While replacing the carb today I noticed a pin hole sized bubbling leak while the engine is running.
Im not familiar with the heads on this engine but the leak is on a seam below the rocker cover gasket
but above where the manifold bolts to the heads.

Its where the screw driver tip is in the picture.

 

There is no joint there on an OEM engine. All I can assume is that your engine has non-stock valve cover spacers to clear taller roller rockers. The only fluid there would be engine oil from the rocker area.

 

Thanks
Im conpletely confused now as the joint runs the total length of the cylinder head.
Guessing I need to remove the rocker cover to see whats going on.
The leak is very minor I can live with it but Im at least relieved its not some issue
where the head has to be removed.
I ve only just purchased the car and would like to get it back on the road before doing
any major work.

 

Hmm , the distance between intakemanifold and valvcover looks to be the same as my 425.
I can take i pic of my head if you want , cyl 3 ??

 

I fixed your picture. I think it is leaking from the valve cover gasket. You can see a trace there.

 

that’s the top of the steel shim factory style gasket your pointing at. if you see bubbles of oil there when it’s running, you have pressure build up in the engine which is forcing oil out under the gasket..showing up as oil all around that spot.. which it clearly is.

are those chrome covers solid without any venting holes?

 

The valve covers are not solid they have the vent in them which goes to the air filter.
Yes there are some oil leaks from the actual valve covers as the bolts were loose
and I havent had a chance to clean up the engine.
The valve covers were barely secured to the heads.
Previous owner let maintenance slide some what.
I will degrease the engine later today.
Im chasing a plug fouling issue which is particularly bad on the left cylinder bank.
Put a kit through the carb, new plugs and wires, did the timing.
If the plug fouling doesnt clear up the it looks like the heads could need reconditioning.

 

Here is a couple pics of my left head and turkey trey. Looks to be at the edge of the turkey trey
were the screwdriver is like Canadianolds wrote ??

 

Thanks
Is the left and right heads the same as in the valve cover bolts to the head.
The left head in the picture has the rocker cover bolted onto the part with the pinhole leak.
Strangely the right head I can tell has the rocker cover on the head without the same part.
I ll get to the bottom of this tomorrow as I spent today on ignition timing and carb tuning.
The plug fouling is no longer an issue.

 

Left and right heads are the same. As I look at your photos again, there is no seam where your screwdriver is pointing, just a step in the casting from machining. There isn't even a cooling jacket behind that wall, so any leakage is coming from somewhere else and running to that point.

 

Found another pic , the machined surface stops at the arrow and below that is the turkey trey.



Better pic from my 98 here so it must be at the edge of the turkey trey the screwdriver is. Here
it,s easier to se.

 

yep

 

yep again….I knew you guys would figure it out, sooner or later.

 

where did he say it was coolant? it’s oil soaked.

in the pic there are two “lines” the upper line is the small machined step, the lower line where the screwdriver is pointing, is the top of the Turkey tray.

this above pic is the best

 

Why would anything be “bubbling” at that location?

 

a video of the bubbling while running, like he said, would be nice to see.

I’ve seen plugged up engines build enough crankcase pressure to push oil out of all the gaskets..enough pressure to push my hand off the oil fill tube .
he said his valve covers have venting, so that may not be happening here.

 

Well when I say its bubbling its like a pin hole leak.
I noticed yesterday it starts a few minutes after the engines been running.
There must be a failing gasket on the joint.

 

What are the odds it’s just oil or water boiling from the heat of the exhaust crossover?

 

Well luck is not on my side.
Fixed the carb rich issue, set the timing, plugs are no longer fouling.
I have fluid spitting out the exhaust when I start the car first thing in the morning or if I let it cool through the day.
Its in the same left cylinder banks Ive been having issues with.
Decided to check the radiator for bubbles as Id previously flushed the system and added a cleaner.
Looks like I ll be pulling the heads darn it.

 

Went and spoke to my mechanic mate this morning.
Showed him the picture of the radiator.
He said thats not an indication of a bad head gasket.
His advice was to pull the spark plugs and pressurise
the cooling system to 10psi watch for leak down and then
wind the engine over looking for coolant coming out the plug holes.
I found the bottom radiator hose was leaking tightened it up.
Kept the cooling system pressurised for 30 minutes.
Nothing came out the spark plug holes when the engine was
turned over.

Next Im going to get a compression tester just to make sure....

 

Just want to say I am totally embarrassed. I could have sworn I was looking at the exhaust side of the head in his first picture

 

Shane what does your mate say it is? What else could cause bubbling in coolant? Sometimes a pressure test will not show a compression/coolant leak. Compression may be 150 lbs and pressure tester pressure only 15 lbs. Also compression leak is from chamber to coolant- Pressure tester is coolant to combustion chamber.

 

That might be normal. If it is spitting black liquid out it is probably just condensation. Especially if it is cold outside. One side is always worse because of the heat riser blocking off one side of the exhaust. Those of us old enough all remember when it was pretty normal to have a black spot on the driveway where you parked because of that. Modern cars with catalytic converters burn it all off so you never see it.

Personally if I were in your shoes I would put it all back together and take it for a nice ride. I bet it is fine.

 

did the gauge lose pressure after 30 minutes?

 

I lost a couple of psi but it held pressure.
The new spark plug wires I bought are garbage they kept coming out
the dizzy cap causing a misfire issue. I ve put the old plug wires back on.
The compression test had less then 10% variance across the cylinders so I doubt
I have any issues with valves or rings.
The engine is running now and the bubbles are gone looks like air was
being pulled in from the bottom radiator hose or somewhere else.

Its tough when you buy a 60yr old car and know old mate didnt look after it well
and had it sitting for a few years. I ve had a number of faults cause this issue.
Its been a bit like whacker mole in the engine bay.