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Oil guage on our cars ( mine is a 78) has 100, 200 and 260, but more than 3 lines. The 200 looks to be almost straight up and down, but the line below is bold...so which marking is 200?
If it's straight up I'm good (never above the line above the center), if it's the other line i have a problem. Although my ir temp gun tells me 200 is the center, straight up line, i thought i would confirm. Silly question to many I'm sure...
Last edited by Vette-kid; Mar 23, 2016 at 07:08 PM.
The temperatures that could be assigned to the lines on the coolant temp gauge are irrelevant, really. None of those gauges are very accurate; if any gauge is within 20*F of actual engine coolant temps, you should bronze it for posterity.
That gauge is for reference purposes only. Normally, a warmed up engine will have the needle on that gauge almost vertical. That is the only useful "point of reference". If the car is warmed up and shows lower temps "Something is Wrong!" Of course, you won't know what is wrong...only that there is something amiss with the cooling system (or the gauge system). If that gauge starts showing higher temps, then it is time to shut down the engine...or risk locking it up--permanently.
There might be some inferrence you could draw from how fast the engine warms, if you really pay attention to the gauge during the warming process. But, that's about all you can glean from that gauge. Basically, if the needle is somewhat vertical when the engine is running and warmed-up, THINGS ARE GOOD!
Forget having an accurate gauge--it's only there to indicate when there is some problem.
Fair enough...the ir gun shows about 190 at the tstat housing with the gauge straight up. Hard to get a real good reading as the reflectivity i believe affects the ir reading. 190ish on the housing, 180 on the upper hose and 160ish on the list hose.
After looking at the link DUB posted i realized that mine does NOT look like that and i must have a different year in there. Appears to be an 80-82 gauge.
Cause of lower than normal temp is a thermostat that is stuck in the full-open position. In warmer weather, this will show as a "longer than normal time" to reach operating temp; but in cooler weather, normal temps may never be obtained. With a full-open stat, there is no regulation of the stat to limit coolant flow.
Thanks...I'm learning a lot about this stuff. I think I'm doing pretty good overall with cooling, although out could be a little lower. Idle for a minute or two will get down to 180...in town is 200ish. Occasionally at highway speed it will reach up to 220 or so for a bit (20-30 sec) and then work it's way back down. It was a bit higher, sealing the radiator brought it down pretty good. I need to get the front spoiler and see if that helps.
You definitely need the front air dam. That had to be there to deflect air [coming under the nose] up and through the holes in the lower fascia and into the radiator. If not there, the engine will always have a tendency to overheat on the highway.
Putting a big, fiberglass 'spoiler' under the nose might look "purty", but it won't last long if you go over speed bumps and/or parking lot tire stops. The original air dam is made out of fairly flexible plastic. It redirects adequate airflow up to the radiator AND can take a hit without shattering.
Actually, just realized something else. My overflow tank is on wrong...the hose feeds the top of the tank. Looks like it is supposed to feed the bottom so coolant can feed back to the radiator( its an aftermarket unit)? Is this a problem likely to cause air in the system?
Actually, just realized something else. My overflow tank is on wrong...the hose feeds the top of the tank. Looks like it is supposed to feed the bottom so coolant can feed back to the radiator( its an aftermarket unit)? Is this a problem likely to cause air in the system?
A PHOTO is needed....a GOOD one so if the coolant reservoir/overflow tank is NOT factory..we can see how it is designed and let you know where the problem may 'possibly' be.
AND YES...it is possible if it is not connected correctly..you can have an issue....but without a photo....it is all a 'guessing game'.
And also...you can 'possibly ' have a problem in your coolant system because you have not used a pressure tester to see IF the coolant system holds pressure. I have tested so many Corvettes that the gauge will drop really slow...and the leak is up high on the engine SO...not water will drip out...but rather the system will 'stream' out and not be easily seen....and ONE DAY...WHAM...the car overheats.
Sorry i don't have any good pics...it's been raining since yesterday afternoon so i can't really get one right now. These are the best i have. Its a cheap parts store universal deal. One line from the nipple on the fill neck to the top of the overflow.
It held vacuum when i filled it and doesn't seem to lose coolant. I will double check when the weather clears.
IF you ahve two ports on this aftermarket bottle for your coolant. AND one is at the bottom. THAT port is where you want the hose form you radiator to attach.....AND...if you have a port that is up high on the bottle....that is where you attach a hose so IF the bottle gets overfilled due the radiator puking into it...you will be able to direct the overflow of coolant where you want it ...instead of it spewing out into your engine compartment and possible getting onto the right tire.
What is ODD to me is why a correct coolant overflow reservoir...like the one GM made can not be used and installed. IT tucks under the right top hood surround area behind the inner skirt.
IF you ahve two ports on this aftermarket bottle for your coolant. AND one is at the bottom. THAT port is where you want the hose form you radiator to attach.....AND...if you have a port that is up high on the bottle....that is where you attach a hose so IF the bottle gets overfilled due the radiator puking into it...you will be able to direct the overflow of coolant where you want it ...instead of it spewing out into your engine compartment and possible getting onto the right tire.
What is ODD to me is why a correct coolant overflow reservoir...like the one GM made can not be used and installed. IT tucks under the right top hood surround area behind the inner skirt.
DUB
Stock absolutely can and will be used. I forgot to source one and have been using this as a stop gap. There wasn't one with the car at all when i got it.
The car had one..and when you install it the holes in the rear portion of the right inner skirt still should be there...so installing it should be quite easy due to not having an A/C compressor in the way.
ALSO...not meaning to get into you business on how you do things....BUT....having the heater hose come off the top of the water pump is a bit peculiar. But...the fitting that DID originally go into the intake manifold is a special reduced fitting...thus slowing down the coolant that is going into your heater core...and should be used. It is a fitting for a 5/8" I.D. heater hose...but the hole the coolant flows through is much smaller and this the wall thickness of this fitting is quite thick.
And if that is your temperature sending switch IN the thermostat housing.....it should be in the LEFT cylinder head...if possible..and if it can not...then at least in the hole you have plugged up on the top of the intake that you can barely see in your photo due to the upper radiator hose is partially blocking it. Having a temperature sender AFTER the thermostat does not make sense to me.
DUB, no offense taken. I don't mind constructive criticism when it is given respectfully ( i believe yours is). I'm here to learn, it's why i took on this car. Knowing full well that my lack of experience here may lead to breakage and self induced problems...that's ok. No-one learns by doing everything the right way the first time, all the time.
That said, i think you misunderstood me. Yes, i know the car had an overflow tank from the factory...just not when i got it. The motor is not anywhere close to original, all accessories and pulleys are likewise aftermarket sbc short water pump items. So the heater hose is ran using the way my wp was setup. If you think it is a problem, please tell me. The port on the intake is damaged and not usable, I'm just happy out isn't leaking right now. But I'm sure any attempt to remove the plug will not go well.
Why is there a problem with having the temp sender in the tstat housing? Once the engine is above 180 shouldn't the hottest coolant be coming out of that location just before going into the radiator? Or do i have something backwards?
Last edited by Vette-kid; Mar 28, 2016 at 08:45 AM.
DUB, no offense taken. I don't mind constructive criticism when it is given respectfully ( i believe yours is).
just trying to offer free advice...and if you choose to use it----fine---if not---that is fine also.
Originally Posted by Vette-kid
No one learns by doing everything the right way the first time, all the time.
BOY...I can AGREE with that. what I knew back in the day compared to what I can do and know now....no where even close to being the same.
Originally Posted by Vette-kid
That said, i think you misunderstood me. Yes, i know the car had an overflow tank from the factory...just not when i got it. The motor is not anywhere close to original, all accessories and pulleys are likewise aftermarket sbc short water pump items. So the heater hose is ran using the way my wp was setup. If you think it is a problem, please tell me. The port on the intake is damaged and not usable, I'm just happy out isn't leaking right now. But I'm sure any attempt to remove the plug will not go well.
The heater hose can come out of the top of the water pump if you choose and it is fine in regards to function.
Originally Posted by Vette-kid
Why is there a problem with having the temp sender in the tstat housing? Once the engine is above 180 shouldn't the hottest coolant be coming out of that location just before going into the radiator? Or do i have something backwards?
QUESTION: IF your thermostat shut down and stayed shut...and DID NOT allow coolant to flow.,...then HOW can the temp sending unit give you an accurate temperature of the coolant that is now stuck in the engine block getting hotter and hotter because the thermostat is closed???? Remember that these type of sending units work most effectively when they are in a liquid.
It is WISE to put your temp sending unit in the LEFT cylinder head...or at least in that area on the front/top of the left side of the intake ..like I wrote earlier.
And...if you do not know....those two ports in the top of your thermostat housing were used by GM...to install TVS's (temperature vacuum switch) in order to control specific functions of some components where GM wanted the water temp to be high enough to switch these components on or off.