Water Distribution Tube/Overheating

[Fleetwood Meadow]

Here's a dumb but not dumb topic. Within the cooling system there are intricate details that are made in order to get uniform heat dispersal. With my Meadowbrook I battle overheating whenever the car is travelling at speeds of 50mph or higher for any length of time over 10 minutes. Periodically when driving around town, I say town but I live in the middle of nowhere so it is not stop and go, the temp gauge will rise above the summer temp. From the research I have seen, not including rust in the block, they all seem to point towards the water distribution tube. They say that it should be replaced. Now the question is, since it is a long tube with slotted holes in it, as long as it is fully in tact and not rusted it is still working effectively? I have battled overheating with this car for many years. I flush it and the rust comes back so I know that that is a factor. I have replaced the water pump, the thermostat, many gallons of coolant and the car is now reaching 240+ degrees. The water in the radiator is around 180-190 on the top, sometimes up to 215 and 150-160 at the bottom of the radiator. With a 4lb pressure cap on it this temp is just too high. To keep oil pressure up I have 15W-40 in it instead of the 30 weight oil. Is that contributing to the overheating? I just replaced the transmission fluid since it was frothing out of the fill hole and that did not change anything temperature wise. She never stalls or gets vapor lock and pushes right through like nothing is wrong but I know that it is not good for the engine to keep overheating.

[ply33]

The water distribution tube has slots on the top that direct coolant at the valve seats and it affects the overall flow of coolant in the block. So if it is rusted out or the slots are clogged with debris it will affect your cooling.

 

Pretty common on an engine of that vintage will be a large accumulation of sludge in the bottom of the cooling passages in the block and no amount of flushing via the radiator connections will get that out. You might consider pulling the core/welch/freeze plugs from along the drive side of the block and flush out the gunk with copious water while probing with a stiff wire or other suitable tool.

 

I'd start with trying to get the gunk out of the bottom of the block first and if that does not improve things for you, then replace the water distribution tube. If you are lucky the tube in your engine will be brass and may only need the slots cleared out. More likely it will have been steel and is now just a bunch of hard to remove rusted pieces.

[Rusty_OToole]

Check engine temps with an infrared thermometer. The back of the engine should be the same temp as the front. If the water distribution tube is rusted out or missing all the water streams up the front of the block and none goes to the back, leading to overheating.

 

I would blow out the rad from behind with a compressed air hose to make sure it is free of dirt and bugs. Check the rad for hot and cold spots with the infrared thermometer.

 

What thermostat? If it is a 180 then temp of upper rad hose will be 180 - 190 or more.

 

Are these temps off the dashboard gauge? It may not be reading accurately.

 

Is your fan belt tight? You should be able to deflect it 3/4" with moderate thumb pressure.

[Curti]

Pull the radiator, have it cleaned out professionally.  Remove the water pump and check it out, extract the coolant distribution tube and the core plugs as Ply33 suggests.  Get a pressure washer and put it in every orifice you can find .

You may get away without removing the head.   Do not attempt to run the engine sans the distribution tube, it will overheat.  

[Rusty_OToole]

You could do some cheap easy tests, diagnose the problem, pinpoint the solution and fix what is wrong. Or tear everything apart and replace random parts until you happen to hit on the right solution by accident. Your choice.

[Fleetwood Meadow]

10 hours ago, Rusty_OToole said:

 

What thermostat? If it is a 180 then temp of upper rad hose will be 180 - 190 or more.

 

Are these temps off the dashboard gauge?

Is your fan belt tight?

The thermostat is 160 like the book says. I’ve tried to do everything the way the book says. The temps that I said in the original post are infared readings. The temp of the top of the block is generally the same from front to back. 

 

I do know I need to flush the system again and wanted to use the wood bleach crystals but nowhere have I seen an amount to be put in that is recommended. Everyone says put crystals in and run it then flush it. 

 

As for the dashboard gauge there are no numbers. The book says that of the 4 lines on the gauge the first from the left is cold, the second is winter normal operating, the third is summer normal operating, and the fourth far right is hot. When idling it usually stays around winter normal. When driving slowly it is in between winter and summer. When driving 45-50+ it passes summer within about 5-10 miles and keeps creeping up. 

 

The engine never pings or bangs and will run strong even when it’s overheating. 

[Fleetwood Meadow]

This engine has never been rebuilt and it doesn’t leak, there is no smoke, and it, with the exception of overheating and a stumble at the initial acceleration that I mentioned in another post, runs and idles smoothly and comfortably. There are no bubbles in the coolant to indicate a head gasket issue. So I’d like to not rebuild it at this time if I can get away with it. I just did that this year with my Cadillac and would like a little break from that.

[Rusty_OToole]

Where do you get your temp readings?

 

Try a cup of wood bleach crystals to a pail of water. You can give it several treatments, draining off the dirty water each time. Blow out the core with an air hose. You may be surprised what comes out.

 

Your symptoms point to a cooling system that is low on capacity. Just slightly lower than the load placed on it so the temp slowly climbs. When your car was new it had plenty of reserve capacity. Something has happened to lower the efficiency of the system. Maybe the rad it plugged up, that would be my guess. But it is pretty hard to diagnose a car you have never seen.

[c49er]

To be sure everything has been done right... no guessing......

.You need to remove the lower two engine block side core plugs to really clean the sludge out of the lower part of the block. .

The radiator needs to be flow checked by a radiator shop...if you can find one nowdays to be sure it fully flows and is not plugged up.

And while there pull the water D-tube to check it is not plugged or corroded.

Use the correct OE design thermostat. 

[JWLawrence]

Another suggestion is to check you ignition timing. Retarded timing will contribute to a hot running engine. Also check the distributor's vacuum modulator chamber. If it is leaking then the timing will be affected and the vacuum leak will cause a lean fuel mixture which will contribute to a hot running and poor performing engine. JWL

[Spinneyhill]

I don't know the engine or the thermostat you are working on. I am going through the same drama with my 1930 Dodge Brothers Eight. I have high temperatures in places on the head and the block, although if the IR thermometer gets near the distributor or a plug wire it seems to read high.

 

I have had the radiator cleaned.

 

I replaced the thermostat with one that works (I tested it) but it still overheated. The IR thermometer showed low temps above the thermostat so it wasn't opening. I think there was an air lock under it so I drilled a wee hole in it (whatever was in the drill press, probably about 2.5 mm). This allowed the air out and a tiny water circulation. The thermostat opened. It still overheats.

 

I rebuilt the water pump last year.

 

I have done the oxalic acid treatment (500 gms in the system of about 12 litres for five days.)

 

I am preparing to remove the core plugs to clean out the block. It will be messy so I will remove the starter and generator (located below the core plugs) and cover the inside of the car (two plugs in the rear of the block) and the bell housing. I suppose I will also removed the water pump to give access to that end of the block, and shield the inside of the radiator. And tow the car to the grass outside.

 

I am not look forward to this activity but it seems the only thing left to do. I just wish I had a "wet" vacuum cleaner to use on it!

 

I will also be re-installing the panty hose "sock" in the radiator inlet hose to catch any left-over debris.

Edited April 18, 2018 by Spinneyhill (see edit history)

[Fleetwood Meadow]

It’s a Flathead 6 230. The thermostat is 160. The radiator hoses are hot on both sides so the thermostat opens. The fan does cool down the fluid a bit as I said in the original post however it doesn’t keep up enough. I’m fairly confident that the cooling system is clogged but I figured I’d ask a couple questions in this thread and open the discussion with people that have far more knowledge than I have. I have a similar issue with my 1952 Cadillac that has a 12-15lb pressured cooling system and it has knocked the cap so the drain seal and the big cap seal have separated from its seat. I intend to clean that system out the same way as Rusty says to do higher in this conversation. That car has sat since 1976 and I rebuilt the engine fully myself. The heater cores were left exposed since the engine was out of the car. I have just the engine connected to make sure the engine runs properly before I replace the heater core lines, flush them, and reconnect them to the system. 

[Rusty_OToole]

If it makes you feel any better the Dodge will be way easier and cheaper to rebuild than the Cadillac. Parts are available from your local parts store, Vintage Power Wagons has NOS pistons for $75 a set.

Edited April 18, 2018 by Rusty_OToole (see edit history)

[Ben Bruce aka First Born]

When you say, the radiator has been cleaned, how?  If it was not removed, taken to a shop, the tanks removed and RODDED out, You are just pi+++ng in the wind.  I owe you a dozen Krispy Kremes if this is not the problem.

 

  Ben

[Fleetwood Meadow]

1 hour ago, Ben Bruce aka First Born said:

When you say, the radiator has been cleaned, how?  If it was not removed, taken to a shop, the tanks removed and RODDED out, You are just pi+++ng in the wind.  I owe you a dozen Krispy Kremes if this is not the problem.

 

  Ben

I don't remember saying that the radiator was cleaned. If i did, I misspoke. I intend to clean it as best as possible via the wood bleach cleaning process.

[Ben Bruce aka First Born]

40 minutes ago, 51Meadowbrook said:

I don't remember saying that the radiator was cleaned. If i did, I misspoke. I intend to clean it as best as possible via the wood bleach cleaning process.

 

 Wasting time. If the tubes are plugged, the bleach cannot get  thru them to clean them. Try this . I believe you said you have a thermal thermometer.With the engine hot , measure the temp of the bottom tank , left to right. Let us know what you find out. I may be wrong. WE will see.

 

  Ben

[Spinneyhill]

In-car cleaning is a waste of time if the tubes are blocked, as Ben said. You need a lot of water so it is very messy.

 

I took it out and tried the water plus pulsed air sparging, backwards. I put a garden hose Y fitting with water in one side and air on the other into the bottom outlet. With the hose turned on full and pulsed 100 psi air, I got more than a cup full of sand and silt out of it. I put a bit of time into it and it was still blocked. I should have been patient and kept at it. Instead I took it to a radiator shop. He showed where the blockage was by wetting it all over, laying it on its front and filling with hot water. It remained wet where the blockage was, a triangle up into the core in the middle at the  bottom.

 

Make sure any shop you take it to has experience in OLD radiators of the type. My first shop didn't and couldn't get the top tank to seal when he put it back on.

[ply33]

43 minutes ago, Spinneyhill said:

. . . Make sure any shop you take it to has experience in OLD radiators of the type. My first shop didn't and couldn't get the top tank to seal when he put it back on.

 

I had a shop try to pressure test the radiator from my old car. Blew the top tank up like a balloon. They immediately gave it back to me and said they wouldn't charge me for what they'd done. Cost me some extra money at a radiator show that knew what they were doing to fix the tank.

[Spinneyhill]

6 hours ago, ply33 said:

I had a shop try to pressure test the radiator from my old car. Blew the top tank up like a balloon. They immediately gave it back to me and said they wouldn't charge me for what they'd done. Cost me some extra money at a radiator show that knew what they were doing to fix the tank.

 

Oooooooo. That's ugly. Pretty dopey lot not watching what they were doing. Clearly they used a LOT of pressure. You should have charged them for straightening it.