Radiator Coolant Flow

[Tim Martin]

Is there any way to measure the coolant flow through a radiator? If an engine is overheating and after trying to eliminate other possibilities I suspect the rad is at fault, is there a way to prove it without replacing it?

[brianp87]

not really the only partial way i look is with a temp gun and half heartily try to find a restriction.

[jbadenoch]

a clear section of rad hose helps. Don't get caught by the water pump impeller seperating from the shaft and not pumping as a result

[JBUTITTA]

Most radiator shops (like me), if you can find one anymore have flow test machines. I dont typically charge shops for this simple test if they buy radiators from me. Jerry.

[ricmorin]

The few I found were identified using the temp gun. Once I had the radiator out, I'd pour water in one side and gravity would hardly get it out the other. That was my confirmation. Not very scientific, but effective.

[Rich]

Know anyone on a local fire department? Call them and see if they will happen to stop by with an Engine. Tell them you heard about something called a "thermal imaging camera". Then kinda hint like "hey I got an idea! Lets go look at this radiator" You will be able to see it with that!

If you were in "my parts" i'd do it for you.


http://www.marylandenergyauditor.com/ho ... al-imaging

[brianp87]

To me its kinda like a process of elimination. Fan or fan clutch works ok. t stat works ok. is outlet temp on rad different then inlet? Also a must is the combustion gas test. Overheating vehicle are sometimes the hardes to figure out.

[Tim Martin]

Most radiator shops (like me), if you can find one anymore have flow test machines. I dont typically charge shops for this simple test if they buy radiators from me. Jerry.

Flow Test Machine. What does that consist of.

Don't laugh, I am revealing my ignorance, I know.

[JBUTITTA]

Im not compruter savy enough to post a pix, but if you go to barbeecompany.com/catalog.pdf and on page 2 they have their RATE-O-FLOW machine. Basically it is a high volume pump with a gallon per minute meter. As a rule of thumb, a 20 in wide radiator with 1 row of 1in tubes(alluminum) , or 2 row 1 1/4 in thick core (copper/brass), should flow approx 20gpm. jerry

[ricmorin]

The radiator shops I've visited had big scary machines like this.

Big Scary

flow1.png (29.93 KiB) Viewed 4666 times

[JBUTITTA]

Ric, that would be a boilout tank for cleaning. Hot caustic soda is pretty nasty stuff, but works great on copper/brass radiators. Just dont try to clean aluminum radiators with it.

[steven kiser]

A bit old school here but the way i test for a restriction is letting it run until the temp reads about 1/3 and running my hand across the radiator. I can feel the cold spots this way. I haven't run into a restricted radiator in years. The more i think about it i've run into impeller issues more than restricted radiators.