Re: 89' 5.0l OMC not cooling
I have had a similar problem, grab some coffee..... I had the outdrive rebuilt, put it back on tested it on the muffs purrrrfect. Put it in the water the sucker would run up near overheating then all the sudden start cooling properly. I couldn't figure out what the problem was, I even disassembled the impeller pump and inspected it, it was all brand new. Longer story short, after a few outings it overheated big time when i wasn't watching the guage and blew the head gasket!!! FIRST WARNING, don't do what I did, make sure you're 100% satisfied you've found and fixed the problem. At that point I replaced the head gasket, flapper, etc (sic) and had the marina pull it out and look at the out drive/impeller pump etc. They could see no wrong. On the muffs perfect, in the water nothing. Eventually I spoke with an outdrive guru who told me to replace the entire impeller pump assembly again, in spite of the fact that they did when the out drive was rebuilt a few weeks earlier. for less than $50 bucks you can buy the whole kit (usually cheaper on ebay) and believe it or not, it fixed it. The parts side by side looked identical (i.e. housings, plates etc). But some subtlety between them was not allowing the pump to prime. The outdrive guru told me he has seen this 6 or 7 times on these engine/outdrives. When he sees these symptoms he replaces the plate and impeller and if it doesn't fix it he replaces the rest. The key is it has always solved the problem for him. It cost me $855 to learn this lesson, today just for you....no charge.....
