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Advice on overheating V8 please


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Hi guys. I hope someone can give me a bit of advice on an issue

I am about to purchase an overheating X reg P38 4.0. I had a quick nose here and the radiator is hot at top cold at bottom. Removed thermostat and jammed open bottom hose now getting warm but not as hot as I would like to see.

Checked circulation to heaters and no problems there. Heater is working fine.

So I thought possible rad blockage.... until I took off header tank cap after about 15 mins running and now have facial burns as the thing decided to blow all its coolant in my face.

Dumb move I know but I didnt expect that much pressure. After recovering cap from nearby hedges I thought I'd have another go so with cold wet rag over my face filled her back up with water, fired it up and off she went.

There is no miisfire when it starts from hot or cold. The oil level is spot on and clean. Theres no oil I can detect in the water, no steam from the exhaust when starting, runs fine when cold but pressure builds high when warm.

I havent removed plugs yet as I retreated to home shortly after.

Any advice on this subject would be much appreciated.

Thanks guys.


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Is it very, very cheap? If not, walk away and find one that's in good order - there are plenty more P38s out there.

High coolant pressure (are the coolant pipes rock hard when it's up to temperature?) could well mean a head gasket is gone (no big deal if you're a competent DIY mechanic, fair bit of labour if you're paying a garage), but I don't know if what you describe would be more than normal pressure. I've never used one, but I think you can get something for testing the coolant for the presence of exhaust gases - also trying taking the coolant header tank cap off (from cold this time :P ) and starting it - watch the coolant to see if bubbles are appearing in it.

When working out whether it's worth the risk, bear in mind that even if the owner is completely honest about all the faults they are aware of, you could fix them to find they've been masking other faults. Been there with a Focus that I thought would be a nice easy fix... :(

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My CSK and my3.9 Vogue had an overheating problems. This turned out to be the cylinder liners dropping which unfortunately a common problem. If you are a competent mechanic as Geoff says it is not a problem. I used ceramic block sealer which cured the CSK but never got round to the Vogue.

If you buy the car be prepared for the cost of a new engine block and figure that into the cost of the vehicle that way you should be OK as long as you take on board any other faults the car may have.

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So I thought possible rad blockage.... until I took off header tank cap after about 15 mins running and now have facial burns as the thing decided to blow all its coolant in my face.

This is normal, isn't it? :blink:

Every car I've ever had has always squirted hot coolant if you are

silly enough to remove the cap when it's hot, with the engine running.

Maybe there are varying degrees of squirting. :lol:

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Could be a number of things including:

Blocked radiator.

Defective thermostat.

Defective water pump, the impeller could be loose on the shaft.

Cracks in the water galleries of the heads or inlet manifold.

Head gaskets.

The big worry is that it could the displaced liner problem & if that is the case then its new block time.

If water is going into a cylinder the plug for that cylinder will look abnormally clean compared to the others.

Are you losing water with no apparent cause?

Get the coolant checked for the presence of exhaust gases.

Run up from cold with the expansion tank top off. Loads of bubbles indicates headgasket/liner problem.

The high pressure is also a sign of head gasket/liner problem

As has already been said, unless it is very cheap & otherwise in absolutely perfect condition throughout AND you could afford to replace the engine, there are a lot of P38s out there & you may be best to give this one a miss

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yea yea i know taking cap of hot header tank is a bit daft but you can normaly hold the things while they release pressure but no chance with this blighter .doesent seem to be massive amount of air bubbles but when warm and cap of if water is topped up to level as soon as it is started the level rises lifting the water out pretty rapid then when you switch of the thing sounds like an airplane lav being flushed..........

also forgot to mention temp gauge climbs slowly to half way and will stay there for a while then quickly climbs to red........

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