M44 overheating

[dave45056]

I hope your problem is that easy to fix! Good suggestion Jess.
This is what the belt routing should look like:

The Orange belt is for the A/C. The other belt drives everything else.

[cooljess76]

Hmmm, after looking at that, I don't know if you can put the belt on incorrectly.

[xxxJohnBoyxxx]

Bill, I see you live in Tampabay. I'm in Gulfport, Florida. Let me know where you live and I will swing by and take a look and try to tell you what it is. I will be in tampa today so if you can reply early I can do it today before noon.

John

Cell 305 742-8559

[bazar01]

Originally Posted by Bills86e

What is still not answered, is WHEN does low speed come on?
I may have burned contacts in ECM?
One thing I have replaced but not wrote is that I bought a plug with
8" of the three wires for fan switch. The old one was heat destroyed
when 1st fan Low Speed went south.
Can you tell me when the low speed fan initiates? (it now works).

Here is what I have researched.

Looking at the X6000 connector,
Pin 57 is the ECM output to the slow speed fan relay coil.
Pin 68 is the ECM input coming from the radiator fan temp switch 80 C contacts. Rad fan temp switch has 2 sets of contacts; slow speed at 80 deg C and high speed at 88 deg C.

The ECM is waiting for a signal input from the fan temp switch 80 C contacts at the radiator. Once it sees the signal, the ECM sends an output to the slow speed relay K21 and closes a set of contacts to run the aux fan in slow speed thru the dropping resistor. So basically, the ECM has a set of electronic contacts in the circuit (switching transistors maybe) to energize the slow speed relay K21.

There is another double temp switch available that is located in the cylinder head according to Pelican parts. I am really not sure which double temp switch the diagram is talking about, whether it is the one located in the radiator of the one in the cylinder head. I will do some more researching.

[Bills86e]

Just burped, 4 oz, then drove it 5 miles with guage at 12 o'clock.
No O-H. low speed fan never came on. Belts routed right.
Will let cool down and then check burp & coolant level.
John, Thank you! I may need to come see you if after driveing
I still have O-H. Where in GP are you? I have a friend on 22 Av s.
50th st. I am in pinellas park. My friend just bought a place north of me. I think I may try adding a clutch fan, just because I'm scared.
Thanks for your interest in my problem.

[Bills86e]

Originally Posted by bazar01

Here is what I have researched.

Looking at the X6000 connector,
Pin 57 is the ECM output to the slow speed fan relay coil.
Pin 68 is the ECM input coming from the radiator fan temp switch 80 C contacts. Rad fan temp switch has 2 sets of contacts; slow speed at 80 deg C and high speed at 88 deg C.

The ECM is waiting for a signal input from the fan temp switch 80 C contacts at the radiator. Once it sees the signal, the ECM sends an output to the slow speed relay K21 and closes a set of contacts to run the aux fan in slow speed thru the dropping resistor. So basically, the ECM has a set of electronic contacts in the circuit (switching transistors maybe) to energize the slow speed relay K21.

There is another double temp switch available that is located in the cylinder head according to Pelican parts. I am really not sure which double temp switch the diagram is talking about, whether it is the one located in the radiator of the one in the cylinder head. I will do some more researching.

I saw you had posted this. Does it work?
Bizar01-----
My fan is now cycling on and off even with the A/C off.

For some reason, the DME (ECM) is preventing my fan to run with the A/C off. I accessed the slow speed relay socket through the bottom of the fuse panel in the engine compartment. I was able to pull it up by unscrewing the 4 torx head screws. I spliced a wire at terminal 85 of the relay and just run it straight to the low temp (80C) contacts of the radiator fan switch. Now the fan runs when called for and stops when no longer needed.

Please ADVISE................Bizar01............Bill

[xxxJohnBoyxxx]

Originally Posted by Bills86e

Just burped, 4 oz, then drove it 5 miles with guage at 12 o'clock.
No O-H. low speed fan never came on. Belts routed right.
Will let cool down and then check burp & coolant level.
John, Thank you! I may need to come see you if after driveing
I still have O-H. Where in GP are you? I have a friend on 22 Av s.
50th st. I am in pinellas park. My friend just bought a place north of me. I think I may try adding a clutch fan, just because I'm scared.
Thanks for your interest in my problem.

I'm at the end of 49th street on Coronado way, corner house 49th/coronado. The one will all the crap in the front yard.

I can drive my car for for hours without the fan needing to come on. It needs to idle after it's hot for at least 10 minutes before the fan turns on. I have real temp gauges so I know it's not overheating before the fans turn on.

Pinellas Park is even better for me to stop by and help. Don't do the fan find the problem...

[bazar01]

Originally Posted by xxxJohnBoyxxx

I'm at the end of 49th street on Coronado way, corner house 49th/coronado. The one will all the crap in the front yard.

I can drive my car for for hours without the fan needing to come on. It needs to idle after it's hot for at least 10 minutes before the fan turns on. I have real temp gauges so I know it's not overheating before the fans turn on.

Pinellas Park is even better for me to stop by and help. Don't do the fan find the problem...

With A/C off, while driving, the fan does not come ON. Only when idling for about 2-5 minutes in traffic, I can hear the fan come ON for 1 minute then turns off. It is loud because I don't have a slow speed on the rad fan. I by-passed the slow speed resistor because it was open preventing the fan to come ON in slow speed. I have a replacement resistor coming this weekend and I can't wait because the fan is too loud in high speed.

[bazar01]

Originally Posted by Bills86e

I saw you had posted this. Does it work?
Bizar01-----
My fan is now cycling on and off even with the A/C off.

For some reason, the DME (ECM) is preventing my fan to run with the A/C off. I accessed the slow speed relay socket through the bottom of the fuse panel in the engine compartment. I was able to pull it up by unscrewing the 4 torx head screws. I spliced a wire at terminal 85 of the relay and just run it straight to the low temp (80C) contacts of the radiator fan switch. Now the fan runs when called for and stops when no longer needed.

Please ADVISE................Bizar01............Bill

Bill, if you want, I can write a procedure how to by-pass the ECM and just run a wire from the K21 relay (first yellow relay 505) located in the fuse box to the radiator fan switch low temp (80C) contact ( blk/green wire)
It really works. I can shoot a short video and post it in youtube and you can see the fan turns ON and OFF.

[Bills86e]

Yes. I am very interested in the proceedure and the video would be priceless! Is it your low that is cycling? overnite I lost 2 oz of
coolant, or air was still in there. A couple more days will tell if I
need an exhaust gas in my coolant test. Please post soon! Thanks

[bazar01]

Originally Posted by Bills86e

Yes. I am very interested in the proceedure and the video would be priceless! Is it your low that is cycling? overnite I lost 2 oz of
coolant, or air was still in there. A couple more days will tell if I
need an exhaust gas in my coolant test. Please post soon! Thanks

I'll write it this weekend. I am tied up at work til 7PM and it gets dark quick now.

Yes it is my low that is cycling when idling for about 3-5 minutes. I can see the coolant level in the expansion tank rise before the fan kicks on and the coolant level drops slowly while the fan is running then the fan turns off, reason it's called an expansion tank. I am replacing my fan temp switch because Autozone gave me a 91C/99C which is I think for a 325 or 328 models. I am waiting for a 80C/88C fan temp switch which will lower the fan operating point.

[Bills86e]

I put this on in and it still does not cycle.
http://www.vierol-webshop.de/oesuche...=true&x=12&y=5

I read this about fan control by ECM:
electrical control unit requires a PWM (Pulse Wide Modulation) signal.

I am looking forward to your info! Bill

[bazar01]

Originally Posted by Bills86e

I put this on in and it still does not cycle.
http://www.vierol-webshop.de/oesuche...=true&x=12&y=5

I read this about fan control by ECM:
electrical control unit requires a PWM (Pulse Wide Modulation) signal.

I am looking forward to your info! Bill

That's an 80C/88C fan temp switch!
I ordered one from Pelican and should have it this weekend.

PWM is a a totally different system. The 318ti only uses an ON/OFF system on the radiator fan through a relay in series with the ECM (DME) and dual fan temp switch. So it's either ON or OFF and no PWM. Injectors do use PWM or duty cycle.

[Bills86e]

Does the engine coolant temperature sensor also come in
different temps? Being that is a dual purpose sensor, 1. to gauge.
2. to ECM. I noticed when I put in the new one it had four pins.
I don't know what the difference is between a switch & a sensor.

[xxxJohnBoyxxx]

Originally Posted by Bills86e

Does the engine coolant temperature sensor also come in
different temps? Being that is a dual purpose sensor, 1. to gauge.
2. to ECM. I noticed when I put in the new one it had four pins.
I don't know what the difference is between a switch & a sensor.

No they don't, they read temps only and send a signal to the DME and gauge. This is the sensor located on the cylinder head.

Are you still overheating? If so maybe I will come by today and try to help you out...

I need to secure a computer network in Tampa from 10-12 then I'm free. Call me if you want me to stop by. John 305 742-8559