coolant temp. questions

[Impala Lover]

Hello ya'll I have a question about the coolant temp. in my 1963 Impala 4dr sedan. It has a 350cid with a powerglide transmission. Anyway, I put in a new 160 degree thermostat and a rebuilt water pump. The coolant is full, the belt is tight and the hoses are new. My question is, what temp. does everyone's car run? With my combo, the coolant temp. gets about 220 in town, and doesn't go down much on the highway. Is this too much? Should I flush out the radiator? Any help is appreciated. Thanks!

[64ss409]

I had the radiator cleaned when the fresh engine went in. With a 180 stat, mine runs 190 on the guage, a little hotter in town. My clutch fan shows some sign of leakage and may run cooler if I replace it.

Your radiator may have some internal corrosion build up and could be the problem. Maybe a can of cleaner/flush from the local parts house would help. How about bent fins from grasshoppers or plugged with bugs? That restricts the air flow.

Do you have a shroud? And does the fan fit it? Approx 1/2 the fan blade in it?

Those old radiators weren't very big and everything else has to be in good shape for proper cooling.

Ron

[bobs409]

I believe the hot light would go on about 240 and is considered overheating so your a bit high at 220.

I would check the radiator like Ron said. Take the cap off and look inside to see if the cores are open. If there is alot of crud, your radiator should be professionally cleaned or better yet, recored. If they look ok, get the engine hot with cap off (or carefully remove cap while hot and running) and see if coolant is flowing through the cores. Could be clean on top but blocked down lower.

Since temps don't seem to change much from traffic to driving, the radiator would be the first on my list.

The fan draws air in to help cool while puttering around but once moving, air is being forced through the radiator from outside so there should be a difference.

With a 160 stat, you should be running quite cool. I would say 160-180 going by my own experience. My 409 ran a bit too cool with the 160 so I went with the 180.


If you find you've exhaust all possiblitlies and want to lower temps, you could opt for a big block radiator. The small blocks used a 2 core which is most likely what you have but you could get a 3 or 4 core.

[TomO]

ImpalaLover – If by chance the engine that you have in your car has the long water pump the fan is probably totally inside of the shroud. This was the case with my car. The underhood temps were very high and the temp gauge would get up to 220 or so on a hot day idling. Just last week I cut down the shroud with a jig saw so that the amount of fan sticking out of the shroud met Hayden specs (in my case 1/3 of the fan in the shroud). The difference was dramatic. Now I can feel the air being sucked thru the radiator and the temp that the gauge reads is very consistent 190 deg. The other big difference is that the underhood temps have dropped off – this is due to the fan sucking air like it should and the under hood turbulence that the fan now creates pushes the air out of the engine compartment.

I was able to leave the lower radiator hose hooded up and the radiator in the car when I pulled the shroud. I unbolted the top of the shroud/radiator and then screwed the bolts in from the front side so that they could hold the radiator in place. The fan/clutch will have to come out. In all it took me about an hour to remove/cut/replace.

This was well worth the effort.

TomO

[MRHP]

Do you have a heat riser on your exhaust manifold? Make sure it is working properly. Also, double check your temp gauge with another temp gauge, either a thermometer in the radiator or use a non contact thermo gun. I once had a car that would run warmer than I would like. Tried everything. I then checked the temp with another gauge and you guessed it! 20 degrees cooler. I then checked with a third thermometer to be sure.