dt 466 overheating

"tim buehler" schreef in bericht news: snipped-for-privacy@posting.google.com...

I don't know this model but in general it sounds like:

- the fan (the fan doesn't run if the engine is hot)

- the fan thermostat (the fan doesn't run if the engine is hot)

- the radiator thermostat (the radator stays cool if the engine is hot)

- the radiator is plugged (the radator stays (partly) cool if the engine is hot)

- not enough coolant (level is too low)

So drive until the enige is hot and then check wether the fan is running and what the temperature of the radiator is, and take it from there. Take care: if all's running well you may burn your hand or get caught in the spinning fan...

Blackbird

The viscous fan clutch on this engine is known for failure. I've replaced three on one truck in one years time.

If all else is working fine and checks out, this IS your problem. You should hear it engage over the engine noise.

The inconsistency with this problem is that at highway speeds the fan is usually needed far less than at lower speeds. Quite often you can run at highway speeds and no fan, and there will be no overheating until you pull off the highway and slow down.

The rush of air through the radiator should almost be enough to cool the engine, whether the fan were running or not.

Does it overheat at low speeds?

There could be several things going on here. Some possibilities: (1) obstruction of the air path through the a/c condensor/radiator (2) collapsing lower radiator hose (3) internal engine problems, blown gaskets, cracks, etc (4) water pump problems...somewhat unusual for this symptom, but not unheard of (5) maybe even a fan problem

the engine does not overheat at low speed or idle, i am having a hard time convincing the dealership that it is the fan clucth which was my original suspicion, as i no longer hear the fan kick in at highway speeds.

thanks all for your input

It *is* the fan clutch. The amount of these failing on the DT466 is nothing short of amazing. So amazing that a new part number supercedes the original. If they won't replace under warranty (and they *won't* - believe me), then spring for a new one anyway. It makes no sense to risk a breakdown, one that can start the process of liner/cylinder/piston gaulding. And get the one with the 170 degree kick in, you'll be glad you did.

Well, Tim, have you solved it? Was it the fan clutch?

Yeah Tim ; was it the fan clutch ? Thanks for the returned reply.