Thread: D2 overheating TOTALLY FINALLY solved v8 and Tdi

Very interesting Pedro and Scott
I am thinking that once Easter comes, and it gets cooler, I will either swap to an inline 87c or may experiment with a standard system but with the 82c setup. I recall my major problem was at idle with the 93c OEM. If I can achieve your temps in the v8 Pedro, I will go back. I am also thinking that the top spring loaded restrictor which has four very small holes in it could be drilled to enlarge these without destroying the unit...just thoughts...as it was this spring at idle that was blocking circulation.

My wife used to remark ... the car seems to smell really hot... and she does a lot of the school runs etc and idles a lot in peak hour heat etc, and she does not connect the OBD on iphone. So i have an engine watchdog for her.

My temps on the weekend, idling at 755rpm for 30 minutes in the glaring sun with no breeze, and the in line stat slowly climbed up to 95c, 96c , 97c, to 100c... so there may be something else or it just needed a rev. I have a new (possibly chinese) radiator and a heavy duty howler viscous fan. It has proper fluid. A 20 second rev to 2000rpm brought them down to 94c almost instantly.

So I am open minded chaps, and I am inclined to think maybe I have other issues in the engine. It's like me... a good design but getting older...

thanks and all the best.

that makes sense to me....

the thermostat was full open. (or as open as it was going to get)

there wasnt enough airflow through the radiator to offload the heat from the coolant completely so the system found an equilbrium point where the coolant heat levels were high enough to force the offload of enough heat to balance the heat being generated.

giving it a rev upped both the airflow and the coolant flow. block temp came down, coolant temp came down and the thermostat started to regulate the flow again.


the discos engine bay doesnt exactly lend itself to efficient discharge of the air from the fan so unless your moving or have some revs on they do tend to warm up . for the V8's You also might have the mix running lean or with too much advance for idle speed settings, they dont like that much and will heat up more in idle.

Hey Dave,, would a cold air intake (from the front) make any sense, improve anything?

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Where did/do you get those vents?
Does water ingress cause a problem for the engine on the v8?
They do make sense as they allow air to escape at idle, especially when facing downwind as I was doing on Saturday when the temps climbed at idle. i am reliably informed that that vehicle has done a couple of laps! So it is proven!

i am considering an additional electric circulation pump a la BMW/VW. They are about $80, and I figure this may address the hot head issue especially after shut down, as a 5 min timer could keep the water circulating. In addition, the pump may be able to work at idle. I have read that the water continues to circulate if unimpeded as hot water rises pulling cool in but not convinced. I would also depend on the restriction of the mechanical water pump impellor. As I write this it is sounding complicated and too hard. Maybe before OBD and watchdog monitoring ignorance was bliss... except for all the blown engines...especially v8s.

Not sure Geoff. It's a vehicle sitting outside Murray's place. Give him a bell. I don't see there would be problems with those vents. Cheers

they will be right over the plenum intake,,
so rain/water will fall on the upper intake manifold

a pic of the underside would be nice,,
the bracing would decide where the vents end up.


for some reason I think over the exhaust manifolds would be the place?