I pulled both head off my 01' Expedition 5.4L v8 assuming the head gasket was blown as it was billowing white smoke and the oil is orangish-brown and running through coolant. When I got the heads off the gaskets look in better condition than I thought they would be... but very worn around 1 problem cylinder, can this much wear of the black material cause the coolant to leak from those passages into the cylinder?



If so then I only wonder why the intake runner on that cylinder is so much cleaner than the others, this makes me wonder if my head is cracked or I have other issues.

Here is what the head looks like:





here is what the problem cylinder intake runner looks like:



here is what all the other intake runners look like:




So will a leaking gasket cause that much effect on the intake runners, and why is only the exhaust valve discolored?

Thanks for the help in advance, just trying to get some clarification from someone who knows more about any of this before I throw this all back together. Also, should I have these cleaned somewhere before I reattach them? or what is the best procedure for that, I heard getting them milled might not be a good idea on these engines, true/false?

 

definitely looks like coolant in the cylinder, but it could have also come from a leaking lower intake gasket, which would explain the intake runner difference as well

Just get several cans of B12 or other intake cleaner and go to town with a small wire brush and lots of cleaner

 

thanks for the tip.

and i thought so as well about the intake gasket, but it seemed to be in good condition... maybe the manifold bolts loosened up a bit somehow and caused a leak.

I just want to make sure my head is not cracked somewhere I cant tell

 

Do you have pics of the other sides of the head gasket? Do you have close ups of the other combustion chambers on that head? Do you have pics of the cylinders?

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The head gasket fire ring is compromised allowing coolant into the cyl. (blown head gasket). The intake port is clean because the coolant leaking into the cyl makes that cyl run colder allowing the raw gas from the injector to clean the intake port. You are probably also getting coolant pushed back past the intake valve/seat as well during compression cleaning the port. The higher heat from the other (normal) cyls creates coking (deposits) in the intake ports from the gas over time. The exhaust valve is discolored as well from the coolant being concentrated as it flows over/around the hot exhaust valve on its way out of the chamber to the exhaust. I doubt the head is cracked but I would clean it up and lay a good straight edge across it and check for flatness. Use a light behind the straight edge and watch for light showing between both surfaces. The rightside cyl head would almost always warp at the rear not the front if overheating occured. The front cover adds support to the front of the right head usually preventing warpage there. Those Ishikowa head gaskets were not the best. A good set of new head gaskets should be all you need. I don't think you had a problem with the intake gasket. Just my opinion. Good luck

 

I would for sure get the heads magnafluxed just to make sure you dont have a cracked head. Sure would suck to find out that head was cracked after you got everything back together.

 

You can get porosity in the casting as well which sometimes because of various casting process characteristics shows up under a valve seat and will leak coolant. A trained eye should be able to detect it though and usually porosity is an infant failure happening early on. His head gasket looks blown to me but stranger things have happened.

 

Thanks for the help guys thats exactly what I needed to know. I thought it was just the gasket like you said because I looked in all the coolant passages around the valves for a crack or anything and could not see one. But I want to be safe so Im taking the heads to have them magnafluxed and cleaned right now, I definitly do not want to put it all back together to find out it is cracked. As far as gaskets go I already have a full set of the fel-pro gaskets for re-assembly.

 

If that's what intake runners are supposed to look like, then maybe the EGR system isn't that good of an idea.

 

Well I knew nothing about magnafluxing before and I wasn't 100% sure these were aluminum heads but you cannot magnaflux aluminum heads which these are. Im having them pressure tested, surface checked and cleaned however...

 

your right here. last I checked you cant magnaflux aluminum, you have to pressure test like you said so your on the right track there. I would also vote that looks like a blown gasket.

deck and go again!

 

Ya we used a two part chemical process for detecting cracks on aluminum. One part was a white powder and the other part was an activator. The product name completely eludes me at this time. Anyway I think your cyl heads are fine just clean them up good and get it done. If you are using new head bolts remember to pre stretch them before performing final torque. Good luck.

 

I thought head bolts were TTY and required no pre-torque, while head studs like ARP require five stretch cycles.

 

During assembly in the factory on the line they are torqued (auto) to 45nm then backed off and then torqued to yield. Service torque is different. We always torqued to 45nm in sequence then back off then 45nm again, then torque 90 degs in sequence then another 90 degs in sequence when using new bolts. Only backing off on the first torque of 45 nm. There are several slight variations to this out there but thats the way we did it on thousands of engines and the method I still use today. Take care

 

Yeah the service manual says 40nm then 90, then 90. Ill follow your advice however, thanks