Suspected blown head gasket

[mikey]

Depends on what colour the smoke was.

The tight engine (slow cranking) does suggest overheating if the starter motor spins the motor freely ata ll other times

If the smoke was white, there is a chance thet one of the heads has warped leading to a head gasket failure. If this is the case, you need to establish the cause e.g. low on water, air lock, leak anywhere. etc. Your temperature sender may not have been giving an accurate reading if it was in the air pocket if this happened as it will have been reflecting the temperatute transmitted through the casting. The problem is it is always difficult to trace back afterwards.

If it was me and the smoke was white, I would firstly be looking if there is any evidence of water in the oil or vica versa.Forget the sludge in the heads check its probably too early and a better way is to drop the sump if its easy enough to do on yours without gearbox removal (also with the new rubber gaskets some allow refitting the sump gasket easily with the engine still in place). Next I would think about taking the heads off and checking whether they are warped using a straight edge and feeler gauge. I am not sure, but I think the allowed tolerence is around 0.005". If they need resurfacing then do this and buy a good gasket set such as Felpro or similar (as you have the heads off, lap the valves at the same time).

An alternative to the above is to get a pressure test on the system which is fine if you know there is no leakage from hoses etc.

Next is to fill with the coolant mix slowly (squeezing the bottom hoze repeatedly as you fill can agitate the coolant and help displace air). Change the thermostat for a high flow unit as a matter of course by yhe way.

When you fill to the mark start the engine up wit the radiatior cap off and let the engine tick over until you feel the top hose warming which means that the thermostat is starting to open. During this procedure keep topping up the coolant as it drops. Do not rev the engine as the agitation may force water out of the neck. At this point replace the rad cap (buy a new one for the price) and rev the engine (not constant) to displace air. Come up to operating temperature, turn off the engine and let it cool down. When cool top the coolant up and run. All things being equal you should be OK, but if you still have an issue horrors such as cracked or porous blocks can be the culprit, but this is extremely doubtful if the problem has just occured.

If the smoke was blue, this could be a ring that has broken and oil is forcing its way into the cylinder and being combusted. It would not be a valve seal if it was sudden and dense.

The way to check this is with a combustion changer tester and RED X or similar although if you have run enough time with the condition, an oily spark plug may give this away. The idea is to take the spark plugs out and test each cylinder. Spin the engine over 6 or 7 times, take out the tester, pour in a pipeete full of RED X, repeat the procedure and if the compression has increased significantly (20psi or so) you could have a broken ring. Depending on the age of the engine, a change in reading could also be worn rings, but I think the difference on a broken ring would be obvious.

Hope you sort your problem out.

Mike

[wilf]

Nick, as a first (and easy ) step, take all the plugs out, checking each one to see if it has oil or water on it, then spin the engine over on the starter with the plugs out and watch to see if anything gets blown out of the plug holes.

Of course, if your engine oil looks milky, don't bother with that, and certainly don't run it any more. Give me a call if you want.

Blown head gasket is not the end of the world, and not too dear to fix. Problem will be finding someone to do it in our area - I have an idea if you need one.

[lutman]

No need to touch the offside head - if the cloud came from the nearside thats the side thats leaking.

[mike huddart]

Originally Posted by lutman

No need to touch the offside head - if the cloud came from the nearside thats the side thats leaking.

That,s fine in theory, but in practice the others usually not far behind.Dont forget this thing has overheated and the heads are not that selective when it comes to distorting......Mike

[the rock doc]

Hate to say it but the same thing happened to me six months ago and it cost me two new heads and four pistons. Turned out to be an airlock and I had only driven one mile down the road.

[mike huddart]

Originally Posted by the rock doc

Hate to say it but the same thing happened to me six months ago and it cost me two new heads and four pistons. Turned out to be an airlock and I had only driven one mile down the road.

Please please, the chaps depressed enough as it is! As a matter of interest, is yours a Chevy or Ford? Mike

[wilf]

Bl**dy H*ll!

Two heads and four pistons in one mile? What were you doing to it? What else was wrong with it?

[stevey]

Originally Posted by wilf

Bl**dy H*ll!

Two heads and four pistons in one mile? What were you doing to it? What else was wrong with it?

sounds like my wife could have been driving when that special time of month was around "I was driving it at 70 mph in first gear because I wanted to, what are you going to do about it?" sound familiar gents?

Steve

[dingocooke]

ahh you mean the 'hide all sharp cutlery' season...

[stevey]

Originally Posted by dingocooke

ahh you mean the 'hide all sharp cutlery' season...

OH YES! hide in the workshop until the nasty monster has gone