Not again.

Hello,

I had a few problems with my p38 overheating in the past as some of you may know, so in the beginning of may i replaced the water pump, viscous fan and radiator, blead the system and all was fine until today.

I started the car and someone came over for a chat about 40 minutes later i drive off, half a mile up the road the car overheated.
Does anybody know:
WHY
WHY
WHY?

It's been running fine til today, the car should be able to idle for 40 mins surely.

Lucky for me there was garage with free water just up the road.

Why? simple it's a V8 by LR.

I don't think they like to stand ticking over for long periods of time.

I don't think the like running for any length of time

Where did you get the viscous fan unit from??

Also have you tried the 'Newspaper' test - get the engine up to temp, and offer to the fan a tightly rolled up newspaper - the result should be a mashed newspaper, you shouldn't be able to stop the fan with it.

THE BUDDAH said:

Hello,

I had a few problems with my p38 overheating in the past as some of you may know, so in the beginning of may i replaced the water pump, viscous fan and radiator, blead the system and all was fine until today.

I started the car and someone came over for a chat about 40 minutes later i drive off, half a mile up the road the car overheated.
Does anybody know:
WHY
WHY
WHY?


It's been running fine til today, the car should be able to idle for 40 mins surely.

Lucky for me there was garage with free water just up the road.

Click to expand...

If you have replaced pretty much all of the cooling system, then unfortunately it's beginning to look like HGF or a slipped liner is the most likely cause of your over heating.

What was the indication of overheating? Just a temp gauge went to red or something else?

Seems everybody new you had a v8 , well you said lucky the garage had water free...... So have you a leak? The question is how much water did you put in. A overheat won't always lose water.

With it being a v8 and worked on before you probably keep a close eye on the coolant level!

If you can feel air and pressure in the top hose then its most likely head gasket or block gone, air stays there and bubbles back to the expansion tank causing the coolant level to vary. Booting it can cause the relief cap to lift, look underneath it for wet patch.

If overheated first then blew the water out then then you are back to your cooling components again, thermostat, fan, rad and pump.

Hard to diagnose if you havent experienced it. Get a garage to test for combustion gas in the coolant.

Do my aircon fans mod for extra cooling.

Hello Guys,

Thank you for responding, quite an event getting home from work this morning.
The viscous fan, water pump,radiator and thermostat were all purchased from island 4x4 usually a good source for parts.

No...no...no....lol....for a start its a 2.5tdi, the fan conversion has been done, it works manual or auto...
Got to the garage just, overheated, loss of power steam and water boiling over SO:

I took the small hose off (The one that sends water from the top of the radiator on the left hand side to the expansion tank) while the car was hot and I put a hose into the expansion tank to fed it a new supply of water while the car was running.
Air did come out of the nipple on the radiator, i kept the car running until the water fed through then replaced the hose.
This is how I filled with water originally.
The thermostat has a 8mm hole drilled in it and the hole is at 12:00 'o' clock, The thermostat was also tested in a pot with boiling water FOUR times and it worked every time prior to fitting.

There is no gunk around the oil cap or in the oil.

This is a complete mystery to me, what else can i do?

Why would the car overheat after all the work that,s been done to it?

Any sensible ideas?

Cheers.

Rather than filling the system via the expansion tank, is there a cap on top of the radiator? either one you can remove by hand or using a screwdriver/spanner?

martin1512 said:

Rather than filling the system via the expansion tank, is there a cap on top of the radiator? either one you can remove by hand or using a screwdriver/spanner?

Click to expand...

No afraid not, the only way to fill the rad and bypass the thermostat is to disconnect one of the pipes and that still gives you air in the system.

THE BUDDAH said:

No afraid not, the only way to fill the rad and bypass the thermostat is to disconnect one of the pipes and that still gives you air in the system.

Click to expand...

Have you checked the heater temp to see if it gets hot while the engine is running? It is possible that there is an air lock in the heater pipes or matrix.

martin1512 said:

Have you checked the heater temp to see if it gets hot while the engine is running? It is possible that there is an air lock in the heater pipes or matrix.

Click to expand...

The heater does not work properly as it only comes out cold on passenger side no matter what setting it is on, drivers side works fine.

Book does come up on the control unit, air con has been gassed.

Cheers.

THE BUDDAH said:

The heater does not work properly as it only comes out cold on passenger side no matter what setting it is on, drivers side works fine.

Book does come up on the control unit, air con has been gassed.

Cheers.

Click to expand...

That could be your blend motor then.

Did you change the header tank cap, could be pressurising and not opening?

The heater is irrelevant unless it's airlocked. As it's a diesel it should idle forever without overheating especially if you have the aircon fans mod.
The usual culprits are the viscous fan, forget that if the aircon fans mod is working, water pump shedding impeller blades, stat sticking, rad silted up, or possibly a duff expansion tank cap.
If all those have been covered, you are looking at a cracked head or HGF

Datatek said:

The heater is irrelevant unless it's airlocked. As it's a diesel it should idle forever without overheating especially if you have the aircon fans mod.
The usual culprits are the viscous fan, forget that if the aircon fans mod is working, water pump shedding impeller blades, stat sticking, rad silted up.
If all those have been covered, you are looking at a cracked head or HGF

Click to expand...

Or a leak.

defender300td1 said:

Or a leak.

Click to expand...

That ought to be obvious if it's boiling