CLEANING RADIATOR

[Guest broker-bob]

I have a 31 plymouth with on original honny comb Rad--------have check all other setting of engine but still, when it gets hot out it over heats----------looking for Ideas for cleaning the rad with out pulling it------------bobnroman@yahoo.com

[Guest Dean_H.]

Wish I could help... I have the same problem with my car. I can drive any speed or climb any hill, if it's less than 70 degrees outside temp. During the summer temps of 100ish, I can still drive the car but have to keep it around 45-50 and avoid hills. I had my honey comb radiator boiled out and even built a fan shroud which didn't help much. I also read if the timing was too slow the combustion would add heat to the engine. So I have tried advancing the timing further which also didn't seem to make any difference.

At this point I'm ready to buy a new modern style radiator. The honey comb looks nice, but who want's to be restricted on when to drive. I suspect these old cars were designed to tool along at forty five and mine will stay cool at that speed. Unfortunately, forty five is dangerous in today's traffic.

Sorry about the rant. :-)

You might try swimming pool acid to clean out the scale. Don't make it too strong - mix with water. After rinsing out, run a caustic solution (lye) to neutralize it.

[Rusty_OToole]

How about CLR calcium lime and rust remover from the hardware store? It is not harsh and will not damage your rad.

[Larry Schramm]

One of the items that can cause a car to overheat besides the radiator is timing, fuel, and especially the rate of flow of coolant through the system. If the coolant moves too fast, then it does not have time to transfer the heat. Might check that.

[Guest broker-bob]

thanks for the response I understand how timing and fuel mixture can contribute to temp I rebuilt my carb and set the float Power timed the engine back flushed the rad and cleaned with arm and hammer washing sodia still not great a friend got a mixture from a book 2 gal water 2 cups of washing soap and 2 qt of kerosen any one here of that--BR

[Bhigdog]

If the thermostat is not the problem In all probability you will need to have it recored ..............Bob

[Guest broker-bob]

new thrmo-----------------------in the summer I will try again to clean it if not I already have a recored rad for the car I just thought it cool to run the honycomb----------------BR

[W_Higgins]

I'm not trying to be an idiot here, but is it supposed to have a thermostat? Lots of cars at the time still didn't. Some people add them to their Model A's, but for whatever reason I never could make mine work with one. On hot days I'd overheat. After a summer of fighting with it, I finally removed it and never had another problem in 20,000 miles, much of that 90+ degree summer days in the south.

Also, did you do a flow test on your radiator? You can only clean it to a certain extent in place. Flow test would be taking off the lower hose, holding your hand over it, filling to the top, removing your hand, and it should dump its entire contents in about three seconds if it's clear.

[keiser31]

I'm not trying to be an idiot here, but is it supposed to have a thermostat? Lots of cars at the time still didn't. Some people add them to their Model A's, but for whatever reason I never could make mine work with one. On hot days I'd overheat. After a summer of fighting with it, I finally removed it and never had another problem in 20,000 miles, much of that 90+ degree summer days in the south.

Also, did you do a flow test on your radiator? You can only clean it to a certain extent in place. Flow test would be taking off the lower hose, holding your hand over it, filling to the top, removing your hand, and it should dump its entire contents in about three seconds if it's clear.

Yes...it is supposed to have a thermostat.

[W_Higgins]

In that case, what temp range is it? If it's just a standard inline thermostat like used in modern cars (not a thermostatic shutter), that's a "tunable" component.

[scot]

Use Citric acid. You can get it at a MB dealer or a beer and wine making supply shop. Use a degreaser first or the acid will not work. Citric acid removes the rust scales but doesn't eat up the radiator. This is a maintance item with MB. One that is often overlooked but still a maintance item.

[Guest broker-bob]

my car came with thrmo from factory to my knowledge fits in goose neck have a new one 145 last summer the engine got up to 200 and it in not pressureized system looses all the water Have you used the citric acid ????? I guess just put it in and run the car till hot ??????? thanks

Edited January 7, 2011 by broker-bob (see edit history)

[Guest Silverghost]

Do not underestimate the benefits of reverse flow back-flushing a radiator !

You can in fact do this yourself !

Often one of the radiator tanks can also be removed by a good radiator shop so that the core can be properly rodded-out !

If not rotten and leaking most old V-cell & Honeycomb radiator cores can in fact be cleaned so that they work very well !

Replacing that old core, with an original cell style can be very costly.

[Guest Madison]

The biggest problem with radiators is hardness (sometimes called teakettle scale) that deposits on the coldest part of the cooling system which of course is the radiator. To avoid it I always use distilled or deionized water in my cars. The basic problem is that this scale, calcium carbonate, is a thermal insulator and keeps the heat from passing through to the wall of the radiator. Citric acid may disolve some of it. I used to use oxalic acid which I got at the auto supply store. It may still be available I don't know. Both citric and oxalic are weak acids. Now, as a last resort, before you throw the radiator away you could try a dilute solution of swimming pool acid which is hydrochloric acid, a strong acid. I would take the radiator out of the car. Dilute the acid about 10 parts water to 1 part acid. Fill the radiator with it being very careful not to get any of it on your body or your clothes. Use safety glasses and rubber gloves. Don't do it on a cement surface as it will etch and probably stain it. Leave it in the radiator a couple of hours and then dispose of the acid properly. Flush the radiator thoroughly with a garden hose. It should help a lot. You may be able to get this done at a radiator shop. Ask around.

[W_Higgins]

my car came with thrmo from factory to my knowledge fits in goose neck have a new one 145 last summer the engine got up to 200 and it in not pressureized system looses all the water Have you used the citric acid ????? I guess just put it in and run the car till hot ??????? thanks

Have you done the flow test? If so and it passed, just take out the thermostat for kicks to see what effect it has on it. I've seen some of these modern ones that are pretty restrictive, but they're built for a different application as the modern cars they're for have higher flow pumps and larger reserve capacity with more efficient radiators.

Also, check the impeller on your pump. The vanes could be deteriorated or just plain inefficient. There are "improved" pumps for early V-8 Fords on the market (notorious overheaters) and you'd be amazed at the difference in design from them compared to originals. It's a wonder they pumped any water at all. A combination of things could be contributing to the problem.

[Guest broker-bob]

only a bad thrmo will cause over heating my engine was rebuilt and there are not 1000 miles on new engine the pump idea is a good sugestion though I would not have put it together with bad pump it's been awile but will keep it in mind thanks for your input spoke with some one that sugusted CLR again may try that when it gets worm----------------BR

[W_Higgins]

only a bad thrmo will cause over heating my engine was rebuilt and there are not 1000 miles on new engine the pump idea is a good sugestion though I would not have put it together with bad pump it's been awile but will keep it in mind thanks for your input spoke with some one that sugusted CLR again may try that when it gets worm----------------BR

A restrictive thermostat can cause it, too. Some are more restrictive than others.

Your engine is still tight. Under what driving conditions does it overheat other than just being hot out?

Have you done a flow test?

Edited January 8, 2011 by W_Higgins
Referenced wrong post above -- sorry -- now corrected. (see edit history)

[W_Higgins]

Wish I could help... I have the same problem with my car. I can drive any speed or climb any hill, if it's less than 70 degrees outside temp. During the summer temps of 100ish, I can still drive the car but have to keep it around 45-50 and avoid hills. I had my honey comb radiator boiled out and even built a fan shroud which didn't help much. I also read if the timing was too slow the combustion would add heat to the engine. So I have tried advancing the timing further which also didn't seem to make any difference.

At this point I'm ready to buy a new modern style radiator. The honey comb looks nice, but who want's to be restricted on when to drive. I suspect these old cars were designed to tool along at forty five and mine will stay cool at that speed. Unfortunately, forty five is dangerous in today's traffic.

I'm only replying to this because it might be relevant to the o.p.'s problem:

Aren't you the guy that knocked out a main tooling down the freeway? If you're pushing your car at those speeds and it takes a 100 degree day for it to overheat, there's nothing wrong with your car. They were never designed to be run that hard beyond intermittent use, if even that. Buying a car 20 years newer is the answer to your problem.

[Guest Dean_H.]

Walter, I tend to agree with you. I've been driving a little slower and the car is running better than ever. It's fun to push the little car, but it's really not designed for high speed.

[W_Higgins]

Walter, I tend to agree with you. I've been driving a little slower and the car is running better than ever. It's fun to push the little car, but it's really not designed for high speed.

There just weren't many roads back when your car was built that would allow you to do what you want to do now, so manufacturers didn't build them to suit anymore than that purpose. You might be able to put in a modern core and get the temperature down, but then you run into a whole host of other problems -- you'll need bigger brakes, bigger tires, engine modifications that can take the sustained higher speeds, and the task of reengineering and rebuilding will never stop. Some people are into that. Most have a bottomless pit of cash to fund the experiment.

If you don't want to get killed on the freeway, or at the very least get tickets for impeding the flow of traffic, you just have to choose your battles by picking roads that work. Enjoying the car for the purpose it was designed to fill is just part of the experience. Everybody else builds cars that somewhat look like what we drive and then call them "street rods".

Edited January 8, 2011 by W_Higgins (see edit history)

[Guest Dean_H.]

I'll pass on the street rod thing. My car is very close to having adequate cooling. If I get on the freeway and cruise at 60-65 on a 100 degree day, it takes about twenty miles for the temp to slowly creep up towards H. I generally slow down or take back roads and still get to where I want to go. It's almost good enough. - Back in the day, we'd turn on the heater for extra heat dissipation. But this Hupp doesn't have a heater. :-(

A few months back, I found another original honey comb radiator for my car. With the fall/winter weather the car runs cool, so I haven't installed it yet. I'll try some of the cleaning methods and back flushing mentioned above before putting it in. It is a shame to put a modern radiator into cars of these vintages. Hopefully this 'new' rad helps otherwise I'll probably just live with the cooling issues to keep the cool look.

[W_Higgins]

Well, you're really pushing the limits of your car. I applaud you for using it as much as you do. I drove my Model A as my sole daily driver for two years putting 20,000 miles on it and did a little freeway driving, but only during certain times of the day. There were certain bridges for which there was just no other practical option. It can be done, but you have to pick your battles wisely. I hope you don't have a plate glass windshield in that thing because someday some dope smoking moron is going to think he sees a giant talking banana standing in the middle of the freeway, slam on his 4-wheel antilock disc brakes with tires that have three times the tread contact you do, and the rule of two objects not being able to occupy the same space at the same time is going to be proven.

[Guest Dean_H.]

20K miles in a Model A! And you're telling me to be careful???

[W_Higgins]

20K miles in a Model A! And you're telling me to be careful???

Yeah man, but I'm still here to talk about it. 99.5% of that was around town. When I did drive on the freeway, it wasn't exceeding the limits of the car and included driving very defensively.

Just watch out-out there. It's just like with motorcycles. Most of the time the people around you don't realize what kind of negative effect their (often) unnecessary actions can have (like cutting in front of you and slamming on their brakes). Things can start to close in really fast when things go wrong.

[scot]

my car came with thrmo from factory to my knowledge fits in goose neck have a new one 145 last summer the engine got up to 200 and it in not pressureized system looses all the water Have you used the citric acid ????? I guess just put it in and run the car till hot ??????? thanks

Yes I have used the citric acid flush on my two MB cars. Always seems to do a great job of cleaning it out. Here is a link to a site that shows it being done on a MB. Obviously yours will be different. When I do mine I drive the car for about an hour with the citric acid in it and then flush, drain, flush, drain, flush, drain and then fill back up with fresh coolant mix.

Mercedes Citrus Flush

Best of luck,

Scot