hills hills hills!

[Amedias]

afternoon ladies and gents, just a quickie. . .

been out and about today, took my housemates up and across dartmoor, didnt stray offroad at all and wasnt pushing it but there were some quite steep and lengthy hills, i had to stop and pull over 3 times cos the temp gauge started to climb, ive already had a new head and rad on the machine so now i watch the temp like a hawk so i pulled up as soonas i saw it rising.
After a few mins it went back to normal and we carried on but like i said it happened a few times and the last time the AT temp oil warning light came on as well!

do you think this is all just because of the hills or indicative of other problems that may need sorting?

thanks!
Matt
2.4 TD k reg.

[Rob]

Shouldn't get that hot, IMO.
Obvious things first...
Check coolant levels when cold. Rad should be filled to the brim and expansion bottle should be at Full.
Make sure the outside (cooling fins) of the rad is clean. It can be hard to tell sometimes unless you take it out.
Are you using coolant (antifreeze and water mix) or just plain water? Should be coolant obviously but probably won't make a big difference in this case.

Other things to check/fix/replace etc:
radiator cap
thermostat
viscous coupling for the main fan
I'd also be temped to take the radiator to a specialist for inspection / testing / flushing.
I'd also check your automatic transmission fluid - the condition of it and the level.
Hope this helps. There's a thread somewhere with details of testing the fan somewhere, might want to see of you can find it.
Cheers
Rob

[sparkyaj]

Surfing uphill

Hi, we live in newton abbot, pop out to dartmoor all the time.

Our surf seems to get the fan on by time we hit the top of a hill.... but within a min or two it's off again.

My temp guage seems to hit the middle and stay their all the time.

even when the fan kicks in.........

They are very nasty hills and bends out their and bare in mind you are shifting a 2 tonne hunk around.

might meet up some day

good luck

[Amedias]

thanks for the replies so far guys! the rad is new about 3 months ago so should be ok, a bit muddy but nothing much really.

Just been outside to have a peek now its had a few hours to cool, found the top hose from the rad was 'sucked' in like it had a vacuum in it. Popped the rad cap and it went 'woosh' and filled out again. coolant was a bit low so topped up and made sure the expansion pbottle had water init up to the mark on the side but no higher.

ran the engine with the rad cap off and all seemed ok, didnt spew loads out or anything.

checked ATF BTW and all fine.

does this sound like it may be thermostat/rad cap issue? i assume when it got hot the rad cap opened up, water goes to expansion bottle and then when it cools it 'should' suck water back in but clearly this didnt happen as the hose was squashed so there was obviously a lack of water in the system. . .or is it likly to be somehting else?

thanks! and im in a red K reg with rear mounted spare and white 8spokes if you see me! no side steps or mud flaps!

matt

[Chillitt]

could the pipe to the overflow be blocked if the system isnt drawing anything back in when it cools?

[Amedias]

definately not blocked cos if you fill it up at the rad cap and the squeeze the top pipe with the tube to the expansion bottle hanging out over the front grille it trickles out so i don think thats the problem. . .

thanks, keep em coming!

[Rob]

yeah, change the rad cap, see how it goes. As you said, it should allow coolant to be sucked back into the rad when cooling down. Glad it doesn't sound major!


Oh and make sure you clean the rad out really well if its muddy. I thought I always did mine well until i started over heating. Took the rad out and found it to be about 65% blocked with mud. Took me an hour sitting down with a beer pointing a hosepipe at the rad until all was gone.

[Silversurfer]

Hot Surf

definately not blocked cos if you fill it up at the rad cap and the squeeze the top pipe with the tube to the expansion bottle hanging out over the front grille it trickles out so i don think thats the problem. . .

thanks, keep em coming!

Could be a number of things - best to check each in turn.

Rad Cap - If the rad cap doesn't seal properly then as the temp rises the coolant expands and is just blown straight out. There has to be some pressure to raise the boiling point of the coolant. If the rad cap is sticking then the system will go over pressure and eventually blow the coolant out when the rad cap does release, ( or blow it out somewhere else ie. via the hoses etc). That may be the cause of the hose being sucked in as when the coolant does cool back down instead of being able to draw back in from the expansion bottle it will cause a vacum. Definately worth investing in a new rad cap.

Thermostat - If the thermostat is knackered and doesn't open then the coolant flow is obviously restricted and overheating will occur - as the water pump is still pumping away it will cause some excess pressure.

Air Lock - An air lock can cause problems as air can be compressed whereas a liquid can't. The air lock will compress to a point and then blow back once the rad cap lifts. How long ago was your head changed ? - has the temp been OK since then - does both front and back heaters get hot OK ? There is a good FAQ on "Burping the Cooling System" on the Forum that is worth a look at.

Water Pump - Is the water pump OK - is it noisy ? - if the impeller is slipping then the coolant isn't being pumped around quick enough. Check the fan belts are OK - if they are slipping then neither the fan or the water pump will be doing their job properly.

AT - The oil cooler for the AT is part of the coolant radiator so if the radiator is overheating then it will affect the AT temp.

I know the above sounds a bit horrific but the problem is probably just one of the above.

There is an on-line workshop engine manual at the below URL. It's for the 1KZTE 3lt (I know yours is a 2.4) but the info is good on testing the cooling system components

http://www.showmesome.info/hilux/info/manuals/1KZ-TE/

[Koi]

Would check small hose from rad cap to expansion bottle, everything else may be fine butif this hose is perforated it will allow coolant out and as the engine cools it will just suck air back in, goes for the tube in the expansion tank its self, is it the end of it actually submersed in the coolant.

[RMS_CLK]

Drove down to Dublin yesterday with a car on a trailer, every hill was a nightmare. Even hills that dont look like hills on the motorway. Temp was in the red for half the journey. On the way back with no trailer i was flat out. Temp went off the scale an the engine cooked. Stuck in the middle of the republic with a big useless 2 tonne turd. No water with me so had to wait 2 hours on the AA coming with water. Topped her up, took it a bit easier on the way home and no problems. I think its to do with having a water-cooled turbo. If held on boost for too long, it heats the water.