Cooling Question: SOLVED!!!

[Don S]

Re: Cooling Question: SOLVED!!!

You probably just need to replace the manifolds and risers. They can get plugged up in places you can't get to for cleaning. Besides, having to clean them means they are past their useful life anyway, and cleaning could end up putting a hole in the web of the manifold and water into the engine.

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

I cleaned them last year but didn't pressure test them. Could the manifolds be the reason for air getting into the system?

 

[Don S]

Re: Cooling Question: SOLVED!!!

Like I said before, you will not get air in the system on the pressure side. Only on the suction side of the raw water pump, and it's in the drive, so any leaks on the pressure side would leak out, not draw air in.

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

Are you saying, I wouldn't get air in the system even if I had a gasket leak or a warped head? Wouldn't compression gases or exhaust gases get in, they are at a higher pressure than the cooling system??

 

[Bondo]

Re: Cooling Question: SOLVED!!!

Try Sealing Off different parts of the cooling system,+ Pressurize it with Air,+ Listen for Leaks.......???<br /><br />Isolate the Block,.. or Manifold,. or Whatever section you want to Test.......<br /><br />How about Compression,+ Leak-down Tests....????

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

I checked the compression last night:<br /><br />#1 - 145<br />#2 - 145<br />#3 - 150<br />#4 - 145<br />#5 - 150<br />#6 - 150<br />#7 - 110<br />#8 - 150<br /><br />This was done with a cool engine, however the numbers look good other than the #7 cylinder. Could be where I am getting some compression gases in the cooling system. I will perform leak down test tonight. Any comments or tips?

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

I also forgot to mention that I noticed a couple of exhuast valves that were almost white in color, the rest were a brownish color. I can' t remember which ones off hand, I'll let you know tonight.<br /><br />What does the white color mean if anything?

 

[Bondo]

Re: Cooling Question: SOLVED!!!

What does the white color mean if anything?

Usually a Lean condition...............<br /><br />For a Leak-down test,.... I bring the piston to the Up-stoke, on the compression cycle,.... <br />Hold the motor so it can't turn,+ blow in Full Shop Air.......<br />And Listen.........

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

Thanks Bondo,<br />I will be doing the leak down test tonight. From your experience, would a blown head gasket or leaking head gasket into the cooling system still give me 100psi compression on that cylinder? <br /><br />Let's say that it is a blown head gasket on that cylinder, shouldn't I have water in that cylinder or water in my oil as well?<br /><br />Thanks<br />Keith

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

Before doing the leak down test on the bad cylinder I performed another compression test. Keep in mind these are cold compression numbers.<br /><br />Results after 4 strokes:<br />#1 - 135<br />#2 - 140<br />#3 - 150<br />#4 - 140<br />#5 - 155<br />#6 - 150<br />#7 - 125<br />#8 - 155<br /><br />I performed a leak down test on number 7, since it was the lowest on both compression test and I heard air coming out of the carburetor, a lot of air. To make sure I wasn't doing something wrong I tested cylinder number 8 and got a little air coming out of the oil galleries of the heads. <br /><br />I assume that this means I have a burned intake valve on 7, and maybe some worn rings on 8. However, I would think that with a cold engine you are going to get some leakage past the rings right?<br /><br />I know, I need to complete the test on all cylinders, however time is a problem for me. <br /><br />What should my next steps be other than completing the leak down test? Pressurize the cooling system and listen for air or see if water fills any cylinder?

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

Hey....I'm back..same problem.<br /><br />I replaced the head gaskets after I took the heads of for servicing, cleaned/flushed out the block (man! was there some scale in the block!). Cleaned out the manifolds and risers with fresh water....have great flow through them . I put clear hoses as I have before from the leg pump to the thermostat housing and from the thermostat housing to the risers. The water is moving through there but just doesn't look fast enough. How much water should be pumping through the engine at idle? It just looks like the water is pumping through there so slow that it is keeping the block from staying cool. <br /><br />Here is what I did as far as test runs:<br /><br />With the thermostat installed the engine will stay at a constant temperature of about 150 at idle rpm of 700. When put into gear at about 1500 rpm the temp slowly climbs to about 160. Then when up on plane at 3000 rpm the temp slowly climbs up past 190.....I then put it back in neutral and reved the engine up and it would only cool down to about 175.<br /><br />Took the thermostat out and it would run about 140 at idle rpm then when up on plane at 3200 rpm would slowly climbe to 175 and hold that forever. When put back into neutral and reved up it would cool back down to 150. <br /><br />I bought a new water pump kit for the outdrive and will replace that tonight (the impeller was replaced by a local mechanic last year). I just want to know how much water should be pumping out of the leg pump at idle?<br /><br />Also, the clear hoses show small air bubbles, about the size of BB's or smaller when running.

 

[Haut Medoc]

Re: Cooling Question: SOLVED!!!

Is it possible that you have a heat distorted water pocket cover or pump base. You see bubbles? How many? A lot? ACHRIS posted some stuff about that, you might look at some of his posts......J

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

It is not many bubbles coming from the drive pump. Sometimes the clear hose from the drive pump looks completely solid with water and then sometimes it has very few but steady small bubbles coming in. I see more bubbles going out of the thermostat housing than I see coming into the thermostat housing. Not sure why??

 

[Haut Medoc]

Re: Cooling Question: SOLVED!!!

That I would think is just the water getting heated, and the gases expanding...J

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

That was my thought as well, as I have all new gaskets and am 99% sure I have no manifold leaks. I'm going to be taking the lower unit off tonight to replace the entire water pump/housings. Anything else I should look for while I'm in there or any tips you can give me? Didn't you have some trouble at one time with the water pocket cover or water tube?

 

[Haut Medoc]

Re: Cooling Question: SOLVED!!!

No, but while you have the drive apart, you should really look the water pocket cover & tube....My problem was my heat exchanger...Good Luck......J

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

Got the drive apart last night. As you know the first step is to drain the oil....guess what. I had a milkshake in their. And only drained about 16 oz. out of the 32 oz. that should be in their. Not a good start. Took the water pump apart and what do you know, worn out as hell, two fins broken and barely hanging on, dry rotten. The o-ring seal around the drive shaft was not even there, and I had a milkshake on the drive shaft splines. The water pocket cover looks fine, kind of hard to tell whether it is in good condition or not. The water tube and grommet looks good, it feels a little loose but not sure how loose it should feel. <br /><br />Goes to show you what the mechanic did last year. I paid him to service the outdrive: new water pump kit, pressure check the gearcase, and refil with oil, and check my shifting. I trusted him on that, and have done all this work since then thinking I had another problem other than the water pump, when all along the damn mechanic didn't do his job. I just can't see a water pump looking like this when the boat has been run maybe a total of 8 hours since this time last year trying to figure out why it was still overheating. <br /><br />I also don't understand how the gearcase oil ended up like a milkshake. I saw the mechanic draining the old oil out and it looked good, he supposedly pressure checked and refilled the drive. Now I have very little oil in their and am getting water in somehow. No wonder I was hearing a slight roaring sound from drive!!<br /><br />As for the water pocket cover, what is the best way to go about checking it without taking it off? Should I plug the water tube with something and hook a water hose back from thermostat housing, put a little water pressure on it and see if leaks? <br /><br />What about my gearcase....where would the water come in from?

 

[Haut Medoc]

Re: Cooling Question: SOLVED!!!

What a bummer.... Bad bellows would be the first obvious guess....If the water pocket cover looks O.K., don't mess with it.....Water can get in through the shift shaft, prop shaft,water pump base or the gasket between the gimbal ring/drive. Was there water/oil present in your bellows? Your drive needs to be dis-assembled, cleaned out, replace any worn or damaged parts and re-sealed at the very least.You probably need a new drive. You also need to check the condition of your bellows. I would have a talk with the person/marina who performed the previous work ...J

 

[kwoolard]

Re: Cooling Question: SOLVED!!!

I just removed the lower unit from the upper unit, didn't completely remove the drive. So not sure about water in the bellows. However, I just replaced the bell housing and seals, all new bellows and gaskets on the stern drive. The only that I am not sure about are the prop seals, the shift shaft seal, and the water pump base seal (all in lower unit). Hopefully, it is the water pump base seal since that is going to be replaced. I think the gears and everything in the housing are fine, was just low on oil and had some water intrusion some where. Oil could have been low because it was leaking out. What is the best thing to flush the upper and lower gear housing with to remove all the water/oil without disassembling?

 

[Haut Medoc]

Re: Cooling Question: SOLVED!!!

Without dis-assembly the best thing I can think of is to add/ drain gear lube several times and run it in between. You really need to pull the top of the drive off and see whats going on inside the bellows....If you have a water/gear oil mix, your yoke/yoke seal is shot and your drive will not hold the lube inside. When you pump it in it will just go past thst seal into the bellows. Sorry, but it doesn't look good..J