1988 4.3 l/x alpha one overheating

[bobnorwich]

Hi People, the temp warning buzzer sounded today on my engine. I had been moored with the outdrives facing an incoming tide so possibly something got hooked on the leg and got sucked in. The pipes felt hot below the stat housing but cool at the risers, i think this might have been decieving as i pulled the stat which is about a year old and looked in good condition. I would like to know if there is a logical approach to solving this problem. Is a first step to remove the hose from the outdrive pump to the thermostat housing to see if there is water coming out? I'm sure an overheating problem solver for my engines is out there but i couldnt find it on here. Also, i want to try to avoid taking the boat out of the water if possible as its 32 foot! If the water in take pump has sucked something in, can air be blown down to get rid of it (the drives were serviced last year). Thanks in advance guys.

 

[Don S]

Re: 1988 4.3 l/x alpha one overheating

First thing to look for in an overheat on a marine engine is the raw water pump impeller.
On an Alpha I drive, the impeller should be replaced every other year. With an overheat, it's still the first place to look.

Also, i want to try to avoid taking the boat out of the water if possible as its 32 foot!

That is the hazards of having a big boat with outdrives. Especially ones with raw water pumps in the outdrive.
With that type of boat, change they yearly before the boat goes into the water. Then you have 2 less problems that require the boat to have to come out of the water for repair.

 

[Uraijit]

Re: 1988 4.3 l/x alpha one overheating

Hi People, the temp warning buzzer sounded today on my engine. I had been moored with the outdrives facing an incoming tide so possibly something got hooked on the leg and got sucked in. The pipes felt hot below the stat housing but cool at the risers, i think this might have been decieving as i pulled the stat which is about a year old and looked in good condition. I would like to know if there is a logical approach to solving this problem. Is a first step to remove the hose from the outdrive pump to the thermostat housing to see if there is water coming out? I'm sure an overheating problem solver for my engines is out there but i couldnt find it on here. Also, i want to try to avoid taking the boat out of the water if possible as its 32 foot! If the water in take pump has sucked something in, can air be blown down to get rid of it (the drives were serviced last year). Thanks in advance guys.

Pretty much. I just went through this myself.

Pull the hose off of the inlet to the power steering cooler, and fire it up for a few seconds. There should be good flow of water through that hose. If you're not getting water though there, you either have a blockage in the pickup, or you need to replace the impeller. If that's the case, the boat's gotta come out of the water.

If you're getting water flow through the transom, your problem lies inside the boat, and you can work on tracing it out, with the boat still on the water. Put the hose back on, and pull the hose from the 'stat housing, and see if you're still getting good flow. If not, your power steering cooler is probably plugged.

If that all checks out, just keep moving further and further along the line, until you find where the blockage is.

In my case, it was at the circulating pump (the water pump on the engine), I'd installed it with gasket maker, instead of gaskets, and I'd used a bit too much, which had squished out and blocked some of the water flow...

If the impeller hasn't been replaced in the last 2 years, you should replace it now anyway...