Just changed the oil to finish my winterization. Water is bright milk coffee colored. I'm going to run a compression check.

I did just replace the intake manifold, maybe it's a water crossover. Or maybe a head gasket or worse. How do I check and troubleshoot?

do a leak down test on the cyl's...that will let ya know if the head gaskets ok and the valves are seating correctly. If you get any hissing noise from the carb the intake valve has issues....and from the exhaust then obvously the exhaust vales the problem.....if you dont et any hissing but the leak down is excessive then head gasket is most likely shot. If all that checks out.....then i personally would yank the exhaust and inspect all gaskets especially around the risers...they leak all the time. If that checks out then that leaves the intake gasket.....and since you nead to take that off and break engine gaskets to check i mentioned it last. If everything checks out then you may have bigger problems...like a crack in the block or head somewhere.....or even reversion if you canged the cam to something other then stock.......good luck!

Double check that all your intake bolts are tight 1st.
Running a t-stat with your crossover? Bypass hose?

Auto tech here.....You just did an intake manifold.....look for a problem there first....gasket slid etc., how many hours? Condensation maybe......Keep us posted!! Obviously you live where it gets cold so you have some time to figure it out an get it fixed.

Just did a compression test- 118 to 130 in all cylinders. Most plugs look good. Back left two corners have some light rust, the front left corner looks very clean. All others nice brown color.

I'm suspecting the intake gaskets since I had to remove/install the intake 5 times before I ground enough of metal off the edelbrock intake casting bosses for it to seat down into the intake valley.

Just finished draining it filling with a mix of oil/varsol (paint thinner) new filter, running for one minute, drained the whole mess, loaded it up with fresh oil and filter, ran it again for a minute, then fogged the engine for the rest of the winter.

In the spring I'll redo the intake manifold gaskets and hope for the best.

There is definitely water getting in somewhere. Since you just had the intake off it is the most likely culprit. The increase level on the dipstick will give you some indication as to the severity of the leak. Do not start the engine. Check you intake.

Zimm, Do you keep the boat in a garage or is it outside? I'd get on it now...that way when the spring comes round you will be boating.....not working on it. I keep my boat in a Hi-Dri facility and can't get to it til April....thats why I can't wait til the garage project is done!!

I'd put my $$ on the intake mannifold. I had a simular expirience last spring with a friends excalibur. The intake itself did not sit perfectly flat against the heads. We had to use a feeler gauge and record where the voids were in order for the machinest to mill them. You can actually look at the old gasket to determine crush. 2 N.I.B intake manifolds were installed with 1 being defective.
The other possible issue is...using the cork that sit on top of the lifter valley. What that does is raise the manifold for an improper seal. Did you happen to use them ???

No, I used silicone RTV on the end seals. It's hard to explain, but on the upper edge of the heads, where the valve cover gasket is, there is a cast lip. The Edelbrock intake would not go past these and even sit in the valley. I could get one side, but not the other. On the intake there were 4 "cubes" cast in- one at each corner. These were interferring so I gound them off. Then I could at least get the intake to go into the valley, but the bolts holes barely lined up. Then my new ARP bolts wouldn't fit. I guess the metal is thicker on the new intake. ARP sent me 1/2" longer bolts. I'm pretty sure something is still interferring with it.

I can't work on it yet, I'm in the process of moving from Pensacola, FL to Virginia Beach. (I'm in the Navy). I just towed the boat to my parent's house for now for safe keeping.

Oh and the tranny in my F250 powerstroke just let go too. What a week!

exhaust,then head bolts...