T-stat replacement, wax everwhere, do I need to flush coolant? 180hp, 3.7L, 4cyl Ford

J

johnmogs

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Apr 24, 2011
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180hp 3.7L, 4cyl, 1987 MerCruiser IO, with 4" heat exchanger so it's using coolant.
Engine SN: B748434
Just purchased a 1987 4Winns Candia and have had it running, went around the lake but the temp gauge wasn't moving, so I stopped. Gauge works when shorting the sender wire to ground, so I decided to replace both the sender and the T-stat..... I think the T-stat is the problem as there is wax everywhere and I understand that's how they open/close.
I'm going to clean up the t-stat housing and any wax I can see, but should I also flush the system somehow or take apart the heat exchanger? Any idea if the wax that's in the system can cause issues?

I'm also stuck because one of the bolts snapped, but with enough length for me to grab with a tools, but it snapped again, then I drilled it and the removal tool broke inside of the hole.... so I hope the last attempt at removing the bolt is going to work.... I have about 3mm of stud still sticking out. Removing the exhaust manifold is not something I planned on. Any tricks

Thanks in advance!
John
 
Don S

Don S

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Re: T-stat replacement, wax everwhere, do I need to flush coolant? 180hp, 3.7L, 4cyl

T-stat replacement, wax everwhere,
Click to expand...

Wax????? if there was any wax in the thermostat, it would be a very small pellet, not something that is going to be everywhere. Look at the thermostat, not very big.
 
H

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
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10,083
Re: T-stat replacement, wax everwhere, do I need to flush coolant? 180hp, 3.7L, 4cyl

Any idea if the wax that's in the system can cause issues?
Click to expand...
Howdy,

Just replace the t-stat, flush and fill with water/coolant....... get it hot. any residual wax will melt and float on top......pump a little water in to the heat exchanger fill and you will probably float the majority of it out of there.

Even if the 'stat failed and leaked, (Like Don said) there's not going to be a lot........ If there is, it's either NOT wax, or it's other "stuff" that looks like wax. .................
 
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