QuestionQUESTION: Hello! I've got a '68 Impala with a 327 that has been overheating for some time, and I can't peg why, despite what I've done.
I've installed a temp gauge to replace the idiot light, and it routinely shows 195-210 degrees, even without the A/C on, and with 60-degree outside air temps. I've replaced the fan with dual 14" electrics (shrouded and mounted on radiator), replaced the coolant (system is pristine-looking inside, if radiator was any indicator-it was perfectly clean, but developed a pinhole which got it replaced) I also put in an additive for lowering the temp, replaced the stock 180-degree thermostat with a 160-degree model, and still the temps are close to 210! If I use the air, I boil over in 10 minutes! The only thing I haven't done is replace the water pump, but that's because upon feeling the upper and lower hoses, they both feel hot (though I can't tell the differential, if any). A friend used an infra-red thermometer all over the block (top to oil pan), heads and all around the block, and never saw a temperature over 185.
Even though the pump is exhibiting no problems, I must wonder: will a new pump fix the problem, or might there be a blockage of some type in the system that would necessitate a chemical flush before a pump replacement? This car is also a daily driver and our only other car. Can you help? Chuck cmk59@yahoo.com
ANSWER: Chuck
Hi well before you go and spend a lot of cash I would first flush the cooling system out real good, than fill it with coolant or if you just put in new coolant save it to re use but drain it than use water with the flush. than when all is clean. fill it with coolant and do a radiator pressure test, it might show you where the trouble is , and did you check for any freeze out plugs leaking. and if the water pump is bad it will only get worse.I hope you do not have a cracked head ? do a check on the spark plugs and do a pressure test to check for a crack .
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QUESTION: The only thing you mentioned that I've not done is pressure-checked the cooling system. Everything else is buttoned-up tight...no leaks, no drips, no oil in coolant or vice versa...in fact, the coolant is not only clean, it was replaced totally when I put in the new radiator. Compression checks confirmed no problems there, so I'm thinking it might have to be the pump. As my wife and I also use "Max" for road trips (frequently on Route 66) and MUST use the A/C, I'd rather have it run cool than warm, y'know? (Eventually I'll have it restored inside and out, though not a 'rotisserie' resto...it'll be a driving resto, and look like one of the early Redline Hot Wheels cars I always collected, Cragar S/S wheels and all). Thanks! Chuck
AnswerChuck;
I will tell you something that all of us did in the 50-60-70 cars in new york we all took out out thermastats in the summer, and my 69 ss 396 that had a cam,headers,head work,holly elect,dist. and a lot -more well I never had a themastat in it and I ran at 165-180 max and my 63 vette with a 327 that was bored/stroked alum intake,headers,cam,etc. never had a thermastat in it. it ran cool and had heat in winter. so if you think you wish to try it take yours out and leave it empty clean the old gasket off and replace the gasket and I will bet you it will run cooler and it will hurt nothing.and with the A/C it will run cooler.and run better try it.
