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My 1973 Pontiac has been the most reliable car I have ever owned, but for the past 5 years, the heat gets only warm at best. Its the thermostat I know, because the engine never gets hot. I can drive for 50 miles and if its below 40° outside and you stop, you can about touch anywhere on the engine and its only warm.
Last winter we tried removing the bolts, but they would not budge. I was afraid of rounding off the bolts. I know I could spray more lubricant on it and let it soak and try again. I am assuming its original and after 38 years, it dont want to move.
Any one else run into this and have any suggestions? Thanks
Keep soaking it... If you can get your hands on PB-Blaster it will do wonders. If that does not work you will need MAPP gas or propane to heat the bolts. At least with heat, the bolts are almost completely guaranteed to come off. Just make sure you remove any burnable parts near the "blast" area.
Keep soaking it... If you can get your hands on PB-Blaster it will do wonders. If that does not work you will need MAPP gas or propane to heat the bolts. At least with heat, the bolts are almost completely guaranteed to come off. Just make sure you remove any burnable parts near the "blast" area.
Thanks. I think I put some PB on there before and had no success. I had thought about the heat deal too, but not sure if it would make it worse... so with what you said, I will give that a whirl. It dont get that cold here, but since I am selling my Lexus next week, this old car will be my work car again for awhile and as harsh as this winter has been so far, I am sure we will have many more under 35° mornings and I will need heat.
To start with if the engine does NOT get hot then the thermostat is probably stuck open and allows the water to circulate without staying in the engine long enough to get hot.
If the thermostat was stuck SHUT then the water would get hot real quick by not circulating thru the radiator.
In any case the first is the less evil...otherwise the engine would be boiling.
Due to the age you can leave it alone or take to a mechanic who may heat the head bolt or try to break it loose and possibly SNAP off and need to be drilled and re tapped.
Trying it yourself and snapping the bolt and your in tow truck expense country or doing the shop fix.
As a former mechanic (now retired) have been there and seen it happen.
Is that an aluminum intake? If so, don't go too nuts heating the bolts because you could end up galling the threads. I would heat it, then oil it in several cycles. Heat it up a bit, then spray oil on it and let it cool. Repeat several times. Usually the expansion and contraction of the bolts will allow some oil to get in there and it will break free.
Thanks. Yeah it must be stuck open as it never gets hot... warm at best.
Quote:
Originally Posted by Steve Bagu
To start with if the engine does NOT get hot then the thermostat is probably stuck open and allows the water to circulate without staying in the engine long enough to get hot.
If the thermostat was stuck SHUT then the water would get hot real quick by not circulating thru the radiator.
In any case the first is the less evil...otherwise the engine would be boiling.
Due to the age you can leave it alone or take to a mechanic who may heat the head bolt or try to break it loose and possibly SNAP off and need to be drilled and re tapped.
Trying it yourself and snapping the bolt and your in tow truck expense country or doing the shop fix.
As a former mechanic (now retired) have been there and seen it happen.
Steve.
Thanks. Nope its not aluminum. I dont think there is anything aluminum on the engine of this car... all cast iron as far as I know. Its a 455 V8 - 1973.
Quote:
Originally Posted by stanman13
Is that an aluminum intake? If so, don't go too nuts heating the bolts because you could end up galling the threads. I would heat it, then oil it in several cycles. Heat it up a bit, then spray oil on it and let it cool. Repeat several times. Usually the expansion and contraction of the bolts will allow some oil to get in there and it will break free.
Those things can be a real bugger. Like Steve said, you might considering having a shop do it, so that if the bolts snap they'll have the ability to drill and re-tap the beast.
I guess I'd suggest making sure you have a 6-point socket or box-end wrench. They won't round the bolt shoulders like a 12-point will. If you have access to a smaller impact wrench, you might try it. Sometimes the rapid vibration of the impact will break the bolt loose. Do not use a really powerful impact though.
You could also try using a punch and hammer, and repeatedly tap the top of the bolt. That might help break it loose. Just don't damage the bolt head.
Another way is to sacrifice the t-stat housing. With a small, sharp chisel crack the housing between the bolt head and the intake. You may have to do this in several places on the housing but the key is to get the housing out of the way including the pieces surrounding the bolt. Then you can apply heat or even grip the bolt with vise grips or a small pipe wrench. It will also allow the penetrating oil to work it's way down around the threads. Once the bolt breaks loose, work it back and forth till the bolt feels like it's loose enough to take out.
All of this is assuming it's a pot metal housing and you can also get a replacement for it. Good luck
Hey this car is actually old enough that I have some idea of how to work on it. (with new cars I am pretty useless).
Back then (in the 1980s when we had early 1970s cars) we always used heat. It always worked. PB Blaster did not exist as far as I know. I am not even sure that we had WD-40. I think that you can buy a small pencil torch for less than $40. You may have to heat it more than once to get it free. If you use impact wrenches, be very very careful. It is easy to strip the head. I would use a very high quality six point socket with a long breaker bar. It is worth spending a lot of money ont he socket. It is much cheaper than cutting the darned thing off and drilling and tapping it.
I would remove the hose first obviously. Heat and rubber are not a good mix. You will probably end up replacing the hose anyway if it is original or even very old.
When you get it off, black flush the system, change the coolant and then put in the new thermostat.
If you have a small local mechanic who works on your cars, they may break it free for you at little or no charge.
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