yes .

 

If the engine has run low on coolant and overheated, then it will probably be the head gasket failed. If you put a little oil down each cylinder, it will help seal the piston rings at cranking speed. If the compression raises significantly, then the problem is most likely rings or bores, if it makes little difference, then more likely head gasket or valve. Try the oil test first and then try looking in the ports and through the plug sockets to check valves.

You will need to remove the engine assembly to remove the cylinder head and this will not be possible, or safe, to do so "do all this work on street no roof and garage !"

If you attempt this, I expect to see the car selling for parts in the not-too-distant future.

 

Hi,

I suspect the motor is coming out of the car for some form of rebuild. How badly damaged the internals are remains to be seen. The good news is that they are Ford internals. Everything that could go bad from an engine overheat can be either bored out, skimmed or replaced.

FWIW, here's my old thread on getting a motor out and rebuilt. https://www.6speedonline.com/forums/...-2006-db9.html

ATB & Good luck!
Larry

 

Larry !
I read you written experience about rebuilding your car engine very unique amazing job and very helpful thank you so much

 

Ugh.... looks like a head gasket at minimum....

 

If you pull the intakes and the valve covers and observe the valves you can see the back side of the intake valves and you can see if the exhaust valves are opening/closing. It could be a stuck valve, which would be obvious. A bore scope would confirm if it was a burnt valve. Burnt valve/blown head gasket - if it's not pump water into the oil or vice versa it's likely a burnt valve.

I have seen threads on this forum from folks who have removed the front of the motor without removing it from the car. the heads are pretty deep, I don't know if there is sufficient room to remove a bolt from the back of the head in the car... For sure it's almost impossible to reach behind it to attach/disconnect connectors!

 

My money is on a dropped exhaust valve seat. Either way, engine out and rebuild if your going to do it correctly.

 

Thank you for your advice I will try my best !

 

Glad to see more people trying to restore these old beasts. Post pictures of your car.

You can also put your scope into the top of the primary catalytic converter to see if there has been any breakup of the catalyst element. This can signal more internal damage.

 

Nice color combination. Good luck!

 

Looks like a valve strike to me. The valve stem will be bent and the valve unable to close. That's likely your primary reason for zero compression. What you don't know is what caused the valve to stick open in the first place. It's sad to say, but I think you're got a lot of work ahead of you.

 

Overheating aluminum engine, rear cylinders are always the hottest temperature. That's when valve seats tend to drop on valve opening. Sometimes it corrects its position so there isn't mechanical noise, but still not fully seated.

 

Sorry to hear that. Obviously you will check everything once the heads are off but you need to take a close look at cylinder 10 also, that compression is too low. There is a fair bit of performance increase to be had porting these heads too so once the damage has been sorted, treat yourself to a set of ported heads, it will at least soften the blow of stripping it all down just to end up with what you should have started with.

 

What is your goal? Are you restoring the car for yourself? Then change the gaskets otherwise you will have to do every job two times. How many miles on the car? If you're going to take the heads off, I would change all the consumables, gaskets, PCV valves, spark plugs, ignition coils etc... Most things (except for gaskets) can be purchased aftermarket if you're trying to keep costs down.

 

You only need to replace one, but I have never not removed them all and replaced the valve seals. Thus things never last...

Congratulations on getting the head off. You have nimble fingers!