4.6 p38 lost coolant over 150 mile trip?

Hey chaps, think I have found the source, but unsure of whether its the real culprit.

Since i have had the old girl i have been changing coolant bits and pieces none stop. Thought I had fixed everything.
Changed matrixs o-rings, then the matrix, then the vaporisers on the lpg.
Still slowly loosing water.
Put a filler in the top hose to get rid of the pain in the arse air lock that always appears there. And because I am a Paranoid Android I stuck a pressure guage on it to check the pressure.
Seems good, 7 psi when cruising, give it the some stick and it goes to 9 psi temporarily then comes back down.
Anyway, notice when I turned it off a hissing sound comming from the coolant expansion tank filler cap. I changed the o-rings around the insert but still does it. So I think the safety valve is passing slowly?

Anyone else had this problem? Should hold upto 14 psi no? I think my coolant is escaping as vapour through this as its running?

Bought a new so I will report back if its true.

Cheers

Chris

Right, It wasnt the safety valve, Changed the rubber gasket on the cap and it stopped hissing.

Got it up to pressure and it stayed there, good stuff.

Just checked it this morning, and becasue there is no escape of pressure from the cap it had pushed the coolant out somewhere else.

Overnight it had dropped down about 2 inches. Topped it up and came to work, Mirror and torch time I think.

Where oh where is my coolant going now?

Right, Had the mirror and torch out and can't see any traces off coolant anywhere around the engine, Water pump looks good, radiator looks good.

What I did notice is a oil leak from between the head and block which will have to be done some time. so that will be new head gaskets.

After I had finished looking I started her and gave the exhaust a good sniff, no small of coolant, just fuel?

Still no Idea, anyone have a similar problem, If it was the block/head gaskets it would be boiling the water, no?

Where are you filling it to and when. Coolant must be topped up only with engine cold and only to level line on tank. Cap must seal and should hold 15 PSI. Tank is not called an expansion tank for nothing, coolant level will rise from normal cold level when engine is hot, any excess overfill will be ejected through overflow.

Always fill it when cold to the level just under the seam on the expansion tank. Left overnight to cool after a run the level drops down about an inch. I top it up to the line again and it does the same thing level back down.

I just pulled the carpet up in the drivers footwell, its dry.

have a look at the two hear pipes on the trottle body look for white crap aroud the ally pice the pipes fit on to ..

cljcars said:

Always fill it when cold to the level just under the seam on the expansion tank. Left overnight to cool after a run the level drops down about an inch. I top it up to the line again and it does the same thing level back down.

I just pulled the carpet up in the drivers footwell, its dry.

Click to expand...

You may have a slight leak thats drying as it comes out due to engine heat. Have a look where J says common problem. Or get it static tested and have a bloody good look around.

About to go and put some pressure on whilst its cold, Will have a look at the throttle body pipes, cheers, don't think I have checked that yet.

had a look, pumped it up to 10 psi, found top hose filler cap was leaking and the gasket I made on the expansion tank was still leaking slightly, (new one hasn't arrived).

Fixed top hose filler and tightened the expansion tank as much as I dared. its lost 1/2 psi in 1 hour. Getting there slowly.

cljcars said:

had a look, pumped it up to 10 psi, found top hose filler cap was leaking and the gasket I made on the expansion tank was still leaking slightly, (new one hasn't arrived).

Fixed top hose filler and tightened the expansion tank as much as I dared. its lost 1/2 psi in 1 hour. Getting there slowly.

Click to expand...

Think a new cap if that is what's coming is a good investment.

Fingers crossed this is the last leak. Full of coolant and ready for the trip home. Check again in the morning to see what the levels like. With any luck the new cap will be on the doorstep and I can fit that once its cooler later.

Cheers for the advice.

hi cljcars, is it a manual??

P38 4.6 HSE auto. 96. 120k.

Well, back in work just.

On the way in this morning all leaks must be fixed. Gave it a bit of gas and after it had a nice smell of coolant.

Lifted bonnet, coolant had blown out of my filler on the rad top hose. The gauge was reading 15 psi I had installed on tickover.

Me thinks I have a inherited a cracked block.

What are the options prices to sort this out once and for all?

I know top hats are the best way to go but very expensive, anyone know anywhere that does the machining?

Cheers

i did mine last year i got my short engine from emmotts of clone if you need his number send me a pm .. good luck and sorry to hear about your engine ..

Yeah hard luck mate, worth a try though. Another one bites the dust.
Landrover have a lot to answer for. Top hat liners in the much over bored block would have cost a couple of hundred quid to fit as standard on the production line. That would have resulted in a reasonably bullet proof engine. They don't all go though, so maybe it's also down to how certain batches of casting were stress relieved in the foundry.

The work starts tonight so she will be off the road for a bit if it is the block, hey maybe its just the Head gaskets!

Thanks for help anyway chaps.

I can't afford a new block at the moment so I was researching the best method of putting a temporary fix in place with the least possible side effects. Lots of people seem to be using irontite, its expensive for a temporary fix, works for some very well though. I came across k-seal, in the midst.
So did a bit of research and found a few examples of sucess, even if temporary!
It even has an expedition type company recommending putting this stuff in even if you haven't got a leak?. Apparently crysler put mopar antifreeze in some engines, which has sodium silicates in to plug cracks if they appear.
All found on the net, so might be a load of rubbish, but i am fed up of filling up the coolant so I thought what the hell, something has to be done.
Out of all the stuff I found on the net, my opinion, k-seal was the easiest to apply, no further draining of the coolant then fill with just water as some need. I know I have a small crack in the block or a minor head gasket leak, from the scribble k-seal is advertised as a permanent fix for this. I am sure that with a good heavey right foot I can dislodge the gloop that is blocking the crack.

Seems though that it is working, the top hose is no where near as hard as it has been after a run, and thee filler has stopped slowly hissing. It is all back to standard now without a top hose filler.

Watch this space, intend changing the block when I get the cash, and the time to swap all the bits over.