First "real" ride

[daddyo23]

Hey all, took the '48 P15 for it's first "real drive" since I got it last Nov. Did a 160 mile round trip to a car show/service on the northwest side of the twin cities. I've had it out for 10-30 mile rides but this was highway speed, 4-lane type traveling:D . I had done a little bit over the winter, re-built carb, fixed some wiring and replaced ignition parts. This was going to be the test.

I was surprised at how well it handled speeds between 55-65. The motor was revved but not screaming. She actually ran really good. The only problem I had was water temp. When I was about 10 miles away from my destination, I noticed the temp. creeping up. It got to 190, it had been sitting at 180 all the way up. After it cooled down, I put close to a 1/2 gallon of water in, but I didn't see any leaks. When I left, it went right up to 180 and stayed there for awhile. About 40 miles into the ride home, it started creeping up again. I stopped, got some fuel and bought some 50/50 antifreeze. It took about 1/3 of the gallon, and I was off.

Another 20 miles, heating up again! It never pegged the needle, but was between 190-205, mostly about 195. This time when I stoppped, some antifreeze was dripping from the front of the motor. It didn't look like it was coming from the water pump, so I think maybe from a drain type plug in front? I'm going to climb under there today to look.

On the whole, I was really happy how that big old yellow boat floated down the highway. What should I do about the temp? Boil the rdiator? Do the "dist. tube dance"?Not worry as they run warm?I plan on re-doing the motor in the fall so I would rather do what I need to to keep her on the road. Thanks for putting up with this long diatribe. Any suggestions are welcome and avidly read. Wayne P.

[Young Ed]

Wayne Great to hear your car was out of the garage. Its too bad I was out of town at the cabin and couldn't join you at the show. We did manage to successfully install countertops on sat though. I would take another look at your water pump. There is a hole that will leak after the interal seal is gone. I believe its at about the 5 or 7 oclock position. I suspect its leaking and your rising temp issue was due to low water level in the radiator. My pickup did that on a newly installed pump after about 150 miles.

[mikehalek]

Hi Wayne, congrats on a succesful run. These old P15s are tougher than people give them credit for. Have a couple of questions for you, will try to call tonight. mike

[daddyo23]

I would also check the oil to see if it's over full and has water in it. You could have a blown head gasket. Does the car put out white smoke? If it does' date=' the oil will be normal when checked because the water could be going out the exhaust as steam, if the head gasket is blown on the exhaust port side.[/quote']

I thought about that too, Norm. When I got home I checked the oil, was fine. Had to add a quart, and I didn't see any smoke. The thing is, when I got home the rad was about full. It still leaked a little down at the bottom. It could be the pump, but it sure didn't look like it was coming from there. Still going to crawl under, let you know what I find....

[Jerry Roberts]

Um , how would water get in the oil ? Not from a blown head gasket .

[Captain Neon]

From a guy that's blown two head gaskets on my P15, yes, water can and will get into the oil. If the piece of missing gasket is big enough and it is near an open intake valve, one can get A LOT of water in the oil. I blew my headgasket in 2001, parked it and filled up with coolant. In the spring, my radiator was low. Changed the oil and I must have had a quart of green coolant pour out. The rest of the oil looked like mud.

[Jerry Roberts]

If the head gasket blows it can allow water to go into the oil pan through the piston and valve ports. If it blows on the exhaust side, normally there will be no water in the oil because it goes out the exhaust ports, and turns to steam on it's way out. All depends on where the head gasket blows if you get water in the oil or not.

If the water gets past the open intake valve , it goes into the intake manifold not the crankcase . If water gets past a piston it would have to get past 4 piston rings to get to the crankcase rather than take the easy way out through a valve ....hmmm

[Jerry Roberts]

The intake valve ports go to the intake manifold .

[Captain Neon]

If the water gets past the open intake valve , it goes into the intake manifold not the crankcase . If water gets past a piston it would have to get past 4 piston rings to get to the crankcase rather than take the easy way out through a valve ....hmmm

Do I know precisely how water got in my oil after a blown head gasket? No, but it got there and lots of it too. I replaced the blown gasket and the cracked head and guess what? She doesn't use a drop of water now. It was either the blown head gasket or some one was playing a very elaborate and sick joke on me since she was stored in a fully locked storage building.

[Normspeed]

daddyo23, I say check into the easier and cheaper stuff first. Fill the rad and observe how much it really does leak in an hour or two. Keep an eye on the water pump to see if that bushing is leaking. Check for leaky heater hoses and fittings, including that one at the rear of the head. Wipe the suspect area with dry rags, so any fresh external leaks show up better. The head gasket I would look into only after some easier things were checked out, especially if it's running good, no water in the oil, no oil in the water, and plugs look good.

Glad to hear you're getting it out on the road.

[Jerry Roberts]

daddy023 , If you don't find any leaks in the obvious areas , let your engine warm up and open your radiator cap to look for bubbles . Bubbles will indicate air getting into the system , possibly combustion gasses from a blown head gasket . Then a compression check is needed . The Motors manual says that if a head gasket has blown that you should change all of your coolant as it becomes acidic from the exhaust gasses , so don't just drain the coolant down low enough to do the job but flush it out too . The Motors manual doesn't mention water contaminating the oil but if I thought that water was in my oil I sure would change it .

[swiftshifter67]

I have seen many different types of sings your head gasket blew. If the oil looks like chocolate milk or yoo-hoo, you have water presenting itself in the crank case. if you are shooting steam or moist air out the tail pipe, it is being sucked into the intake side. Like the other guys said, it's usually something basic. I.E. water pump, freeze plug. Pressure test that bad boy and see what happens. Good luck.

[Don Coatney]

Pressure test that bad boy and see what happens. Good luck.

How do you pressure test a vented radiator?

[Don Coatney]

Hey all, took the '48 P15 for it's first "real drive" since I got it last Nov. Did a 160 mile round trip to a car show/service on the northwest side of the twin cities. I've had it out for 10-30 mile rides but this was highway speed, 4-lane type traveling:D . I had done a little bit over the winter, re-built carb, fixed some wiring and replaced ignition parts. This was going to be the test.

I was surprised at how well it handled speeds between 55-65. The motor was revved but not screaming. She actually ran really good. The only problem I had was water temp. When I was about 10 miles away from my destination, I noticed the temp. creeping up. It got to 190, it had been sitting at 180 all the way up. After it cooled down, I put close to a 1/2 gallon of water in, but I didn't see any leaks. When I left, it went right up to 180 and stayed there for awhile. About 40 miles into the ride home, it started creeping up again. I stopped, got some fuel and bought some 50/50 antifreeze. It took about 1/3 of the gallon, and I was off.

Another 20 miles, heating up again! It never pegged the needle, but was between 190-205, mostly about 195. This time when I stoppped, some antifreeze was dripping from the front of the motor. It didn't look like it was coming from the water pump, so I think maybe from a drain type plug in front? I'm going to climb under there today to look.

On the whole, I was really happy how that big old yellow boat floated down the highway. What should I do about the temp? Boil the rdiator? Do the "dist. tube dance"?Not worry as they run warm?I plan on re-doing the motor in the fall so I would rather do what I need to to keep her on the road. Thanks for putting up with this long diatribe. Any suggestions are welcome and avidly read. Wayne P.

Keep in mind that the radiator has a vent tube located at the side of the radiator. If you over fill your radiator the excess coolant will exit the radiator through the vent tube. Once the radiator coolant level is where it needs to be the venting will cease. This way the radiator seeks its own level. If you continue to add water to fill the radiator to the top it will once again vent to seek its own level.

[daddyo23]

For all the advice. I started her up and ran it for about 20 minutes. Went up to 180 ( have a 180 thermostat) and stayed there. No bubbles, rad was at right level ( Thanks for the reminder about that vent tube Don. I did that once before), everything seemed normal. Didn't see any leaks. Checked idle,between 475-525. Timing is at about 2 btdc, it seems to like it there. Have just a slight "cough" at idle, but otherwuse runs great. Like I said, I've done alot of 15-30 mile trips, but this was the first time at a good clip for a long (1hr 15 min.) duration. I need to pull the gas tank to fix a small hole near the top of the tank and I think I'll pull the rad at the same time and have it boiled and checked. Maybe I loosened something up in there, I don't know.

We'll keep driving her with an eye on the temp and a smile on my face:D . Man, that car is a gas! Wayne P.