Replace radiator - need foam?

[JACA]

On my way back from Florida a couple days ago, my truck started overheating. I found a leak in the radiator, so I limped to the nearest service shop to have the radiator replaced. They put in an aftermarket radiator, which was fine with me. After the radiator replacement, everything worked fine, and the temps were back to normal. After I got home, and looked at the mechanic's work, I noticed that he did not put the foam seal around the radiator, like the OEM.

I've read on other threads that some folks use 3/4" weather-stripping (high density, closed cell) to seal up the gap around the radiator.

My question is: Is this really necessary? I understand that it's supposed to improve the flow of cool air into the radiator, but does it really make a significant difference? Seems to me that there are many other gaps around the radiator and fan shroud that are not sealed. So, should I replace the foam gap filler, or just leave the gap?

 

[Spike555]

I wouldn't worry about it. Unless you can't sleep at night thinking about it. I'd call it good.

 

[Trunk Monkey]

Watch your temps, if they're not where they were previously, try adding the foam. My take, it was there from the factory for a reason. Just like the shroud, keeping air flowing through the rad and not around is good for cooling.

 

[JACA]

After the radiator replacement (without the foam), I drove 200+ miles at highway speed (70 MPH), fully loaded with passengers/cargo, pulling a loaded trailer, AC on high, and temps were in the mid 90s. My dash temperature gauge was exactly where it always was - right smack in the middle of the range. So, I guess I'll go without the foam for now, and maybe replace it someday when I have nothing better to do. Thanks for the responses.

BTW, the radiator that I replaced was the original OEM one - not bad for 16 years and 215,000 miles!

 

[Spike555]

Get yourself a Ultra-Gauge, you will not be sorry. I've had mine for 6? years now and I can't go without it.
When this one dies I will be buying another.
Google it.

 

[Keowee]

^^^ This. Way better readings than factory gauges. Also a good scare while sitting in traffic on 100 degree days.

 

[ponytl]

A couple points....
A. the gap the foam closes equals about 12sq inches so yes I'd replace the foam... that is a huge volume of air that is now being forced under the hood with zero net gain... might as well use it to cool the radiator...
B. 90% of the replacement radiators I've run into are 2 row vs the 4 row OEM meaning you need that air flow
C. 2 row not really a bad thing... in a previous life I was around air flow and heat transfer and often the first rows were so effective that by the time the air got to the 3rd & 4th rows it had little heat absorption... basically just added weight and the amount of coolant it held...
D. your temp gauge won't show hot when you have a catastrophic coolant system failure because the temp sending unit has to measure the coolant temp... if it ain't there... no reading...
E. Opinion... I think most 2 row radiators will more than cool the 4.7 toyota.... and increase performance by a very small %... less restrictive = better mpg, less weight = better mpg, less weight is less prone to typical failure at the seams less stress and more surface area at the seams on the ones I've seen...
F. the 2 row are less than $100 online

I have 2 in use now... and I do watch them I have experienced 4 failures in 4 row radiators and so far none with the 2 row... but I check my oil at every fill up and look for signs of radiator leaking...
p