96 Disco (US located) overheating

My 1996 US spec Disco began to overheat. I have tested the thermostat outside of the engine and it functions as it is supposed to beginning around

88 degrees Celsius. All fuses appear to be okay. Thoughts of what else to check myself before taking it to the service center?
Reply to
C R
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Presumably you guys have higher ambient temperatures than we do at the moment. Have you checked to see if the Viscous fan is working ?

Steve

Reply to
Steve Taylor

Define 'overheating' ....

Is it just the indication on the gauge that is higher than normal? - Check radiator for external blockages or too many fins off the core, check the gauge with the sender in water of known temperature.

Do you have other signs of overheating - water being expelled, pinking....?

Reply to
Dougal

If the Landy just idles, it can idle forever with no change in the gauge. After about one to two minutes of driving, the temp gauge shoots up. Once parked after that, I do have steam coming from under the hood, but no hoses have ruptured (yet). Don't know about pinking though, is that a reference to the color of the coolant/antifreeze? I have also seen puffs of white smoke every once and a while through the rear view mirror that appear to come from the exhaust pipe. No apparent blockages or damage to the radiator. Have not yet checked the sender.

Reply to
C R

Are you losing water from the cooling system? Is it pressurising more than usual? If you (carefully) take off the radiator cap at normal temperature or when cold & run it at 1000 - 1500rpm, can you see foam/ bubbles in the coolant? *Don't try this when it's overheating, you'll get a fountain of boiling water if it's the head gasket.*

What you describe *could* be a blown head gasket or cracked head. A competent garage can check for this in a couple of minutes. Large amounts of white smoke when cold or white smoke while the engine's hot is a strong indicator of a blown head gasket, unfortunately:-(

"Pinking" is a light tapping noise, usually heard when you run the engine slowly under heavy load. It indicates either incorrect ignition timing or fuel of too low an octane rating. It can also be caused by carbon build up in the cylinders. It can cause or be caused by overheating. It also only happens on petrol engines.

Tciao for Now!

John.

Reply to
John Williamson

It's not the gauge or sender then! Regrettably it sounds more serious.

('Pinking' - pre-ignition. Don't let that worry you either.)

Can you see the source of the steam? Are you losing coolant?

Check that the coolant filler cap is in good condition and properly fitted. I don't expect you to find that wrong either. I wouldn't expect a problem here to show itself after only a very few minutes driving.

'Tis beginning to sound like a blown head gasket (especially with the white puffs from the exhaust).

Do you see bubbles in the coolant when running the engine with the coolant filler cap off? Care! - don't remove the cap when the engine is hot.

Take out the spark plugs (I'm assuming that this is a V8) are any obviously cleaner than the rest? Do any have water on them? Note which cylinder(s) are affected.

Reply to
Dougal

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