Author Topic: ECOdiesel After run fan problem (Read 4178 times)

toddo · « **on:** August 11, 2006, 09:21:16 pm »

I have an irritating problem with my '91 ECOdiesel. Occasionally my cooling fan will stay on longer than 15 minutes after turning the car off. If I unplug the back of the fan and immediately plug it back in, it stays off. My fan switch at the bottom of the radiator is new as well as the relay that controls the high speed of the fan. My Bentley shows an after run thermo switch that supposedly is bolted to the cylinder head, but I can't find this anywhere. I'm guessing this thermo switch is bad, anyone know exactly where it's at? I have the dual fan set-up if that makes a difference. Thanks for the help.

Todd A.

jtanguay · « **Reply #1 on:** August 12, 2006, 12:01:48 am »

Well it shows that the thermoswitch turns off at 103 deg C :shock: so your car must be super super hot :lol: or there is a bad sensor (bad sensor obviously... otherwise your car would be overheated to death)

Look at this:

toddo · « **Reply #2 on:** August 12, 2006, 01:17:28 pm »

Quote from: jtanguay

Well it shows that the thermoswitch turns off at 103 deg C :shock: so your car must be super super hot :lol: or there is a bad sensor (bad sensor obviously... otherwise your car would be overheated to death)

My car tends to get pretty hot this time of the year. I live on a military base which means I'm driving only 35 mph with the a/c on most of the time. I'm in the Mojave Desert, that probably has something to do with it as well.

Back to my original question... I can't find the thermoswitch, any ideas where it's located on my 1V motor?

jtanguay · « **Reply #3 on:** August 13, 2006, 12:07:51 am »

Quote from: toddo

Quote from: jtanguay
Well it shows that the thermoswitch turns off at 103 deg C :shock: so your car must be super super hot :lol: or there is a bad sensor (bad sensor obviously... otherwise your car would be overheated to death)

My car tends to get pretty hot this time of the year. I live on a military base which means I'm driving only 35 mph with the a/c on most of the time. I'm in the Mojave Desert, that probably has something to do with it as well.

Back to my original question... I can't find the thermoswitch, any ideas where it's located on my 1V motor?

hmmm i think its on the head... but i could be wrong

if your car takes 15 minutes to cool down to below 103 deg C then I can just imagine how hot it is where you are! If you drive it hard make sure you let it idle for 30-60 secs just to let the turbo cool down so the oil doesn't coke from the excess heat.

My old 8v gas golf's fan would stay on for about 30-60 secs on a hot day. Up to 2 minutes if i drove it hard enough :twisted:

toddo · « **Reply #4 on:** August 13, 2006, 01:49:02 pm »

hmmm i think its on the head... but i could be wrong

if your car takes 15 minutes to cool down to below 103 deg C then I can just imagine how hot it is where you are! If you drive it hard make sure you let it idle for 30-60 secs just to let the turbo cool down so the oil doesn't coke from the excess heat.

My old 8v gas golf's fan would stay on for about 30-60 secs on a hot day. Up to 2 minutes if i drove it hard enough :twisted:[/quote]

According to my Bentley there is supposed to be a sensor on the head. There isn't anything that I can see. I've looked all over and traced every wire I can find, nothing grrr! I'm starting to wonder if the ECOdiesel has a different set up with the after run.

My car doesn't take 15 minutes to cool down, at the worst it only takes about 5 minutes. That's when the after run is doing what it's supposed to do. I think I'll ask some ECOdiesel owners directly to look at their motors for me to see if they have the thermoswitch on their cylinder heads.

toddo · « **Reply #5 on:** August 19, 2006, 04:47:33 pm »

A follow up to my problem - I removed the 2 relays by the brake booster, I discovered the terminals were really corroded. I cleaned them up, replaced and the cooling fan after run functions perfectly now. I'm a happy guy. Now I need to start on some performance mods...

jtanguay · « **Reply #6 on:** August 19, 2006, 07:28:43 pm »

yeah I have had to fix many many many corroded wires... After fixing it I put some anti corosion die-electric grease on the contacts, hopefully that will fix the problem for a while.

For the 1st performance increase, try using a diesel fuel lubricant/additive. Look for one that says it increases the Cetane number too. Power Service makes a really good one. It is a slight power booster, and gives better mileage, while protecting your fuel pump from wear by lubricating it.

http://www.powerservice.com/

I mainly use it in the winter time for its anti-gel, but works great in the summer too!

They also have a nice additive called diesel kleen, more suited for you since you don't have to worry about sub zero temps