above the ECT?
http://www.fordscorpio.co.uk/24vcomponents.htm

Title: Re: Overheating/weird autobox
Post by scorpio_man on Jul 27^th, 2005, 6:55am

hi there

off the top of my head, i'd say it's the temp sensor for the dash. or it could be the pcm! (can't remember which way round!);D there's 2 sensors, 1 for the dash and 1 for the pcm. it's the pcm that controls the engine fans.

hth

Title: Re: Overheating/weird autobox
Post by Alf on Jul 27^th, 2005, 7:10am

Thanks!

The pcm's sensor is a 2 wire sensor, and the dash gauge sensor is a single wire, am I right?

Title: Re: Overheating/weird autobox
Post by Alf on Jul 28^th, 2005, 5:08am

News: I've found out what's the problem, I just don't know why does it occur.

Yesterday I've replaced the coolant in the system, so I could watch how the system operates. After the fluid change, started with totally cold engine, both the fans came on for a second, but after that one was stopped and the other was running all the time. I don't know which is the primary fan, but if I'm at the front of the engine compartment, the left fan is always running, and the other (the right one, which is a bit upper than the left) doesn't come on at all. Either if I turn on the air conditioning, it doesn't move at all. So, the temperature was rising, the gauge passed it's half way, only one fan runs. When the gauge was in the red area, still only one fan runs. ???
Then I disconnected the wires from the ECT sensor, hoping that both fans will come on, but that didn't make any difference in operation (still only one fan runs, continuously). ???

Now what? ???

Is that possible that my ECT sensor is broken? I've ordered one, I'll receive it today afternoon. But is that possible, that this is my problem? ??? If not, then what? ???

Again, summarized: only one of the two fans runs, but that runs continuously, independently of coolant temperature and A/C on or off!!!
(this behavior explains why it takes so long for my engine to get to normal temperature and the same to get cooled down - so there's no half-way open thermostat or anything else)

Any ideas, thoughts? I'm going crazy! :'( Totally fed up. :-[

Title: Re: Overheating/weird autobox
Post by scorpio_man on Jul 28^th, 2005, 8:01am

hi alf

now we're getting somewhere! BOTH fans should run! the scorpio's fans have 2 speeds, fast and slow. with the a/c on, the fans will cycle on and off with the compressor (slow speed). they only run on high speed to cool the engine temp when needed.

so, the fan problem first. broken fan, bad connection to fan, bad relay (the big green one in the engine bay), problem in fuse box, wiring. you said with the connector off the ect sensor, both fans worked for a second or two, so i'd start with 12volts from the battery straight to the 'broken' fan just to check it's ok(not part siezed). then check all fuses. then the big relay.

temp issue. still not happy with that. my 2.3 starts to heats up within 2-3 minutes, normal in 10mins max. then stays there (even with lpg). i would look to change the thermostat even if it looks ok. i had to change mine when i got the car as it ran cold. the 'stat looked fine when removed (never tested it).

try these points. we'll get to the bottom of this yet! ;)

btw, just noticed you have a 24 valver. if i remember correctly, these are bad for getting air locks in the system. try pointing the front up a steep hill, then run the car with the coolant cap off. every now and then switch between hot and cold temp settings. watch and see if any air bubbles come out.

Title: Re: Overheating/weird autobox
Post by Alf on Jul 28^th, 2005, 8:36am

hi,

just for correction: when I start the engine, at that time will both of the fans come on for some seconds. When I disconnect the ect, then nothing happens (nothing chenges in operation)!

Upon these, I think the fans are OK.
The problem could be around the fuses or the relay or the ect itself. May be. ???

This big relay sits in the fusebox (if yes, in which?), or somewhere in the engine bay?

***Update: I've found the relay behind the headlamp assembly ***

Thanks very much for the tips, I'm continuously online till this is solved!

Title: Re: Overheating/weird autobox
Post by Alf on Jul 28^th, 2005, 8:38am

One more thing, we can forget the air bubbles, I did the mentioned job yesterday.

Title: Re: Overheating/weird autobox
Post by scorpio_man on Jul 28^th, 2005, 9:49am

hi alf

have a look at this http://www.anyboard.net/autos/cars/scorpio/posts/226.html

might be of some help. sounds like ect sensor after all. when you take the lead off and turn on the ignition BOTH fan will run in fast mode (tries to move the car ;D) try that again, then put it back and do the same to the other one just to make certain we have the right one. do you have an OBD-2 lead? you can monitor the sensor using it. still can't figure out why you just one fan running, though. again check everything. also check/clean the 2 square 'box' things with all the wires going into them. they have a 10mm? nut on them. i'm running out of ideas, i'm afraid!

Title: Re: Overheating/weird autobox
Post by Alf on Jul 28^th, 2005, 11:01am

Checked the fuse and the big green relay, both is fine.

I'll check the link you posted...
For the ect, if I take the lead off, the situation is the same. :-/

I don't have an OBD lead yet.

Yes, the strangest thing of all is that only one fan runs, but that runs continuously. The other only spins up and stops when I start the engine.

2 square boxes?? what do you mean exactly?

I'll check the other leads now.

Thanks for the ideas!

Title: Re: Overheating/weird autobox
Post by scorpio_man on Jul 28^th, 2005, 1:50pm

http://img.photobucket.com/albums/v521/scorpio_man/DSCN0725.jpg

also check the big multiplug at the front of the main fusebox. you can get all sorts of problems with that.

Title: Re: Overheating/weird autobox
Post by Alf on Jul 29^th, 2005, 5:36am

Now, you won't believe this.

Yesterday evening I traced and measured all the wires regarding the fans and fans' control. Triple-checked everything, cleaned all the electrical connectors and terminals, took apart the fusebox near to the battery, checked all the multiplugs, the two 'square boxes', etc.

Here's the result at the moment: both fans are operating, but they are in high speed mode all the time. ??? ;D

Does this system acting upon sun-spot activity or alien mind control or what the +%!"!§'#&@ !! ;D

Title: Re: Overheating/weird autobox
Post by Alf on Jul 29^th, 2005, 5:48am

This is a quote from the document you linked yesterday:
'Please note in order for the slow speed to work correctly both fans need to be connected and working.
If 1 fan is disconnected then both fans will not run.
However the pcm will turn on the high speed signal on when temp reaches a higher point and the 1 remaining fan will now start spinning.'

Upon this and experiences about my situation, I think that for some reason, my pcm switches high speed signal all the time, but my second fan's leads or connections were broken, that's why only the other one worked.

If I'm right, then the next question is why the pcm switches high speed signal all the time? ECT sensor failure?

((the new ECT sensor i've ordered doesn't match to my engine, does anyone have a part number?))

Title: Re: Overheating/weird autobox
Post by scorpio_man on Jul 29^th, 2005, 7:45am

hi alf

now you have both fans working again, did you check them with the a/c on? if so, it could be an a/c issue like craig had http://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl?board=Problems;action=display;num=1120764379

even if you had the a/c on just for a few seconds, ie. the compressor has/had engaged, the fans will run in high speed mode (pressure problem) for ages after you switch it off.

give that a check and report back.

Title: Re: Overheating/weird autobox
Post by Alf on Jul 29^th, 2005, 7:47am

OK I'll check, thanks for the tip!!!

Title: Re: Overheating/weird autobox
Post by scorpio_man on Jul 29^th, 2005, 8:14am

hi alf

i've just found this.............
http://www.anyboard.net/autos/cars/scorpio/posts/311.html
http://www.anyboard.net/autos/cars/scorpio/posts/312.html

might be a bit late ;)

Title: Re: Overheating/weird autobox
Post by Alf on Jul 29^th, 2005, 8:36am

hi andrew

Yes, it's 24 hours' delay ;D ;D

Thanks anyway, you can't have enough documents for a car like a Scorp ;)

About the aircon pressure switch: is there any way to test that? I mean for example if I unplug the leads from the swich, the fans should operate in normal mode or not operate at all or something? ;D

Title: Re: Overheating/weird autobox
Post by scorpio_man on Jul 29^th, 2005, 9:07am

hi alf

better late than never! }{

if you remove the plug form the pressure switch beside the headlight, a/c will be disabled, but the fans should work as normal (ie. fast mode only for engine cooling only). might be an idea after removing the pressure switch lead to try the ect sensor again (remove lead and BOTH fans should run in fast mode). then again.... :-/

Title: Re: Overheating/weird autobox
Post by Alf on Jul 29^th, 2005, 9:23am

Andrew,

Thanks for all the information, now I have to leave :(
On the weekend I'll test the system, I'll post the results on monday!

Bye

Title: Re: Overheating/weird autobox
Post by scorpio_man on Jul 29^th, 2005, 9:27am

hi alf

good luck with it. ;)

Title: Re: Overheating/weird autobox
Post by Alf on Aug 3^rd, 2005, 4:55am

Hi Andrew,

I have a lot of questions now (again). :)

First, I disconnected the plug of the pressure switch, but the fans are running in hi-speed, so I think that my ECT sensor is dead. I measured the resistance when it's cold, it was 21k Ohms.

Questions:

1. What is the operating range of this sensor in Ohms?

2. Is that possible that if the temperature of the autobox oil is too high, then the ECU shuts down the engine?

3. In what cases the ECU prevents to start the engine? (I mean, it doesn't engage the starter motor, like when the selector of the autobox is in Drive position)

4. What does a platinum spark plug look like? Like a normal spark plug or different?

5. What is the reason for using platinum tipped spark plugs in this engine?

I forgot the other questions ;D

Title: Re: Overheating/weird autobox
Post by scorpio_man on Aug 4^th, 2005, 6:07am

hi alf

re spark plugs. this is what i use...http://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl?board=Advice;action=display;num=1111665462;start=4#4

i'll get back to you about the other questions if i can think of an answer ;)

unless someone else knows more! ;D

Title: Re: Overheating/weird autobox
Post by Alf on Aug 4^th, 2005, 7:44am

hi andrew,

Thanks for the link about the plugs, I'm just going to buy a set.

I'm waiting for your creative inspirations to come. ;D

Title: Re: Overheating/weird autobox
Post by Alf on Aug 5^th, 2005, 5:13am

Somebody (who has a good working engine cooling system) please measure the resistance of the Engine Coolant Temperature sensor!!!

(the sensor with the 2 leads going to the ECU)

Thanks in advance!