Radiator performance? Life expectancy?

[BobsYourUncle]

Just thought I'd put this out to you guys, since you are all so smart!! :B

Truck in sig, getting old. 393,500 K on the odometer. (244,509 miles)

I noticed while towing 8000 pounds of trailer in addition to my rack and toolboxes at about 2000 pounds, that it was really easy for the temperature to creep up going up minor grades. It was Saskatchewan in August, pretty warm, but not real hot. Not a lot of serious hills in Sask.

Took it very easy, cruised st about 60 - 63 MPH most of the time, watching the gauges like a hawk. Fan kicked in a few times as the temp gauge crept up.

I don't recall this ever being an issue in the past.

Planning a trip through the Rockies close to the coast of BC in a couple weeks. Some really serious grades to pull on that highway.

I'm wondering what I should expect from my radiator. It is original and has never been touched, flushed or anything.

I wonder what the life expectancy of the rad is....

Further wondering if it could be starting to plug up inside, with reduced flow.

I have always kept the proper mix of Dexcool in it since new.

Any thoughts?

[BobsYourUncle]

Thanks for the comments and insight everyone.
I appreciate you all.

[BobsYourUncle]

theoldwizard1 wrote:

So you have the original coolant in it ! That would make me nervous also. Dexcool turns to sludge if it gets too hot. Really hard to clean out.

Guess I should have stated myself better and more clearly.
Not the original coolant in there.

What I meant was I have never done the service work of a power flush to clean it out.

When I replaced both heads last summer, the coolant was in fact replaced, just not flushed as we do to clean it all out.
There was a little residual in the bottom of the block, but nothing more.

[RLS7201]

Bob, you mentioned new head gasket. I suggest you have the coolant system checked for combustion chamber gases. The possibility exists for the new gaskets to be leaking. Low cost item.
It looks like the general consensus is to just throw $$ at it, no matter what the cost, instead of analyzing the problem.

Richard

[Cloud_Dancer]

One look inside the radiator is all it would take for me to decide to replace it, AND the water pump. But, I would first do the best engine flush possible.

[fj12ryder]

Just be aware that "Water Wetter" is not an anti-freeze.

[mapguy]

STAY WITH DEXCOOL -don't create extra issues to deal with, changing can lead to other issues like sludge build up from incompatible coolants. You cannot get all the old dexcool out...…

Replace the radiator if at all concerned with its integrity. Use OEM or OEM replacement like Modine from napa.

I would check to see if the fan is coming on at the right temp. It is a thermal fan. These are known to stop working or "engaging" at the proper temp over time.

Cleaning the radiator stack would be a good move, too!

[the_bear_II]

The times I have had cooling issues with an older truck it was the fan clutch twice and the thermostat once. I did replace the radiator due to a leak but it wasn't causing a heating issue.

On my daily driver car with a plastic aluminum radiator the plastic developed a crack. I was able to keep up with the water leak for a few weeks while I looked for a replacement radiator. One day while driving to work the temp gauge pinned hot. The radiator still had plenty of water. The thermostat had stopped opening.

So I would check the operation of your fan clutch. It may be coming on but not strong enough under load. And make sure the thermostat is opening or not clogged.

There is a product be RedLine called "Called Wetter Water" I used it in my truck and it kept the temp 20 degrees lower while pulling my 5th wheel up a grade that we travel often. It works as advertised.

[_1Flyboy]

I did not mention it but please forget the Dexcool ( Deathcool ) & go with your favorite Name Brand 5 year / 150,000 mile antifreeze ( full strength NOT premixed ).... When you get done changing all the parts & flushing out the motor before refilling REMEMBER THIS: You will probably have a couple of gallons of water / old coolant left sitting in the motor ( unless you have drain plugs on the engine block )....

[theoldwizard1]

BobsYourUncle wrote:
I don't recall this ever being an issue in the past.

Not a good sign ! If you did not swap it ahead of your trip, I would carry a spare (OEM).

BobsYourUncle wrote:
I'm wondering what I should expect from my radiator. It is original and has never been touched, flushed or anything.

So you have the original coolant in it ! That would make me nervous also. Dexcool turns to sludge if it gets too hot. Really hard to clean out.

I do all of my own maintenance including radiator "flush". Drain, fill with fresh water and Prestone Flush chemical. Drive for at least 30 minute. Drain, refill with fresh water, drive for 30 minutes. Drain and refill a second time and a third 30 minute drive. Drain, fill with coolant.

The problem is, it is pretty much impossible to drain all the old coolant/water out of your system which is why I do TWO fresh water rinses. When putting new coolant in, I use 100% non-diluted. Use your favorite procedure to remove air. Check the strength. Adjust with water or coolant to meet the strength requirements.

[shum02]

Replaced the rad in the SD last year with just over 400k kms on her. Started to leak past the seals on the bottom of the core between the header and the bottom tank. Not to bad I think.

I replaced the egr and oil cooler at the same time along with a new t-stat and overflow bottle.

A solid weekend of my own labour and parts so not too bad.

Can tow my 8000lb camper and barely push 200F for oil and coolant and around 170F for trans fluid, t-stat keeps her right around 190F empty.

Worth the trouble.

[maillemaker]

You can flush it and free up some space, but it is old and other issues with them is they can leak, and you cant flush that issue away.
Get a new one.

I tried radiator flushes with my 30-year-old radiator, it had zero effect. I do not think anything short of acid would take the mineral deposits out of a radiator.

I even tried following the "extended flush" instructions of driving around with the stuff for a week.

Don't mix metals. If heater core is aluminum then get aluminum radiator. If copper then copper…

My OEM radiator was copper. I went with an aftermarket aluminum one because they are thermally more efficient. Even though brass has better thermal conductivity, the solder reduces that and makes the aluminum ones generally better. They are also considerably lighter.

You do have to worry about galvanic corrosion with aluminum radiators. To solve this, I installed a sacrificial zinc anode in mine.

https://www.amazon.com/Flex-lite-32060-Anode-Drain/dp/B001GR09S4

My radiator had a dedicated port for the anode so I could also have a standard drain petcock.

Steve

[time2roll]

How old is the coolant? I read random troubles with Dexcool so I would probably be flushing that out and refill with regular universal juice. As long as all that is getting done I would have a new radiator, new thermostat and possibly water pump replaced at the same time.

My radiator is original with 18 years and 205,000 and seems to cool fine. Standard Prestone coolant. VERY difficult to get my temp gauge to budge. Last time was 115F up a long 5%.

[MEXICOWANDERER]

#1Flyboy is right and here's why.

Brass radiators have fragile copper heatsinks. I've have seen far too many cases where a brass radiator looks good but the heat sinks are all but disconnected.

And hydraulic fan controls that malfunction windmill rather than spin. Blocking 70% of the airflow. Quicksilver has a differential driven fan gearbox. And a 9 blade Horton Fan that will damned near knock you off your feet. Five-row radiator and has functioned well in 122F ambient. A hell of a lot better than the diver 😞

[_1Flyboy]

......if you have a Duramax you should have a P/A ( plastic/aluminum ) radiator; VERY efficient; not common to plug up internally but rather the airflow plugs up ( high fin count ).... The big issue is that the plastic tanks crack....If it was ME, I’d have every belt, hose, tensioner, thermostat, water pump, ,radiator, etc replaced & stick with OEM thermostat & water pump at a minimum....if you are happy with the truck & don’t really wanna buy a new one.....There’s some good & some bad aftermarket parts out there...I’m on 2nd Duramax and have some experience in the industry....