white smoke above 2000 rpm

[rlg]

After a test cruise, she's still smoking. I went to Westerbeke who say its definitely not the exhaust mixer... as you'd expect them to. (I bought it from them and installed myself btw)
They suggested its low flow of raw water causing the problem. I said water flow seems normal...he insisted...
So Ive taken off the HX, it doesnt look too bad,going to get it boiled anyway.
The next step assuming HX is ok is the combination coolant tank/exhaust manifold. Maybe theres a leak between the exhaust side and raw water???
Ive seen this on some other post once.

SO thanks again for all the help and Im still listening if anyone has any ideas..

[tdoster]

There is a post and a person you should talk to on this forum.

Saltyhog is the person, and appears to be online now. This is from another thread:

I know the thread is old, but I thought I'd add something that I hope will help you (and other Westebeke owners) in the future. I noticed in the pics of your W46, you have the older 3 piece exhaust manifold. This was an idea they had to permit using an extrusion for the manifold that could be cut to different lengths depending on the engine / number of cylinders. The caps on the end, along with their seal, keep the coolant in the jacket separate from exhaust. The problem is if that seal begins to leak, you'll get coolant into the exhaust, and eventually in the cylinder. This usually occurs in number 4 cylinder, as the engine tilts that way. Westerbeke corrected this with a later version of the manifold that is a one piece casting. You may want to keep an eye on that manifold / seal. The only way to check is to remove the end piece and at that point, you might as well replace the gasket. I learned of all this from a diesel mechanic in Annapolis who taught the marine diesel class I took. BTW, I guess you figured out what a PITA is is to drain the block of coolant. You have to remove the starter to get to the block drain plug. I keep hoping someone will enlighten me with an easier way, but so far nothing.

[mikereed100]

Originally Posted by rlg

They suggested its low flow of raw water causing the problem. I said water flow seems normal...he insisted...

You may have already done so, but I would again urge you to take a look at the strainer and hoses on the upstream side of your raw water pump. If there is any air getting into the system you may have adequate water flow at low rpms, but as the rpms increase, any loss of vacuum could be limiting your water flow enough to produce steam in the exhaust.

It could be something as simple as a hairline crack in the acrylic lid of the strainer (as it was on my boat), an old o-ring on the strainer lid, a cracked hose, loose or broken hose clamp etc...

[rlg]

Thanks Mike! I found a bit of debris clogging the thru hull for the raw water intake. I freely admit how incompetent I am as a mechanic, I should have double checked after finding the strainer OK twice. The HX is going to get a hardly needed cleaning, I have a couple hours work to do, but thankfully no real financial consequences.


Thanks again to all for their input, Rob

[mikereed100]

Rob,

I once spent an entire day tearing apart a strainer, raw water pump, heat exchanger and exhaust manifold, chasing down an overheating problem, only to realize the temperature guage was bad.

[rlg]

Maybe we should start a new forum topic of mechanical blunders! I have at least a dozen..

[carstenb]

Originally Posted by rlg

Maybe we should start a new forum topic of mechanical blunders! I have at least a dozen..

it would be a never ending thread. lots of contributors (me included)

[a64pilot]

Originally Posted by mikereed100

Rob,



I once spent an entire day tearing apart a strainer, raw water pump, heat exchanger and exhaust manifold, chasing down an overheating problem, only to realize the temperature guage was bad.

that happens more often than you might think

[westwinds]

Have you checked the impeller in the raw water pump? I like to replace every few years whether outboard or inboard engine

[SkiprJohn]

Originally Posted by carstenb

it would be a never ending thread. lots of contributors (me included)

I'll contribute several.

[Tyrone777]

I had a similar white smoke problem. Turned out it was the impeller.