The Stovebolt Site Forums The Shop Area The HiPo Shop #8 cylinder is taking on water

350 with 90 miles since rebuild.
While changing out a badly scored oil pump from failure to prime the oil system at initial startup (no age limit on rookie mistakes. I read that somewhere), I found a tiny bit of beautiful green ethylene glycol in the oil pan. The #8 spark plug is showing the telltale sign of antifreeze contamination and it actually rusted after a day on the work bench, while the other 7 plugs did not.
I removed the two intake manifold bolts at the rear near the #8 cylinder, put some high temp RTV on the threads and torqued them down. I drove the truck for 40 miles with new plugs and the #8 showed more evidence of antifreeze on it.
What would be a good course of action for me to follow to find out the source of the leak?

Pull the cylinder head(s) and change the gasket. If you're getting coolant into the cylinder, it has to be getting there by a piece of debris under the gasket, or a crack in the head. If the driver's side head isn't showing any leakage, you can probably leave it on, but the intake and passenger side head is going to have to come off, unfortunately!

Pull the block drain plug on that side- - - -as soon as you loosen the head, coolant will flood the crankcase if the block isn't completely empty, and draining the radiator won't get the job done.
Jerry

Thanks Jerry. I pulled the intake and right head and there is indeed a crack just above the intake valve. I called the guy who built this engine 2 years ago and he is going find another matching head and rebuild it for me and use my springs in order to keep everything the same from side to side free of charge.
As bummed as I was, when he apologized to me for my troubles, It completely changed my demeanor and actually put a smile on my face knowing that there are indeed stand-up guys still out there today!
I told him straight away that he did not need to apologize to me and that I knew that he was stand-up guy. I'll be heading down there tomorrow to drop off the head.
Carl

When I was making a living bending wrenches, I found that a few happy customers were worth a million bucks' worth of advertising, but one disgruntled one could spread more ill will than anybody could imagine. Of course, some folks would gripe if they were hung with a new rope, but all the local shops knew who they were. We usually shared that information among ourselves pretty quickly.

Jerry

Its simple. The guy was professionally embarrassed and wanted to make it right. The problem is that the good guys with self respect and a sense of duty are getting fewer and farther in between.

I went down to drop off my head so the guy could take my springs off for the other head, and was expecting to head out and wait for him to call me when it was ready.
Much to my surprise, he had the new head all cleaned up, had finished the valve job, had the modern seals installed, and was waiting for me to get there to put my springs on! 30 minutes later I was back on the road back home.
What a guy!