Radiator protection - OEM foam strip

[alrock]

Looking through JPaul's thread, I was reminded of a GM fix for how the radiator comes in contact with the H3 body. Reloader pointed this one out to me.

If you look at the parts listing for Alphas you'll see a foam strip available as a part. It's just a wedge-shaped piece of foam with doublestick tape that attaches to the radiator. It helps push the radiator away from the frame and it help prevent air loss over the top of the radiator. You want the air going through the radiator. For some reason this part is not listed for the 3.7s or 3.5s even though it came on some of them.

All you have to do is remove the top brace on the radiator, clean the mounting surface on the radiator, push the radiator back a bit from the body and install the foam. Then reattach the brace. The foam will help prolong the life of the radiator by reducing impacts from the frame.

It's part #16 in the picture and can be ordered through Amazon. GM Part 15806298

You can see the foam strip installed here. Note this is on a failed radiator so it doesn't prevent all failures, but it can address a particular weak point in the design.

 

[Clwnshu99]

Good to know, I tried door edge guard after replacing my radiator, but I wanted to be sure that it did not happen again, So I egged out the hole that the retaining bolt goes through and slid the bracket (and thus the radiator) back towards the engine about 1/4 and re-tightened. I am fairly certain that i will never see that problem again.

 

[brokenaxle]

Good to know, I tried door edge guard after replacing my radiator, but I wanted to be sure that it did not happen again, So I egged out the hole that the retaining bolt goes through and slid the bracket (and thus the radiator) back towards the engine about 1/4 and re-tightened. I am fairly certain that i will never see that problem again.

Moving the radiator closer to the fan will increase the likely hood of you over heating your vehicle. For your engine fan to work at maximum efficiency. You need a portion of the fan blade to stick out of the shroud.

I'm a mechanical engineer and I design agriculture equipment. I found this out when I had to spec a reversing engine fan for one of our machines.

Every fan seems to be different. For the reversing fan it was 1/3 of the blade needed to stick out past the shroud. And for the John Deere stock engine fan it was 1/2 of an inch.

Sent from my XT1058 using Tapatalk

 

[JPaul]

Brokenaxle, you make a very good point, but even with the "extreme" amount that I pushed my radiator back (check my build thread to see what I did), it's still only about 3/8" at most farther back than stock. The fan still sticks out past the shroud by a good inch or so. I doubt the 3/8" difference is enough to noticeably affect the efficiency of the fan. Plus, this would only come into play while idling or driving very slowly so that you are having to rely on the fan alone for cooling. Even then, I think me putting a winch in front of my radiator has a bigger effect on reducing efficiency than pushing the radiator back a little bit, though with the Thor bumper I think it probably made it even better since it really opens up airflow to the radiator.


alrock, adding the foam is probably a great idea, but I think it was mostly for airflow than anything else. With mine at least it was within a tenth of an inch of the body in stock form, I don't think adding foam would have helped prevent the radiator breaking (ok, maybe it would've helped a little bit, but not enough really). To my mind, if anything it'd potentially help accelerate failure as it allows vibrations to transfer more readily to the radiator housing and induce fatigue fractures in the plastic.

If they really felt it was an issue, they would have designed it so that the radiator wasn't sitting right up against the bloody beam. But obviously someone didn't think it'd be an issue. Plus I strongly suspect that they had quality issues with the radiators and the plastic was too thin in spots. The break on mine really looked like that was the case, but sadly I didn't think to ask them for the radiator so that I could cut it open and check. I'd love to see someone else that has a broken radiator cut theirs open and see what the thickness of the plastic is like on them.

I think a combination of nudging the radiator back away from the cross beam and adding the foam is a good solution to helping avoid failures as well as increase cooling efficiency since you're directing the airflow better with the foam.

 

[rsc]

Mine had no foam and no contact with the frame when it cracked. I think the radiator plastic is just sub-par. Probably planned obsolescence.

 

[ABNTROOP]

For those of you with a radiator failure under your belt, how obvious was it? Was it just puking fluid? What should I be keeping an eye out for?

 

[rsc]

I smelled radiator fluid for a week or two before finding any wetness on the radiator core and tank. I think it was burning off, after the crack was fully developed it spread out quickly to a couple 4" long cracks on either side of the support. It would then leave a small puddle on the ground when shut down and would weep fluid freely from the cracks.

 

[SedonaBound]

Mine had no foam and no contact with the frame when it cracked. I think the radiator plastic is just sub-par. Probably planned obsolescence.

If the H3 was made by Boeing, a pressure component made by bonding plastic to metal would probably be dependable. But we're talking about GM here.

 

[rsc]

Every other car maker out there can make a radiator that lasts longer than 5 yrs/80k miles. Why can't GM? Hell, Honda even figured out how to weld aluminum and steel together. Why can't GM make a plastic radiator?

 

[alrock]

Not sure if my failure was so much about the tanks as it was about the tubes

 

[alrock]

alrock, adding the foam is probably a great idea, but I think it was mostly for airflow than anything else. With mine at least it was within a tenth of an inch of the body in stock form, I don't think adding foam would have helped prevent the radiator breaking (ok, maybe it would've helped a little bit, but not enough really). To my mind, if anything it'd potentially help accelerate failure as it allows vibrations to transfer more readily to the radiator housing and induce fatigue fractures in the plastic.

True, but I've also seen H3 radiators with gouges in the plastic tanks from contact with the body. Most failures are away from these contact points, but my point is that reducing contact, impact and vibration in this area could help reduce failures in other areas.

 

[JPaul]

At the end of the day, the engineer responsible for this mess up should be slapped by every H3 owner that has had to deal with these flaws.

If you still have that busted radiator and it's OEM I'd still love to see the tank end cut into sections and see what the thickness is like through out it.

Was the foam only added after a certain year? My 2008 didn't have it.

 

[Clwnshu99]

For those of you with a radiator failure under your belt, how obvious was it? Was it just puking fluid? What should I be keeping an eye out for?

As stated above, the smell of coolant grew over a few days, less than a week for me though. On the final day, when I got to work, I noticed a bit of steam coming from the front of the hood/grille area. Got out and a small puddle was forming drip by drip under my truck. Popped the hood, and found coolant was misted across the engine. Wiped the bulk of it down and traced it back to a 4" long crack right where the pinch weld seam of the core support butts up against the radiator. It was evident that the vibrations between the rad and the core support wore the rad thin in that spot.

 

[SedonaBound]

...Wiped the bulk of it down and traced it back to a 4" long crack right where the pinch weld seam of the core support butts up against the radiator. It was evident that the vibrations between the rad and the core support wore the rad thin in that spot.

Was it a plastic-to-metal seam?

 

[Clwnshu99]

Was it a plastic-to-metal seam?

Its a metal seam (Circled in yellow) that runs the witdh of the engine bay. The Green area is where mine cracked. **This isnt my engine bay, just an image from google.

This the actual picture of my radiator and the crack, you can see it is perfectly straight across, and while it was pushed away in the picture, it would have matched right up to that pinch weld seam of the core support.

 

[Dennis]

That foam strip does little in the way of protecting the radiator tank from rubbing against the frame brace...

It is though there to help keep the air flow over the radiator....And I was able to find an OEM replacement, but it was pricey

I ground down the edge of the frame to a point that in no way did it ever touch the radiator tank again...as that was what caused mine to also crack in that same area

 

[amrg]

My first radiator replaced at 35 k miles, had the foam piece. When I had it replaced at the dealers under warrenty, they didnt instal the foam thingie. The Second radiator lasted 50k miles...

 

[SedonaBound]

If the foam is fully compressed, it may be transmitting enough force from the normal flex and vibration of the cross piece into the thin wall of the upper tank, causing eventual brittle fatigue failure of the tank wall. It sure look like that's whats happening in the pics. I still haven't got a feel for the percentage of H3s that experience the problem. I can say that I've received class action lawsuit info on a far lesser problems on other cars I've owned.