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So,I've owned my 1963 for 40+ years,and just installed a 383 stroker and been having trouble with cooling system...gauge will go back and forth from 180-260-200-180-260 and then back down to normal...assuming an air bubble in system...I've taken hose off at manifold and filled block direct and it seemed to help,but now doing same thing after a couple rides.I've read all kinds of remedies,jacking car up and filling..etc..and now watched a video on Utube about using a "spill-free-funnel" but it seems that needs to go directly on radiator,which the 63 doesnt have a cap..its the recovery can...so one question,if I use the spill-free funnel way and it fills the can totally up to top and gets air bubbles out,would I then need to siphon half out since you dont want the can filled to top....OR..anyone have any suggestions....dont want to use car with temp. gauge going crazy like that and possible engine damage...and..YES...its a new gauge,so thats not the cause...HELP...we only get to use a few months a year in RAINY Wa. State....THANKS
Every small block I've ever worked on has "burped" itself after being filled and run up to temperature. Seeing as the temp gauge is new, I'd suspect that first. What did the old one do that you replaced it? If the old one still works, I'd try it to see if that's the problem. Also get an IR temp gun and check to see if the gauge is reading the real temps when it's jumping around. . Good luck.
Duane
Every small block I've ever worked on has "burped" itself after being filled and run up to temperature. Seeing as the temp gauge is new, I'd suspect that first. What did the old one do that you replaced it? If the old one still works, I'd try it to see if that's the problem. Also get an IR temp gun and check to see if the gauge is reading the real temps when it's jumping around. . Good luck.
Duane
all true, one thing u can do is overfill the rad and watch for bubbles, if no bubbles are visible after a few starts and idling a few minute each time then I would certainly suspect the temp sensor and gauge have corrosion or loose connection. rem once u shut off the engine during the visual test there will be significant overflow past the cap to the floor.
Every small block I've ever worked on has "burped" itself after being filled and run up to temperature. Seeing as the temp gauge is new, I'd suspect that first. What did the old one do that you replaced it? If the old one still works, I'd try it to see if that's the problem. Also get an IR temp gun and check to see if the gauge is reading the real temps when it's jumping around. . Good luck.
Duane
Hi Duane,
Actually it usually does "burp" itself "sometimes"....after driving for 15-20 minutes,temp goes back down,but just never know if and when it will happen again,so usually head home rather than risk it.....and sometimes it just keeps jumping around ....I do not think its the gauge because I have driven it without this happening.....its one of those things that happens only to you,then you take to mechanic and its fine...its a total mystery to me.....It is an aftermarket gauge I placed under the dash when the original went bad and just never got around to replacing the original...so I really doubt its the gauge.....
Last year when it happened I filled block up directly from manifold with a funnel..then filled the hose with funnel....was surprised how much when into the block,even though the res can was 1/2 full....and I actually used it 5-6 times after that with no problem....parked car for winter..used it 2 times this year,and bingo..3rd time...problem is back....driving me crazy.....there are no leaks anywhere and res. can is always filled to level,yet just never know when that bubble will come back.....
I'm gonna try running with cap off like several have suggested.....and see what happens......
Thanks,
George
all true, one thing u can do is overfill the rad and watch for bubbles, if no bubbles are visible after a few starts and idling a few minute each time then I would certainly suspect the temp sensor and gauge have corrosion or loose connection. rem once u shut off the engine during the visual test there will be significant overflow past the cap to the floor.
Hi Sam...
After all my searching and some of the replies on here,think I'll give that a try and keep fingers crossed....might just invest $30 and get that Spill-Free Funnel Kit I've seen on Utube...will save me the messy overflow...
THANKS..!!
George
Hi Sam,
Guess anything is possible at this point...and I'll give another check...but I did total engine and compartment rebuild..everything new,water pump,hoses,clamps..etc....EVEN took old Radiator out,& replaced with hi-flow racing one,which didnt help.... :-(...Replaced clutch fan..no luck..tried several different fans..no luck.....I think it could maybe be something with the heater core?but never checked to see if heater is working correct,since we never need it....
One other thing I didnt mention is since its an on again off again thing with temp bouncing all around....when it does settle back down to 180 and driving a steady speed with good air flow,it stays stable....but if the car has to sit for more than 5 minutes or so,it starts right up again..so thats made seeing a traffic jam ahead a NIGHTMARE....LOL...
At first when I redid the engine,etc I thought I might of crossed the heater hoses,but have checked and everything is as it should be.....I even changed the water pump along with Radiator....tried 2-3 different temp thermostats ..several different pressure radiator caps...different fans......Beats me.....nothing wrong with engine...runs like a bat out of hell....its just this damn air bubble.....
Sure sounds like You have thrown a lot of parts at it. You say that You doubt its the Gauge because its an aftermarket to me that makes it more likely that's the problem. So is it a Mechanical type or with a sending unit and wired ? Has this thing actually overheated and boiled over ? An Inferred Temperature Gun in your pocket on a test drive sounds in order. When it acts up I'd be checking the Engine close to the Temp sensor both before and after the problem. Is the Gauge Sender in the original spot probably in the Head, or someplace else ?
Sure sounds like You have thrown a lot of parts at it. You say that You doubt its the Gauge because its an aftermarket to me that makes it more likely that's the problem. So is it a Mechanical type or with a sending unit and wired ? Has this thing actually overheated and boiled over ? An Inferred Temperature Gun in your pocket on a test drive sounds in order. When it acts up I'd be checking the Engine close to the Temp sensor both before and after the problem. Is the Gauge Sender in the original spot probably in the Head, or someplace else ?
Hi Gale...
Well,you got that right....alot of parts and headaches....you ask 10 guys,and you get 10 different options..so you start trying them one at a time.....and that was just local guys...tonight I remembered about Corvette Forum and thought I'd give it a try,and now have another 10 things to check..LOL....
I say its not the gauge because thats the one thing I DIDNT change when I redid the engine and engine compartment....the original went bad and I put the under the dash unit..which is just a mechanical hooked up into the manifold.....I had a 350 with a high-rise dual carb. set up & nitro in the car (my younger crazy days),with the same gauge and never had the bubble problem.....this all started when I put the 383 stroker in it....
So in answer to your questions.....Sending unit is in same place and no,car has never actually overheated or boiled over....like I said in to others..it will go from 180 to 220-240-260,bounce around from 260-240 for a while..drop back down to 200..back to 260....and always seems to then level back out at 180...I say 'always seems" because alot of times it starts up faster than others and I just turn around and go home,rather than chance that it might go back to 180..and sometimes I say WTF..its gonna stop and just keep driving......but one thing is for sure...even if it goes back to 180,it I stop and idle for more than around 10 minutes,it starts all over again....
I've owned the car since 1973......and never had problems with the 327 in it and could sit in traffic all day with no problems....thats whats driving me crazy...I'm sure there are alot of 383 strokers in Vettes that can sit in traffic all day too...so I think its just some stupid simple thing....and just to be sure......well,one more part...might as well change the gauge,not like $20 is gonna break me after what I just put into it to bring it almost back to stock (except the 383)...and like it was when I bought in 1973.....
Thanks,
George
well the issue really is which is the culprit, gauge or air. as the op have said a bouncing gauge is suspect because temps generally only rise and slowly return, 2 additional things do come to mind however. thermostat can be bad, even brand new out of the box ive heated them on the stove and they don't work. the other issue is I assume with all the work you went with an aluminum radiator and overflow bottle, the rad cap may not be working correctly, theres a wide range of psi rates and although rare the relief valve in the cap to the bottle can be faulty. very nice car, I can tell you spent a lot of attention to details, but we all make mistakes, assuming theres no oil pump problems or transmission cooling issue that is rapidly changing the coolant temps thrugh the aluminum rad I am leaning towards the actual temp sensor mounted on the block, its the bouncing part, air bubbles should be fairly easy to remove, and an air locked pump doesn't flow worth a damn it doesn't spurt some coolant then pause, the heater core is fairly much just a big looped tube and it cannot cause blockage unless something is really wrong with it such as caked up stop leak etc, I am curious if u run the heat on full blast during this temp bounce thing, if its really an obstructed coolant flow then the heater should give really hot then cooler air which will coincide with temp gauge readings, if heater core heat is constant but temp gauge is bouncing then the coolant temp is constant and the issue is definitely in the gauge.
keep us posted, esp when u find the problem, its got me curious.
Hi Sam,
Thanks for the compliment....yes...I bought the car in 1973 while in High School with a bad engine...I know I'm gonna get **** from guys,but back in 73,who knew...junked it,and rebuilt a 350 for car...car has had 3-4 different engines in it over last 40+ years...including a dual high rise tunnel ram (didnt cut original hood),and nitro....So several years ago I decided,well never gonna have original #'s matching car,although everything else is original,but engine isnt,so did my best to at least make it look original...I'm still kicking myself for my mistake in 73..but sure have had fun with the car all these years...
Anyway..I'm going to take it out this weekend and will check the heater as you said...I honestly dont think I've even touched the ***** to turn on in over 10 years...
George
Go to Amazon.com and buy a $20- IR spot thermometer. It has a million other uses, and you will be able to check the thermostat opening temp, flow through your heater coil, etc.. If you are a Prime member, it will arrive before we are done speculating about the other 27 things it could be.
You won't get any grief from me about your engine. A NOM car that you actually drive and enjoy is worth ten numbers matching trailer queens!
unless I missed it above, there is no mention of trying a different thermostat or when the engine starts to run hot, stopping the engine and assuming you have a fan clutch try spinning the fan by hand to see if there is resistance.
I agree with bikespace, IR guns are cheap.
What happens to the coolant level in the expansion tank? Does the level return to what it was when the car is cold?
first step verify your gauge, no cost true temperature verification,
remove sending unit, connect with long jumper wires to your car. put into boiling water, gauge should read 212.
do this first.
first step verify your gauge, no cost true temperature verification,
remove sending unit, connect with long jumper wires to your car. put into boiling water, gauge should read 212.
do this first.
That sounds simple enough...and will give a try....but another member suggested my heater hoses might not be correct.....My T to expansion tank is on the hose from bottom of firewall to intake manifold,and it looks like,from drawing he sent the T should be on the top hose from firewall to to water pump..??
first step verify your gauge, no cost true temperature verification,
remove sending unit, connect with long jumper wires to your car. put into boiling water, gauge should read 212.
do this first.
That sounds simple enough...and will give a try....but another member suggested my heater hoses might not be correct.....My T to expansion tank is on the hose from bottom of firewall to intake manifold,and it looks like,from drawing he sent the T should be on the top hose from firewall to to water pump..??
Water level in tank is always the same..I'm not losing any..once and a while might just top up very little...
Check your timing. I had this issue that when I came to a stop lights the gauge would go up to 210/220. It would drop back down once I was moving again.
I found that the bolt to the clamp was not tight enough and I was in retarded zone!
Check your timing. I had this issue that when I came to a stop lights the gauge would go up to 210/220. It would drop back down once I was moving again.
I found that the bolt to the clamp was not tight enough and I was in retarded zone!
LOL...glad to see I'm not the only one that gets into that retarded zone...seems to happen more as I get older...BUT...you bet..on my list to check this weekend....but really thing I was retarded when I hooked up the heater hoses.....Keeping fingers crossed...we dont get many "good" days to drive out here in WA> state,..even though it use to be my daily driver when back on East Coast in 70-80's...car has not been driven in rain or snow for 32 years now...1986..moved to the RAINY STATE...!
08-08-2018, 08:16 PM
Air bubble in 1963 Corvette
