Crusader 454bs higher temp and steam

"Lately,my port engine is runn

"Lately,my port engine is running about 20 Deg hotter than starboard plus steam. Rebuilt raw water pumps this year. Any ideas?"

Air leak before the raw water

Air leak before the raw water pumnp. The tiniest of air leak drives the temp high.

Jeff

Thanks-will give it a try
Kei

Thanks-will give it a try
Keith

"Do you change thte zinc penci

"Do you change thte zinc pencils in the oil cooler regularly? I've found most don't and they do breakdown. the residue inhibits the water flow out of thte cooler and everything downstream gets hot, too."

"Our season is almost up, so I

"Our season is almost up, so I will start going over the heat exchangers.
Do I need to remove the oil cooler to clean it?
Thank you
Keith"

"It is possible to open the oi

"It is possible to open the oil cooler with MAP gas, clean it, and reattach with good results. In the 3 that I've cleaned, I found zinc eroded from the pencil plugging some 15 of 21 or so copper tubes. Not cleanable by a simple backflush, you need to open it up. I'm pretty convinced that periodic replacement of the zinc actually makes the situation worse. What I see is erosion due to water velocity wearing away the zinc pencil, and redepositing it nearby on the copper."

"I did desolder a u-cooler on

"I did desolder a u-cooler on the tops, filled it with muriatic acid (50/50) and the brown foam and gunk that came out was impressive. Flushed it out several times, rinsed it with plenty of fresh water and re-soldered the caps back on. While it works just fine and things are normal, I have been advised that this is considered a wear item and replaceable. While I know it is replaceable, I was anxious to know how it works and why it clogs. Once opened, it was easy to see that. I carry a new one JUST in case as the other engine needed a replacement when I discovered small beach pebbles stuck in the core. The engines did NOT have sea strainers when I acquired the vessel....BUT IT DOES NOW!"

"the owner's manual I have

"the owner's manual I have says swap them out every 30 days. In the 22 years I've had it, the only time we have had the blockage problem is when we failed to satisfy the 30 day requirement. There's not much, if any erosion during that time frame. It's like that old fram commercial...pay now or pay later.

I'm convinced the oil cooler zincs are much more susceptible to this issue than the ones in the HX. I believe the flow rate thru the oil cooler is much higher than the HX due to the passage size difference. Also, the oil cooler zincs are smaller. It's been a while since I've had to take an oil cooler apart but I'm pretty sure it's water tubes are smaller than those in the HX.

I've been successful in backflushing mine but I'm prettty good at not letting it get too bad. If you haven't been good about zinc maintenance, take it apart as Dave suggested, and go from there"

After I desolder the u-cooler

After I desolder the u-cooler and have it apart-how do I clean out the zinc material that has bonded to the copper tubes?

"The redeposited zinc is britt

"The redeposited zinc is brittle and breaks off with a dull, metal tool. I did not find it necessary to pull off both caps, only the bottom one. It would be interesting to see how the zinc reacts with an acid cleaning, for that matter, the copper also. There is an aftermarket oil cooler (coolcraft?) that has a larger lower water passage, that should reduce this issue."

"You can use muriatic acid - a

"You can use muriatic acid - any good hardware store - dilute it 50/50 and rinse well afterwards with plenty of fresh water. It will disintegrate any zinc flakes but usually isn't necessary. As Dave said, the remnants come off with minimal effort. If you are not certain about what this entails, just take it to a radiator shop and ask them to clean it.

If you want to be really thorough, get an oil galley cleaning brush and make a few passes thru both vertical legs while it is apart."