Yet again a 4.6 P38 with pressurising and over heating problem

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badlandy

New Member
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43
Location
Walsall West Mid's
P38 4.6 over heating and pressuring
Hi, I am adding this post on behalf of my brother in law he brought a P38 4.6 last year we now the car well and this is the reason he brought it. It had a replacement engine 50,000 miles ago with bills to prove it. It’s the later engine i believe it to be the Thore type. Any way he boiled it over and added cold water to the header tank to get him home but the damage had now been done in my eyes.
Since then it has been in to the garage and had the head gasket’s replaced but this didn’t cure the problem of the car over heating and Pressurising. He was then advised the block may be cracked so on this he had it removed and had new liners installed the heads skimmed. But hay its still over heating and pressurising. He has now replaced the water pump radiator and the stat tried a second set of heads which have also been skimmed but the issue is still the same, can anybody now shed any light on what may be the issue??????? Oh he has also bypassed the LPG system and the heater matrix but its the same somebody has now advised him it could be the inlet manifold??????
Please help him as he is getting some major grief from his better half
 
blocks are prone for cracking ,its the thin aluminum bore that cracks behind the liner and is not usually visible ,needs pressure testing to prove ,new liners ?which type putting in std type would be pointless ,top hat liners are used as the top flange can be sealed to block negating the effects of cracked block, block can be pressure tested with heads and front timing cover off ,to test them myself i block top water ways x 2 1 front 1 back (flat plate with rubber gasket bolted over hole)and use a plate with trye valve in it clamped onto front water way ,fill block with hot water a pressurise using air line it will leak out between liner and block if cracked,refitting std liners can make a cracked block more likely
 
after all the money he has put into it i would try a bottle of iron tite read the bottle first and do what it says, if it stops the over heating bet for sure the block if fecked..
 
when the heads where taken off was the gaskit gone? has he made sure its not a bad air lock ? start it up and take the thin pipe off the top of the rad if you just water out its not aip locked but if your getting air and water keep it off till just water comes out. sometimes its best to jack up the driverside to help it bleed out..
 
All sorted hopefully Yea real bad air lock, I had to jack the drives side up as high as we could took both pipes off the heater matrix and re fill the cooling system from that point once water was coming from the small hose on the rad re connect all of the pipes apart from this one, and start the engine. Once the water came through the small pipe on the rad re connected this one and Jobs a gooden. Drove the car for a good 20 to 30 mins no problem. We left his car over night to see if the water level had dropped we had lost 2 Lts of water. NOT good gets under and has a look found 2 large cracks in engine block. The guy who fitted the engine and fitted the new heads didn’t put any ANTIFREZZ in the car and the block cracked while he had it he had told us he had a core plug which was leaking NOT. (2nd weekend) Just taken the engine out and had the block welded up re fitted the engine re filled water and the Brother in law has now drove it for 2 days with only needing to put a cap full of water in. Fingers crossed this has worked.:rofl:
 
Just out of interest. During the second world war a company in Sydney Australia manufactured Merlin aircraft engines during and after the war. They took 20,000 hours against 2,000 hours in the UK to make, so they made fifty and gave up! Apparently about fifty percent of the castings were discarded due to porosity, until an expert arrived from the UK. He said you boil them under pressure in linseed oil and that is what they did. Porosity was then no longer a problem.

Anyone got a big pressure container that can boil Land Rover engine blocks in linseed oil?
 
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All sorted hopefully Yea real bad air lock, I had to jack the drives side up as high as we could took both pipes off the heater matrix and re fill the cooling system from that point once water was coming from the small hose on the rad re connect all of the pipes apart from this one, and start the engine. Once the water came through the small pipe on the rad re connected this one and Jobs a gooden. Drove the car for a good 20 to 30 mins no problem. We left his car over night to see if the water level had dropped we had lost 2 Lts of water. NOT good gets under and has a look found 2 large cracks in engine block. The guy who fitted the engine and fitted the new heads didn’t put any ANTIFREZZ in the car and the block cracked while he had it he had told us he had a core plug which was leaking NOT. (2nd weekend) Just taken the engine out and had the block welded up re fitted the engine re filled water and the Brother in law has now drove it for 2 days with only needing to put a cap full of water in. Fingers crossed this has worked.:rofl:

Bit confused by this. Can you really weld up a cracked aluminium block? I would have expected frost damage to have just pushed the core plugs out rather than cracking the block in any case.

Don't really follow how this relates to the bleeding operation. Surely you'd be losing water all the time, not just overnight?
 
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