Cooling issue

[POINTER94]

I fired up my 88 5.7L mercruiser w/alpha 1 after being winterized two seasons ago. New babay boy took up my free time. I hooked everything up and turned on the water and she fired right up. Problem is that the hose water was not discharging from the stern drive. The engine ran clean - no white smoke and I didn't see any water going into the bilge. She got up to about 200 degree before I killed it.

This is very preliminary but other than the impeller which I may have messed up, winterizing with a novice who did what he was told but had no clue what he was looking at (shame on me) and I was trying to run antifreeze (pink stuff) thru. It never made it after 6 gallons thru the bucket. I drained the water at the petcocks and put her up.

Any chance of freeze damage causing this lack of cooling water or just the likely suspects of impeller, thermostat, etc.

 

[HT32BSX115]

Re: Cooling issue

Problem is that the hose water was not discharging from the stern drive. The engine ran clean - no white smoke and I didn't see any water going into the bilge. She got up to about 200 degree before I killed it.

So you didn't see ANY water coming from anywhere at the back of the boat?

(um.....did the hose have a kink in it?)

 

[POINTER94]

Re: Cooling issue

Yes, there was water going thru the hose but nothing coming out around the transom bracket or out the end of the prop.

 

[Don S]

Re: Cooling issue

Impeller is the first thing to look at.

What was done during winterization? Was the impeller changed?

 

[POINTER94]

Re: Cooling issue

Thanks Don,

I replaced the impeller midseason two years ago (about 50hrs of duty before stored for 1.5 years) due to creeping temperatures at idle. It was replaced with one of those blue ones that are supposed to be resistant to running dry. FWIW this did not fix the creeping increasing temps at idle.

Winterization includes:
Outdrive gearcase lube change. Grease zirks.
New fuel filters.
Oil Change/filter.
Engine fogging.
Fill fuel to 95% and stabilized.
Run pink antifreeze thru the power steering hose lines. Drain the petcocks.

I will change the plugs after first use of the season.

 

[Don S]

Re: Cooling issue

It still come down to you need to check the impeller first. Assuming you have a raw water cooled system on the engine. Disconnect the hose at the thermostat housing that goes back to the transom shield.
Aim the hose out of harms way and start the engine (With muffs and water on of course) You should get a good flow of water out of the hose in just a couple of seconds.

 

[HT32BSX115]

Re: Cooling issue

You may have the remnants of a previous impeller failure plugging up your oil cooler or thermostat housing

 

[POINTER94]

Re: Cooling issue

Thanks Don, its been a while since I have messed around in the engine. I'm not thinking clearly. I'll hop on that and see what happens.

Ht32 - Good point about the remains of the old clogging things up I can pull the housing and see what is on the thermostat. I was tracking your post from earlier tonight.

 

[HT32BSX115]

Re: Cooling issue

If that engine has an oil cooler, it'll be between the raw pump and the thermostat housing, those pieces will be crammed in the oil cooler depending on the type of heat exchanger it is.

When I found mine plugged I was amazed that Any water got thru it!


Regards,


Rick

 

[POINTER94]

Re: Cooling issue

Rick, I am not sure if the engine has an oil cooler or not. Where would it be located. It is your typical chevy 350 where do they put it. The water pump is on the fron of the engine and the thermostat just above it. There are four hoses entering the thermostat housing. This has been a fresh water boat exclusively if that matters.

 

[HT32BSX115]

Re: Cooling issue

There's a water hose that comes from the transom to the thermostat housing It's the raw water line supplied by the raw water pump. If there's an oil cooler there it will be in that line usually. Mercruiser puts them all over the place. side, back and front of the engine.