2.3 OMC overheating!!! HELP!

[outboardrookie]

Hey folks. The boat is a 1989 19' Bayliner with a 2.3 OMC Cobra. I've done tons of research and haven't been able to solve the problem as of yet. I purchased a boat a couple weeks back and it is now overheating, which I'm sure was a problem that wasn't disclosed when I made the purchase but it's my problem now. I had it out a couple times and it was fine, but now it is overheating at idle. I changed the impeller, which actually appeared to be fine but I changed it anyway. I then ran it with the muffs and it still got hot. Planning ahead, I ordered a new thermostat so I figured I take out the old one and change it, and that I may as well check the old one to see if it was the problem. Well, when I removed the thermostat housing, THERE WAS NO THERMOSTAT!! Boy, was I happy about that! So I put one in and ran it with the muffs. It got up to about 175 then it appeared the thermostat opened and it cooled down and maintained temp just below 175 at idle for ten minutes. Problem solved, right? WRONG.

I took it to the lake today with it all loaded up for fishing and tubing, and the whole family along. I let it sit at the dock and warm up to temp, and it began overheating. I turned it off, then performed the test to make sure the impeller is pumping. I only let it run for about five seconds, and very little water was just bubbling over the top of the hose. I brought it home and checked the impeller and it appears fine as it is new and I just put it in a couple days ago.

Now, one thing I did notice after I changed the impeller is that there is water leaking from just above the bottom bolt from the inside of the impeller housing. That is not supposed to discharge water, correct? My new theory is that I was scraping the old gasket sealant off of the inside of the housing when I replaced the impeller and I may have cracked the housing, now allowing water to be pushed out of the impeller housing instead of through the motor. And the reason it may have not been overheating in the driveway is because the hose was providing enough pressure to get the water up into the motor. I also flushed the motor with the hose and water is running throughout, so I don't think I have a blockage anywhere. ANY SUGGESTIONS???

Thanks!

 

[MRS]

Re: 2.3 OMC overheating!!! HELP!

Your cover should not leak any where that means air getting in can cause over heating. But you should have a vent hole if the same as mine I think it is below top left bolt (4.3-86) Plus if water is not coming out vent make sure it is not plugged it can plug and cause overheating also happened to mine once.

 

[outboardrookie]

Re: 2.3 OMC overheating!!! HELP!

Your cover should not leak any where that means air getting in can cause over heating. But you should have a vent hole if the same as mine I think it is below top left bolt (4.3-86) Plus if water is not coming out vent make sure it is not plugged it can plug and cause overheating also happened to mine once.

Thanks for the input. I checked the vent and it doesn't appear to be plugged. I just blew on the vent in the impeller housing and air flows through, and I also blew on the vent hose going to the lower unit, and air is coming out of that as well.

I think the housing is screwed. I don't know the history of this boat. The previous owner said he took "great care" of it, but I found out his buddy owned it for a few years and he just bought it back. It looks like the plastic on the housing where the metal liner rests that the plastic melted, so I think at one point they ran it without water and it melted the housing, thus making a crack in it.

I ordered a new housing, so hopefully that will do the trick.

 

[MRS]

Re: 2.3 OMC overheating!!! HELP!

Ya if melted you do need to change plus on that vent water should squirt out of it when running.

 

[outboardrookie]

Re: 2.3 OMC overheating!!! HELP!

The vent tube connects to the vent on the housing so....(stupid question) should I disconnect the hose from the housing while the motor is running to see if it is venting properly? If so, water should be running out...correct?

I honestly thought I could fix this myself, but I may be bringing it in and spending more money on this boat. We'll see.

 

[MRS]

Re: 2.3 OMC overheating!!! HELP!

Leave hose on you should see water coming out I only said because you said it was melted could have sealed the vent hole.

 

[jpwilly]

Re: 2.3 OMC overheating!!! HELP!

I noticed the temps rising on my 2.3l OMC on the second outing of the year. I knew it had to be in need of a new raw water pump so I tore it down and verified. Then I ordered the impeller kit, comes with new houseing etc and I followed a you tube video for proper installation. You'll need some copper based anti sieze, grease and avaition gasket sealer to do the job right. Fortunately on the Cobra this is an easy job... just be sure to do it right and you can be sure that the Raw water pump isn't the issue. Next check the water pump on the engine and then I'd check the manifold at the elbow to be sure it's not rusted up and water is flowing out of the manifold and into the exhaust properly. You could find a fried flapper or some debris plugging up the works.

Good luck.