Volvo Penta Cooling Issues

[Bonezink41]

I have recently bougot a boat that is equipped with two old Volvo Penta Tamd41P-A engines. The port side engine gets hot while running at speed about 3000 to 3200 rpm.
It cools fast when I drop Dow to about 2000 rpm. Heats up again when I try to get it out of the hole and back at cruising speed. The Starboard engine stays at a constant 180 degrees.
I changed the impeller today with a brand new one and it didn’t solve the problem. Was hoping for the simplest fix but no such luck.
I’m new to this and not very mechanically inclined but trying to learn. Any help would be greatly appreciated. Thank you in advance. Bonezink41

 

[phillyg]

I'm assuming you're looking at the temps on dash gauges. First thing I would do is check with an IR thermometer at multiple places on the motor to see if it's really overheating. If it is, start with the thermostat. Also search for a couple of VP overheating threads on this site for some solutions.

 

[Sea Rider]

How old are both motors, were run in fresh or saltwater ? What' the gauge temp shown for the motor that's overheating ?

If a motor was not heat tested at different parts with a IR gun when new or out of the box soon after won't have the slight idea which temp to look for at such parts for comparison purposes which will indicate that the motor heats more or it's overheating extremely bad.

If plan installing a new thermostst check the internal housing to see if gunked, salted, rusted or a combo of most of them depending on where you had the motor running and the crap formation that has collected so far,.

Happy Boating


​

 

[Horigan]

I have the same engines on my Commander 30 and one runs 10 degF hotter than the other one. First confirm the difference with an IR gun, per above. When were the heat exchangers last cleaned? If you don't know, then get that done. Swap the thermostats between engines to see if the problem follows the stats. There are two per engine. Finally, the raw water pump interior surface can wear and result in lower cooling flow. They can sent in to get overhauled, but it's not cheap, nor quick. We intend to get a spare pump so we can get our hotter engine pump overhauled.

Here's a good link for Volvo diesel engine parts.
Volvo Marine Diesel Engines

 

[QBhoy]

So many things can affect these and their temps. Other than water pump, Things like
Sea strainer blocked
Heat exchanger between raw and closed cooling needing cleaned
Valve clearance needing set (as they do every few hundred hours)
Turbo exhaust elbow getting carboned up (famous for it)
Leaking injectors (but doubt it would have a huge affect)
Oil cooler needing cleaned out
Intercooler needing cleaned.
one drive not trimmed as well as the other an loading up engine more than the other.
But as said earlier…dash gauges are not too accurate and most of all…I’ve never seen a twin engined boat with tamd’s that run the exact same temps. One always starts better than the other too. Haha.