Failing cyl gasket 3.2, am I in trouble?
 

Hi,

I just started to get my 3.2 ready to swap into a 1970 T Coupé. The engine is on the engine stand to figure out the condition. So far I checked the lower head bolts which were ok. The exhaust was easy to remove, it was barely secured to the engine.

Anyway, I found a few disturbing things. First, the whole underside was spray painted silver, right over the old grime, and now with new grime on top of the paint. Second, the pass side bank had some goo all over it. It looked like they had JB welded the oil return tubes, and also the rearmost cylinder was full of gasket silicone.

http://forums.pelicanparts.com/uploa...1348504978.jpg

http://forums.pelicanparts.com/uploa...1348505285.jpg

I removed all that stuff to find this:

http://forums.pelicanparts.com/uploa...1348504868.jpg

How much in trouble am I in? That looks like the cylinder foot copper gasket, that have crawled out a couple of millimeters. The engine leaked some oil, but nothing as I would have expected from this. What can I do about this, except the obvious, replace it?

And, the exhaust valves doesn't look the same. One is pretty black, I guess carbed up or from oil:

http://forums.pelicanparts.com/uploa...1348504944.jpg

This might indicate worn valve guide, I would guess? Or could it be that it need a valve adjustment? And the other ones all look like this, light brownish.

http://forums.pelicanparts.com/uploa...1348504984.jpg



Any thoughts on how to proceed?




egards,

johan

Honestly that suspect cylinder base gasket is the worst of your worries IMO. That mess in the first picture is astonishing. I could hardly even tell what I was looking at!

Your valve guides don't seem alarmingly bad. A valve guide with some leakage will show up wet in the port like that. A dry one like the gray valve is of course what you would typically like to see. The valve guides that are extremely scary are those that leak so bad that you find a pile of carbon buildup in the port.

Take a look at the spark plug in that wet cylinder. If it is very fouled, then I would be concerned. If it is fairly dry and the plug is mostly clean, I would not worry too much about it.

But in all honestly, an engine that looks like the first picture needs to be completely gone thru to see what other sins have been committed on it. JB weld on oil return tubes? That's absurd. The oil return tube is such an easy fix (a simple o-ring for crying out loud) and it never ceases to amaze me the awful things people do with sealants to stop the leakage.

3.2
 

I agree with Kevin, that is a mess ! The engine should be taken apart and inspected before it fails and you have nothing to rebuild.
Mike Bruns

Agreed, it is a mess. But a shady mechanic trying to stop leaks the wrong way doesnt nessecarily mean it needs a rebuild. It runs great, passed smog with flying colors and has great oil pressure. But the base gasket really worries me. How do I adress that? Can I expect a severe leak from there? What would be the best way to fix it? How much work am I looking at?


Regards,

Johan

Base gasket
 

I usually see the base gaskets poking out like that on the turbo cars that detonate and pound the head and cyl like a jack hammer and it beats the shim right out, the way they find the problem is the messy oil leak from it. The non turbo cars especially the DME engines rarely have an issue with detonation but still possible. It may have a long/short cylinder on that side, It needs to be fixed whether you do it now or later
Mike Bruns

Well my guess would be the last person fiddling with the top end (heads, camshaft housings which are above the cylinders) may have allowed the cylinder to come off the base gasket when rotating the crankshaft. Then when he was putting it all back together he didn't get the gasket centered on the cylinder spigot. I would not worry very much about it. I have seen some top ends done w/out replacing the base gasket and they did not leak.

If you want to fix it you have to take the cylinder off the engine case. The base gasket is a complete ring of copper that has to be slipped under the "seat" of the cylinder. Only way to do that is to slide the cylinder all the way off the piston to clear the head studs. That means you must remove the camshaft housing and heads (can be done as an assembled unit) and you'll have to re-time that camshaft. So you'll need some specialty tools to loosen & tighten the cam and also a dial indicator to measure the camshaft lift spec at TDC overlap. Also will need a suitable ring compressor to compress the three piston rings back into the cylinder w/out breaking them. Gotta have a ring compressor. It's impossible to do by hand.

My racecar engine had rather leaky base gaskets that were sealed with the Loctite 574 sealant goop. They were annoying drip leaks (no more than 4-5 drops at startup or after sitting to cool down) but not huge puddle-maker leaks. This base gasket is not in a location where there's actual oil pressure occurring. The only pressure is air pressure from the engine rotation and much of that pressure is relieved by the vent hose attached to the oil tank.

Bottom line is that it is not a gasket that is going to cause a gushing leak any time soon. If it bugs you, put some more sealant on the pesky spot. Your engine is already familiar with that stuff anyway! :D

edit.... I certainly defer to Mike's extensive experience on this. I had forgotten about the potential broken head stud which could allow the leak to be more of a problem with the cylinder actually moving. Not as likely on a 3.2L N/A vs. more likely on a turbo engine. Still a possibility when driven hard with cylinder movement.

Low head torque would either be somebody not tightening enough or a broken head stud. The head studs are not tightened very much. Only 25 ft-lbs or so.

Thanks Mike,

Very appreciated. Can I remove the heads on that side like a unit and just replace the shims there? What would be the easiest way?

Any chance it pushed out due to low head bolt torque?


Regards,

Johan

Thanks Kevin, you answered while I was typing.... :-)

Johan