Pre-war (up to 1942) 1939 LaSalle - Overheating, Generator Failure

[harry s]

Back to what Bob said about the Cadillac procedure. Just running water through the block will not clean the lower areas of the water jacket where stuff has built up. We took the head bolts out and I made a special copper tubing adaptor for my power washer to go all the way down to the bottom with a split orifice on the end. Realize that what you think is the bottom may not be the bottom because of the build up of crud. It will feel hard. When it is clean you will definitely feel and hear the difference when dropping a metal rod down the holes:-)
     To illustrate what Dave said about the bottom maybe not being the bottom here is a picture of what came out of the rear cylinder area even after being hot tanked for a couple of days. I used a long narrow screw driver to loosen up the sludge then a pressure washer to flush.    Harry

[Daryl Chesterman]

Retarded timing will contribute to overheating!  Set the dwell first, then set the timing to specs and see if that doesn't help.  The reason I say to set the dwell first is that the dwell setting (when the spark occurs) affects the timing.  Assuming the distributor has a vacuum advance, I would also check to see that it is working properly, so that you are getting all of the advance that the engine was designed for, when you are running at highway speeds.  Same thing for the centrifugal advance.

Daryl Chesterman

[wheikkila]

Hi Harry
I have a 1940 La Salle. It was sitting for about 20 years before I purchased it. When I first started driving it, it didn't overheat. But, the more I drove it the hotter it started to run. The water pump started leaking and one of the freeze plugs started leaking. I pulled the water pump, removed the heads, I record the radiator and removed all the freeze plugs. I used a pressure washer to flush out the block. Yes, I got a lot of crud out of the block. Fast forward a couple years. I had to rebuild the engine due to low compression. And it is still in the machine shop. But, when I tore it down. I was surprised at how much crud was still in the block. I had a hard time driving the car in 90 + weather for a long time. I live in Texas so hot days are common. I'm looking forward to a long drive after the engine is rebuilt. I feel your pain.
Thanks Wayne         

[bill_boos]

In the spirit of reporting back on the resolution of problems solved I've attached below posts from this topic and one other to summarize how a number of CLC members chimed in to share their experiences. Thanks to all.

1947 Cadillac Started Overheating

A HAPPY ENDING !! PROBLEM SOLVED --- at least for the moment

I say at least for the moment as I've become skeptical having been down so many roads. I've learned that overheating has more causes that can be counted one hand or maybe two -- thermostat, radiator cap, radiator, water pump, retarded timing, collapsed hose, head gasket, clogged heads/block, temp guage, temp sensor, leaking hoses, low coolant level, heater cores, air in system, ...

I've copied posts from another topic below but the bottom line is this:

I think I got lucky. After running water through top hoses into the heads and seeing crud and rust before running clear, a thirty minute test drive would only get guage to almost N whereas before it would peg at H. Infrared readings are about 190 at radiator tank and 200 at the heads. This kind of flushing apparently is not very effective as it cannot break away hard deposits. I've had the car for only a year and driven it about a hundred miles. I believe it was restored 5 or 6 years ago and not driven much. Perhaps rust accumulated but hardened too much. I'm not a metallurgist so I have no clue.

Another post below outlining what I did in attempting to chase down the problem. A side effect is that I fixed the hesitation/carb spitting problem with a timing advance trying to fix overheating problem. My thanks to several of you who suggested a timing check and to all who made suggestions on possible causes. In searching the forum, I was amazed at the number of overheating problems especially on flat heads.



Re: 1939 LaSalle - Overheating, Generator Failure
« Reply #38 on: Today at 01:07:27 AM »

Quote from: Bobby B on August 22, 2019, 06:34:42 PM
Jon,
Are you 100% sure that the Impeller is not slipping once the engine comes up to temperature and the clearance between the impeller and the pump housing is as close as it can be without scraping? Ask me how I know  ........I always "tack" my impellers on after rebuilding. Pontiac 400's always run hot and an easy way to shave 5-10 degrees off your temp is to close up the gap between the pump impeller and the body. It does work. There's no need to spend money troubleshooting this problem.
                                                                                                                                   Bobby
                                               
Rather old topic, but would appreciate your opinion re  " as close as it can be without scraping?"
My '47 Cadillac is overheating and I just removed the water pump. Impeller seems tight on the shaft and blades are about 1/8" from body. Is this adequate for water flow?

Radiator is reading around 200 and heads 280 to 350 depending on location. Just ran water from each top hose through engine to water pump outlet and got about 30 seconds of rusty water from each side before it began running clear.  This may not be enough to clear passages. Will refill with coolant to see if any improvement. Thermostat temporarily removed. Spark was retarded causing hard start and carb backfiring . Advanced about 1/2" without timing light --- starts in about 2 seconds now  and no hesitation/backfire when accelerating. Still no pinging. Runs better than it ever did.


Re: 1939 LaSalle - Overheating, Generator Failure
« Reply #40 on: Today at 10:12:56 AM »
Quote
Quote from: DaveZ on Today at 09:34:18 AM
Back to what Bob said about the Cadillac procedure. Just running water through the block will not clean the lower areas of the water jacket where stuff has built up. We took the head bolts out and I made a special copper tubing adaptor for my power washer to go all the way down to the bottom with a split orifice on the end. Realize that what you think is the bottom may not be the bottom because of the build up of crud. It will feel hard. When it is clean you will definitely feel and hear the difference when dropping a metal rod down the holes:-)