Acid flush raw water system.....

[oscarvan]

Here are the "before" pictures. Rigging the plumbing as we speak. I don't know if it's bad enough to cause it to run warm, but it certainly looks like it won't hurt. Can't seem to get them in focus but you get the idea.....

 

[jim rosenthal]

How long for the "after"?

 

[racclarkson@gmail.com]

I’ve seen lots worse, it needs it in my opinion.

 

[oscarvan]

Not what I wanted to hear...... If it's not "that" bad it may not be the cause of my temp issue. The impeller was in good shape. There was a lot of scoring in the plate so that's being replaced.

Still waiting on a temp sender. The one in there may not have been the right one.

Meanwhile after 45 minutes the solution is turning black.

During:

 

[GCSI]

Keep in mind that even if the impeller "appears" to be in good shape, they can loose their elasticity and not pump as efficiently as intended. If there is any doubt, go with a new impeller.

 

[rustybucket]

Can you give us an idea of what your temp issues are? Have you verified anything with an IR temp gun? Any details may help others get you pointed in the right direction.

I agree that what you are doing was probably needed, but was it the cause of the overheating? maybe, maybe not.

 

[Boatsb]

Rebuilding pumps that are worn out may he the problem.

I send customers pumps to depco all the time. Funny what they find. Its worth it.

 

[oscarvan]

Keep in mind that even if the impeller "appears" to be in good shape, they can loose their elasticity and not pump as efficiently as intended. If there is any doubt, go with a new impeller.

It feels pretty good, but nevertheless there's a new one going in.

 

[oscarvan]

Can you give us an idea of what your temp issues are? Have you verified anything with an IR temp gun? Any details may help others get you pointed in the right direction.

I agree that what you are doing was probably needed, but was it the cause of the overheating? maybe, maybe not.

According to the gauges it runs 5º warmer (180) than the port side at 13-1400 RPM. At 1800 RPM the port side goes to about 185-190, but the starboard side heads above 200. Again, according to the gauges.

Couldn't find anything above 193-194 with the IR gun, aiming at fresh water pump, the pipes where the senders are in and the thermostat housing. That's too warm though.

SB mechanical gauge is hard to read due to very coarse calibration but also heads north of 200 at high RPM.

Never did get an alarm.

 

[madhatter1]

Oscar, When I had overheating issues on my 34 it was never one problem. A series of issues that all added up. Intake, impeller, rubber pieces stuck, fuel cooler, trans cooler, All contributed some. Then on once with a new impeller raw water did not flow right. That turned out to be worn lobe on the pump itself that would not flip the impeller blades enough anymore. Didn't even know that was possible.

Save yourself some time. Go through every aspect of your cooling and raw water systems as a whole. Then grab some more sunrises and sunsets.

 

[jim rosenthal]

Depco do a great job. You might give them a shot at rebuilding both pumps. Also make sure none of the sewater intake hoses are soft- if they delaminate, they can obstruct the flow of water under suction from the pump, they will actually close up a bit.

 

[oscarvan]

Oscar, When I had overheating issues on my 34 it was never one problem. A series of issues that all added up. Intake, impeller, rubber pieces stuck, fuel cooler, trans cooler, All contributed some. Then on once with a new impeller raw water did not flow right. That turned out to be worn lobe on the pump itself that would not flip the impeller blades enough anymore. Didn't even know that was possible.

Save yourself some time. Go through every aspect of your cooling and raw water systems as a whole. Then grab some more sunrises and sunsets.

Doing it, one step at a time.

 

[oscarvan]

And here are the afters..... Although it appears to have improved I am not having a "wow" moment.

 

[SKYCHENEY]

I would change the thermostats and seals. One theromstat that sticks just slightly short of fully open can cause the same issue.

 

[racclarkson@gmail.com]

And here are the afters..... Although it appears to have improved I am not having a "wow" moment.

I don’t like that either. What solution are you using?This is what it’s supposed to look like.

 

[oscarvan]

I don’t like that either. What solution are you using?This is what it’s supposed to look like.

Klean Strip Concrete and metal prep..........

 

[Boatsb]

Its a green solution so it leaves some color. This the downside of it.

 

[oscarvan]

I would change the thermostats and seals. One theromstat that sticks just slightly short of fully open can cause the same issue.

New thermostats in stock. And I agree with that assessment. It was the next thing on the list. Which brings me to the following......

The manual I have is (also) for trucks. They have radiators and things look slightly different. The main characteristic of the thermostat housing is the square with four bolts. I am 99% the first pic is it on top of the fresh water pump with the electrical temperature probe in it's body. (Not visible in the pic) I assume the sender on top is the alarm.

So that begs the question: What is the second pic? Square housing, 4 bolts, connected to the fresh water reservoir and the transmission oil cooler in the bottom of the reservoir/heat exchanger. It also has the mechanical temp probe in it. (Visible in the picture) Out of the bottom comes a tube to the exhaust manifold.....

 

[racclarkson@gmail.com]

You have thermostats on each bank. I have four per my 12/71. You can test the thermostats. But I think you’ve got to get those pipes clean. Mix is 17 quarts water to 3 quarts acid for 5 gallons total. Probably 90 mins and a good rinse.

 

[SKYCHENEY]

I would suggest a slide hammer seal puller to replace the seals and new bolts when you reinstall the housings.