White smoke in E38 Universal diesel engine

Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
Marie,

Well, maybe your video shows steam. If true, that's better than smoke. (Actually, as a result apparently of temporary site migration issues, your video now displays not either, but instead my friend Olivia Wyatt in a music video--at least on my computer).

I have steam in the exhaust ,too. Also, not as much water burping out of the exhaust as expected. That prompted me this week to rip out my entire cooling system to replace all hoses and revise the heat exchanger/water heater path. Overkill, no doubt.

As Bob says, often steam is result of not enough raw water entering the exhaust system. That may just mean servicing the heat exchanger, or finding some other constriction in the raw-water cooling circuit.

I'll report next week on whether my steam is reduced by a clean heat exchanger.

Oh, and your rpm is lower than expected*, even with a 3-blade (*if you have the typical Universal 5432; mine runs at 2300 cruising). Often tachometers are incorrectly calibrated. If you can make the expected 6-7 knots, that might be it. At only 1700 rpms I'd be making about 5 knots with my 3-blade Sailor prop.
 

Baslin

Member III
Marie,

Your prop may be oversized or the pitch is off. Might want to check if the prop has been replaced at some point or possible bent.
 

debonAir

Member III
I'd expect top RPM to be a bit low when in gear and tied to the dock. The water is moving about 7kts slower past the prop than it would underway, but 1700 does seems low even there.

When was the last time your raw water pump was serviced (new impeller and clean raw water strainer at least)?

You probably have two coolant reservoirs. One that is connected with two sturdy hoses to the engine's fresh water pump and heat exchanger which is the regular one like you'd have in your car, and the other one would have a small hose to the exhaust manifold which is just an overflow tank for the manifold's coolant supply. I think the manifold can get hotter faster than the engine block and the expanding coolant needs a place to go before the thermostat opens and the main coolant tank would take it?
 
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Christian Williams

E381 - Los Angeles
Moderator
Blogs Author
Marie,

Here's my full report on steam in the exhaust. https://ericsonyachts.org/ie/threads/cooling-system-upgrade-2020.17240/

Also: The plastic jug is a coolant overflow container. It connects by a small rubber hose to a stub under the pressure cap on the engine. If coolant expands while the engine is running, it rises into the plastic jug. When the engine is shut off and the coolant cools, it gradually returns to the manifold tank on the engine.

I usually have very little coolant in the jug even when running.
 

MCD

Junior Member
Good news, we were able to take the boat out and make the compression test, and I think we can rule out any serious compression issue!
The rpm reached 2100-2200 full throttle, which is what we used to have if I remember correctly. And when opening the oil valve at the top of the engine while running, not oil splash.

My plan is to investigate the cooling next.
When was the last time your raw water pump was serviced (new impeller and clean raw water strainer at least)?
We had an issue with the raw water intake earlier this Fall. We turned out to have the through-hole blocked by growth and were able to unclog it. Before finding out though, we replaced the impeller and clean the raw water strainer (it was a little dirty bot not much).

Thanks Christian for pointing that out. It's nicely documented and will for sure be super handy if we have to do that too -which I'm afraid we may have to do. Patience as you said!
 
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