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King Trashmouth
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Discussion Starter #1
Since the last head was junk, the gf elected to scoop up a cheap Jasper reman engine. I got everything cleaned up and installed, filled it up, and fired it the first time today.

It caught almost immediately, jumped to 1000RPM for a few seconds, then dropped to 750 for a couple minutes, and then it slowly dropped down to 500 and stalled. This pattern repeated.

Meanwhile the coolant didn't deaerate quite like I hoped. It did rise a little and I think I saw a wisp of steam after several cycles. The upper hose and radiator were pretty toasty when all was said and done.

First thing that comes to my mind is I haven't set the timing with a light yet. It being too far retarded could cause higher engine temps and poor idle. Other than that I would guess possible rough idle candidates would include TPS, IAC, EGR, oxygen sensor, and ECT.

I suppose running the OBDI codes wouldn't be a bad idea either.
 

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I would set timing first before you get too worried about it.
 

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King Trashmouth
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Discussion Starter #3
Got a chance to check timing with where I reset it; 12 deg base timing, good enough.

Took it out for a few drives, coolant temp gauge showed it didn't get hotter than 5/8 up the gauge, and the fan kicked on. That all seems good.

However it still felt and smelled hot by the time I parked it. The outlet hose and radiator were hot to the touch, hotter than I would expect for ~200 deg F coolant. It also pushed a little bit of coolant, ~8oz into the recovery tank.

But I would note that the engine is a fresh reman, and all the hoses are new. It's only been through 2 complete heat cycles so far, so that could explain the smell and puking.

Am I just being paranoid or should I look into this more?
 

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Do you have a temp gun so you can check the hoses to see what the actual temp is? I would run the engine a bit more before I got worried about it
 

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King Trashmouth
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Discussion Starter #6
I instrumented the water outlet with a thermocouple. The thermocouple was showing 10-20 deg F higher than the less than precise gauge on the dash. I ran it up to 205 F by the thermocouple, and it was showing 190-195F on the gauge. I don't think it's that far out, especially considering that was monitoring the water outlet and the sensor is in the intake manifold which is somewhat isolated and a heat sink.

What that does mean is that the engine doesn't really get hotter than 220F during operation, and the fan kicks on somewhere around 215F, with the system usually stabilizing around 205F. Seems a tad on the toasty side, but that's just me.

Related; the thermostat definitely works. You can see the water level drop at exactly 180F when it cracks open.

So is this reasonably accurate, and they just run pretty hot? I know the "red" area on the gauge is freakin' 270F! This seems way hotter than most vehicles I've run.
 

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I'm not sure what they usually run but 215 wouldn't bother me too much. My old mustang ran about 210 and never gave me any problems. At least not related to heat
 

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King Trashmouth
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Discussion Starter #8
Update: It seems like it's perfectly normal. I did some cross referencing on the fan switch and it's listed as a 219F fan on switch, which corresponds to the 220F on the gauge I see before it kicks on.

The discrepancy between the thermocouple and sensor seems reasonable as well, seeing as the thermocouple is the true water out temp and the sensors are all in the big aluminum intake manifold that draws from the center of the head and has a small orifice vent line to the heater. I would expect it to be much lower than the true water out temp.

All in all it's weird, and warm, but working as designed it seems.

Maybe I can find a lower set point fan switch in the future. 40 deg F between fan on and thermostat open is way too big for my liking.
 
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