U900 running hot??

[_tc]

Hello, my U900 has been a great workhorse for the last nearly three years i have owned her. She has had the occasional blocked rad with woodchip so gets cleaned out as and when with and airline. She normally runs at approx 75 degs when driving and warms to about 80 when running the PTO, now however over the last few jobs i have noticed her running nearer 90 when running the PTO but normal when driving/ticking over. I can see the rad is clear and the fan is fixed so i thought the only onther options might be the thermostat or the water pump. I had the garage take the pump off( i have a 2 week old ababy and just cant find the time to do it myself) and they found the bearing a bit tigh so i decided to fit a new one and do the thermostat whilst there. They had her ticking over for and hour and all fine so i just picked her up and didnt make the 10 min drive home without having to stop to let her cool down. She went up to 90 and above but cooled a couple of degrees whilst staionary.

Does anyone have any ideas why she may be running hot? the header tank is topped up and water appears to be flowing but will have another look.

I am stuck without her so all suggestions recieved greatfully.

Ed.

[renewablejohn]

Are you losing any water on a journey.

 

Is pto and gearbox full of oil.

[Mike Hill]

Are your Hoses in good condition?

 

If they are old,they may be constricting the water flow.As the water gets hotter,they Bottom hose may become more pliable and squeeze in a bit.

 

If you've had her a while,might be an idea to replace the hoses,after you have pulled the Rad and given it a good clean out.

[geoff]

Yep,start at the rad clean & main hoses if the thermostat opens fully.

[niftysteve]

theres a large plate on the side o the engine that has water ways running through it i was told by Tim ibbbet that these sometime s get blocked and cause the engine to run hot the plate can be removed fairly easy cleaned then replaced with a new gasket

[cosworth]

does it have a viscous fan or a electric fan?does it go over 90 or just sit at 90?

[david]

are you sure it is actually running too hot?

 

is it loosing power? smell warm? etc

 

could it be an eletrical problem?

 

i take it the engine oil is fresh enough

 

 

[_tc]

Ok i had a go at running with out the thermostat in place. she went better but still got just over half way when chipping for 30 mins or so. I then decided to blow the rad clean with an airline and a suprising amount of dust/chips came out so when she cooled i put the stat back in. a few days past until i drove her again. she heated up superquick again and i had to pull in. let her cool for a few hours and took stat out again and got her back to the yard.

Bit stuck now as to which way to turn. Stat is brand new and should be fine. i dont think i can fit it wrong?

Anyway, gutted she isnt right. i have spoken to Alex price and he says he is lost for ideas. the cab hearter is blowing nice and warm and she still drives well. She hasnt had the pump turned up either so lost.

can anyone recomend where i go next?

Head gasket perhaps?

[stuartc44]

I did have a similar problem on my car, draining the coolant and flushing the radiator through both ends with a hose pipe to clean it seems to have fixed it.

 

Might be worth a try.

[Cracker]

Get it hot and then feel the top and bottom of the radiator. If you can't get your hand in there use a non contact thermometer at an angle >45.

The rad should be a uniform temperature across the whole area. Any cool areas indicate blocked cores.

 

Your problems sounds like classic blocked rad symptoms. Try back flushing with water under pressure. There's a tool we used to have in the garage that plugs into a air line and hose pipe, allows you to blast water through the rad, you could probably improvise one.