yet another problem. overheating is it blocked rad?

Sorry I'm asking a lot of questions but I need to be pointed in wrong direction fitted 2nd hand rad into my p38 ( I'm broke couldn't get a new one). Drover less the 2 miles and it overheated. I felt the radiator the top was red hot but the rest of the radiator was stone cold. And the heater was blowing cold. The range has no previous over heating issues only needed a rad cos the old one split. Could it be blocked rad or thermostat? Possible air block

More than likely stat failed shut or a big airlock. Petrol or diesel?

Diesel it's weeks like this I grow ever fonder of my discovery over the rangie lol

marty_b said:

Diesel it's weeks like this I grow ever fonder of my discovery over the rangie lol

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Bottom of RAD may be silted up as it's secondhand or the baffle in the header may be missing.
The top does get hot first as there is a small flow across in the bleed tube and past the baffle, rest should get hot when the stat opens unless the baffle is missing.
Did you follow the correct fill procedure?

marty_b said:

Diesel it's weeks like this I grow ever fonder of my discovery over the rangie lol

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You can get a serious airlock in the diesel if it's not refilled correctly. On the diesel the heater should be the first thing to get warm. If you remove the radiator it does not drain the head and block. Filling the rad separately is a good move on reassembly. Then run engine and fill slowly as level drops burping hoses. Leave to cool and top up as needed. Make sure bleed pipe from top of rad to header tank is free of coolant for initial fill to let air out of rad. Discos are ok but nothing like as good as a P38. It's like comparing a model T Ford to a Sierra Cosworth.

I created a little airlock in my system a few weeks ago causing the engine to get warm, the guys on the forum gave me this filing procedure, no problems since.

Start again with a cold engine, top up, start the engine and continue to top up with the engine idling, ensure you have water coming out of the return pipe from the top of the RAD to the expansion tank as this is where air bleeds out too, I also find it helps to rapidly squeeze and release the main hoses in a kind of pumping action plus a few short bursts of revs. Helps too if the nose & driver side of the car is a little higher than level. When you stop getting air bubbles from the return pipe and the level is good, refit cap and see what you get. (assuming the viscous is OK)


2nd hand rads can be a bit tricky but you could be lucky

Good luck.

Thermostat removed as soon as I start it up it over pressuring straight awa so can't have top of expansion tank

marty_b said:

Thermostat removed as soon as I start it up it over pressuring straight awa so can't have top of expansion tank

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You mean it's blowing water out of the expansion tank? If so, your overheat has either done for the head gasket or more likely cracked the head. Overheating can be death to this engine unfortunately.

Hmm scrap yard it is then.

marty_b said:

Hmm scrap yard it is then.

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Bit premature for that IMO. Boiling due to a serious airlock will also cause it to expel water.

Right rad flushed and flowing fine new thermostat started in up. Which takes a lot of cranks. Drover for less then 2 miles and overheated straight away. So I'm guessing it is the head how much is it to have a new head gasket done.

marty_b said:

Right rad flushed and flowing fine new thermostat started in up. Which takes a lot of cranks. Drover for less then 2 miles and overheated straight away. So I'm guessing it is the head how much is it to have a new head gasket done.

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How would you know thet the RAD is not silted up at the bottom? Does the RAD get hot all over?
Did you test the replacement stat before fitting? many are faulty from new.

The rad gets hot all over and yes the stat was tested. Only other thing is the sill has gone on the expansion cap will this cause a problem.

marty_b said:

The rad gets hot all over and yes the stat was tested. Only other thing is the sill has gone on the expansion cap will this cause a problem.

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If you mean seal then yes it would

Yeah the o ring around the expansion tank cap is missing

marty_b said:

Yeah the o ring around the expansion tank cap is missing

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Get a new cap.

Idling the car is fine just when I drive it overheats. So a cap would cause overheating?

marty_b said:

Idling the car is fine just when I drive it overheats. So a cap would cause overheating?

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Yes, the pressure raises the boiling point.

Well new cap no leaks thermostat working good. Started overpressuring straight away and overheated soon after so I guessing time to stop clutching at straws and settle on the fact it's the head. Any ideas whether it's gasket or needs new complete head.

Strip it down and see, you may need the head pressure tested if nothing is obvious. Don't buy a second hand head that has been skimmed. If it's skimmed it's scrap