Packard Forum Index » Post-War (1946-54)

Some cars just seem to defy attempts to get them to run as cool as others of the same year & model. Perhaps a shift in cores while casting the block, or some other anomaly. I had a friend with a 23rd series Eight (288/standard with OD) that defied all atttempts. While it never boiled, it really only maintained a reasonable temperature while at road speed; stopping in traffic even on a moderate day you could almost see the needle moving to "H" where it pegged, though never boiled.

We installed a new 4-row radiator, new water pump & distribution tube, had the head boiled and magnafluxed for internal cracks, removed core plugs to examine the jackets for accumulation of salt cake. Timing was on spec, exhaust inspected for undersize tail pipe, and MUCH more. Never found the problem; the only clue we saw was that the fan blade to radiator distance was just a bit greater than typical measurements, about an inch or perhaps a hair more vs. a more typical 3/4 or so. Other than that, the car was a fine performer, did many long distance tours w/o issues and generally in all other respects ran like a Packard should. Problem remained unresolved when the car was sold.

Hopefully this one will not defy attempts to fix.

Sure it is something stupid that I have overlooked.

To answer some questions:

* I did better with the transfer tube, I removed it and checked the water passage. Clean as a whistle.

This vehicle underwent a complete rotisserie restoration then garaged for 15+ years. The engine and entire vehicle look brand new. Doubt there are 200 miles on it since the restoration.

*The lower hose has the pipe in it. No way it can collapse.
*Suspected new trans overheating the engine. Although I was told there is no way this could happen. I added a huge trans cooler in front of the radiator.
*I haven't opened the engine except for water pump and transfer tube check. There are no leaks that I can see around the head gasket. Doubt there is a leak into the cooling system. The coolant is too quiet in idle.
* Restrictive exhaust is possible. Can a vehicle go 80+ on the highway without missing a beat with a restricted pipe ?

There is a retired guy near me that is supposed to be a master mechanic. May let him look at it with fresh eyes.
Look at something long enough it starts to look ok.

I'm curious about the fuel mixture at idle. Running lean could cause temp to climb fast, but on the freeway you're not really using the idle circuit, so it could avoid it unless you're idling.

Quick way to test the theory, start it, let it run at about 1/2 throttle instead of idle and see if it stays cool. Would narrow it down some to something that happens only at idle (water not flowing fast enough or idle circuit maybe.)

Good idea. Might try a quarter turn on the jets and see what happens. Think that should work real quick. What do you think ? Believe it or not I was thinking about putting
an O2 sensor in the pipe with a guage.
Now is that desperate or what?

Not desperate at all! I'd love a tailpipe tester to tune mine...exhaust seems too hot coming out the back.

You can get a gauge at advanced auto for about 30 bucks that will connect to any 1, 2, or 3 wire O2 sensor, which can be cheap. Weld a bung in the exhaust and connect it to tune, then take the gauge out. Later, you can connect it under the hood to see how the car is doing during tune ups.

Hrmm, i might do that too. Even if everything is fine, it'd be nice to KNOW that.

In my experience it's very unlikely that too-lean an idle mixture will lead to significant overheating, and if that's the case the engine will idle very poorly and should be rather obvious. Set the idle mixture with a vacuum gauge if you're at all in doubt. Screw in until the engine falters, then out gradually to maximum vacuum - should be 18-21 inches of Hg.

Lean mixture on the high speed system (and/or a vacuum leak) is another matter and can lead to overheating problems at road speeds.

You may have already commented on this, pardon me if I missed it in earlier posts, but overheating problems are often found to be the result of an incorrect width fan belt which rides in the base of the pulley and not on the flanged sides - have you checked this?

PS - otdgy asks: Can a vehicle go 80+ on the highway without missing a beat with a restricted pipe ? Depending on the amount of restriction, I'd say yes, but the exhaust valves and seats will quickly become toast.

Dear otdgy:

Given all this information I would suspect a defective radiator.

I dealt with a brand new radiator on a 6th series car once that boiled like crazy. In those days spare parts were easily borrowed and so we installed an original radiator and tested the vehicle.

Then we took the owner of the radiator shop for a ride.

He conceded that his radiator didn't work.

As regards exhaust restriction, the standard method is to hook up a vacuum gauge and raise the RPM to say, 2000-2500, and hold it there. If the exhaust system is restricted then the vacuum should begin to fall and be lower than idle. Additionally, the car should lose power on long grades and under heavy acceleration.

A note here about timing. On these Packards correct timing always seems to help a lot and is sometimes not easily achieved. I usually don't have much success without doing it by the book. Anytime I check what I think is right by ear it isn't. Although I will say that when correct the exhaust note is a lower pitch than a modern motor.

Good luck.

These are some great ideas. Need to check the vacuum gauge and rev the engine. Didn't know that was how to check for a blocked exhaust even it it does make sense.

Took the radiator down to a local shop when I first got the car thinking it needed to be rodded out. The shop said it passed with flying colors, didn't need anything. Someone earlier said to use a UV temp device and note the temp at
each tube to check for temp differences. (excellent check by the way). Unfortunatly (?) the flow and per tube temps checked perfectly. If I remember correctly there was about 15deg drop bottom to top of the radiator. Didn't seem like much, still doesn't.

A question about timing. There is one mark on the balancer and a pointer. Is this mark TDC or where the timing should be ? Haven't pulled the #1 plug and checked it. I believe the marks are aligned.

Going to take it out this weekend. Supposed to be 35+ degrees out. Wonder if it overheats and if it doesn't wonder what that proves ?

Owen; I agree that the mixture isn't likely. On aircraft the mixture is adjusted to get max rpm then opened an addl 1/4 turn. The addl richens the mixture and cools the engine.
More likely to foul the plugs than cool this beast. ;)
I purchased the fan belts from NAPA they look ok, however I am not real sure what a "bad fit" would look like. If it doesn't fit right wouldn't it squeal or something ? Don't understand how it could change things if the belt is bottoming out since its not slipping.

Just remembered. The radiator guy said the fins in the radiator are too close together and that restricts the airflow. However as noted earlier this radiator has as many fins per inch between the tubes as all of yours. Assuming original is correct this shouldn't be a problem. Noted that after running the engine on the hose I wasn't getting real wet from the spray until I revd the engine then the fan started pulling the water from the fins of the radiator. Seems the dude was right to some degree. Problem is it would cost over $1500 to recore this radiator again.

OTG

I got my "wrong" fan belt at napa and asked owen the same question. They just gave me a 1/2" industrial belt i believe, something for a mower or elec motor or something.

It didn't "Squeal", but basically riding on the base of the pulley doesn't give enough grip so the pulley slips a bit. If you have the right belt, it grips the sides of the pulley because it's pulled down into the V without bottoming out.

My water pump was tired anyway, but that slippage was all i needed when the pump was about done to make it cool only at highway speeds. On the last trip home from Columbus (about 3 hours) before i parked it for service it was hot only when not moving to well in traffic, and fine on the highway. At the very end of the trip it was running hot all the way around. It could only have been the belt or water pump, but i ended up putting a 327 in anyway or else i would have swapped the pump. (It was starting to rattle.)

If all else fails you could try mounting a 6-volt electric fan in front of the radiator. It could be controlled by a switch under the dash that could be turned on when the car is idle or moving slowly. These electric pusher fans move a lot of air through the radiator. I had one on my '47 Custom Clipper before I replaced the radiator with a staggered 7-row type core. I would watch the temperature gauge and see the engine temperature drop 20 degrees with the fan on. It was not necessary when the car was moving. Good luck.

(o{I}o)