over heating C1

[Stewart A.]

Finally got my car on the road and was spoiled by the motor overheating. I had never driven the car previously. Before I put the car on the road I had the radiator cleaned out. Which required the top tank to be removed. The radiator shop said the radiator was blocked to the point of not being able to get a rod through it, so he soaked it over night in a bath of solvents and then cleaned out the pipes. The block was cleaned by me so I know there was no muck in there. I am running a 160 thermostat, it has the proper shroud and clutch fan, water pump was put straight back on so not sure if that could be the problem as well.The distributor also has no vac advance. The cars gauge is around the 180 mark when the thermostat kicks in and then slowly creeps up to 200-210 on the highway. The fan does not help while driving at 60 mph, if the car is getting hot on the open road with a cool day does that mean the radiator is not doing it's job. Which part should I do first.
Stewy

[Terry D.]

Re: over heating C1

Stewart
Please check the archieves, this subject has been discussed several times in depth. Timing is very critical to the early Corvettes as is a good radiator. Also are you sure your temp gauge is accurate? Did you check it with an IR gun?
Terry

[Paul H.]

Re: over heating C1

If your gauge is accurate, high temps on the open road usually point to a radiator flow problem. Cleaning an old radiator is rarely successful. I would put a new Dewitt's aluminum radiator in it and be done with it. Then you can enjoy driving and not have to watch the temp gauge creep up.

[John T.]

Re: over heating C1

First step is to check the temperature with an IR gun. The currently available C1 temperature senders are often wrong. Find out if you have a real problem first.

Good luck

John

[John H.]

Re: over heating C1

First step is to check the temperature with an IR gun. The currently available C1 temperature senders are often wrong. Find out if you have a real problem first.

Good luck

John

I agree - step #1 is to verify that you really have a problem, knowing the wild variation in accuracy of temp sending units, particularly replacements. If an I.R. gun "shot" of the upper radiator hose just above the thermostat housing shows the gauge is accurate, it's time for a new radiator.

[Stewart A.]

Re: over heating C1

Thanks guys !! I can get my hands on a IR gun but the gun shows different heat all over the car e.g. radiator, top hose, sender unit, heads, bottom hose and so on. Do you know what temp should the IR gun be reading and where is the best spot. Do I allow for heat sink to set in before I read it. Thanks guys xxoo

[Jack H.]

Re: over heating C1

We typically shoot the bottom side of the rad hose just as it exits the engine. Rubber is a pretty poor heat conductor so it should be 'close' (conduction from hot coolant flowing) to what the temp sender sees...

[Stewart A.]

Re: over heating C1

Hey Jack what type of temperature should the car be reading at idle after a good drive. I'm not sure if I should be seeing temeratures above 180 or below 180 on the electronic gun.

[Jack H.]

Re: over heating C1

Once the engine has idled down from the drive and 'normalized' I'd expect coolant temp to return to the 180F range. Of course, this depends on how good/fresh your radiator is and the health of your fan clutch.