5.7 4V Running Hotter........

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Fordiesel69

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Finally got the four winns back from steering shaft failure. I can I/R the elbows and get 128 F, and the intake manifold crossover near the tstat is 175 F as well as the reading on the dash. I do not believe the engine is supposed to run that hot. Good news is it never changes, it is 175 f at WOT or near idle. Any idea's?

Can someone I/R their engine for me?
 
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Lyle29464

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Re: 5.7 4V Running Hotter........

If I was not on salt water I would be happy with the numbers you have.
 
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Fordiesel69

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Re: 5.7 4V Running Hotter........

Fresh water without closed cooling. Water temp is in the mid 60's.

I thought the engine shoudl be in the 150's?
 
Lou C

Lou C

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Re: 5.7 4V Running Hotter........

I have an original 88 4.3, I IR'd the intake where the thermo housing bolts to the intake, about 155, tops of the risers (hottest area) after running on plane 135. You probably have a 160 thermostat, for it to run up to 175 is OK. Keep in mind a 160 stat does not start to open till 160 and is supposed to be fully open at about 180 (according to the OMC shop manual I have). IR measurements are helpful but remember that you are measuring the temp of the metal of the housings, not the water inside, which is what the temp sensor measures, so there will be a difference...
 
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Fordiesel69

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Re: 5.7 4V Running Hotter........

So is this safe to leave it in?

Should i swap it out for a 140?

Am I wearing it out much by the extra temps. My risers elbow are nice and cool at 125 degrees on cruise. New water pump with gobbs of flow.
 
Lou C

Lou C

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Re: 5.7 4V Running Hotter........

I've looked but never seen a 140 for either an OMC or the Volvos that use the same design thermo housing, maybe a 140 merc one could be used if it has the same diamater and length. BUt I think it's OK to leave it in...I looked because I heard its better to be cooler in salt
 
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