Packard Forum Index » V-8 (1955-56)

FWIW....

When I got my car three years ago, I had it professionally flushed and installed name brand anti-freeze.

Recently have been having air added, and since the radiator was coming off, had it flushed again. I'll bet most people here would have thought that silly, but a record amount of crap came out...

Car ran cool, but was unhappy with extended delays in traffic on hot days, the worst being a fourth of July parade in 100 degree weather. It ran rough at the finish and took a while to cool down.

Normally needle doesn't come up a lot, but it went to 3/4 on that day.

Dear Pat:

Very common problem as cars age. Including modern cars.

The radiator is rather small to start with, but with A/C there is an additional load. Also, if the idle speed is near the 400 rpm spec there may not be enough flow from the fan.

Solutions are easy to test. Just let it sit in the driveway on a hot day. I have always felt that 400 rpm idle is too slow and inhibits oil splash, so I would raise it to 550 rpm and see how it does. After that some shrouding around the A/C condensor the same way as modern cars. Maybe try the shrouding first.

Beyond that, old cast iron is less efficient and radiators cores do wear out. Also, less that top compression runs hotter so if your gas mileage is not so hot check that as well.

Overall, as long as it is not boiling you are doing pretty good. I did a 56 Carribean that idled hot even with a new core. It had a junkyard block and so was rather weary.

The hoses do not kink when it heats up. A handful of possibilities have been suggested. I need to start taking one thing at a time.

First thing I'd like to point out, which I think is important is this:

When I was going down the freeway in 100-degree weather, it got pretty hot after about 15 - 20 minutes (as in needle was way way up there). A few minutes later, it cooled down quite quickly, as if the T-stat opened right at that moment. It was pretty obvious how quickly it cooled down. Then, after 10 more minutes, it was back up to very hot again. At this point, I was close to home, and that is when the fuel pump pin came out and I died. When I popped the hood, I noticed coolant had bubbled out.

So, first item up for order:

Will T-stats fail to open and close properly (at the right temps), or are their malfunctions limited to either working right or not at all?

Jeff, I like the idea of you investing in one of those small, cheap laser pointer temp gauges and see what the actual coolant temp is. It's really hard to tell if this an actual overheating issue or a gauge malfunction. When a car overheats, you know it: Leaking coolant, steam, the whole Cecil B. Demille production you see at the side of the road with OTHER people.

T-Stats are cheap and easy, go get a new one. They're made of a special metal that expands when hot, which opens the valve, allowing the coolant to flow. Typically, they either work or they don't, they don't go back and forth btw'n open and closed when hot. That sounds more like an electrical issue with either the sending unit or the gauge itself...or maybe lots of crud moving around in the radiator and plugging it up. It's a new radiator with new, properly blended 50/50 coolant, right?

I would check out RMI-25, i use it, and have great results. google it..they have a video i think...

Hello,

Hmm, +1 for Bobby.

I think also a checkup with a thermometer will give you a right answer.
I once had it with my Dodge Ram Van, the gauge went to max temp, al lot of warning lights went on; just like a X-mas tree.
I pulled over and take a look under the hood, all seems be fine: result: the engine ran fine at nominal temperature, it was the gauge electronics that went bananas... !

If your radiator is not clogged, the thermostat works ( your radiator is equal hot the whole surface ) and your waterpump runs fine, your cooling system should work fine.

An external thermometer will give you the solution.

When I make a trip with my 56 Clipper, the gauge shows from cold to nearly halfway to Hot. When I stop and I open the hood, the heat is coming out the block, but that seems to be alright; no hissing or steam but ready to boil some eggs on the block...

Grtz.

Xavier

Quote:

When I broke down 2 weeks ago, there was not steam and all, but coolant did overflow.

You think this is something that can occur without overheating? If so, point me to the small, cheap laser pointer thing. I am not sure what exactly this is. A link to a product would be great.

Thanks.

Here are a couple but are at the cheap end. I have the laser light one and it does the job. Riki probably speaks of a better quality item.http://www.harborfreight.com/catalogsearch/result?q=infrared%20thermometer

Howard's right, as usual...get the $19.95 one from Harbor Freight.

Coolant overflow? Do you have a new, proper lb. pressure radiator cap? What happens is that when the coolant expands naturally as it gets hot, the radiator cap spring will react to the amount of pressure the hot coolant is giving off, and when it passes a certain, predetermined temp, it will allow it to escape. This is to protect the cooling system/heater core from excessive pressure. If you don't have the right cap (or it's old and malfunctioning)..this is simple, I know..it won't operate properly. If you're not sure, go NAPA and get a new cap. Coolant (COLD) should cover the honeycomb part when you look down from the open cap. If you add more (Like to the very top) it will flow out, not so much b/c it's actually overheating, but, recall from high school, that things expand when heated, so hot coolant overfilled will spill out.

Is this a new radiator and coolant, Jeff?