Mayonnaise at the end of the season

Hi y'all,

It's been a while since I've posted here. Been around reading though, no worries...
But the awesome weather and my second hobby (RC flying) have kept me away from forums and such

So regarding the topic title... It was (luckily) the end of september and two buddies and I went on the river for some barfoot runs before the training of our waterski club.
First run went as the always go. Issueless.
Second run not so much. I cut the throttle after my barefooter let go and as I want to throttle back up to get him, the boat is shaking all over the place... Idled back to our dock and from there a friend towed me back to the marina.

My first thought was: ignition. I knew my spark plugs and cables, distibutor cap, rotor and points needed replacmement. But after having replaced all these, the engnine still wasn't turning right
My buddy Jo and I continued troubleshooting and when I pulled the dipstick out... Mayonnaise!
"Well Jo, I found the issue I guess", I said to him while showing him the dipstick. "Yup", he replied, "better start shopping for some gaskets haha".

So as I was preparing for my NATO mission in Lithuania, we winterized the boat and put her to sleep. We plan a little meeting among boat friends after the winter and we will pull the engine out... Nothing a few tech savvy buddies, some wrenches and some beers can't fix... We will have her back on the water next spring

Anybody have some GT-40P heads laying around they want to get rid of...? I can arrange for the US Air Force to ship them to my base here in Belgium

Intake manifold gasket failure?

SNobsessed wrote: Intake manifold gasket failure?

We'll go step by step... But we are pretty much convinced it's a head gasket failure.
It isn't my mechanic buddies first rodeo... Nor mine.
Anyway, gaskets will be ordered for: intake manifold, valve covers and exhaust manifolds.
I have the head gaskets already.

TRBenj wrote: Head swaps do not require pulling engine

I know... We won't pull the engine for just that.

TRBenj wrote: and you don’t want to bolt them down to a cracked block!

I sure hope I don't have a cracked block...
You really think it could be cracked?

Tim, what do think this would be in your expert (I regard you as one of the experts on this forum) opinion, just out of the top of your head?

Anyway, we'll do some serious testing first (leak test, compression test to start with)

A couple of years ago Tim helped me diagnose one of mine. Turned out to be an exhaust manifold. I had run it first and had found a sparkplug that hed been "steamcleaned" so I had an idea of what side to look at. A very small leak between the riser and manifold leaving a track in the manifold was the confirmation. Did not take much water to make a mess.
Good luck and post up some pictures of what your flying

Crack in the water jacket of the intake (or gasket failure that extends towards the valley) will allow water to enter the valley and mix with oil.

Crack in an exhaust manifold or riser gasket failure will allow water to enter the exhaust (gas) area of the manifold and gravity drain into a cylinder (or several cylinders), then drain past the rings and enter the crank case.

Like Joe said, a failed Comp test will identify a leak path in the upper cylinder or combustion chamber area (cracked block or head, head gasket). Lack of water in any cylinder likely exonerates the exhaust. I would have perhaps expected a steam cleaned plug if the leak was coming in the cylinder/piston area. Can’t think of why it would “run on 7” if there is no evidence of water in a cyl... let’s see what that compression test tells you.

Kristof wrote: Anybody have some GT-40P heads laying around they want to get rid of...? I can arrange for the US Air Force to ship them to my base here in Belgium

Hi Kristof - just saw your post, been busy myself and decent boating weather has long since left us here in Kansas. Certainly not what anyone wants to see, even at the end of a season.   But to the question at hand, yes I do happen to have a set of GT-40P remans setting around. Bought them for my boat last year and ended up getting a whole new long block instead so if you're still interested, PM me. A plus is I'm only a few miles from McConnell Air Force base so transfer would be quick & painless.

So where did the water come from?

Timing cover is the inspection point. Gaskets interface w/ oil galleries in the blocks.

Steve

Your back cylinder in the photo above had water in that cylinder. See how the piston head is cleaner that the others. Water in there while it is combusting will steam clean the piston head.   Either exhaust manifold for that cylinder or head gasket is letting water into the cylinder.

Kristof wrote: Thanks for all the pointers. All the parts will get thoroughly cleaned and all gaskets will be replaced. Mountain Man wrote: Timing cover is the inspection point. Gaskets interface w/ oil galleries in the blocks. So should I really pull this one too? Damn, just ordered gaskets at Skidim and these are not in my order...

I'm thinking this was a suggestion to inspect these if there didn't seem to be an obvious culprit when tearing down the top end. Based on your pics above and observations of others I'd say you're good without tearing into the pump.

And pressure test the manifolds. Every time I’ve had water in the cylinders (and the resulting milky oil), it was due to a cracked exhaust manifold (or 2).

Maybe it’s the language barrier, but the message above doesn’t seem to be sinking in.

TRBenj wrote: And pressure test the manifolds. Every time I’ve had water in the cylinders (and the resulting milky oil), it was due to a cracked exhaust manifold (or 2). Maybe it’s the language barrier, but the message above doesn’t seem to be sinking in.

I got the message... I promise you I will be a good boy and pressure test the manifolds
But just to be absolutely clear... Pressure test manifolds as well as risers right?

Edit: can I mount the manifold and riser back together with the new gaskets in between. Then put them on the bench in a position similar as on the boat, connect the garden hose to the water inlet of the manifold and let the water run. Then check the exhaust inlets if there is water trickling down...?

MrMcD wrote: Tim, can you weld the manifolds to repair or is replacement the only option? I have seen some shops that can weld cast iron now using new techniques. The hard part is welding and not distorting.

I am still not Tim - but cast iron can be welded successfully sometimes. High Nickel rods along with extensive cleaning, preheating, and controlled cooling are required.   Even then the success of the process often depends on the quality of the casting and the particular location being repaired. There's a good radiator shop around here that will give it a shot for about $150 bucks but no guarantees.   They are batting .500 on the manifolds I have had them try, maybe a little less in that the one that worked they needed to touch up a few small leaks after the fact. The one that didn't work would just crack again next to the weld while cooling. Those were external cracks, something internal that would leak into the cylinders is much more complicated. At those prices/risk it is generally not worth the effort for any cast iron manifold that can still be bought new.    

PCMs are hard to pressure test, but as this happened during the course of the season and ice was likely not involved the gaskets would be the primary suspect. Filling with water and looking for leaks is a good first step. Planning on cleaning up the surfaces and replacing the gaskets at this point would seem to be warranted on a refresh of this extent even if there was no water in the oil last season.

MrMcD wrote: Joe, Thanks for the cast weld information. I saw a process known as cold welding and wondered if that could work. They flow high volume air on the weld as they weld so the surrounding metal does not get hot.   You can weld and pick the part up with a bare hand no glove right as you finish welding.   I was wondering if this technology had migrated to fixing cast iron. Tim, is TRBENJ, I originally responded to his note about cracked manifolds. Mark

Cold welding typically refers to welding (often aided by pressure) of clean surfaces in a vacuum - We do that where I work. It is also what happens when I let the green lake prop shop sell me a stainless prop nut instead of a brass one.   I haven't seen the process you are referring to yet but would be interested to, although I would have to give it some deeper thought on whether it could help with the problems of stress cracking in repairing castings - you would have less overall expansion and shrinkage but higher localized temp gradient which is why it cracks next to the weld - I'd need a beer to figure on it proper.   

Pretty sure I met that TRBENJ fellow before... and half sure he is sending me cracked exhaust manifolds in the mail today...