3 or 4 core radiator Chevy Express

[wander2039]

After our recent trip on Highway 50 and I70 with the ole RV pondering upgrading the radiator. The 6.0 has enough power to pull hills probably faster than it should but the cooling system says oh no you don't! Because of that I typically hold it back and crank up the heat. Keeps it around 210 but kicking on the heat gets tiring after the 4th time in a row. Keep in mind this is a Express not a truck.. the Express probably runs hotter. It does have a heavy duty clutch fan. I also know the LS can run hot without issue but I don't like to push it above the 210 but have seen 225, maybe a little higher.

Radiator express has a 3 or 4 core all aluminum radiator for the Express. The 4 core is $100 more than a 3. From what I've read the 4 core might be excessive. Could have issues with the stock water pump? Maybe reading too much on it. We don't do a lot of winter driving but would like to have heat.

 

[atikovi]

How much more heat does a 4 row give up compared to a 3 row? It's not 33% more as the math would suggest since the rows are stacked in front of each other. Do you have external oil and transmission coolers? They would help a lot too.

 

[ls1mike]

I'll be honest with the old 02 2500HD 6.0/4L80E, I have seen 210 to 230 running up Vantage in 110 degree heat with no issue.
I never really thought about it. I am not even sure how big the radiator was in the truck.
I think the 4 core is going to be fine if that is what you want to do. The best thing I did was put the Tru-Cool 40K cooler on for the transmission.

 

[wander2039]

How much more heat does a 4 row give up compared to a 3 row? It's not 33% more as the math would suggest since the rows are stacked in front of each other. Do you have external oil and transmission coolers? They would help a lot too.

That's what I was reading and understanding also. There's no external coolers, not sure I want to go that route yet. We travel long distances so simpler would be better.

I'll be honest with the old 02 2500HD 6.0/4L80E, I have seen 210 to 230 running up Vantage in 110 degree heat with no issue.
I never really thought about it. I am not even sure how big the radiator was in the truck.
I think the 4 core is going to be fine if that is what you want to do. The best thing I did was put the Tru-Cool 40K cooler on for the transmission.

The truck might have more cores.. may not though. I haven't looked but I bet no one makes a kit for the Express. But as I said earlier I prefer simple but maybe that's not a issue.

 

[atikovi]

There's no external coolers, not sure I want to go that route yet. We travel long distances so simpler would be better.

If the transmission cooler in the radiator starts leaking, you'll wish you had one.

 

[marc1]

There is never any concern with having too many cores other than physical fit of the new radiator. Sometimes the tanks are wider to accommodate the additional core(s) and this can cause issues with mounting back in the stock location. This is something you can establish before you buy. If the fit is fine, always go with as many cores as your budget will permit.

Is your existing radiator a "high efficiency" radiator? These are radiators where the core column density is increased. They will have the same number of rows but the rows are placed closer together allow for more columns. If you do not have an HE core radiator sometimes just going with the HE core with the same number of cores is sufficient to help. The most cost effective option there is to have a radiator shop that does HE cores do the work on your radiator. But you need to know if you already have an HE core or not. One way to tell is to measure the distance between the columns, HE radiators are closer together and have more. Your rad shop can verify as well.

Forgive the crudeness of the diagram. Looking down from the top:

 

[GMBoy]

Not sure what year, miles and condition of the coolant and radiator but from the factory the cooling system was pretty good. Any heat you can get away from the radiator will increase your cooling capacity so I would go with an external trans cooler at least and a flush and complete coolant replacement at 50/50 to 60/40 ratio using dexcool and 1 bottle of redline water wetter. Running synthetic oil will offer some additional help if you don't already. If the radiator is older than 10 yrs you may opt to replace it with an upgraded unit but the stock spec unit will still be fine. When towing close to max capacity with my Seirra Denali pickup (6.0L) it never got over 220-225 in 100 degree texas heat and that was only after pulling a hill and then immediately stopping for traffic. The electric fans brought everything back down within a few minutes. I think your current situation is fine as is but the above ideas can maybe give you a tad bit improvement and peace of mind. You could also get a tune to turn on the electric fans earlier if you wanted - not sure it you have those with the clutch fan my Denali doesn't but my RAM has both.

 

[wander2039]

There is never any concern with having too many cores other than physical fit of the new radiator. Sometimes the tanks are wider to accommodate the additional core(s) and this can cause issues with mounting back in the stock location. This is something you can establish before you buy. If the fit is fine, always go with as many cores as your budget will permit.

Is your existing radiator a "high efficiency" radiator? These are radiators where the core column density is increased. They will have the same number of rows but the rows are placed closer together allow for more columns. If you do not have an HE core radiator sometimes just going with the HE core with the same number of cores is sufficient to help. The most cost effective option there is to have a radiator shop that does HE cores do the work on your radiator. But you need to know if you already have an HE core or not. One way to tell is to measure the distance between the columns, HE radiators are closer together and have more. Your rad shop can verify as well.

Forgive the crudeness of the diagram. Looking down from the top:



View attachment 168984

Interesting.. not sure on this as it's the factory radiator. The stock 2 core is less than inch thick but the 3 is a 2 inch and 4 a 2.5 inch. But should be enough spacing.

 

[wander2039]

Not sure what year, miles and condition of the coolant and radiator but from the factory the cooling system was pretty good. Any heat you can get away from the radiator will increase your cooling capacity so I would go with an external trans cooler at least and a flush and complete coolant replacement at 50/50 to 60/40 ratio using dexcool and 1 bottle of redline water wetter. Running synthetic oil will offer some additional help if you don't already. If the radiator is older than 10 yrs you may opt to replace it with an upgraded unit but the stock spec unit will still be fine. When towing close to max capacity with my Seirra Denali pickup (6.0L) it never got over 220-225 in 100 degree texas heat and that was only after pulling a hill and then immediately stopping for traffic. The electric fans brought everything back down within a few minutes. I think your current situation is fine as is but the above ideas can maybe give you a tad bit improvement and peace of mind. You could also get a tune to turn on the electric fans earlier if you wanted - not sure it you have those with the clutch fan my Denali doesn't but my RAM has both.

I spoke too soon on the coolers I'll check later.. it might have a separate trans and oil cooler being a 3500. Currently I run PUP 5w30 and Dex 6 so I have those bases covered. I put some sort of water wetter in last flush but can't remember which. No electric fans maybe that's all it needs. The temp does drop quick on the flats.

 

[GMBoy]

I spoke too soon on the coolers I'll check later.. it might have a separate trans and oil cooler being a 3500. Currently I run PUP 5w30 and Dex 6 so I have those bases covered. I put some sort of water wetter in last flush but can't remember which. No electric fans maybe that's all it needs. The temp does drop quick on the flats.

3500 is a nice van! Sounds like you have all the bases covered then. You can buy electric booster fans that might be the easiest and cheapest route.

 

[Creekside]

Can you install an electric fan in front of the new radiator on a separate control and kick the fan on before you start into the hill? Many OTR trucks are similar with a toggle switch for auto or manual fan control to lock the air clutch. I also second an external trans cooler. Get that heat out of the radiator.

 

[Nick1994]

I don't think that's too crazy hot. However, I'd replace an 18 year old radiator no matter what, especially on a vehicle that's for long distance driving. If it was an in-town vehicle, maybe ride it out. Might as well upgrade it if replacing. New hoses too.

How old is the fan clutch? Is it OE? Might not engage well enough. How old is the thermostat? If it's aftermarket it may have a smaller opening. Had that issue with my grandparent's '02 Trailblazer. A Stant thermostat had a significantly smaller opening.

 

[wander2039]

3500 is a nice van! Sounds like you have all the bases covered then. You can buy electric booster fans that might be the easiest and cheapest route.

Can you install an electric fan in front of the new radiator on a separate control and kick the fan on before you start into the hill? Many OTR trucks are similar with a toggle switch for auto or manual fan control to lock the air clutch. I also second an external trans cooler. Get that heat out of the radiator.

That was another thought.. The question would be pusher or puller? Pusher would be more difficult. Puller could interfere with the mechanical fan, but I'd get one without a shroud so it should be minimal.

 

[wander2039]

I don't think that's too crazy hot. However, I'd replace an 18 year old radiator no matter what, especially on a vehicle that's for long distance driving. If it was an in-town vehicle, maybe ride it out. Might as well upgrade it if replacing. New hoses too.

How old is the fan clutch? Is it OE? Might not engage well enough. How old is the thermostat? If it's aftermarket it may have a smaller opening. Had that issue with my grandparent's '02 Trailblazer. A Stant thermostat had a significantly smaller opening.

I'm not to worried about 18 years.. it only has 102k. The thermostat I did replace as a test but it remained the same as the factory thermostat. Fan clutch I replaced 9 years ago and it works darn good, you can hear when it locks up.

 

[dumkid]

That was another thought.. The question would be pusher or puller? Pusher would be more difficult. Puller could interfere with the mechanical fan, but I'd get one without a shroud so it should be minimal.

I've always seen them set up as pushers, exept for on the 2006 jeep Cherokees. And remember, a locked up mechanical fan can pull more air than an electric fan, especially at higher rpm. So whatever you do, don't ditch the clutch fan. If there's enough space inside the fan shroud I would probably try a puller fan.

 

[dfarr67]

I've had very little issue with what GM blessed me with. But I have also upgraded the old k1500 with a BBC alum rad- direct fit, unloaded the trans cooling to a separate cooler, got rid of the clutch fan for twin electric- corvette pullers that only run in slow traffic, good clean system, quality coolant, I add water wetter- just because, and I have added later model rad support ducting to make sure the air goes through the rad instead of bleeding off anywhere else.

 

[Chris142]

Stop saying cores! The radiator has 1 core. It's between the tanks and has rows of tubes. It may have 1row,2 rows,3 rows etc..

The thermostat isn't even fully open till about 210. If you think you are going to drive across the desert in a heavy van and keep the temps under 210 you won't.

The fan clutch won't even fully lock up until about 225. The aftermarket radiators do not have the same fin count as the one radiator does so they won't ever cool as well. How many miles are on the van?