Overheating Problem

[Bludger]

I've just got back from a trip down to Somerset, and have noticed my temp guage showing the truck is running a bit hot.

I've just read the 'Revs' thread, so am happy that 3000rpm at 80mph is ok, because that was my first concern.

However, I did a run at 90mph for about 5 minutes and noticed the Temp guage go right up to just below the red. As soon as I slowed back to 75-80 the guage went back to about 1/2

Upon arriving home (120 miles later) I immediately checked the water level and saw it was almost empty even though I had filled it up just before leaving Somerset.

This morning there was a small puddle on on the ground just below the front passenger side mud guard.

Would a leak cause the temp guage to be so erratic? Can anyone shed any light on where the leak could be if it is dripping down the Front Passenger side mud guard?

Should I be checking anything else as well?

Cheers all.

[MattF]

Are the rad cap and thermostat new or the original
ones that were on the vehicle?

[Bludger]

Are the rad cap and thermostat new or the original
ones that were on the vehicle?

All original. At least I think they are. I haven't changed them, and I'm the first private owner since it came off the boat. The only other owner was the dealer, and I doubt he did anything to it.

[dirtydog]

get them changed ASAP and see if it still loses water. if so it could be the pump.

[jotto]

I've just got back from a trip down to Somerset, and have noticed my temp guage showing the truck is running a bit hot.

I've just read the 'Revs' thread, so am happy that 3000rpm at 80mph is ok, because that was my first concern.

However, I did a run at 90mph for about 5 minutes and noticed the Temp guage go right up to just below the red. As soon as I slowed back to 75-80 the guage went back to about 1/2

Upon arriving home (120 miles later) I immediately checked the water level and saw it was almost empty even though I had filled it up just before leaving Somerset.

This morning there was a small puddle on on the ground just below the front passenger side mud guard.
Would a leak cause the temp guage to be so erratic? Can anyone shed any light on where the leak could be if it is dripping down the Front Passenger side mud guard?

Should I be checking anything else as well?

Cheers all.

This could be from your air con

[Bludger]

get them changed ASAP and see if it still loses water. if so it could be the pump.

Ok, I've got hold of a new rad cap & thermostat. Just need to pick them up tonight.

Can anyone give me an idea how to change the thermostat?

[Bludger]

This could be from your air con

Definitely the water, because it had anti freeze in it, and the tank was almost empty after filling it up last night.

Do they use the same water supply?

[dirtydog]

as long as you know where it is then its easy.
not sure where they are on a 3.0 though.

should be a few bolts to undo the housing then swap them over, make sure it goes in the correct way (have a look at the one you take out).

[andycook]

when you say tank empty?

do you mean the expansion tank connection to rad?

water probably coming from overflow pipe on that

Also check water level in radiator ASAP

[Taliesins]

Definitely the water, because it had anti freeze in it, and the tank was almost empty after filling it up last night.

Do they use the same water supply?

No they dont use the same water. the water from your aircon would only be condensation.
The thermostat is found by following the bottom radiator hose to where it goes into the engine . There are 3 bolts holding the housing on and another bolt lower down to support the housing. liue under the truck after dropping the sump guard, undo the bottom hose from Radiator. (After draining the rad) undo the bolts and waggle the housing free. The new thermostat should come with a new o ring gasket replace this (by fitting it to the new thermostat) and replace ensuring the little toggle thingy on the thermostat is uppermost then reassemble. It may be worth doing a flush of the rad and heater matrix while the stat is out. Hope this helps.

[Bludger]

when you say tank empty?

do you mean the expansion tank connection to rad?

water probably coming from overflow pipe on that

Also check water level in radiator ASAP

Yeah, the plastic tank in front of the right hand side battery.

I thought it could be the overflow, but overflowing from where? I topped it right up, and then this morning it was barely half full. I wouldn't have thought the overflow pipe would drain it that much.

I'll check rad water level now and get back to you all, cause I know you are all on the edges of your seats

[Bludger]

OK the radiator level was fine. Topped it up with about 250ml, but nothing significant.

I've topped up the plastic tank with about 1.75 litres so it is to the brim. no sign of leaking yet, but I'm sure it will be there when I check again in a couple of hours.

Could it be any of the hoses? I'll change the rad cap and thermostat anyway, but is there any danger if it isn't sorted immediately? So long as the water level is kept topped up it should be fine. Shouldn't it?

Thanks for all your help so far.

[Taliesins]

OK the radiator level was fine. Topped it up with about 250ml, but nothing significant.

I've topped up the plastic tank with about 1.75 litres so it is to the brim. no sign of leaking yet, but I'm sure it will be there when I check again in a couple of hours.

Could it be any of the hoses? I'll change the rad cap and thermostat anyway, but is there any danger if it isn't sorted immediately? So long as the water level is kept topped up it should be fine. Shouldn't it?

Thanks for all your help so far.

The expansion tank should only be filled to the max mark which is around where the bottle gets thinner roughly 1/3 full. Water when it gets hot expands and goes into the expansion tank then as it cools it should suck the water back in thus keeping the Rad full all the time. So when its cool the level will be lower than when its hot. So if your filling it right up it will expand and overflow out of the tank when hot.
If your temp is fluctuating I would take care until the problem is resolved

[andycook]

and because you are filling expansion tank up - when coolant heats up and expands, its dumping out of overflow, cos you have filled up all the expansion space!

1/4 litre is still a reasonable amount of water to lose in rad - bung a new rad-cap on

[mooter]

and because you are filling expansion tank up - when coolant heats up and expands, its dumping out of overflow, cos you have filled up all the expansion space!

1/4 litre is still a reasonable amount of water to lose in rad - bung a new rad-cap on

see, that's what I thought too. I fill up the rad through the metal cap, and only leave a little bit of water sitting in the bottom of the plastic expansion tank. if that tank was full up then all it will do is overflow when the water heats up, leaving you with not enough water in there the next time! could this be the source of your problems?