Overheated OMC 2.3L

[aJohn79]

I have a 1990 2.3L OMC. Ihave owned it for two years with no problem. I took the boat for the first ride of the year on Sunday and it overheated. It run well for like 20 minutes while on no-wake zone. It overheated after runing a bit below WOT for 5 minutes. After that I let it cooled down a bit and started again to see if I can go back. Nope, the temperature went up again to 240 and tuned off inmediately. Tried at idle and with a little gas and had the same overheating problem. The lake water still is very cold (~55).
The day before, Saturday, I run the engine with the hose connected and run with no problem for a long time while I did tune up and adjusted/cleaned the carb.
The water intake screen was clean. I also examined the impeller and it is in very good shape. I don't see any excessive wear. What are the typical problem areas? pump, thermostat? what is the best way to diagnose?
Thanks.
-Please read my update below -

 

[Boatin Bob]

Re: Overheated OMC 2.3L

WIth the engine cold I would start it up (in the lake) and remove the input hose from the t-stat and hold it facing up, you should get a 2 to 4 inch head of water out of it letting you know the impeller is working ok.

 

[aJohn79]

Re: Overheated OMC 2.3L

I probably could try starting the engine in the garage and submerging the bottom of the stern in a bucket, right?

 

[aJohn79]

Re: Overheated OMC 2.3L

Update and questions:

I connected the garden hose to the lower unit (via the ears, which I don't know the correct name for) and,
- with impeller out, water came out through opening on upper unit.
- with impeller installed and with engine off, water did not come out though the t-stat input hose. I was expecting to see water coming through it due to the water pressure from the hose. Is this correct?
- started engine, impeller installed, with the garden hose still connected, water did not come out through t-stat input hose.
- impeller looks in good shape. I am able to turn the shaft that drives the impeller with no effort. Does this make sense? Shouldn't it be connected to the drive shaft and require a lot of effort to turn?

Any help? am I missing something?

 

[aJohn79]

Re: Overheated OMC 2.3L - shaft? no water?

Re: Overheated OMC 2.3L - shaft? no water?

I guess, if the impeller is not turning, it may not allow water to flow up to the engine when off. But, as I explained in the post above, when I start the engine I did not get any water either. If the impeller is turning, I should get water at the t-stat hose either due to the impeller working or the pressure from the garden hose. I am still confused on why I can turn the impeller shaft so easily. I refer to the shaft coming from the upper unit. Any ideas?

 

[Maclin]

Re: Overheated OMC 2.3L

I am thinking you should not be able to turn the impeller shaft at all, and that you are about to find out your problem...missing keyway or broken shaft or gear somewhere.

 

[bruceb58]

Re: Overheated OMC 2.3L

You should not be able to turn that water pump shaft by hand. It is directly connected to the u-joint shafts coming from the engine.

 

[aJohn79]

Re: Overheated OMC 2.3L

is it easy to open the upper unit to inspect? what could have happen for it to break? the propeller turns fine so at least I know I have rotation down there and that the u-joints are ok. Then, how can the shaft break?
I also noticed that the shaft can be easily moved a up and down.

 

[Don S]

Re: Overheated OMC 2.3L

The shaft the runs the raw water pump impeller is obviously broken. How and why? Can you say metal fatigue. No way of knowing for sure, but trust me, things break sometimes for no apparent reason. And boats are no different.
Best be looking for a dealer. Without the special tools and a manual, there is no way you are going to be able to replace that shaft acccuratly to allow long outdrive life.

 

[aJohn79]

Re: Overheated OMC 2.3L

I will open up the top lid of the upper unit to inspect. Fixing this is starting to sound like an expensive endevour.

 

[aJohn79]

Re: Overheated OMC 2.3L - How far can you go w/o impeller?

Re: Overheated OMC 2.3L - How far can you go w/o impeller?

How far can you boat w/o the impeller? Does the engine get any water at all? Can I use an electric pump or similar as a quick fix? This repair looks like a big deal and I want to still go out tomorrow. The sand bar is 10-15 minutes at low speed from the launch place.

 

[Don S]

Re: Overheated OMC 2.3L - How far can you go w/o impeller?

Re: Overheated OMC 2.3L - How far can you go w/o impeller?

How far can you boat w/o the impeller?

Till it locks up, shouldn't take more than a few minutes if you use plenty of throttle.

Does the engine get any water at all?

None at all

This repair looks like a big deal and I want to still go out tomorrow.

It is a big repair, and you need to jump into a case of reallity.

 

[aJohn79]

Re: Overheated OMC 2.3L - How far can you go w/o impeller?

Re: Overheated OMC 2.3L - How far can you go w/o impeller?

it was a silly idea.... just frustrated...
Today I opened the cover of the upper housing and pulled out a piece of the impellet shaft. I can see the problem now. The oil level was low, just below the bearing of the impeller shaft. I think that explains why it broke.
It doesn't look too hard of a job. The manual lays it out pretty well. At least that's what looks like.
My guess is that I start taking apart the drive unit, take the lower and upper out. Pull the drive shaft out, disconect the u-joint, change the shaft (if I can find it with the helical gear on), reconect the u-jont, insert, and assemble again. Do I have to align? that may be the hard part. Any suggestions?

 

[Lou C]

Re: Overheated OMC 2.3L

If the oil level was low you've got big problems there. That job is one for a mechanic that has the tools and the experience to set up the upper gear housing the right way. The set up of the upper gears is not a job for someone who has not had training in rebuilding outdrives. Plus if you ran it low on oil, there could be wear particles throughout the drive and the lower will have to come apart and get checked as well. Sorry about that, many Cobras got ruined because they were not filled properly, they take 64 oz of gear oil (regular Cobra) and have to be filled from the screw that is near the joint between the upper and lower housings, not the lowermost screw.

 

[aJohn79]

Re: Overheated OMC 2.3L

yeah, you are right. After reading the manual more carefully, I realize I have to hire out the job. Even though, to be honest, I hate the idea. If I only knew the good ones in my area.

 

[aJohn79]

Re: Overheated OMC 2.3L

If anyone is reading this thread, I posted a follow up question, in regards to the repair/exchange/new, on this thread,
http://forums.iboats.com/showthread.php?t=255289

 

[Dakota47]

Re: Overheated OMC 2.3L

do it yourself. you need a alinment bar to install the drive.

 

[wecoyote]

Re: Overheated OMC 2.3L

I probably could try starting the engine in the garage and submerging the bottom of the stern in a bucket, right?

Why not get the part and give it a try yourself? The worse thing that could happen is that you couldn't do it and your out the cost of the shaft and some gaskets. If you are going to buy a used outdrive, you already have the old one off, and all your out is the cost of the shaft, and maybe a repair manual (advisable).

 

[becon776]

Re: Overheated OMC 2.3L

1990 baliner capri 21' cuddy -- ford 2.3 omc cobra
Jeez, the same problem.... only I just had a new cylinder head and block machined new head gasket... engine completely out of the boat. Now, after two day and like 10 hours on the engine I tubed and then went to pick up some ladies at the dock. Immediatly after taking off from the dock (3 min) the water started coming in thru the boat thru the engine compartment. I thought oh **** what now... well we found that a hose had popped off right off near the transom. the hose that supplied the fresh cooling water to the engine. So... I was like YES! they just hadn't clamped the hose on tightly. Get the hose back on... start her up and bingo.. but then within a minute I look and see the I am running at 200 and climbing. Edging at 225. turn off. let sit for a bit. Then turn back on. temp starts out a drops quickly but then climbs back up within 3 minutes. Now here is what I know. Everything ran beuatifully for the two days 10 hrs. I took it easy for the first 6 hours but then said ok let's creep into wot. No problems.

The reality? when that hose popped off... the boat ran wo water for maybe 5 minutes or enough to fill the engine comp.. with water. ?'s are
thermostat?
water pump?
impeller?

it's weird because if I let the boat sit and temp goes from 225 to 200 then start it it will drop immediatly to 150 then climb right back up again. weird. I would say that it is just amatter of the engine being out and put back and soemthing small needing to be fixed but it ran fine till that damn hose popped off. I am getting so damn discouraged. 3 years with zero problems and quite honestly I am OUT of $$ for this freaking thing
1990 baliner capri 21' cuddy -- 2.3 omc cobra