Heads are off and no real smoking gun

[66FAIRLANE]

Ok so after my issue detailed here http://fepower.net/simplemachinesforum/index.php?topic=5697.0 I have the heads off.

Remember, coolant in oil. No oil in coolant. Coolant was most likely very low when I started driving it. I did not realise anything was wrong until I got home &  topped it up and it took 7 litres. Checked oil, milkshake. Had to move car so started it for about 5 seconds to get moving down a hill into my workshop. Started & idled normally.

The inlet manifold gaskets show no signs of failing at the head coolant passages although it has definitely been sucking oil. Pulled the heads and everything looked quite normal.... except the top left rear head stud (pictured). It was covered in the milky oil. All the others were dry or normal looking oil. The gasket however shows no signs of failure in this area. Bores look pretty good, all the plugs came out dry and no evidence of coolant in bores.

I still have a lot of digging to do.  Any suggestions though?



 

[fekbmax]

Check close for a crack from water passage to head bolt thread pocket.  I have seen this a few times, sometimes I'll t shows at the deck and other times it's down in the block/water passage. You can use air and put pressure inside the head bolt thread pocket and see if it bleeds through into the water passage.

[cjshaker]

Ditto what Keith said. I'll bet you'll find a crack in that area.

[66FAIRLANE]

Thanks guys. Will inspect that area closely.

[driveamerican]

I had a crack in # 4 cyl that I had to warm up with torch to find. That's when I learned about sonic testing. No more 428 bore without it again.

[66FAIRLANE]

Pulled the sump etc today & had a bit more of a look. Still no gun!

Yes there are small cracks in the deck between the rear head bolt holes & water jackets. I am pretty sure they were there when I first built this thing 20 years ago and doubt they caused this. I pressurised all the head bolt holes as best as possible, heard no leaking and all seemed to hold pressure. The head gaskets exhibit no evidence of coolant migration from the coolant passages. Bores look good with no evidence of water ingress. Rrrrrrgggghhhh!

[TomP]

That is where the oil drains back from the heads, could be the milky oil just left it there passing through rather it being the source. I suppose though it coolant was seeping up at the deck it would go up there and dump into the back of the lifter valley with the oil.

[My427stang]

How much water did you actually find?

Was it in both heads?

Are both heads vented to atmosphere or is one a PCV?

Humid weather and short trips can cause sludge in even modern cars with good evac systems, if you had a marginal PCV or none, could have just built up in the heads

Now if you found liquid water and crap everywhere, then all bets are off, better have block and heads pressure tested

[66FAIRLANE]

Afraid its not that simple. Heres the story

"Well you see, it has had a bit of a weep from the water pump for a few months. I have been ignoring it, topping it up, thinking I will do something about it over winter, after all it just a little weep. Took it for a drive the other weekend, got into it a lot, it was going well, enjoying the new efi. When I got home I parked it up and after a couple of hours thought 'I haven't checked the coolant level in a while'. I also remembered that the last time I drove it the weep had turned into a bit of a stream. Not sure how I forgot about this. Popped the radiator cap & could see no coolant. Topped it up, it took 7 litres!! Sheeet! Checked the oil, milkshake. Damn. Had to start it to move it & it started & idled normally. I reckon I have blown an inlet manifold gasket as there is no oil in the coolant. Damn thing was oil cooled for quite some time.

Anyway its all coming out & the birthday I have been threatening it with is now going to happen.

On the up side the efi is doing its job. The plugs were as clean as I have ever seen them."

Still no obvious answer. Could be a few pressure checks coming up. A few more pics.

[TomP]

Those gaskets have never given me a problem. Possible the intake has porosity getting coolant into a pushrod hole? Or heads, maybe the threaded plugs on top under the rockers.

Or perhaps you go to the full serve gas station with the good looking blonde chick and when she added that last quart of oil it was in a Prestone jug?

[machoneman]

A bit hard to tell from the pic but those intake gaskets look pretty good. That is one of the worst milkshake I've seen posted here...or elsewhere.

[KMcCullah]

Sorry to hear of your issues, Andy. Especially after having so many trouble free years. I'd start with pressure testing the block and intake.

[Heo]

I had a milkshake maker like that, the pressure test gave nothing
i found the crack when i started to grind on the block and the iron
dust gathered along the crack
was cracked in liftervalley above lifters  most likely from Freezing
But i dont think you have problem with freezing where you live

[Stangman]

Hey Heo in the third picture is that the oil supply to rockers that possibly isn’t
A good seal and right next to it is round water hole?

[Heo]

Yes Stangman it looks like there is some buildup
of oil and water there interesting to wipe that
of and have a look at the gasket
Nr 8 piston crown is clean. A sign of water