TopCat

I've read the t-stat threads, but was wondering if anyone else installed a 180 and then ran at temperatures higher than the stock t-stat :mad

Is this typical, or was I the :jester for not checking the damn thing in boiling water (w/thermometer) first......and end up with the 1 in 10,000 that didn't work right? :cuss

Update - Guess I should have contacted Hypertech first. Here's the spec's they gave me for typical results from their thermostats:

180F T-stat - 185-195 while driving

160F T-stat - as low as 175, but generally 180 while driving

My t-stat is running a bit hotter than it should, so I guess I'll return it and see if they'll send me a 160, since I want to run around 175. Should have saved my money and just cut the spring on an original :rolleyes:


[Modified by TopCat, 1:21 PM 10/21/2003]

Hypertech didn't hesitate to accept my 180F t-stat back and will be replacing it with a 160F t-stat. Just wanted everyone to know that they're a vendor that is standing behind their product....they've also spent the time to inform me as to what coolant temps I should see with each of their t-stats. Sill shooting for 172F in the summer, though. Probably won't be possible without an aftermarket radiator, though. I wonder, has anyone run without the t-stat in the summer? What were the temps recorded?

TC


[Modified by TopCat, 8:47 AM 10/30/2003]

Evil-Twin

for some reason there have been many Tstats that are not opening at the advertised temp....I went through three stats before I got one that opened at the proper temperature.. I always test a new stat... the third stat I bought was a Hyperteck.. and it opened when it was suppose too... its a 160 F stat.. thats my spring summer fall stat... and I have a stock one that opens correctly... for the winter months,.... it only takes five minutes to swap them out... very few problems reported with hypertech

carpe dm

The aftermarket stats may open correctly (wax melts at the right temperature), but might not flow as well as the OEM unit. Mine did exactly the same thing. :rolleyes: :sad:

MTWallet

The 180* stat is designed to OPEN at 180*, not keep the engine at that temp. The fans are what keep the temp where you want it. You need to lower the fan temps to get the operating temp down. I have the 160* Hypertech and I stay at 179-189 in the heat of the summer.

FunDriver

I have a 180 degree Hypertech but the engine still runs at the same temp as before because I haven't changed the fans yet. The car will still get hot, etc. just like with the stock thermostat.

leadfoot4

I tried a 180 Hypertech t'stat without any change in operating temps. I was totally dissatisfied with the unit. I had it too long to return it to where I bought it, so I just tossed it in the trash, and wrote it off as a bad investment.

I then modified my stock t'stat following the procedure that was posted on this site about 18 months ago, and my operating temps dropped about 8-10 degrees. This is WITHOUT changing anything else, such as programming, etc.

TopCat

All right, here's the deal. If it does open at 180 (which I will check by this weekend) then I'll know the flow is off and I will be thoroughly pissed. I'm aware of the fans, but they become a factor at low/no speed. My comparisons are at 45-65 MPH, steady state, no A/C. This morning ambient temp. was 56F. The temp was fluctuating between 192 to 194 at 65MPH and 194 to 196 at 45 MPH. This is, I assume, due to the slower water pump revs and less air through the radiator. However, I never saw this temp. fluctuation with the stock t-stat. On a cool day, regardless of car speed (45-65 MPH, still), the temp would not exceed 190 and would sometimes fall to 188. I have to assume the flow is not there. I guess I'll send it back and try to get a refund.



[Modified by TopCat, 1:25 PM 10/21/2003]

Evil-Twin

a tstat controls how cold it will get ( the lowest controlled temperature.. Not how hot it will get... if you are saying that at at 65 with ambient temps at 56 F (unless your radiator and AC condensor are blocked... ) the tstate you have in there is controlling at 190 F. which means it wont allow the car to get any lower than 190 F...

Bling Bling

I had the Hypertech 180 stat and my engine was running hotter at crusing speeds. From what I heard the Hypertech flow is more restricted then the stock stat. I bought a 178 stat from Breathless and its basically a modded stock stat to open ealier. I liked it alot better then the Hypertech and I was running typically 183-185 crusing speeds.

TopCat

Correct. But at the air / coolant temp difference, I should be approaching 180 with a 180 t-stat, IMHO, if the stock t-stat allows me to approach 190 under the same conditions. This morning, with 50 ambient, I was still fluctuating between 194-196 at cruise. My guess is the flow isn't there or the thermostat only begins to open at 180 and isn't fully open until 194-196. Regardless, Hypertech said to return it to them and they'll send me another one. Can't get a refund from the vendor I bought it from. I wasn't aware of the assumption that flow through aftermarket t-stats might be lower. I might save the hassle of shipping it back and use the shipping charges to purchase a "stock" thermostat from NAPA and modify it myself. I will, of course, carefully examine it to see if the body is similar in design and should flow like the GM t-stat. If not, I'll either choose to port it or return it and get a GM replacement and modify it for 172-176 temps without the temp fluctuations I'm seeing with the Hypertech. My goal is to reduce pre-ignition through reduced head temps so the PCM won't pull timing. I mean, I only popped over 200 if it was hot out this summer with the stock stat. After hitting 1.5 miles of 45 mph city roads and a few slow turns into the parking lot, I was hitting 202. I don't like temps that fluctuate that much.

Evil-Twin

You do not have a 180 stat... even though the box may have said it///if your at 190 /192 then you have a 190 stat... which is a common problem... getting the wrong temp stat in the box...

TopCat

If that's true, :mad :mad :mad

Gramps

Checked the "Tech Tips" for the procedure and did not find. Anyone have a reference?

Dr.Ron

I got a hyper tech 180 tstat from Corvettes of Houston. My temps have not budged!!! :confused: I recently had LS1 edit tuning done & they lowered my fan settings like 25+ degrees...STILL no changes!!! I may change to the 178 from Breathless too. But tell me (at the risk of sounding ignorant)what are you doing w/ the coolant (ie;Draining, or a trick so it doesn't end up all over my driveway)? I know the actual bolt off/bolt on takes 5 min., but I don't want a coolant river!! :thumbs:


[Modified by Dr.Ron, 2:42 PM 10/22/2003]

TopCat

:D
I flooded my garage!
Had to replace @ 1-1/4 gallons of fluid :cry

Tried clamping off the reservoir tube, but I guess it wasn't tight enough. Couldn't get the new t-stat on quick enough to keep the engine from draining....the trans fluid lines leading to the radiator are right in the way, the socket wrench will fit, but I had to 'spring' it against the lines. Once the new one was on, fluid was still coming out. FORTUNATELY, the hose wasn't stuck to the original t-stat or else that would have been a real bear to remove. Might I suggest that if you take the quick 'move&replace' route to make sure the hose isn't stuck to your t-stat before removing the t-stat body. Next time, I'm putting a pan underneath the car and using my air wrench :D

I still plan on losing 1/2 to 1 gallon of coolant :(

Oh well. I'm not sure there's a better way. I seen people write that they can change them out in 5-10 minutes, total. After much practice, I might be able to also :lolg:

Dr.Ron

Yeah,5-10 min is fine, except in that 5 min you have no coolant left!!! :lol:
It's not the time issue I fear, it's the flood issue. I wish there was a way to change w/o draining the fluid or having a flood!!! I was able to hold the hose up buy the engine coolant drained all over the floor!!


[Modified by Dr.Ron, 3:48 PM 10/22/2003]

Evil-Twin

Ive changed my stat twice a year...for the last four years... 160 for the summer 190 for the winter...
here's what I do...
remove the radiator cap to relieve any pressure, then put it back on...right away !
cold engine..... this means the stat is closed.. you can remove the radiator hose, and you wont lose a drop from the engine side....lift the hose higher than the radiator and you wont lose anything from it either... I tuck the radiator hoseunder the heater hoses to keep it our of the way...
at this point you should have lost only a pint of colant at the most...
now you have two bolts holding the stat in place... .. if you remove one completely you still wont lose any fluid...
Nw you have to have the other stat right there on the wheel well with the "O" ring greased in place).

this next part is critical...
break the other stat housing bolt lose aand press the stat against the motor,.. with one hand and remove the bolt with the other hand...
with pressure on the housing you wont lose any coolant.. even at 16 psi.. you can hold it back...
put the bolt down and pick up the housing...
now with the hand holding the old stat.. remove it and rep[lace it with the new stat... applying pressure... this will stop anyrelease of coolant..
in the switch you may lose another pint... put in one bolt , then the other...torque to spec.. and you can relax...
Now all you have to do is put back the radiator hose and clamp it.
start the engine... remove the cap... bring it up to temp and add whatever you lost... maybe a quart or two... max... I lose less than a quart, but ive done this 8 times...

yankeevetteconvert

I modified my stock stat. this summer and lowered my fan temps.Depending on the ambient temp. and vehicle speed I had engine temps. of 168/highway or 187/192 trafic. Yesterday the ambient went to 52*. and I got engine temp. of 158* on highway at 55mph.My check engine light came on and when I checked the code it was PO128-ENGINE COOLANT BELOW REGULATED TEMP. Anybody had this problem? Is thre a way to change this spec? My stat. checked out a 160* when I bench checked it befor install.

Dr.Ron

I see you've moved on beyond the little spat we had here a few weeks ago. Glad to see it. Thanks for your post.
When I tried your method to remove the stock tstat, I had my car in my driveway nose first & the driveway slopes down quite a bit. When I removed the hose I did get a decent amount of coolant out of the engine side. The engine was cool. Don't remember if I had driven it prior though. Maybe it was because of the downward slope of the driveway??? I may have to try again & use your method. The first time I did a slow version of your method (wasn't too sure what I was doing), next time I'll try it verbatum & FAST!!!

Evil-Twin

We had a spat??? wow ... that is so out of character for me.. IM such a wuss.... are you sure it was me?.... I avoid controversy at all cost:blueangel:
OH BTW turn your car around nose up.... it will help... nose down helps only if your changing your oil....