Any PSD experts out there with knowledge about the cooling fan giving problems at around 2700 rpm while carring a heavy 5er?

quote:

Originally posted by dth:
Any PSD experts out there with knowledge about the cooling fan giving problems at around 2700 rpm while carring a heavy 5er?

In addition to some advice you will get from this board, here is a good link to a PSD site. You might have to register to ask questions but it's free.
http://www.freeautoadvice.com/board/

Here are a couple more sites with forums that may be of help also.



http://www.thedieselstop.com/


http://www.ford-trucks.com/

http://fordtruckworld.tenmagazines.com/

Thanks for the freeadvice site. I read some stuff about the fan on that site. Still not sure what control sensors cause it to come on. My problem is that it oscillates up and down when I pull my 13000# 5er in 3rd at around 2700 rpm's. It also has a "chirp" sound at the low point of the oscilation. Never have a problem with it while in 4th at around 2000rpm's.
What say ye?

What year is your Ford? My '07 does something similar, and Ford can't duplicate it unless I take the trailer to them.

dth, welcome to iRV2. WHat year is your PSD. I have a 2002 F350 dually with the 4.10 axle. We pulled a 36.5' with it and the fan as a bit more noisy than the previous 1997. On the newer one, the fan seems to be kicking in and out more, but never had any tendency to overheat.

Post on the diesel stop and they can probably help. A lot of gear heads over there.

Ken

When running on flat road with 14000 trl fan quite unless over 90 deg .Then come to hill long pull whats that roar noise ,fan kicked in tnis is normal.If you dont hear it once in awile somethings wrong.Fan is a viscous coupling silicone fluid in fan hub controled by bymetal spring in front of hub.If fan not working an overheating you can rotate spring counter clockwise to ingage all time,this is hard to get at but doable.

The chirp sound might be belt slipping ck fan belt condition na tension

Talk to a Ford Dealer. There is a TSB out on the problem. Replaces the fan clutch, belt, pully, and tensioner.

I have been reading all of those sites too, and posted a few responses.

My `06 makes that "tea kettle whistling" sound only with the trailer (16K) hooked up and when the fan gets to its next to certain speed. It seems at lowers fan speed, the fan runs at variable speed. At higher speeds it appears to speed up or down in steps. When my fan gets into that higher range is when I hear the noise. It seems to happen only at the next to highest speed. The noise goes away when the fan goes to the highest or drops down one speed. From what I've been able to determine it has nothing to do with engine RPM, but rather fan RPM.

I have read many "theories" on those sites ranging from a fan issue to head gasket leaks to the overflow tank cap leaking. All are substantiated with very good backup logic. I side with the fan theory. But I am not a Ford trained mechanic.

I looked thru the TSB sites and have found nothing about this noise, neither has my dealer, so if anyone has a link to the TSB for me, or the TSB #, I would be most grateful. To date it has been in 2 times with nothing found; DUH! I don't take the trailer to the dealer.

Wow, my first question and you guys are great. I am really getting some great ideas on this problem. In case I forgot to mention it I have a 2000 F250 with a 7.3L and 3.73s.
It is the fan's rpm that varies not the engine's. Also the engine temp gauge is rock solid, never moving from the reading it usually has. It usully happens when I make it downshift into 3rd at about 60mph, which puts the tach at about 2700. I had the fan clutch replaced at the Durango, Co Ford dealer while we were out there, not as bad but problem persist. That is interesting about the TSB. They made no mention of it. I did have the main belt replaced before we left for the trip. Maybe I should check for proper tension.
I am beginning to believe it is the nature of the beast, and I just need to drive slower. On the way back to FL I kept it from downshifting until around 50mph which kept the tach at about 2300 and it never had a problem. It just seems that I should be able to do a little better than 50mph befor downshifting. I am concerned on future trips that take me over mountain passes. I expect I will have the engin reving around 2700 in 3rd for extended time to climb a hill like that.
Thanks for all the great thought!

Go over to thedieselstop.comand do a search on oscillating fan. This is a common problen and there is a TSB and a kit to fix the problem. The Ford dealer probably didn't mention the TSB if you didn't say anything about it oscillating. If you did and they didn't tell you about the TSB, then I wouldn't go to them again. When the engine gets warm enough for the fan clutch to engage, there can be issues with the belt slipping causing the oscilations. The kit replaces some pulleys and the tensioner and a new belt to resolve the problem.

Well my fan started doing the same thing while on my "Trek" in May. I changed the fan cluch on mine when I got back and the problem went away.... On our Florida trip in June everything worked as it should.

The fan clutch is easy to change too. It unscrews from the water pump. (Yep, no bolts) It actually tightens up against the water pump pulley. Fan and clutch come off as one piece then you can remove the fan from the clutch. The thing that takes the most time is removeing the fan shroud and radiator. Radiator for more working room, but I guess it could be done without taking the radiator out. I just wanted to make SURE I did not go and hit it with a wrench or someting and cause another problem.