1985 3.0L OMC Inboard Cooling problem

[denis21]

Hi I'm Denis

I have a 3L OMC with a cooling problem.

First of alll what should this engine be running at on the TEmperature GAuge?

It was showing 180 so i did the following things to help correct it.

1. I replaced the impeller in the lowere unit.
This did not change the temp readings on the gauge still 180

2. I changed the thermostat (160 RAting) no difference

3. I changes the temp sending unit and the temp gauge.

Still no difference in the readin on the gauge.

So I put a new water circ pump in, And this made no diference.

So i boorowed a Laser temp gauge and I noticed the engine seemed to run at around 135 to 140 on the block and the temp of th outgoing water at the outdrive was aroung 100 t0 110

I thought maybe a poor wire between the sender and the gauge so I connected it directly still ne diff.

Am I missing something??????

Any ideas???

Denis

 

[chiefalen]

Re: 1985 3.0L OMC Inboard Cooling problem

Should have posted before you spent all that money 180 is fine. If it ever goes to 190-195 than you have a problem and remove the riser.

Would you know when the riser was last changed?

You run in fresh or salt water?

 

[Don S]

Re: 1985 3.0L OMC Inboard Cooling problem

With your temp gun, check right at the base of the temp sending unit. That is basically what you should see on the temp gauge.
If at the sender you see 140? and the gauge at the helm shows 180? then you have a gauge or sender problem. You can test your sender with an ohm meter in hot water, here are the readings you should see.

Water Temperature ----- Ohms Reading
140?F (60?C) ------------- 121-147
194?F (90?C) -------------- 47-55
212?F (100?C) ------------- 36-41