Where exactly do we look on the E39 radiator for telltale cracks?

Originally Posted by chiefwej

That is a CLASSIC radiator failure. Exactly where mine cracked.

I'm glad you spoke up because the whole point of this thread is to show pictorially where to look for radiator failures, the most common spots first.

I needed something like this and so does anyone who is new to the radiator failure on their BMW!

Thanks.

Originally Posted by chiefwej

That is a CLASSIC radiator failure. Exactly where mine cracked.

I'm glad you spoke up because the whole point of this thread is to show pictorially where to look for radiator failures, the most common spots first.

I needed something like this thread when I went looking for cracks ... and so does anyone who is new to the radiator failure on their BMW!

Thanks.

In keeping with the nature of this thread to show pictures of various E39 radiator failures, here's one where there was a coolant "spray" all over indicating a pinhole leak somewhere ...

Here is another radiator failure picture, from:
http://img161.imageshack.us/img161/7...ollapse3dg.jpg

This one leaked at the replaceable nipple where the expansion tank hose attaches to the radiator.
Nipple R&R instructions are here.

In keeping with the concept of visually showing where folks' radiators leaked, here's a thread where the leak to look for was around the blue drain plug on the driver's side (bottom of the radiator).

Mine started to leak exactly where bluebees did. This happened @ 65,000 miles. I replaced the entire cooling systym.

Actually, all those leaks were in other people's BMWs.

Oh my! I spoke exactly one day too soon.

Here's my very first actual cooling system leak.

Another place to look for leaks is in the lower radiator hose cooling temperature sensor o-ring (which turns on the electric fan).

And, a common failure INSIDE the expansion tank is that the level sensor mechanical stick disintegrates...

I was looking for information when I saw this, new location of a radiator failure, from MatWiz.

His failed at the little hose that connects to the expansion tank, at the expansion tank, where the tube that comes out of the expansion tank at the top broke where the hose connects to it under the fan shroud.

In addition, his shroud was all busted up.

This cooling system potential leak can only be seen once you remove the fan shroud!

It's a minor blowout in the lower hose, maybe because of oil dripping down on it from a leaky valve cover gasket?

one of the easiest ways to look for a little vapor is to get her nice and hot and open the hood. Keep the headlights on and get a flashlight. LED lights work great for this as they really light up any vapor. If anything is leaking steam you should be easily able to see it this way. The darker the environment the better... If this helps anyone great...

-Steve

Originally Posted by abanjableu

one of the easiest ways to look for a little vapor is to get her nice and hot and open the hood. Keep the headlights on and get a flashlight. LED lights work great for this as they really light up any vapor. If anything is leaking steam you should be easily able to see it this way. The darker the environment the better... If this helps anyone great...

-Steve

Actually, if you are using BMW coolant you will see the tell-tail white deposits any place there is the slightest leak.

Originally Posted by chiefwej

if you are using BMW coolant you will see the tell-tail white deposits any place there is the slightest leak.

As shown in this picture below from a thread opened this week on an E39 with 44K miles ...

after inspecting lower radiator hose new temp sensor oring stopped leak

Originally Posted by energizedmortal

add bottom of lower radiator hose that connects to radiator to the list ... mine expanded and drips where the metal clamp slipped a bit...will get temp sensor o ring while im at it

From a thread opened today, here's a picture of the lower radiator hose dripping from where the temperature sensor was reused. Similar lower-radiator-hose temperature sensor leaks are discussed here and here and here with a summary of the solution here.

Hy BlueBee!
About your exploded tstat's housing...
What the reason was?

Originally Posted by bluebee

Here's another exploded radiator upper milk-jug plastic hose that happened in this thread today.

What the reason was?

^ 40 k valued cars coming with fisher price plastic = sickening damn germans can almost conquer the world but they can't build a dependable cooling system...color me confused

Originally Posted by energizedmortal

^ 40 k valued cars coming with fisher price plastic = sickening damn germans can almost conquer the world but they can't build a dependable cooling system...color me confused

We could only wish...There are Fisher Price plastic toys laying around my house that are left over from my now adult kids. Many are 20 or 30 years old, and the plastic far outlasts any BMW radiator.

Originally Posted by chiefwej

Fisher Price plastic toys ... far outlasts any BMW radiator.

I must agree ... I suspect Behr used both the wrong plastic and skimped on the amount, in addition.

Just like Hella used the wrong PBT plastic for the headlight adjusters, they clearly skimped on the plastic in addition, whereas Delrin or HDPE or Teflon adjusters would have been much stronger and not much more expensive considering the cost is just pennies apiece no matter which plastic they used. But, Hella not only saved pennies, but Hella gets rewarded when you buy equivalently low-quality Hella replacement headlights.

My recommendation is to NEVER reward Behr for making those poor quality radiators. I avoid Behr if at all possible. Go with Nissens if for no other reason than to not reward Behr. Or Zionsville if you're willing to go out on a limb to reward better design and engineering.

BTW, there are about twenty or so pictures of what an engine looks like, on the inside, after a radiator failure over here in today's cn90 thread.

after replacing my radiator with the help of GSA1 with a behr from autohausaz i have driven more than 3,000 miles without any coolant loss (even though its only a matter of time before white stains resurface i won a battle but not the war lol). The first time i paid an indy to replace my radiator it leaked within 800 miles going with nissens next time to compare performance

2001 540i
radiator blew at the top where the hose fitting joins the radiator housing; ie the classic location. It blew getting on freeway (probably) and I got the low coolant warning 3 miles later then temp started to rise .5 mi later with immediate shut down of engine. Car had 62.5K on it when that occured, and I had replaced thermastat and expansion tank just beofre at 56K. Concensus of the v8 is that this was typical mileage so if you've got 80k, just do it before it blows up on you at an inopportune time and place.

Here's another E39 failed fan clutch horror story, causing the whirling fan blades to tear through the shroud to puncture not only the hood but the front quarter panel too!

For those of you playing at home, here's a thread with subtle photos of the cooling system leaking at the heater pipe.

"The inlet of that heater pipe has two orings which degrade over time, and a leak will spring out from there. This is the condition of mine when I pulled the pipe out of the block."