Hello forum,

I had to have the radiator replaced but my mechanic didn't install any foam around it (said it wasn't needed). I saw several posts about this subject and it seemed to me the consensus was that the foam was required, especially in hot weather areas, such as Los Angeles.

Is this something I can do, although the new radiator is already installed?

As always, thank you for your kind guidance.

 

Jag4, I will liken your question to running through a forest. If you try to run through a forest that the trees are all jumbled up and you are having to dodge and weave through the trees, you are not going to be able to run too fast. Where, if you are in a forest that had the trees planted and they make a nice straight row, running around is pretty easy and you can get a lot further, faster. Same thing with your radiator. Your radiator is the jumble of trees. Sure, you can go through it, but if you are also running next to a well planted forest, are you going to want to run in the jumble of trees or in the nice straight rows? The point I am making is the air is going to want to take the path of least resistance. Where there is no foam, you have a wide gap that makes a simple 180 degree turn. Not too much restriction there. Where the radiator has all these small holes in each of the cooling cores (keep in mind, you also have to think about the A/C condenser, tranny cooler, etc). So, this path is not going to be easy to make it through. So, some of the air will naturally go through the radiator, but some is also going to go around the sides. So, you want to force the air to have to go through the radiator and not sneak around the sides. So, installing the foam is a good idea.

With all of this being said, you do have a fan that will run if things get too hot and this pretty much forces air through the radiator as it does not suck from the sides (all air has to come through the radiator). But, if you can let the natural flow of air go through the radiator as you are driving down the highway, this will save wear and tear on your radiator fan.

You should be able to reach in from the engine bay side and pack in the foam. May have to cut it into say 1" or so wide strips to fill the gap, but you should be able to get most of the gaps. If you don't get 100%, not that big of a deal. You are forcing the majority of the air to go through the radiator.

Hopefully this all makes sense and explain why it may not necessarily be a problem, but it is in your best interest to have the foam.

 

Thanks Chris. I'll install the foam, closed cell foam, I'm guessing. I am finding 1 x 3/4in. w/adhesive on Amazon. And, I'll stack it if there's space to do so. Top and bottom only, not sides, correct? Be well.

 

Jag4, 360 degrees. All the way around. Anywhere the air can go around the radiator is that much less the radiator will get. Like I said, you don't need to go killing yourself to cover every minute bit of it, but the more you can get, the better off you will be.

 

Also the fan creates a low pressure area in front of it and a high pressure behind it. Air wants to move from high pressure to low so when the car isn't moving the hot air exhausted by the fan will recirculate around the radiator and go back through the rad if those seals aren't there. 100 years ago doing some work with Jeep we were overheating a prototype vehicle in "city traffic" test cycles. Stop and go, like on your highways out there in LA. The fix was a $0.50 piece of foam to block the recirc flow. Knocked the coolant temperature down significantly on that particular vehicle.

 

Good to know the hard data. Thank you.

 

jag4, I am not defending the mechanic, but you have to look at it partly from his point of view. You have a line of cars going out the door and everyone wants their car fixed yesterday. Are you going to spend an hour going from this site to that site, over to this other site, just to save a few bucks? Or as you going to go through your normal distributor and if they say it costs XXXX amount, that is what it costs? As for time, I know a lot of mechanics, since they work on multiple cars at a time, just charge a book rate. They have a book that says replacing a radiator in a Jaguar X-Type should take YY hours. So, regardless of whether it took them 1 hour or 20 hours to do the job, they charge you the YY hours. That may work to your advantage, it may not. This is where the good mechanics can make killer money because they can put in a 10 hour day and get say 20 hours of billable service time. Some shops also use this book time so if the mechanic does short the customer and the customer brings the vehicle back, the shop does not have to give the mechanic more money as he "has not finished the job properly".

Not saying that he isn't doing something funny, but playing the devil's advocate to show that there is another side that a lot of people do not understand or know about.

 

Hey Chris, I understand and agree with what you're saying - for the most part. I own my own business and operate in a similar fashion; that is, charge a flat rate much of the time. Nice guy and I like my mechanic. But the difference between what he was going to charge, if I had said nothing, and me asking a couple questions was 50% less. I know I'm being a bit unreasonable. Just bitchin' I guess.