Logo
FULL SITE MENU

50 GL Engine running cold

J

jerryl

New member
"I have a 2000 Larson with twi

"I have a 2000 Larson with twin Volvo 5.0 GL engines that I purchased and just put in the water. I boat on an upstate NY finger lake so the water is fairly cold this time of year. One engine runs fine and the temperature is approximate 170 degrees after it warms up. The other engine however will not go above approximately 100 degrees at idle. Once out at a 30 mph cruise it reached 115 degrees. The only difference between the two engines is that the one running cold does have taps that go to the hot water heater and back to the block. I have replaced the thermostat which did not help. When feeling the thermostat housing, hoses, exhaust lines, etc. they are not warm so the engine is not getting hot. Does anyone have any ideas what the problem may be? I can find nothing wrong. I would appreciate any ideas I can get. Thanks.
Jerry"
 
"First check your sending unit

"First check your sending unit and temp. gauge. You can do this by dropping the sending unit in boiling water.

What type of 'hot water heater' do you have? Onboard domestic? Chances are water is circulating through this heat exchanger and lowering the temperature. I am not familiar with the setup, but I would imagine there is some form of control valve, or isolation."
 
"Thanks for the feedback. I f

"Thanks for the feedback. I fixed the problem this weekend. The thermostat housing was clogged with old impeller pieces. The 5/8 input and internal bypass hole in the thermostat housing was clogged. You could not see it, only when you tried to push a screwdriver through would you know it was clogged. Other test would be to put a hose to the input of the housing and see if water came out all ports. Fixed this and the engine now runs at the correct temperature. I never checked for a clog the last time because I thought a clog would make an engine overheat. Learned something new. Thanks for the help
Jerry"
 
my volvo 5.0 runs hot when I g

my volvo 5.0 runs hot when I get on plain will drop back when I go back to idle or run slow.
Any idea on what to chek. Just put a new rwp on also Had the engine pulled and the transum housing tightened because it was leaking could they have pinched or plugged something?
 
"Scott, I would open a new pos

"Scott, I would open a new post on your problem. Running hot could me a lot of things. If rwp is a raw water pump then I would assume you also replaced the impeller. Then it could be the thermostat or a blockage some where. If it worked before the engine was pulled, I would assume that something was put together wrong or got kinked on reassembly. The only way I know is to step by step eliminate the possiblities.
Jerry"
 
Back
Top