Radiator question
 

My 04 X5 3.0 is currently at 42t miles or so.

Looking under the hood, I see some water at the radiator core/end tank seam near the upper radiator hose neck.

I cleaned the area and drove for a bit and it was wet again when I checked it after the drive. There were no cracks. It looks like it's coming from the seam.

I come across this video by the guys at BMP. They say it is a common leak point in BMW radiators caused by heat cycling/flexing of the radiator causing the crimp to loosen.

Seeing that it looks like I have this exact same problem, I am thinking of having the area re-crimped. I have a good radiator shop nearby who has repaired similarly crimped Mercedes radiators for me in the past and thinks this is worth a shot.

What do you guys think?

Will post pics of leak and link to BMP Youtube vid later, internet is kinda slow here.

If you use BMW antifreeze, when it dries, it would leave white residue. That'll tell you there's a coolant leak.
Waiting on the posted pictures.

Yup it has BMW antifreeze, and there were white stains in the general area. That and the seam actually being wet after a short drive removes any doubt for me that there's a leak.

Will try to upload the pics now tmv, thanks!

Pardon the crappy phone pic!

The dark spot in the lighted crimped area is water.

Will try to get better pics

http://i239.photobucket.com/albums/f...ps394e1b2c.jpg

BMP youtube vid mentioning leaks in that area caused by heat cycling/flex

http://http://m.youtube.com/watch?v=...%3D7WsBma6NLYM

how much is it to do the re-crimp? that may be a decent short term solution, but if its your original radiator, at close to 10 years its probably time for a new one anyway. The nylon/plastic they use for the cooling system starts crumbling around then.
A new radiator from Pelican is $187 (Nissens) or $290 (Behr).

True on the age, that's one factor that makes me consider just replacing the rad.

There is the posibility the radiator has been replaced by a PO, the truck is an 04 but there is a sticker on the radiator that says 05 somewhere that seems like a date, but am not sure so am erring on the side that this is the original rad.

I've priced out the radiators, thank you, but the thrifty in me kinda balks at replacing for a seam leak that seems it could be re-crimped. Of course if there were any sort of cracks or indication of weakness I'd replace it in a heartbeat, but it seems to be still structurally sound.

This radiator shop once did an e46 for me. Temp would climb when on the highway at speed. Ended up pulling down the radiator and they opened up the rad, cleaned, re crimped, and pressure tested. Problem solved thankfully, or I would have been pulling down the cylinder head next. That was 2 years ago and that rad is still fine to this day.

So previous experience was that Behr plastic rads can be opened up/repaired, but would love to hear people's experiences and comments as well.

If you plan to keep it for a while, I'd just go with a new rad. You're going to waste more time pulling it out, getting it fixed and then possibly having to pull it again down the road if, but more realistically, when the thing starts to leak somewhere else since its nearly a decade old.
Just my $0.02!

To update, after a pressure tese, turns out there is a crack in one of the plastic flashing lines that weeps a bit under pressure. In a way, I'm glad, as it makes replacement a no-brainer. I plan on keeping the truck a while, so it's ok.

Upper radiator hose was replaced a few months ago when I did the trans oil cooler, so I got a new lower hose so both are pretty much new. Re-used the coolant temp sensor on the lower hose as it is easy enough to swap out if there is a problem. Held off on the thermostat and waterpump as they are accessible without removing the radiator, so I will deal with it when time comes.

While everything was out, I added another clamp to the bottom power steering reservoir hose which I hope will take care of the leak there. Took a hose to the AC condenser as well, as there was a bit of gunk on the fins from highway driving.

Also during all of this, we pulled the air intake elbows for easy access. In a happy coincidence, this exposed the steering shaft universal joint. Was finally able to confirm this is causing the steering wheel knock when turning the wheel slightly left to right!