Thermostat problem, maybe?

Posted By: Jay68RR

Thermostat problem, maybe? - 06/16/08 02:15 PM

383 is running hot. Not sure if the guage is faulty or if there's a problem. This weekend it went north of 220 then settled in at 215. Other days the thermostat seems to kick on and it stays about 190. Can a thermostat stick and not open sometimes?

No overflow, no weird smell, no leakage that I can see- any thoughts?

Posted By: RapidRobert

Re: Thermostat problem, maybe? - 06/16/08 03:05 PM

not sure but when you open it up to check it out I would drill a small hole in the stat to let the air out, makes it alot easier when refilling coolant.

Posted By: BobR

Re: Thermostat problem, maybe? - 06/16/08 03:15 PM

Yes they can stick. It won't cost you much to find out if that's your problem. Get a high flow unit while your at it. They sell them at Summit Racing. -Bob

Posted By: NachoRT74

Re: Thermostat problem, maybe? - 06/16/08 03:19 PM

one way to know if Tstat is stuck is try to press the upper hose when hot. If is hard to pressure then Tstat is working propperlly or at least is opening

Posted By: Jay68RR

Re: Thermostat problem, maybe? - 06/16/08 03:31 PM

Thanks guys. I've never heard of drilling a hole in the Tstat.

Posted By: Jay68RR

Re: Thermostat problem, maybe? - 06/16/08 05:42 PM

1 more thing: If I replace the Tstat, should I go 180 or 160 degrees??? I know the 160 will kick on sooner, but is there anything else I should know?

Posted By: RapidRobert

Re: Thermostat problem, maybe? - 06/16/08 06:00 PM

180

Posted By: NachoRT74

Re: Thermostat problem, maybe? - 06/16/08 06:09 PM

factory were 195�

Posted By: RapidRobert

Re: Thermostat problem, maybe? - 06/16/08 06:30 PM

Quote:

factory were 195�

yes for emissions control.160 for drag racing. 180 is better for fuel atomization & I would drill a 1/16" hole roughly halfway between the outer edge & the center.takes only several minutes & saves ALOT of time by bleeding the trapped air out as you are filling it & can help elimate hidden trapped air pockets. One guy jacked up the front of his car which burped it like a baby which fixed his until that point unfixable overheating problem which was a trapped air pocket(s).

Posted By: coronetkid

Re: Thermostat problem, maybe? - 06/16/08 08:28 PM

is there any other way to tell if you have trapped air pockets? i'm having the same issue with my 383. i put a new 160 tstat in 2 weeks ago and she still runs anywhere from 220 to 200.

Posted By: 79powerwagon

Re: Thermostat problem, maybe? - 06/16/08 08:36 PM

Quote:

is there any other way to tell if you have trapped air pockets? i'm having the same issue with my 383. i put a new 160 tstat in 2 weeks ago and she still runs anywhere from 220 to 200.

That's about where an engine runs. Todays cars run even hotter. That's why the system is pressurized, to raise the boiling point of water above 212�.

Posted By: Paul_Fancsali

Re: Thermostat problem, maybe? - 06/16/08 08:48 PM

I just went to a 195 to get my car between 195 -200 it plain runs better then when it is at 160-170. Higher comp seem to like 180's make sure that your antifreeze level is no more then 40% Anti 60% distilled water. Too mucj anti freeze will make a engine run hotter.

Posted By: scratchnfotraction

Re: Thermostat problem, maybe? - 06/16/08 09:47 PM

check your timming and check carb to make sure its not lean

those will cause it to run hotter

feel by hand the rad core when hot to see if you can feel cold spots on the rad...cold spots are where the rad is blocked

do you have a spring in the lower hose?

does it have the shrod in place?

is the clutch fan working properly?

yes a small hole will burp the air out and no need to run to temp and wait for the t stat to open to finish the fill

try some water wetter in it also...

Posted By: coronetkid

Re: Thermostat problem, maybe? - 06/16/08 10:18 PM

lower hose does have a spring. i do have a shroud. i know my carb is rich. timing i'm not sure of the car will be tuned soon (i hope)clutch fan does work properly. problem seemed to develop when the weather got warm winter and fall i had no probs. by the way what is water wetter? i have never heard of that.

Posted By: RapidRobert

Re: Thermostat problem, maybe? - 06/16/08 10:44 PM

there was a very comprehensive thread recently with over 125 posts on an individuals overheating problem.Dont know if it could be retrieved or not. If so it might be worth reading for you.

Posted By: DZJim

Re: Thermostat problem, maybe? - 06/17/08 12:16 AM

Not worth fooling with. Just replace the thermostat with a new one 180 deg. I had a one year old Robertshaw 195 in my 318 stick on me one night. Limped home two miles at a time with a cool down in between. Tested OK on the stove next day. Never heard of 195 stock in the 60s

Instmt lights are pretty dim on my old '72, lucky I noticed the temp indicator heading North before any detonation or boil over. Wish it had a big red "idiot light" too...

Posted By: Jay68RR

Re: Thermostat problem, maybe? - 07/16/08 05:16 PM

Update- I changed the stock 195 tstat to a 180 tstat. When the guage reads 180-190 it kicks on and goes down. Just as the 195 did around 200. But then the same thing happened: it creeps up past 180 (195 before) and keeps going. Now it settles in around 205 until I stop at a light. Then it goes up very quickly to 220. That can't be good.

I do not have a shroud. Could that be the answer?
I'll search for the other thread mentioned.