Archived High Water Temps Pulling Grades while towing & warm AC at idle

[GShail]

Well I thought I had this problem worked out but now it is back, very frustrating to deal with . . here is the scoop.



A few months ago my water temp gauge started to fluctuate up and down while towing on grades (not heavy) After this happened I noticed my AC temperature was warm at idle. It would get colder when driving. There were no codes present to indicate a fan clutch failure, but I couldn't hear the fan kick in like it normally would at about 210 degrees. Temps got up to about 240 degrees.



Took it to the dealer, they did a resistance test and they replaced the fan clutch under warranty.



The problem returned about 12,000 miles later and the dealer fixed again (replaced fan clutch) even though I was just out of warranty.



These problems were prior to my recent installation of my TST.



Drove the truck another 10,000 miles and the problem returned. Took my truck this time into a dealer in Riverside , CA and they replaced the fan clutch AGAIN and they ALSO did a TSB reflash.



Drove the truck another 3,000 miles and bingo, here it is again. I'm thinking this is definitely something more than bad fan clutches. My temperatures are fluctuating again, my AC temp is warm at idle again, and I am ****** again.



Some things I tried -

1. I checked the coolant level, it is good and the coolant is new.

2. I relocated the ground wire from my TST to the inside dash panel. Tomeygun posted that this helps thew AC problem, it didn't.







TSB reflash

 

[seagrave2001]

When I was towing with my truck my temp would go above 190 (not as high as yours) but just running around town it would stay at or below 190. So one day when I got done an oil change I sprayed the intercooler, ac condenser, radiator & transmission cooler with a strong degreaser & let it set for a while. I then got out the pressure washer and started to rinse everything and you wouldn't believe the amount of dirt & grease that came out of all the fins. I was amazed. Now when towing the temp doesn't go above 190 & stays below it around town... Plus the AC Stays cold now when idling...



It may be that everything is just gritted up and the fan may be trying to pull air and after a while just hurting the fan clutch... I'm not saying this is what it is, just a guess to try to help you out.

 

[nps]

Clean your radiator.



To confirm, in the dark take a drop light and hold it on the fan side of the radiator. Look through the intercooler while moving the light and see the spots where the light is blocked.



Just because the fan side looks clean doesn't mean that air is getting through.

 

[DennyDay]

nps and engcogod are right on the money, just went through the same problem with my 01. Cleaned the radiator (a real pain) but the resultes we worth the trouble.



Denny

 

[K5IP]

Are you saying that in every fan failure case, the fan was failing to kick in?

Rog

 

[seagrave2001]

It probably was kicking in and was trying to cool, but because everything is blocked up it is probably under a lot of strain and that is causing the fan to fail fast...

 

[Elite1]

Could Very well be just a dirty radiator... check this thread out, I really got a kick out of "prodriver the expert" ... LOL

https://www.turbodieselregister.com/forums/showthread.php?t=137584

 

[GAmes]

Although it isn't likely on such a new truck have you checked the lower rad hose to see if it will collapse? If the spring is missing or corroded the suction will close the hose and inhibit water flow, thus cooling.

 

[blkdragon]

I am having the same problem with my 97 auto. Whats the best way to clean everything? What kind of degreaser? The pressure washer doesn't bend the fins? Any help will be greatly appreciated. Thanks

 

[seagrave2001]

My buddy has a detailing shop so i went down and used a degreaser like simple green & turned the pressure down some on his hot water pressure washer. I have a pressure water at my house and i can turn that down as well. . Just use common sense and don't put the njozzle right up against the fins...

 

[Alphacowboy]

if you use a pressure washer, I have always done this, and never bent a fin, holding the sprayer at ~30* in relation to the radiator, then move the sprayer in the direction of the fins, top to bottom. if you spray up close and at a 90* angle (straight at it) you bet you will bend a flin, been there, dont that.

 

[GShail]

OK, here is an update on my fan clutch/high water temp situation. I had the fan clutch replaced under warranty again by the dealer. I followed the advice of cleaning the fins on the AC, Intercooler and Radiator. There was some crud and bugs and such, but not all that bad. Additionally, I took the time to straighten any bent fins with my fin comb. I have driven around 1,000 miles since this most recent fan clutch was replaced. I had the truck put on the DRB yesterday and the new fan clutch tests out as working perfectly. AC temp at idle is quite cold. Fan Pulse Width Modulation while running was 15% at around 865 RPM. When I took the truck in to look at the initial problem, Fan Pulse Width Modulation was 99% and only 185 RPM. Tomorrow, I will put it all to the real test when I do my weekly run to California and back to Idaho. Taking a 68 Bronco, 2005 BMW 330i and 2006 Lincoln Navigator down. Bringing back a 2003 Chevy 2500, 98 Neon, and a 76 Firebird.



I hope I don't encounter any water temp problems on this trip but will post my results. Generally I am an optomist but I am betting there may be another fan clutch failure in the near future.



By the way, on a positive note my Phat Shaft 62 has around 5,000 miles on it and thus far I have been extremely pleased. My EGT's are down almost 300 degrees from before and I am able to use my TST on 6/6 for most loads. Fuel economy is up and the slight white smoke at cold start is gone altogether. It is so much easier to maintain proper RPM and I swear I shaved nearly an hour off what is normally a 10 hour trip to California.