RRS 3.6 overheat

Hi,
Just wanted to get some help with an overheating problem on a 2008HST 3.6 V8. Two days ago lost power on the motorway, realised the temp gauge was off the top, never been past half before. I stopped within a mile or less,as soon as I pulled over the temp gauge went back to normal, car smoked a bit but nothing exploded in the engine bay etc. Car drove home with temp ok as long as it didn’t go over 40. Next day it started with a bit of white smoke from exhaust so I left it. Today it started ok, runs absolutely fine on idle or less than 30mph ish. As soon as you accelerate over 40 it overheats.

Head gasket sounds most likely?
Thanks,

Have you checked the coolant?

The TDV8 has a common leak point to check, the thermostat housing, it's not really apparent because of the location, the water evaporates before it hits the ground, so a visual leak may not be seen.

The EGR coolers can also leak..

The gist of it is to check the coolant

The slightly more worrysome issue is Headgaskets - This is a known issue but not too common, in your case however with it being cooked, i'd be expecting that soon.

TBF i'd get a sniff test done..

Also worth Noting another possible culpret is the Waterpump.

Coolant required 2 litres to get back to the top of the the cold level indicator.
No idea last time it was topped up or if it’s been bled properly when serviced etc.

Just can’t work out why its ok on idle (even at 3k) revs but shoots up when over 40mph?

txm0984 said:

Coolant required 2 litres to get back to the top of the the cold level indicator.
No idea last time it was topped up or if it’s been bled properly when serviced etc.

Just can’t work out why its ok on idle (even at 3k) revs but shoots up when over 40mph?

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Engine working harder and if there is a leak, as the pressure rises it will make the leak worse. With no pressure in the system an overheat is guaranteed. Pressure raises the boiling point of the coolant. Hope you are not topping up with water.

Datatek said:

Engine working harder and if there is a leak, as the pressure rises it will make the leak worse. With no pressure in the system an overheat is guaranteed. Pressure raises the boiling point of the coolant. Hope you are not topping up with water.

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No, topped up with coolant and water, 50/50.

Any ideas of approx cost to replace gasket at an independent? I know costs can rise if pistons etc are damaged

txm0984 said:

No, topped up with coolant and water, 50/50.

Any ideas of approx cost to replace gasket at an independent? I know costs can rise if pistons etc are damaged

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It's a bit premature to talk about replacing head gaskets if that's what you mean. Check for coolant leaks and a working water pump first. If the water pump impeller is plastic as is the case on some BMW engines, they can start to break up blocking waterways and reducing flow.

Datatek said:

It's a bit premature to talk about replacing head gaskets if that's what you mean. Check for coolant leaks and a working water pump first. If the water pump impeller is plastic as is the case on some BMW engines, they can start to break up blocking waterways and reducing flow.

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Not trying to be too pessimistic, I’ll make sure the garage diagnose it properly this week.

Can’t imagine the gaskets being ok as I had a puff of white smoke out of each exhaust the day after overheating. Can’t think of anything else causing the smoke but for coolant getting through the gasket

txm0984 said:

Not trying to be too pessimistic, I’ll make sure the garage diagnose it properly this week.

Can’t imagine the gaskets being ok as I had a puff of white smoke out of each exhaust the day after overheating. Can’t think of anything else causing the smoke but for coolant getting through the gasket

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White smoke could just be water vapour, most if not all cars produce a little white vapour on start up depending on the weather.

the TDV8 is a Ford Lion Unit..

The Thermostat hosuing cracking is as common as rain..



It sits just in front of the Oil filter housing, only issue is most of the ancilaries have to be stripped off to replace it..

Look in the V for any coolant puddles, also look underneath, not sure if the sport has a Belly pan, if it does check to make sure it isn't holding the coolant.

The problem with the Thermostat leak is the water evaporates in the V and a drip is never seen, just look with a torch when cool.