[fe7565]

I’ve come to the realization that placing discreetly chicken wire type of protector behind the kidney grills is the way to go to prevent your condenser fins from getting pummeled by stones.

If you’re looking at the photo, I can use a fin comb in some areas only, because a large number of fins are bent way beyond it. So I’m planning to painstakingly one by one pull the fins back out where I can insert the fin comb between them.

Would it be easier, and more efficient, to push them out from the other side of the condenser coil?

[pbonsalb]

You can certainly make an improvement by painstakingly combing the fins, but you won’t make the heat exchanger like new. I have done this on some cars. The fins are staggered so you are really going row by row and nit combing. I use a small thin screwdriver and a small pair of needle nose. Have fun.

As for the screen, too fine a mesh blocks airflow. I don’t know what the ideal mesh square is. 1/4? 5/16? 3/8? Have thought about this myself. You can make your own, but Zunsport and other companies may sell premade ones.

[afadeev]

Originally Posted by fe7565

I’ve come to the realization that placing discreetly chicken wire type of protector behind the kidney grills is the way to go to prevent your condenser fins from getting pummeled by stones.

Wow, what roads do you drive?
Rally-cross much?

Originally Posted by fe7565

If you’re looking at the photo, I can use a fin comb in some areas only, because a large number of fins are bent way beyond it. So I’m planning to painstakingly one by one pull the fins back out where I can insert the fin comb between them.

Nothing is impossible, but how much would a new radiator run you? $500?
How much do you earn per hour?

Originally Posted by fe7565

Would it be easier, and more efficient, to push them out from the other side of the condenser coil?

Unless this will be a labor of love, I'm thinking you will be better off buying a brand new replacement!
OTOH, if the car is nowhere close to overheating and you live in the colder climates, why not leave it alone?

HTH,
a

[fe7565]

Originally Posted by pbonsalb

You can certainly make an improvement by painstakingly combing the fins, but you won’t make the heat exchanger like new. I have done this on some cars. The fins are staggered so you are really going row by row and nit combing. I use a small thin screwdriver and a small pair of needle nose. Have fun.

As for the screen, too fine a mesh blocks airflow. I don’t know what the ideal mesh square is. 1/4? 5/16? 3/8? Have thought about this myself. You can make your own, but Zunsport and other companies may sell premade ones.

Yes, it’s not like an HVAC residential coil…these contain small squares of fins, and it will be very painstaking. So if staggered, won’t be able to push them out from the engine side…

As far as the protective mesh. I saw some photos of people doing it, and it didn’t look ghetto. I will try to look it up to see what size mesh they used. But there is a valid concern, as far as the size and blocking airflow, otherwise BMW would’ve had these coming installed from the factory.

[Mech Spec]

Don't bother, you won't notice any improvement and your time/money would be better spent replacing the part.

I know it "looks" like all those bent fins are hurting performance of the Exchanger, but I promise its nowhere near as much of a performance hit as you think. Maybe 5% loss in effectiveness

[fe7565]

Originally Posted by afadeev

Unless this will be a labor of love, I'm thinking you will be better off buying a brand new replacement!
OTOH, if the car is nowhere close to overheating and you live in the colder climates, why not leave it alone?

HTH,
a

Some valid points. It’s a 15-year-old car. But now that I’m thinking about it, I think many of the major dents were caused by me. I regularly wash the condenser coils with high-pressure water. And if the fins are bent from road rock damage, the high-pressure water hitting them at an angle will bend them further.

I don’t mind trying to straighten out as many as I can…I’ve been known to spend days on $100 retrofits I am in the DC area, but soon moving to Florida, and this will be the backup car.

I agree with you, the best thing would be to replace the condenser coil, But I think I can restore the majority of lost airflow, which should keep me still safely within the design parameters of BMW. Even now I’m not experiencing any overheating issues.

[fe7565]

Originally Posted by Mech Spec

Don't bother, you won't notice any improvement and your time/money would be better spent replacing the part.

I know it "looks" like all those bent fins are hurting performance of the Exchanger, but I promise its nowhere near as much of a performance hit as you think. Maybe 5% loss in effectiveness

I share your assessment that the blocked airflow (still even now) is within the BMW design envelope. But I will be retrofitting PDC on the front and will have the bumper off anyway, so will do as much as I can to straighten the fins. I believe that dirty coils would have more effect on heat transfer vs bent fins (to some limited extent).

However, I think it's worthwhile to check into a protective mesh that looks and works fine. And DO NOT USE high pressure water jet to clean your coils. Use low pressure.

[pbonsalb]

I’d price out a condenser. On my 2018 M5, I also have heat exchangers in front of each front wheel fed by ducts and they are beat up as well. I spent some time repairing fins while I had the bumper off to install yellow DRL and supplemental intercooler heat exchanger, but will probably just replace the ones with damaged fins in a few years. Maybe as a 10th birthday present to the car. The M5 has an oil cooler, transmission cooler, AC condenser, two engine coolant radiators, and three intercooler heat exchangers (I added the third). No power steering cooler because it is electric power steering.