Engine will not reach operating temperature

[blrnar]

Hi, this engine is a 2000 Volvo penta 4.3 gl(carb) ,this engine always runs cold, replaced the thermostat and tested the new thermostat, however engine still runs way too cool, I can touch the intake manifold as well as the thermostat housing and they are both cool to the touch. What would cause this??


Thanks,

Brian

 

[Don S]

Re: Engine will not reach operating temperature

What temp does it run under a load. On muffs without a load, many never warm up.

 

[blrnar]

Re: Engine will not reach operating temperature

Hi Don, I had it out this evening and under load for about 1/2 hour and it still runs cold under 100 degrees, both the thermostat housing and the intake manifold are just barely warm to the touch whereas the port engine comes up to temp in about 10 minutes. So whats going on ???


Thanks,

Brian

 

[cr2k]

Re: Engine will not reach operating temperature

We have had this problem on 3 boats now. Seems there is a piece of an old impeller stuck in the thermo housing. Hard to see but I bet it is there. Seems like it plugs up and the resulting rise in pressure forces the water out the thermostat and by-pass hoses and doesn't slow down in the block.

 

[blrnar]

Re: Engine will not reach operating temperature

CR2K, I checked the thermostat housing again, this time with a super bright led pen light and I found pieces of an old impeller left by a previous owner in the by-pass passage, removed and re-installed housing and victory problem solved. Thank you very much for your response as it has saved me a huge amount of troubleshooting time.


Thanks,


Brian

 

[air2raley]

Re: Engine will not reach operating temperature

how does an impeller piece get by the power steering cooler.? Is this the impeller you are talking about? I have a similar problem but have a power steering cooler inline with the lower impeller pump.
Is the By pass the hole that is in the Tstat housing that goes to the engine water pump or the hole that goes to the exhaust ?

 

[Don S]

Re: Engine will not reach operating temperature

The power steering coolers aren't all the same. Some (like the Volvo and newer Mercs) have a large open hole in the center, instead of the older small tubes that could get plugged up. Then again, many 4 cylinder engine don't even have power steering therefore, no cooler.