thermostat

[78doba400]

hey guys i have a 1978 cordoba and am having issues with my heater not being hot enough. im currently running a 160 degree thermostat and am wondering if i upped it to a 180 if that would solve my problem..as it is the car usually runs at a quarter on the temp gauge and i have a rad cap that tells the temp and usually runs at 180 .also wondering if maybe the 180 would make it run too hot thanks guys

 

[Histoy]

Back in the sixties cars came from the factory with a 180 degree thermostat. Some customers were concerned about over heating in the summer, so we installed 160 degree thermostats for them each summer, but we had to put 180 degree ones back in for proper heating during the winter months.

 

[bobs66440]

Back in the sixties cars came from the factory with a 180 degree thermostat. Some customers were concerned about over heating in the summer, so we installed 160 degree thermostats for them each summer, but we had to put 180 degree ones back in for proper heating during the winter months.

The problem is possibly a partially clogged heater core. Very common problem. The thermostat may be part of the problem. Why are you running a 160? (most common is 180) Is 160 what it calls for? If so, I would leave it and try to flush the heater core with a garden hose. In any case, it wouldn't hurt to flush out the heater core. Do the easiest thing first. A t-stat is simple to install. Try it and see what happens.

 

[Slantsixdan]

160° thermostats were for use with alcohol-based coolants. Neither those thermostats nor that kind of coolant were recommended, but back then people did all kinds of dumb things with their cooling systems (run alcohol, run plain water, run mineral oil...). Most of that stupidity is behind us, but people still run without thermostats or with an under-temp thermostat (160°) because they are uninformed or misinformed. The hotter you run the engine, the more complete is the combustion. It means less and slower contamination of the engine oil with water and acids, less engine wear, better fuel economy, and warmer toes. The limiting factor in an old car is the carbureted fuel system; hotter thermostats will raise underhood temperatures which can create driveability problems by boiling the fuel in the carb. Still, I've used 195° thermostats on carbureted vehicles operated in cold wintertime conditions, then switched back to 180° for summertime use. Either that or a 180° thermostat all year round. But never a 160°.

 

[78doba400]

when i got the car i put a dual plane aluminum intake as well as a edlebrock 750 cfm carb (which i think is to much) shortly after i experienced overheating problems and had to replace the rad thermostat and waterpump my mechanic said to put a 160 thus the reason i put a 160. im just learning and dont know too much so i listened to him my car usually runs around 180 degrees and about a quarter on the gauge sometime its get hot while going up long inclines but has not for awhile my heater sucks *** and the higher i turn the fan the colder it gets.. should i up it to a 180 and back to a 160 in the summer? i just dont want to end up overheating and messing the engine up seeing as how ive dumped 15 g's into my car any help is greatly appreciated as i am a "noob"

 

[78doba400]

also i would like some tips on my timing.. i just bought a new distributor as well as mopar ignition box. i have a timing chain and gears as wll but that is yet to be installed thanks

 

[Meep-Meep]

160° thermostats were for use with alcohol-based coolants. Neither those thermostats nor that kind of coolant were recommended, but back then people did all kinds of dumb things with their cooling systems (run alcohol, run plain water, run mineral oil...). Most of that stupidity is behind us, but people still run without thermostats or with an under-temp thermostat (160°) because they are uninformed or misinformed. The hotter you run the engine, the more complete is the combustion. It means less and slower contamination of the engine oil with water and acids, less engine wear, better fuel economy, and warmer toes. The limiting factor in an old car is the carbureted fuel system; hotter thermostats will raise underhood temperatures which can create driveability problems by boiling the fuel in the carb. Still, I've used 195° thermostats on carbureted vehicles operated in cold wintertime conditions, then switched back to 180° for summertime use. Either that or a 180° thermostat all year round. But never a 160°.

Exactly! However, I used to run soluble oil and water because it was cheaper then antifreeze. Never had an issue and better than plain water.

 

[bobs66440]

when i got the car i put a dual plane aluminum intake as well as a edlebrock 750 cfm carb (which i think is to much) shortly after i experienced overheating problems and had to replace the rad thermostat and waterpump my mechanic said to put a 160 thus the reason i put a 160. im just learning and dont know too much so i listened to him my car usually runs around 180 degrees and about a quarter on the gauge sometime its get hot while going up long inclines but has not for awhile my heater sucks *** and the higher i turn the fan the colder it gets.. should i up it to a 180 and back to a 160 in the summer? i just dont want to end up overheating and messing the engine up seeing as how ive dumped 15 g's into my car any help is greatly appreciated as i am a "noob"

As mentioned, I would put in a NEW 180 t-stat (I have a feeling your original one went bad somehow when you switched intakes and that's why it started overheating) and see if the heat improves. Keep an eye on it when the weather warms. It shouldn't overheat as long as the t-stat is working properly. If the t-stat is working and it's still overheating, then something else is wrong.

 

[Propwash]

The problem is possibly a partially clogged heater core.

I agree....Flow check or have a Rad. shop Flow and Leak check. If junk, blow the 40-50 bucks and be done with it.

As far as your overheating, could be a number of issues. Timing, carb set lean, crossovers on intake, head or intake gaskets junk or installed incorrectly causing an air leak.....ect...ect..

If your juggling through themostat's left and right trying to fix an overheating problem your waisting your time and money. Pretty much tossing a band-aid at a symptom and not the problem.


Good Luck

 

[78doba400]

ok ive fixed the overheating problem and now it seems i have a bigger issue.
the car was back firing but not from the exhaust pipes it sounded like it was coming from under the hood i dont know much but im thinking maybe blow head gasket or possible blow exhaust manifold gasket..when i give it just a little bit of gas it stutters and hesitates then when i juice it it seems to be fine any tips are greatly appreciated thanks alot

 

[Propwash]

Timing??

 

[MarPar]

Timing??

X2...

 

[bobs66440]

ok ive fixed the overheating problem and now it seems i have a bigger issue.
the car was back firing but not from the exhaust pipes it sounded like it was coming from under the hood i dont know much but im thinking maybe blow head gasket or possible blow exhaust manifold gasket..when i give it just a little bit of gas it stutters and hesitates then when i juice it it seems to be fine any tips are greatly appreciated thanks alot

Sounds like it's backfiring through the carb. Be very careful, keep your air cleaner on while running it because it can backfire and start a fire in the carb (ask me how I know). The air cleaner will supress the flame. If it's backfiring through the carb it could be timing as mentioned, or a bad coil (happened to me recently). If you have a spare coil, try that.

A bad head gasket would cause you to lose anti-freeze (burned with the fuel) or there would be coolant in your oil or it would be leaking into the exhaust and cause white smoke out of the exhaust. If you have a breather cap or oil fill cap on one of your valve covers, pull it and look inside the cap. Do you see a whitish chocolate milk type substance. Also, pull the dip stick and look at the oil. If you see whitish residue then there's a problem there.

A bad exhaust gasket would be a constant steady ticking or popping noise coming from the engine.

What was the cause of the overheating?

 

[Slantsixdan]

my mechanic said to put a 160 thus the reason i put a 160.

That "mechanic" was wrong. Maybe out of ignorance and maybe out of stupidity and maybe out of both, but however which way, 160° is wrong in any/every season. A lower-temperature thermostat is not a cure or preventive for overheating, any more than stuffing a cork in the tailpipe "cures" or "prevents" a smoky exhaust. Find and fix the problem, then the overheating goes away.

 

[Slantsixdan]

As quickly as you can, get the three books described in this thread to learn how your car (really) works and how to (really) keep it working.

 

[78doba400]

thanks very much for all the info...i dont think it would be the coil as i have replaced the original with a super coil.. as it is with the 160 my car runs at a quarter on the gauge and from 180-200 on my rad cap that tells the temp...if im driving around and its running at a quarter and then turn the car off if i turn it back on 5 mins later the gauge will be up too like a half but then cool down when the coolant starts flowing again my worry is that if i put a 180 degree thermostat is that i think it will be running at a half and maybe 220 degrees. is that too hot? and if its running at a half then i turn it off it heats up and will it heat up and be too hot? thanks for the tips guys major help

 

[Revhendo]

thanks very much for all the info...i dont think it would be the coil as i have replaced the original with a super coil.. as it is with the 160 my car runs at a quarter on the gauge and from 180-200 on my rad cap that tells the temp...if im driving around and its running at a quarter and then turn the car off if i turn it back on 5 mins later the gauge will be up too like a half but then cool down when the coolant starts flowing again my worry is that if i put a 180 degree thermostat is that i think it will be running at a half and maybe 220 degrees. is that too hot? and if its running at a half then i turn it off it heats up and will it heat up and be too hot? thanks for the tips guys major help

The guage will read high from heat soak. The coolant isn't circulating when the engine is off, so the heat will just kind of collect for awhile. (Soak). Plain water is by far the best medium for transfering heat. Antifreeze/cooant/whatever, is added to the cooling system to inhibit corrosion, lube the pump bearing, increase the boiling point and lower the freezing point of the water. The thermostat is the actual control device of the cooling system and your engine temp should run just above that device's opening point.

What distributor, coil and box did you use? Were they all Mopar? Was it something else? Some ignition systems require a full twelve volts to work, others use ballast resistors (4 ohm and 8 ohm are typical). If you don't have the proper voltage you could very well have the type of stumble and backfire that you are describing. (Ask me how I know this).

 

[78doba400]

the distributor and ignition box were a kit i ordered from mopar. and the coil is called super coil its big and yellow

 

[MarPar]

i didn't see this mentioned, but it's not like it would be the first time somethin' slipped by me...lol

It sounds like you are using the stock gauge?

it would help if you could get a new temp gauge with numbers on it, you will get a more accurate reading from that. the stock gauge maybe a bit worn or just not working properly. DAMIK :eusa_boohoo:

then you could go from there, with good temp readings...


btw if IIRC, a 78 doba was lean burn (?) i am assuming you took all that performance sucking equipment off??? :icon_hang:

 

[Revhendo]

the distributor and ignition box were a kit i ordered from mopar. and the coil is called super coil its big and yellow

I'm guessing you used the ballast resistor supplied with the kit? (They still do that?) Try putting your stock coil back on. See what happens.