overheating

[77-dogg]

hey guys

can anyone help here while im towing Its fine until I get over 70ks then she heats up and at any speed on a hill and also overheats trying to hold 110ks on the hiway up a hill any ideas.

has
new radiator
thermostat
no air locks
fans still good
no leaks have had it pressure tested


thanks

 

[Old.Tony]

The fan may still seem good, but the fluid couple could be shot. It's easy to test.

Start the car and drive it until it reaches normal operating temperature. Pull over, kill the engine, pop the bonnet and carefully try to turn fan by hand. It should be very stiff.

If it's loose, your fluid couple is shot and needs to be replaced. Same thing happened to mine.

 

[kernels]

Water pump ? Seems like the only bit you didn't replace. Make sure to test the fan first as described above by OT. Could also be a crook temp guage ?

 

[77-dogg]

would getting it to running temp then kinda being a little dodgy with the old new paper trick work??

 

[kernels]

would getting it to running temp then kinda being a little dodgy with the old new paper trick work??

You really want to avoid damaging the plastic fins on the fan, so Tony's method of stopping the car and giving it a whirl by hand is a bit safer. If you get it to the overheating point, then turn off the car and try to turn that fan by hand it should be very difficult to turn, as in almost locked to the shaft. When cold it should spin with a bit of drag, but relatively freely.

 

[77-dogg]

ok and at normal temp it should just be firm? sorry guys

 

[77-dogg]

and wouldn't it get hot in traffic?

 

[kernels]

Diesels seem to generate their heat when you are pushing the engine, so sitting mostly idling in traffic wouldn't generate that much heat.

Yup, fan should be quite stiff at normal operating them, if you shut down a normal temp engine and give the fan a spin, I would expect it to be quite stiff, I will get a video of mine for cold and normal operating temp later this afternoon, that should give you a good indication of what to expect.

 

[kernels]

OK, ignore all my previous comments, this video shows the operation of the fan at the various temperatures:

https://www.youtube.com/watch?v=xFTtoUDvj5o

Basically, when stone dead cold, the fan was a little bit stiff
- Idling for 1 minute, fan became quite loose
- Drive around until I got up to normal operating temperature - fan still quite 'loose'
- Let car idle for 5 minutes - fan still quite 'loose'

So I couldn't really get my fan to the point where it engages firmly, further research shows that the fan really only engages well over 100 deg C

 

[Old.Tony]

The fan should be fully engaged at normal temps - and the thermal fan should come on at 105C.

We towed our 1.8T caravan up to Queensland for the 2013 muster with a busted fan, so picking it is not easy. At normal temps the fan should be stiff - mine is now (a near new fluid couple).

The newspaper trick used to work when fans weren't so fragile, but there have been a couple of people post photos of their fans on this site, where cracks had begun to appear in the blade root. If the fan blade breaks while it's tractoring hard (which is when it's likely to break) it will ruin the radiator.

 

[77-dogg]

just looked at normal temp it spun freely then it sat for about 2mins and started to stiffen up sound bad I take it then thanls guys

 

[kernels]

just looked at normal temp it spun freely then it sat for about 2mins and started to stiffen up sound bad I take it then thanls guys

Did you have a look at that video I uploaded ? Sounds like yours is behaving similar to mine, which is working fine as far as I know.