LLY: LLY overheat after 72R Install, thermostat issue ?

dirtymax36

2nd place is last
Apr 11, 2013
367
2
18
Having issues with my LLY randomly overheating, cruising the streets it'll now run 197-208 and idling with the electric fans manually turned on 24/7 it won't go under 197. It use to idle around 171 when warm. Now when hooking up to a trailer it skyrockets. I've bled the system, no air bubbles. The coolant tank is full. I'm running mishimotos low temp tstats that are 171* and 183* and merchant water pump. Possibly one of them sticking ? Anyone on here run mcrats racing thermostats or know where i can get some fast before the weekend ? Thanks in advance
 

skintback

Take this one to church
Mar 5, 2007
919
0
16
Florida
Have you ever pulled and pressure washed the radiator if not worth a shot you would be surprised at what will build up in them.

I have ran the mcrat T-stats and they ran pretty cool.
 

dirtymax36

2nd place is last
Apr 11, 2013
367
2
18
Where dI'd you buy them from? I had the radiator out this past august and pressure washed it all and cleaned it. I'm almost positive it's not dirty I never drive this thing haha
 

Awenta

Active member
Sep 28, 2014
4,090
2
38
CT
Just take them out and run without them. I'd rather do that than run hot.

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dirtymax36

2nd place is last
Apr 11, 2013
367
2
18
Do many people run without thermostats ? I'm getting ready to take off Thursday for Tennessee and will be pulling a loaded 25 foot goose in 95* heat is my main concern.

Electric fans have been on for 1.5 years and I've always towed with them and street drove it. Never had an issue. It actually kept it cooler than it did with regular fan clutch
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,670
5,817
113
Phoenix Az
Do many people run without thermostats ? I'm getting ready to take off Thursday for Tennessee and will be pulling a loaded 25 foot goose in 95* heat is my main concern.

Electric fans have been on for 1.5 years and I've always towed with them and street drove it. Never had an issue. It actually kept it cooler than it did with regular fan clutch

well not everyone can get away with that, i know they wouldnt keep up with me.

but either way, wasnt what i was getting at. are the fans blowing at full speed or do you have one dieing out?
 

IOWA LLY

Yes, its really me
Feb 23, 2007
2,275
4
0
Did this happen right after the mishimoto thermostats?

Sounds like you got there high temperature ones by mistake.....

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dirtymax36

2nd place is last
Apr 11, 2013
367
2
18
The mishimoto stats have been in since 2012 and they have usually done good until now. Maybe the heater core or something plugged ? I've been trying to find mcrats thermostats
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,670
5,817
113
Phoenix Az
The mishimoto stats have been in since 2012 and they have usually done good until now. Maybe the heater core or something plugged ? I've been trying to find mcrats thermostats

heater core wont affect cooling to that degree.

i suggest looking at fans or thermostats. pull the t-stats and put them in a pot of water (making sure the t-stat isnt touching any wall of the pot), put a thermometer in there and see just when they start opening (if they do). at 160ish, they will just start to crack. probably wont be full open to 170-175 if they are the mcrat 160 race t-stats
 

dirtymax36

2nd place is last
Apr 11, 2013
367
2
18
Just checked both fans and they both spin the same amount of rpms. Both my manual switch and a/c compressor switch activate the fans and have been used correctly for the past 1.5 years