Proper engine temp. 3.0 L OMC

[waye45]

I put a new thermostat in my 3.0L OMC. It is in a 1988 Bayliner bowrider. I thought the enigine Temp. was a little high so i changed the T-stat . But engine still Runs between 180 and may be 210 degrees. I can hold my hand on manifold towrds back and feel the thermostat open and shut just by temp. of water going through it goes from hot to cool. when T stat opens and closes . Is this temp. normal for this ehinge. I had a 1986 regal before same GM motor and that ran around 150 degrees.

 

[HT32BSX115]

Re: Proper engine temp. 3.0 L OMC

Howdy,

Take a look at the "Adults Only" sticky above in the forum list here.

You may have a failed raw water pump (in the drive) and/or remnants of a previous failure blocking water flow.

There's a service manual you can download in the above link.

Most hot engine problems are the raw pump and blockage. Thermostats rarely fail.

(all this assumes your riser, manifold, head and block are NOT clogged with rust!)


Regards,


Rick

 

[waye45]

Re: Proper engine temp. 3.0 L OMC

I remove the t-stat and engine temp. does not even on show guage. (Does not move ,no heat) . Does this eliminate the possbility of failed pump or blockage? thanks for your help

 

[HT32BSX115]

Re: Proper engine temp. 3.0 L OMC

Did you test/verify your temp gage? (it may be completely wrong) Can you hold your hand on the block/head when the T-stat is open?

After you removed the t-stat, how long did you run it?

Did you run it at a higher than idle power setting ? Get it up on a plane and run it around the lake for several minutes.

If it does NOT overheat now, did you test the thermostat?

That engine should run around 150 like you observed before. It's probably a 140 degree t-stat.

 

[waye45]

Re: Proper engine temp. 3.0 L OMC

Yes I run the boat under the same conditions without T-Stat as with T-stat . engine dosenot even get warm without T-stat , but temp gauge shows 200 Degrees with T-stat in place.

 

[HT32BSX115]

Re: Proper engine temp. 3.0 L OMC

I'll assume that you have the T-stat in correctly (not upside down)

It might be a good idea to obtain a cheap infrared temp gun like the one below from Harbor Freight.
It's something like $30.....This way you can verify your gage...