1963 thunderbird, rebuilt engine and transmission. 390 4 barrel. runs hot! after a mechanic worked on it and replaced the carburetor,


Asked by Jul 06, 2013 at 01:31 PM about the 1963 Ford Thunderbird

Question type: Maintenance & Repair

we have been checking everything, when we had it at home it did not run hot. we took it to a mechanic because we could not get the idle down. he said the carburetor was bad, got another one from thunderbird headquarters, he said that one was also bad, put a quick fuel technology, off slayer on.  said it was perfect, can't drive it because it runs so hot. we are going to check if he put the thermostat in wrong. do you have instructions on installation and which way the thermostat faces?

20 Answers


Thermostat should be installed with the spring side in the engine coolant, if it's in the other way round it will not open properly. Removal and installation are simple: drain coolant, undo hose between thermostat elbow and radiator, remove thermostat elbow, remove thermostat, installation (annoyingly) is reverse of removal but make sure you use a new thermostat housing gasket.

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Best Answer

OK- you have a classic T-Bird and a sketchy mechanic- do you see a disconnect here?

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Heh, the mechanic is probably part of the OBD-maffia: if there's no OBD socket they're stumped...

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thermostat was in correct. installation was done, new gasket. but still runs hot! any suggestions? did combustion leak test! know mechanic was an idiot! we got screwed but still want to get the car on the road! my dream car, Husband trying everything, please help!!!

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Your car is a very neat bullet nose bird- I'm sure you are being very careful with it- there's a chance that what the mechanic did with the carb and the overheating issue is unrelated- even if it is, at this point care must be taken not to smoke the engine on your car- that's the important thing- did you take the thermostat out to check it? sounds like you did- my suggestion is to just take it out and leave it out- for now- and let's see if it runs cooler- then we will know how to proceed

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Have you checked your ignition timing? He may have hooked up the vacuum advance hose for the distributor wrong. That can cause an engine to run hot. The replacement carburetor may be jetted too lean. An overly lean air/fuel mixture will cause an engine to heat up. Remove and inspect all the spark plugs. If the electrodes are white, pure white, you're running way to lean. HTH. -Jim

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The next thing I would do is to pull the supply heater hose off the heater core, put the end in a bucket and start the car. Make sure there is good flow out of the hose. If not, your culprit is the water pump. Either it was not installed correctly or it is defective. Make sure the fan belts are the correct tightness, too. My next question is about the carb. Did the old carb work properly on the engine before the rebuild? If so, why could you not get the idle down, and how high was it? It could have been a stuck choke causing the high idle. Make sure ALL the vacuum lines are run correctly, as some are timed and some are direct. Make sure any temperature switches for the vacuum system are operating correctly. How old is the radiator? Has it been cleaned out recently? What rad fluid are you using, and is it the correct strength? Is your rad cap the correct one? When the new engine was installed was the correct sending unit for the temperature gauge installed properly? Is the exhaust flowing properly? With the car running, what does the exhaust smell like? Does it smell normal for the car, or is there some other scent to it? Check the state of the plugs for sure. Carb running lean will definitely make the FE engines run hot. If all of that fails, you need to find a REAL mechanic, not a technician. The old FE engines are pretty straight forward, and there should be no trouble getting one to work properly if the rebuild was done correctly. If worst come to worst check and make sure the valves are in sync with the bottom end. If the timing chain was not installed correctly, you could be out by a tooth or two. The car would run, but certainly not properly.

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Hello, Im no expert just a 1963 T Bird owner from London England. I had a similar problem starting with the carb. I couldn't get the speed down. what I did. was 1 release the choke pull off adjuster as far as it would go. 2 ( this alone will enable a fall in speed) 3 assuming the timing is sound then check the whiteness of the plugs as the guy above says. 4 check float level ( lower if too high) 5 now clean out the two adjusting screw holes ( wire through it) 6 finally blow out through the carb with air ( still on the car) hope that gets it down then the heating is probably what the other guys say. Neil


How hot is hot? Is it boiling over hot? Have you replaced the radiator cap recently? If you can remove radiator cap ,when cold,if it's not the old style, were the the tank is not part of the radiator, you should see water moving in the radiator after the thermostat opens,when warmed up . Next. Seal up the radiator,put the cap back on. Warm the car to operating temp and put your hand on the front of the radiator, not the backside where the fans is or you'll ruin your day. Is there hot and cold spots throughout the radiator? If so your radiator is plugged and needs either rodding out or worse replacement. Also you didn't mention if it has A/C. I hope, if it is, they put the right waterpump on it. Because if they didn't you'll run hot,especially if it's a warm day and under a load, like climbing a hill. It has to be a waterpump for an A/C car. One more thing make sure you have a shround on it. It's a plastic housing on the fan side of the radiator surrounding the fan. It's very important to cooling that beast.

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no a/c. hot is 230 degrees and yes boiling over. had radiator checked. all good even added a 7 blade fan with a schroud


Did you ever just remove the thermostat?


Along with some of the others above, I think it may be too lean a mixture. Also, did you put a Holly on it or an original? Was it new or rebuilt? Timing and lean are what I am leaning toward with everything elso you have said about it. Good luck.


Very unusual for the swap of a carb. to cause the prolems your having unless,like oldtimer said, your timing maybe off. But if that were the case it would have been running hot prior to carb. swap. A lean idle misfire can cause the combustion process to run hotter because of the addition of air to the process. I don't run Holley's but I do believe the adjustments on this unit is just the same as most carbs. Turn idle mixture screws in till they seat. Dp this gently so as not to damage the seat, it's calibrated seat and you don't want to open it up by turning the needle to hard into it or you'll never get her to idle properly. Adjust each side one at a time. Seat the needle valve and turn it out 1&1/4 turns both sides. This is a basic starting point. Adjust both sides the exact amount,generally1/4 turn at a time.Wait after each adjustment to see how the engine reacts. The engine should smooth out as you adjust it. But it may be ok after inital adustment. Now like I said this is a genral carb. process and I'm not exactly sure on this carb. Holley' as, I understand, can require several adjustments prior to this process, so look on the internet and see how this is accomlished. It will probably take 2 of you to do it. But, if your timing is incorrect this will just muck up the works and make you mad at me. I don't know the timing on this vehicle and I won't guess but if your to advanced it may run hot and be hard to start. Also your rpm's will tend to run high. Hopefully your timing gears were linged up when she was rebuilt or you'll never get her to run smooth Just 1 tooth off and the engine is 7 degee's off, advanced or retarded. Lot's people blame the carb. for other problems. That high rpm may have been produced to mask other problems.And beings you said all the right things about your cooling system except 1 thing I hope the lower rad. hose is the type with a sping in it. If not it will at some point collapse and cause the heating condition your having. This sounds simple but make sure you have the right rad. cap. I don't really know your problem and I'm just throwing out some suggestions and it's tough to identify the problem your having without seeing the vehicle. But most of the suggestions sent by the other people here are pretty good. I don't know what was the stock carb. for that car but if it wasn't a Holly I would have replaced ,if it was faulty, with the same unit if it was availible. I not questioning your mechanic, lord know's I've made a few mistakes, so I wish you good luck. Nice car by the way. There a joy when fixed up.

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not a holly, its quick fuel technology (off slayer) 600


Is it a square bore (all 4 barrels the same size) or is it a split bore (small primaries, larger secondaries)? If it is a split bore you have the wrong carb for the engine. Fords always do better with the square bore carburetor. I hope the mechanic didn't charge TOO much for the carb. The Edelbrock Performer is a 600 CFM square bore, body 1401, and it is easy as pie to tune and set up. That is the one I've always had the best luck with. It is made by Weber, by the way. Just talk to the technical support people at Edelbrock and make sure you order the correct metering rods and jets for the engine application and how you will use the car. It has to be the easiest carburetor to tune ever, as you don't even need a screw driver or even to pull the breather! The adjustment screws are front and centre, and knurled so you can turn them by hand.

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By Hand! By Weber! By Jove, I want one for my T-Bird!


Jamnblues: It is the standard Edelbrock 1401 carburetor. As stated, talk to the tech centre and they will tell you which jet and metering rods to use for your car, and there is no need to disassemble the carb to change either. Changing the jets and rods takes about 15 minutes. Setting it up properly from there takes about 5 minutes more. It is a terrific carb, and fantastic for fuel economy, especially if you pair it with the Edelbrock Performer intake manifold. It is designed for maximum torque as low in the revs as possible. Simply amazing. My brother had a 79 Thunderbird with an 86 351W and AOD. How does 700 miles on a single tank sound to you?


Since the engine has been rebuilt, it is a possibility that one of the head gaskets was put on backwards. This would cause your car to over heat. Check your spark plugs, if the head gasket is on backwards, the plugs on that side of the engine will be white. I would suggest running Champion Spark Plugs #35 with a gap of .0035.


A lot of good answers. I would like to know more about the Edelbrock 1401 carburetor. My 65, 390 gets about 8mpg at 50mph. Will the Edelbrock 1401 do much better? Can someone give me a link to learn more about it please. Also, any of you not doing anything the first week in October, come join us on the Mississippi Gulf Coast for "Cruisin the Coast". Great time and had about 7000 cars last year.

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T-Bird 390's plugs should be gaped @ 0.035 (35 thousands), NOT 0.0035 (35 ten thousands), an almost invisible gap. Regarding MPG: I only know I have a Holley split-bore 4 barrel. Can not find any ID info on it & it has no tag. I have even checked INSIDE the primaries for a reported ID but no soap. I have averaged about 12 to15 mpg for the almost 25 years I've owned her and almost all of that is around Pinellas County, FL. Little highway excepting a drive to my 50th HS reunion in NJ in 2007 and to the Orlando area a few times. That Edlebrock Preformer sounds amazing. Carb model 1401 - right? Thanks, Murf

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