Lincoln FAIL -- turned around.

[Bill Martin]

Didn't even make it out of California. Was climbing big hill on I-15 when an alarm sounded, and I looked to find the temp gage pegged on my 2006 Dodge Cummins TD. I had climbed a couple other hills without problem, so no clue as to what could suddenly go wrong. Limped home. Runs cool flat & level, but will not climb a hill. Coolant level good. I suppose maybe a fan drive or waterpump. Dunno. My local dealer went out of business -- doesn't look good. Any ideas?

[Theo O.]

That sucks. Will you be trying again if you are able to get it fixed? Could the gauge just be acting up?

This guy had a similar issue. I think the thread conclusion is that a "engine cooling fan clutch" is bad + a coolant flush.

http://www.cumminsforum.com/forum/911-u ... -road.html

[Bill Martin]

Depends on how long it takes to fix it. Not the gauge -- I checked the rad hose with my tire pyrometer. Fan, maybe. Hard to check on a diesel because you can't trigger a test strobe. Best bet is to find someone who's "been there, done that".

Plan for the morning is to change out the fan clutch and thermostat and bleed the system. Kind of a shotgun approach for a quick fix.

[Jayson Woodruff]

thermostat

My dad's problem a long time ago with similar symtoms on a trip to Washington. Mechanic yanked it out and sent us on our way for a free and quick (temporary) fix.

I've had thermostat problems in every truck I've owned (4, not including my dad's above).

Jay W

[Steve Lepper]

Important question: did it lose any coolant?

If not, I'd vote for the fan clutch. Climbing Cajon pass with a trailer, I'd expect to hear that fan roaring like an airplane ready for takeoff. Running on flat ground, you're not going to be in the boost for long enough to build that much heat so it would run fine all day.

Second possibility is it's overfueling under boost... you don't have a chip/tuner on that, do you?

If it lost coolant, I'd look for a pressure loss/leak like a failed radiator cap or a leaking EGR cooler (although an EGR cooler will continue to lose water even if the truck is shut off, so in that case you should still have a problem on the flats.)

[Bill Martin]

1. thermostat. I doubt it because the upper radiator hose temperature matched the dash gauge. (thank you tire pyrometer) So seems the coolant was flowing. But I'm changing it out anyway just 'cause. Flushing and replacing the coolant too, for same reason.

2. fan clutch. My bet too. For some reason mine has never made much noise, so can't go by that. So I ordered one from Napa on my drive home. Got it next morning...wrong part. Napa doesn't carry. Dealer only. Feds closed our dealership (sigh), so ordered one and lost another day. Should get it today.

3. overfueling. chip/tuner? Ummm, maybe. Left to the cruise control the engine pulls too hard. I always take it off the CC when climbing hills and drive by EGT and boost gauge. And have done this for years without the current problem. I think we're looking for a change or failure and this wouldn't qualify.

4. no coolant lost.

Given the radiator and hoses were hot and full, my best guess is we weren't transferring heat at the radiator which means fan drive I suppose. I thought highway speeds provided enough air without a fan, but people tell me otherwise. We'll see.

[Will Kalman]

With the motor running and up to operating temperature, stick your finger in the fan.

If the fan stops, replace fan clutch. If the fan doesn't stop, replace finger.

Glad to help ;)

[Bill Martin]

I'm pretty sure I know what to do with that finger. Thanx Will

[Q V]

With the motor running and up to operating temperature, stick your finger in the fan.

If the fan stops, replace fan clutch. If the fan doesn't stop, replace finger.

Glad to help ;)

LOL, that's one way to find out!

Good luck, Bill!

[Arthur Grant]

Most fans I know of only free wheel at speed. Unless you have pre-electric fan vehicle which this isnt. Since your going all the way on making the fixes may I recommend water wetter. Those of us with Corvette's know about running hot, and water wetter has really helped control mine temps.

Were praying all the work fixes the problem.

[Bill Martin]

Well I'm not really working to improve the cooling. It was more than capable before this "problem". Just need to find it.

BTW, the fan clutch is weird. Like other viscous clutches it's shaft-driven. But it has an electrical connection from the computer that doesn't drive it, but somehow controls it.

They're never happy unless they can work a computer into it. ($$$)

[Fred Reed]

Check front of radiator foe debri. If the radiator is cold in front of fan the fan clutch will not engage.

[Earl Merz]

Bill, on first start up does the fan start turning? Your clutch might be similar to the air operated ones on semis. At idle they won't turn unless the coolant temp requires airflow over the radiator. The electrical connector might carry the signal that engages the clutch. Like on an AC compressor.

Just a thought. I can't help much without looking at the vehicle.

[Bill Martin]

Currently it's out of my hands. I turned it over to a big-rig shop and they're gathering up the various pieces. But I'm interested in that electrical fan control myself. I'll find out more about how that works. I saw wires sticking out of the clutch -- but the clutch spins, so how can that be? Need to get a better look.

[Bob Beamesderfer]

Feds closed our dealership (sigh), so ordered one and lost another day. Should get it today.

That probably would have failed anyway. Chrysler, er, Fiat can't supply enough cars for every dealer that was. Chrysler was already pushing every dealer to go all brands, ie, Jeep-Dodge-Chrysler long before the bankruptcy plan was hatched.

NAPA should have known it was dealer-only. Any way to go to an electric fan? That's what I did when the clutch fan failed on my Toyota truck.

[Eric Clements]

Any way to go to an electric fan? That's what I did when the clutch fan failed on my Toyota truck.

Not if you want as much airflow as the belt driven fan, unless you can find a 20hp electric fan.

At nationals I talked to a DC cooling systems engineer that previously worked on the Dodge/Cummins. We make way more power than we have cooling, and an electric fan just could not keep up.

[Marshall Grice]

Any way to go to an electric fan? That's what I did when the clutch fan failed on my Toyota truck.

Not if you want as much airflow as the belt driven fan, unless you can find a 20hp electric fan.

At nationals I talked to a DC cooling systems engineer that previously worked on the Dodge/Cummins. We make way more power than we have cooling, and an electric fan just could not keep up.

agreed! the fan on Tom's diesel could probably fly a small plane! I swear it provides thrust reverse on downgrades.

[Bill Martin]

agreed! the fan on Tom's diesel could probably fly a small plane! I swear it provides thrust reverse on downgrades.

Dunno if that's still true. My neighbors Dodge has such a fan and I can practically hear it following him up hill. But the new ones like mine are electric/viscous and while it still has viscous drive, the computer now overdrives or underdrives the fan speed based on need. I seldom heard mine, even before the recent fail. Replacing it seems to have fixed the problem, but I don't have a 110 degree day to test it on. BTW, the old viscous drive cost $60. The new one $500. And for the extra money we now get a sudden-failure mode where it used to be just a gradual thing. Bah.

[Earl Merz]

the fan on Tom's diesel could probably fly a small plane! I swear it provides thrust reverse on downgrades.

On the Freightliner I used to drive, turning on the engine fan while going down the grades added 50 braking hp to the rated 430 braking hp of the engine brake.

[Bob Beamesderfer]

Any way to go to an electric fan? That's what I did when the clutch fan failed on my Toyota truck.

Not if you want as much airflow as the belt driven fan, unless you can find a 20hp electric fan.

At nationals I talked to a DC cooling systems engineer that previously worked on the Dodge/Cummins. We make way more power than we have cooling, and an electric fan just could not keep up.

I had a feeling it was going to be an issue of capacity.

When I was at Autobytel, we tested the '08 F-250 Super Duty. To call the radiator huge would be understating it. Easily 3-feet wide--maybe more--and nearly that high.