Cooling system

[gimposarillios]

Iv had a bit of an issue arise yesterday. When I first start my disco 1 3.5 v8 it seems as if all the coolant seems to pump itself into the reservoir and doesn't seem to go down into the radiator.

While driving down the freeway I noticed the temp sky rocket so I pulled over and turned it off. I opened the lid on the reservoir which released the pressure build up. Still plenty of coolant. The cooling system then went back to normal and the temp gauge was back to its usual middle of the dial position. Continued driving to get it home and all seems fine.

Iv since tried it a couple of times with the same result.

I was thinking a blockage somewhere or perhaps some sort of air inlet for the system being blocked. I just got it back from a service as well as it just back on the road after a month and a half not moving.

Any help would be great as iv got no idea and am not anywhere near as mechanically minded as most of you.

Thanks
Ryan

[gimposarillios]

Iv now started it with the cap off popped it back on. Still same issue. Iv got no clue.

[wrinklearthur]

Hi Ryan

I'm defiantly a unexpert on V8's, but I wonder if a radiator hose has collapsed internally.
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[Rick Fischer]

Possibly/probably, you have popped a head gasket and the engine is pumping air into the cooling system, or possibly a cracked head :(

Steam on start up?

Making engine oil?

Engine not still at idle? V8s normally idle so smooth :)

At idle place your hand over the exhaust and count the exhaust beat, check if there is one missing altogether or intermittently, also feel for excess moisture.

Cheers

RF

[gimposarillios]

All the hoses seem intact. As for the head. Hmmmmm I'm quite hoping its not. Oil is almost 150 km old and has been in the car less then a week. Looks like new oil not milky. Running like a heap of u know what but that's standard. As for moisture in the exhaust I couldn't notice any but with a white rag I did see small black specs whilst it was war warming up. Couldn't tell what it was but it cleared up when it warmed up. No steam.

[wrinklearthur]

All the hoses seem intact.

They can delaminate on the inside, slip them off and have a prod around inside them.
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[DeeJay]

Odds on bet it is the Viscous fan not working properly..

[Baggy]

Hi Ryan

Not sure what the reservoir on early Disco's are like but on my 96 V8i disco has similar problem and it turned out to be a faulty cap on reservoir.

That was after I spent 2,500.00c at local mechanic who when he pull off heads found that nothing was wrong with the head gaskets although it would exhibited all the signs of the head gasket problem intermittently:(

Mine was the white plastic type with black cap and I started to carry an extra ones as spares as they do fail.

Cheers

Baggy

[wrinklearthur]

Not sure what the reservoir on early Disco's are like but on my 96 V8i disco has similar problem and it turned out to be a faulty cap on reservoir.

That would do it, there is a valve in the cap that lets air back in as the system cools, If it is blocked or stuck the level would stay up in the expansion tank and air would be drawn into the engine somewhere else, possibly past the water pump seal.

Grab a new cap, lot cheaper than head gaskets to try first.


Iv now started it with the cap off popped it back on. Still same issue. Iv got no clue.

Just read this again, that does rule out the cap.
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[wrinklearthur]

Have you had the radiator cleaned out by rodding lately?
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[gimposarillios]

Poor form by me not updating on the solution.

Thermostat was stuffed. New thermo and good as gold.

Thanks for the input.