Help....coolant problem

[nivapilot]

Hi all
I have a 91, HDJ81, import. 1HD_T 4.2TD engine.
Now when bought it, she had a wrecked engine, No.1 big end gone in a big way and crank wrecked.....also the end of the rod hit the block in the oil gallery and punctured it.
I used steel putty to repair, and have no issues with oil......replaced crank, rod and 6 x pistons, new rings, mains and big end shells.
When I first started her up, she fires on the button, every time, but pressurises the cooling system and blows water out of the radiator into the header/overflow tank.

After 48 hours there is still pressure in the system, you hear the air hiss when the rad cap is taken off.
I need to top up at least 1ltr every day!!

I tried "steel seal" but that didn't stop it..................Now I cannot understand how the system will hold pressure for 48hrs.....so no leakage, but when I fire the engine up, she immediatley, pumps up over 25lbs of pressure??????????? (before I release it)

No combustion gases in the system, according to the CO2 sniffer test. No oil in water or water in the oil.


Anyone any ideas?
I am going to try blanking the turbo water pipes to see if the turbo has cracked? but surely the pressure wouldn't hold?

 

[nivapilot]

Well, blanking both turbo pipes makes no difference.

 

[IRLGW]

are you getting hot air from the front heater? Your heater matrix could be airlocked (mine was) and its slowly bleeding itself.

I'm surprised the the steel seal didn't work though but you do have to do it properly and with the thermostat removed and follow the instructions to the n'th degree. Did you pull the injectors or heater plugs as you went? It fixed a leak on my old defender that was fitted with a fourtrak 2.8 Engine. After the engine cooked I couldn't fill the the cooling system because the water was running straight out the exhaust! I ran it through, pulling one heaterplug at a time and removing the injector pipe for about 10mins per cyclinder and it worked fine.

see if you are getting the same pressure on each side of the thermostat in case it is 'steel sealed' shut and pressurising one siode of the system either through back pressure on the pump or boiling one side of the system....

 

[nivapilot]

Hi IRLGW, yes I am getting hot air in the car, well at least until the water level drops enough to stop it


I followed the Steel seal's instructions and ran the engine without the rad cap on for 1hr, then topped off the rad and put the cap back to let it cool for 24 hrs........nothing......but it wouldn't, would it if I can't lose pressure from the system, the steel seal has nothing to seal?

After a run, before I tried the steel seal, the pressure forces coolant out, and then the pressure in the system will hold for 48 hrs, or more, so pressure builds up rapidly and then won't release.........it's as though, whatever is causing the pressure is like a one way valve.......and that is what I can't get my head around.

 

[Roger Fairclough]

All my problems appear to be caused by a faulty rad. cap.

Roger

 

[BobMurphy]

Do these motors have multi-layered head gaskets (like those on the 90-Series) ??

I had to replace a gasket after I got a blow into the water channels from between the leaves - it actually 'ballooned' one of the plates into a blanked-off hole!

I'm thinking that the thin steel layers could be acting as a duck-bill valve, letting combustion pressure out then sealing when the motor is turned off.

I would consider lifting the head again if its got one of those gaskets.

Bob.

 

[nivapilot]

That seems a possibility Bob....ooh I do hope it's only the gasket....and it was a cheapy from milners.

 

[BobMurphy]

That seems a possibility Bob....ooh I do hope it's only the gasket....and it was a cheapy from milners.

When I put a new head on my 95 I put the new (Milners) gasket in 'dry' - thinking that the black coating was a form of sealant.

It leaked.

I then bought a genuine Toyota gasket and used some thin non-setting jointing compound with it. Its been fine since.

I thought that the face of the block on mine looked a bit worn so maybe that was why the first gasket leaked. Ideally I should have stripped the motor completely and had the block re-faced.

Lifting the head is a bit of a pain, but it may be worth a try.

Best of luck.


Bob.