I am considering a 172 degree thermostat, how difficult is it to change and how much coolant do you lose?? Thanx in advance, Jeff

 

Ok, well....you can do it the right way......drain coolant from drain *** underneath radiator and refill...or you can do it the easy , make a mess way :lol: ..loosen the bolts allow coolant to drain out for a bit.....remove hose.....install new t-stat...tighten down...refill :D

For PROPER drain and fill procedure do a search and there are a few posts on the subject or shoot me an email and I can send you a copy I just typed up for someone :seeya

 

I suggest the proper way. There's a white plastic petcock on the passenger side of the bottom of the radiator. Turn it counterclockwise and allow it to drain. You will drain approximately 1 to 1.5 gallons until it stops draining. Remove the 2 bolts holding the thermostat, remove old stat, replace with new one. Refill with 50/50 pre-mix of Dexcool and distilled water through the recovery tank. Run the engine with the heat turned on and fill the recovery tank until to the full line.
Nothing to it.
You will have to re-program your fan cut in temps when going with a cooler stat.

 

Say Jeff,

Not to hijack your post but what made you decide on the 172 degree thermo and what brand are you getting? I'm wanting to do the same to my '04 Z and need some direction. I think I can change it myself but I'm wondering which one is best.

Thanks in advance.

 

First thing you do with a new stat is to test it.. pot of water, a meat thermometer and the stat.. Note when the stat starts to open... many people buy 170 stats and find that they dont open until they reach 190.... the Hypertech stats made in germany seem to be the best,,,if it says 170 its usually a 170... I went through two 160 stats that opened at 190..before I got a hypertech that opened at 160... always test a stat.. I think some suppliers...repackage their 190s into 170 and 160 boxes...there have been just too many stats problems posted here over the last three years to trust in what the box says...

I change my stat twice a year,...I lose less than a pint of coolant... it takes less than five minutes....the actual stat transfer takes a few second.. that is the only time the coolant leaks...
I just changed to my 160 stat today... its a piece of cake..
with a cold engine, have the new stat ready sitting on the battery with some silicone grease to keep the "O" ring in place...have some anti seize compound ready also..
1) slide the radiator hose clamp up the hose about 6 inches..then remove the hose and stuff it under the radiator overflow hose... ( about an inch in diameter..) pull it up higher than the radiator.. and no coolant will leak out
2) remove the lower housing bolt completely... Note that with a cold engine the stat valve will be close and you will not lose any coolant.. apply a little anti seize to the thread
3) there is no pressure in the cooling system at this point..
here comes the trick.....with a little pressure on the housing ( pressing it to the engine with one hand.... remove the upper housing bolt....with a small amount of pressure you will keep the stat tight to the water pump... Now grab the new stat... with one motion remove the old stat and put the new one in place.. using the same pressure.. ( maybe 20 pounds of force ) the only time you lose any coolant is in the stat exchange..
4) now take the bolt with the anti seize on it and put it in the lower housing hole and tighten it slightly.. this will hold the housing in place.. you may lose a little coolant here..
5) put some anti seize on the other bolt and put it in the upper hole.. tighten both bolts to 89 inch pounds... put the radiator hose back on and slide the clamp back...
6) replace the lost coolant
7) start engine, check for leaks.. let it run up to temp... this is a good time to set your fan....
Im running a 160 stat, and have the fans set at 175...
after the stat opens.. you may see a drop in the coolant level, this is were you add more..


[Modified by Evil-Twin, 8:26 PM 5/13/2004]

 

It's not bad...pretty straight forward. You'll lose about 3/4 of a gallon. Catch as much as possible then add water with a bottle or two of "water wetter".
Did it to my car and it runs 178 with ac on stop and go traffic! :)

 

hello, mr. evil-twin.
could you be more specific on resetting fan? i switched lower thermostat, but not sure they did reset the fan settings. thank you. :flag

 

Went to the dragstrip yesterday, car ran too hot, 85 outside and the car was heating up to 226-228 in the staging lanes. I would shut it off but the lanes were moving to quickly. Performance was down about three tenths I figure due to heat and high IAT's(150 degrees). So I'm gonna put in a 160 or 172 I haven't decided. Jeff

 

Evil Twin-
I can do the fans with my predator, what do you suggest for on off points with the 160 and the 172.

 

Last question anyone have any history with the stats from Corvettes of Houston, they seem slightly less than other places?? Thanx again. Jeff

 

Who are "They"....
you need to reprogram the fan settings with Ls1 edit , or another programer , or a fan controller... you need a means by which you can adjust the factory settings or override them with a fan controller..

 

you do not want the fan to run constantly..
I run y 160 stat with fan set on at 180 of at 172... if your going to run a 172.. I would suggest 190 on.... 182 off... BTW these people who post that they run 178 all the time.. are either insane or have no concept of heat exchange,.,., the C5 is a bottom feeder.. (sucks air from 10 inches above the road surface...) on a 90 + day a blacktop road can reach 160F... you are not going to get much heat exchange at those temps unless you are moving.. so with that in mind... if your in stop and go traffic... its 90+ outside and your on black top.. even with a 160 stat you could see temps in the 200/210 range.. no one runs 178 under these conditions...without the 160 stat and the fan reset these same condiditions would produce 235/245 F.. thats the reason the PCM was programed with a High speed fan setting at 233 F.
Just another note... make sure the radiator and condensor are clean... I blew half cup of sand, lint, bugs, fuzzie stuff and pollen from mine this past weekend, and I have a debris screen which I left off because the stuff that cloggs up your radiaiot is much smaller than the mesh in a debris screen.. it would stop a plastic bag, or some road kill from getting sucked up there..