M20b25 big oil and water problems!!!

[george101]

Right I've just done my engine swap from an m40b16 to a m20b25, finally overcome all the problems I had thanks to everyone that helped me on the zone! But I've come across more problems, this is how it started. So I did my oil change, new oil new oil filter, then I started to bleed my rad, I took the hosing off the top of the engine (thermostat area) to get water into engine quicker I then ticked the engine over for a few seconds to get flow of water.. Then all the water dissapered and all my oil from my oil change came up the waterway to the top of the engine and it's like water doesn't exsist! Is this the head gasket? Or worse.

[george101]

Also forgot to say all the oil from the dipstick has gone all watery too.

[george101]

Sounds like the head gasket has failed between the oil pressure feed to the head and a water gallery. Try pressure testing the radiator. If it is losing pressure, stick a thin plastic tube into the oil filler on the rocker cover and listen for air escaping into the sump.

If you cant get a pressure tester, use a compressor to provide an air feed into the radiator (use a rag wrapped around the air hose in the rad filler neck to provide a sort of a seal and again listen for air escaping into the sump.

You can also use this to determine if the gasket is blown into the cylinders by removing spark plugs and listening into each cylinder while injecting air into the radiator/other cylinders etc. (leak-down testing equipment is preferable to use when testing cylinders)

Ok well I'll give that a go if I can get the tester, what I have tried tho is a compression test to all 6 cylinders, 2 failing one of them at 70psi and another at just under 100psi could this prove it's a head gasket also?

[Grrrmachine]

Oh dear. Which two cylinders failed at 70psi? If it's 5 and 6, this is a common location for cracking of the head on 2.5 engines. What readings are you getting from the other three cylinders?

It doesn't prove it's the gasket, but it does prove something's seriously wrong with the engine, and the only way to find out is to get the head off; that means a new headgasket as a bare minimum (as well as new head bolts and timing belt).

[Andyboy]

More likely a cracked head - they crack under the camshaft into the coolant gallery. I've not yet seen a head gasket fail in this way but there's a first for everything.

[george101]

Oh dear. Which two cylinders failed at 70psi? If it's 5 and 6, this is a common location for cracking of the head on 2.5 engines. What readings are you getting from the other three cylinders?

It doesn't prove it's the gasket, but it does prove something's seriously wrong with the engine, and the only way to find out is to get the head off; that means a new headgasket as a bare minimum (as well as new head bolts and timing belt).

It fail at 70psi on cylinder 2 and just under 100psi on cylinder 3, I'm hoping it isn't a cracked head but you never know. If it was I could get the head skimmed? I havnt checked to see if it's timing belt or chain driven yet also.

[george101]

More likely a cracked head - they crack under the camshaft into the coolant gallery. I've not yet seen a head gasket fail in this way but there's a first for everything.

Can I get the head skimmed to fix this problem? If its not tw worse it could possibly be?

[Grrrmachine]

Skimming is to remove minor distortions from the head surface or trace corrosions; it does nothing to fix a crack which will be running vertically all the way through the head. If the head is cracked, it's scrap.

Also, all M20 engines are belt-driven.

[george101]

Skimming is to remove minor distortions from the head surface or trace corrosions; it does nothing to fix a crack which will be running vertically all the way through the head. If the head is cracked, it's scrap.

Also, all M20 engines are belt-driven.

Ok buddy thanks for your help. Just hope it's not a cracked head.