Volvo MD-11 Cooling Issues

[China_Doll]

I have a 23 HP Volvo MD-11 in my Cheoy Lee 35. Raw water cooled. It starts and runs okay but has very little cooling water through-flow, say 1/2 gallon/minute. Thus it tends to run hot although it never gets into the red on the gauge. (I also tend to avoid long runs and minimize use of the engine because of this issue.) I have changed the water pump impeller and checked for clogging in the transmission and other accessible passages, but have found no problems. This leads me to conclude that the internal engine cooling passages are crusted up from salt accumulation. I have read that this is a common problem on the MD-11.

Questions:

1) Other takes on my diagnosis? What other checks should I run t rule out other possibilities?

2) Can anyone recommend a SF Bay Area diesel mechanic who doesn't charge an arm and a leg to assist with diagnosis and remedy? Preferrably East Bay--Richmond-Berkeley Area.

3) I could also use some additional HP and the thought of re-powering has crossed my mind. Does anyone have budgetary numbers for re-powering to say 30 HP with a new Yanmar or comparable?

Thanks.

[DeepFrz]

Check your exhaust injection elbow. That is likely the place where your water flow is obstructed. Try that before you spend money on a mechanic.

[marlborosounds]

I would check to see if the transmission reverse gear water jacket is clogged up. Volvo's are notorious for this and engine will overheat in just
a few mins due to the water restriction.

[marlborosounds]

missed the trans water jacket. Did you try a new temp guage? Also check the heat exchanger. Maybe the core is getting plugged up.

[Viking Sailor]

You didn't mention it so I am suggesting you check/replace your thermostat. I have had the one on my MD17D rust closed.

Good luck.

[NCboatrx]

I have repaired a number of these Volvos over the years and the only way to do it properly is to remove the cylinders and cylinder heads and have the water passages cleaned out properly. This is where any silt and other sediment settles over the years. The exhaust manifold will also need to be cleaned out properly. If you do all this follow the previous recommendation for a new thermostat as well as new rings and gaskets, you will have your engine running cool for years.

I have had good reports about Hirschfeld Yacht Contracting in Sausalito for both engine work and for repowers.

Good luck, Stanley

[boatman61]

Originally Posted by NCboatrx

I have repaired a number of these Volvos over the years and the only way to do it properly is to remove the cylinders and cylinder heads and have the water passages cleaned out properly. This is where any silt and other sediment settles over the years. The exhaust manifold will also need to be cleaned out properly. If you do all this follow the previous recommendation for a new thermostat as well as new rings and gaskets.

I have had good reports about Hirschfeld Yacht Contracting in Sausalito for both engine work and for repowers.

Good luck, Stanley

I'll second that... one was so clogged that I could not tell by eye what was metal and where the holes were... had to poke with screwdriver... ran like a dream after cleaning the system though... took 7hrs... my first ever stripping of a deisel.. maybe thats why I like em... simple enuf for me...lol
Save your money and she'll go for as long again