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We had touched on this briefly before, but I don't remember where, and I won't whore anyone's thread up. Anyways, I was assembling the 383 in the Camaro, and I got to the thermostat housing. I figured I'd toss it in a pot of boiling water, since we've talked about it before. The one in this motor was an old example, the Mr. Gasket high-flow type, 160*. We've had the engine for about 4 years, and it sat for years before that, so no idea of the actual age. But I did know the age of the other Mr. Gasket high-flow thermostat I had laying around, 160* as well. This was the one I had in the Astre for a total mileage of about 10 miles. Strangely enough, the low miles were... because I would ALWAYS overheat!!!

So anyways... now I have this boiling pot, and two near identical Mr. Gasket thermostats. Once the water reaches 190*, I drop them in! Instantly, the old thermostat opens right up, completely open like it should. The NEW one however... wouldn't open up a crack! I let it sit for about 5 minutes, and no opening.

So this pisses me off. I'd expect a good product from a company like Mr. Gasket. I would think something as simple as a thermostat shouldn't have any issues. I know outsourcing is the rage now... but come on... they can't even build a decent thermostat that opens when it should? So now I'm thinking... my whole overheating issue before... where I'd reach 240* in a matter of miles... maybe it wasn't my radiator at all!!!! Maybe it was my damned thermostat not opening!!!! So I might have been through 3 radiators, and two fans, all for nothing???

Here's the corresponding pic. I don't need to tell you which one failed.

Im haveing a over heating nightmare my self... Im running a 3 core rad from a 68 camaro SS I got 2 oil coolers one for the engine and trans.

Best I have got so far was about 20 miles on a 85Deg. day with a Gallon of water wetter.

You know whats bad. I have a friend with a MGM that has a 350 chevy . He has No over heating!!!!!

you should look into t/stats from MotorRad they make a failsafe t/stat that if it fails it does open http://www.motoradusa.com/products/fail ... index.html

The previous thread is in the product review forum. I'm going to post a link to this post there. My MrGasket t-stat was visibly bent out of alignment. Can you see anything like that on yours? Next time I need a thermostat I'm thinking of going to the dealership. Whatever brand they use, I'm sure they don't want anything that's going to cost them warrantee repairs. AC Delco sells their brand. Maybe that's the one gm uses.

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ah yes i know it well. had the same problem when i tore down my nova's 355 sbc to re certify it for emissions here in California. replaced a perfectly good 5 year old thermostate wit a new one ,middle of the road ,not the cheapest,and it emidiatly over heated the engine. replaced with another one,same problem. tested both in boiling water and one even with a butane torch. bottom line was you couldn't get them to open with a blow torch. so at the moment ,seeing this is sunny California, it's running without a thermostate, which i really don't recommend, as this is not the best thing for your engine to run that cold for that long. really messes with the cumbustion process . i guss now days we are all going to have to boil test our new thermostates before we install them so we don't end up draining our cooling systems a secound or even third time due to a new part not functioning at all............

thinking of running a restrictor instead of thermostat because I don't trust anyone's manufacturing process anymore. that's sad

rtm wrote:thinking of running a restrictor instead of thermostat because I don't trust anyone's manufacturing process anymore. that's sad

It is sad that quality control and the customer coming first has gone way down hill. There are still reputable companies out there but they are few and far between.

my thermostat is a stant 180 degree, says "made in U.S.A." but I'm not sure if that's good or bad.

This is a really big concern of mine. Old used made in USA is probably ten times better than new made in god knows where. I have worked with many Chinese companies and have been there many times. You have no idea what you are getting from one shipment to the next. It's a fools bargain.

I say use the old used made in USA stuff. If it ain't broke - dont replace it with questionable new parts.

Jeff

PS - that would suck if there was nothing wrong with your old radiator.

pss Send Mr gasket a letter with the photo. Maybe somebody would care.

When I worked at NAPA we sold Stant stats and had a few bad ones come back but not alot. Maybe 3 or 4 in 4 years. Best to test it in a pot of water with a thermometer. Could even use a mechanical temp guage.

Just the thing I wanted to hear,,an Independant test with two of the same brand,,,But as he said there is more to the story in each account of product,,I am positive My Mr gasket 180 is working now,,,But my Son' n Law truck 350sbc 69 swb pu needed a new T-STAT,,,, orderd one and he pulled it out of the bag delivered by a lady working at a chain store...that could have damaged just "looking" at it.,,,LOL,,,,,,,,, after removing packging I said take it back and ask for another,,,it had come in contact with something heavy and had visual dammage.,,,,,, # 1 Could it be a contractor is packaging the leftovers that jump off the assembly line and get bent and deliver them to us reguardless of Quality Control,,,,#2 or at the parts warehouse before it get to the counter shelf restocker,,,some one is dropping clutch and flywheel box's into the box with the lighter packaging on the bottom,, going out to the Franchise stores,,discount part's.,,, Something is happening.,,,,, but just to be on the safe side,,You need to have more than a couple of known Thermostat's to test with your new purchase,,, And yes Josh You have made a great discovery,,on your set up,,,,,,,,, Now My overheating for dummmys post,,,, Plus the"Thermostat Releif holes" post was not totaly a loss thanks,,,The secound one deliverd ' was also visualy INSPECTED,,AND tested in the truck and has worked fine .,,,after reading this,,,My Son' N Law is buying a THERMOMETER,, Water POT and Hotplate for the shop,,,Thanks,,,,and Kudo to the info on other option names,, Some places actualy stock Stant brand ,,,but do not push them????Mike

I just bought a new Stant 180* for my 262 hoping to solve my overheating problems. I think I will test it first. My other 'brand new' thermostat is a Stant as well but I believe a 190 or 195. 5-10 minutes in a line up and I am starting to overheat. And thats after the new 3 core rad, new water pump and patched heater core.

funny i have never trusted t/stats ,they all appear to be good BUT most are made in 3rd world countries (or at least assembled in them )
i havealways drilled 2 3 mm holes in every one i have ever fitted ,just as a safety measure ..may take a little longer to warm up but i think it is worth it !

It takes me a LONG time to warm up now. I run the hollowed out thermostat so it's a constant flow always. It's not ideal, but I was just so pissed off with my car I just had to drop the A-bomb when it came to keeping cool. And it does well now.

But no wonder my car would jump to 240* in two miles!!!! If the thermostat wasn't opening, that would heat things up pretty good! Imagine all the grief I could've saved if I just checked the thermostat.

Josh, I know exactly what you are saying. I have a 85 K20 Suburban with a 305. I installed a Holley 600cfm carb, Edelbrock performer rpm manifold, and a MSD HEI coil on it. There was a definite power increase, but something wasn't right. I just figured it needed fine-tuning. I spent the next 5 years find-tuning that truck. I'm talking about trying Jets, secondary vacuum springs, timing advance springs and what ever else I could think of. Just never could get it right. Then over a 1 month period it started getting to the point where it was flooding out trying to start it. Findley one day it wouldn't start. Got desperate and went down to Advance Auto to buy me a new 600 Holley to fix the problem, it didn't. Checked the spark, and it was weak. Back to the parts store to get a new coil. I purchase an Accel coil. Put it on the truck, it started right up. Went for a test drive to see if it ran any better. It didn't run better,,,,,, it ran great. I mean this thing felt like I put a 100hp NO2 plate on it. Then it hit me, I had been chasing my tail around in circles for 5 year because of a faulty MSD coil. It never entered my mine that brand name performance part like MSD could be bad.

Reading this post made me think about problems I've had with thermostat over the years. I can only remember one thermostat go bad in the past 32 years. Out of the 30 or 40 new ones that I have installed, two didn't work. If I take something apart, I've always use new parts when I put it back together. It seemed like the best thing to do. But when you read a repair manual it says test your old one, then reinstall. I always thought they where just being cheap. Now I think they're just being smart. Definitely good to check your thermostat whether its old or new, but if you think about it you have a history with the old one.