New Beetle - Was: Don't get a Mahle/Behr radiator!

[03TDICommuter]

Edit 3-25-2024 - original radiator uses the same assembly technique. fins are thicker/stronger. Ended up putting a Nissens, also constructed the same way.


Edit: My Mahle/Behr radiator arrived today. OMG! I can't believe how cheaply made this was. The fins measured 0.07mm thick, and the metal flanges crimped over the plastic tanks are only 0.55mm thick. See more in my posting down below.




I need to replace the radiator on my 01' Beetle. The crimps on the passenger side look to be un-crimping themselves. It's holding under pressure but if the car sits for a week, I'll get coolant dripping from that seam.

I've scoured the posts here and understand the fender liners, fenders and bumper come off. Then the front is put into service position and I'm supposed to be able to unbolt the condenser and swing it out of the way to get to the radiator.

Question for folks - It sounds like the service position consists of using longer bolts to allow the radiator support to be moved forward. What am I supposed to buy to do this? I found a post that says M8x150mm bolts but that was for doing an alternator swap. Is this long enough for doing a radiator change?

Thanks for any tips you can send my way. FWIW, I have a Behr/Mahle coming. Hoping it comes with the o-rings for the radiator hose coupling.

 

[03TDICommuter]

Found this video that walks through it all. Makes sense now.

Also putting these part numbers in here for the radiator inlet/outlet o-rings, and the fiber washer for the fan temp switch.

Engine Cooling Fan Temperature Switch O-Ring (fiber washer) PART NUMBER: N0438083
Ring. Seal. Hose. Coupling. (Front, Upper, Lower) PART NUMBER: N90765301

 

[03TDICommuter]

Received a Mahle/Behr radiator today for my Beetle. Opened it up to see if I got a high density finned radiator and I did. Really surprised that the fins moved under very light pressure - until I looked at all the metal used.
- Fins measure 0.07mm thick.
- the flanges on the side, the fingers that wrap around and crimp onto the plastic tanks was really thin too - hard to get calipers in there but I measured 0.55mm
- the tubes are NOT brazed to the flanges! They are ALL in rubber!
- the fins are not brazed to the tubes.

Those coolant tubes are round in profile, and there are two side by side in each row. I can't imagine that rubber seal holding up for a decade. And the metal on the tank crimps - that's what is failing on my current radiator - one side the crimps are splaying.

Going to send this back and get a Nissens instead. Hopefully that one is higher quality. Here's photos

 

[oilhammer]

That is a superior radiator than anything Nissens makes. That is how the OEM is.... and they rarely ever fail. 99% of every radiator I've ever had to replace on a NB (or G/J for that matter) was from crash damage, not from outright failure. Volkswagen puts good radiators in their cars. Valeo or Behr are usually the OEM suppliers.

 

[03TDICommuter]

That is a superior radiator than anything Nissens makes. That is how the OEM is.... and they rarely ever fail. 99% of every radiator I've ever had to replace on a NB (or G/J for that matter) was from crash damage, not from outright failure. Volkswagen puts good radiators in their cars. Valeo or Behr are usually the OEM suppliers.

So the OEM uses rubber seals on the tubes? No brazing at all? There's 40 tubes, so 80 rubber seal points. Radiators I've had to replace (even OEM on other cars) the seals between the tank and the flange end up failing. I can't see adding 80 additional rubber seal points to be an advantage.

I can see that what VW would provide would be spec'd better than aftermarket. Or are you saying that the Valeo or Behr aftermarket offering is the exact same part as what the dealer would sell?

 

[oilhammer]

I guess what I am saying is, you may not have let the horse pull the cart.

I've installed a few of those (again, largely from crashes, not leaks) and not had any problems with them at all. If a NB rolled in our shop today, that's exactly what I would install.

 

[U4ick]

I've installed a few of those (again, largely from crashes, not leaks) and not had any problems with them at all. If a NB rolled in our shop today, that's exactly what I would install.

News you can Use!!!!!!! Nuggets of information like this from somebody that works in the business, and aren't trying to sell you something, are worth their weight in gold!!!!!

THIS is why I'm such an ardent fan of these forums!!!!!

 

[P2B]

I recently replaced the radiator in the sedan due to a leak where the core meets the tank - quite common here in the salt belt. The old radiator was a Mahle/Behr I originally installed in one of my son's cars which ended up a parts car. I don't have exact records but I think it lasted 8-10 years in service (plus a few years on the shelf) between the two cars.

The Nissens was slightly cheaper, but my supplier (who I trust) said there have been issues with them leaking after a few months so I went with the Mahle/Behr radiator again

Only time will tell...

 

[Johhny04]

P2B, i think we use the same supplier up in Concord and was given the same advice. When I had to change my radiator a couple of years ago, I also bought the Mahle/Behr option and skipped on the Nissen. So far so good. I also changed all the 4 rubber grommets that hold it in place, since the originals were worn out.

 

[03TDICommuter]

P2B, i think we use the same supplier up in Concord and was given the same advice. When I had to change my radiator a couple of years ago, I also bought the Mahle/Behr option and skipped on the Nissen. So far so good. I also changed all the 4 rubber grommets that hold it in place, since the originals were worn out.

For everyone that bought the Behr, was yours constructed the same as my photos? (Rubber sealed tubes, no brazing anywhere, thin crimp fingers around the tank?)

I don’t think they used this type of tech 20 years ago. I feel like this is a recent change. Everyone else has the brazed tubes to header plate.

 

[03TDICommuter]

I recently replaced the radiator in the sedan due to a leak where the core meets the tank - quite common here in the salt belt. The old radiator was a Mahle/Behr I originally installed in one of my son's cars which ended up a parts car. I don't have exact records but I think it lasted 8-10 years in service (plus a few years on the shelf) between the two cars.

The Nissens was slightly cheaper, but my supplier (who I trust) said there have been issues with them leaking after a few months so I went with the Mahle/Behr radiator again

Only time will tell...

That’s where my OEM is leaking. the crimp is failing on the tank in the right side. OEM on the PT Cruiser was that way too, two of them ( yes, we owned two simultaneously for a while). Older Astro Van too. Makes for mysterious leaks as it would seal up just fine except under certain cases. My beetle only drips when stone cold and sitting for a few days

Photos of the Nissens replacement - I’ve seen two styles. One looks identical to the Behr, with rubber sealed coolant tubes and high density fins. Another looks like what I’d call a common construction - brazed tubes to a header plate, wide but flat tubes, brazed fins.

IDParts sells the Nissens and their photo is the common construction.

 

[03TDICommuter]

I received the Nissens radiator today and it has the same construction as the Mahle/Behr. No brazing, rubber sealed tubes, very fine aluminum fins.

What I didn't realize is that the header plate is steel. That explains why the crimp fingers are thinner. In my photo above of the Mahle/Behr you can see that it was steel too from the galvanization patterning.

I'm not positive these are built in the same factory as the Mahle/Behr. I'll go ahead and install this and will keep my fingers crossed I don't have issues.

 

[03TDICommuter]

Learning more about this new type of radiator construction. It's called "mechanically jointed radiator". Notable appearance are the round tubes, non-brazed joints or fins. I'm not seeing any info claiming an advantage other than weight. Disadvantages are lower cooling performance due to fins not being firmly attached (brazed) to the cooling tubes but instead just by friction fit.

If I'm up for it, tomorrow I'll be doing the radiator swap.

 

[03TDICommuter]

Eating crow here. Apologies to oilhammer - the original radiator on my NB was replaced this weekend and indeed OEM from the factory used the swaged/mechanically assembled radiator technique. The tubes though were quite oval in shape vs perfectly round on the Behr and Nissens. The one side was pink with coolant residue from many many months of having a slow leak. I think it was leaking from the rubber tube to header seals, and not from the crimp area as I have pink residue on the fins near the top and none on the tank side.

Overall, replacing the radiator wasn't too hard of a job, just a methodical order of removing and reinstalling parts. I used new o-rings, and used a thermoswitch gasket that I picked up from the dealer though the original used NO gasket to the tank.

I do have a questions about the rocker panels and whether they're sealed, but I have another post for that.

So indeed, VW used a mechanically assembled radiator and they can last 20 years.

 

[03TDICommuter]

Found out I think I have a low speed fan problem. Was sitting at a construction light waiting our turn and watched the coolant temp climb from 199 up to 210 before I got worried and turned on the AC to get the low speed fans turning. Usually I can tell when the fans come on as the temp will climb to 203-205 and then fall back down to 194.

I know I plugged the triangular connector back on the radiator fan switch when I swapped the radiator. Weird that this switch would have gone bad after being transferred from the old radiator to the new one. Will have to jumper it to see if the problem is the switch or wiring.

 

[oilhammer]

When do you think the cooling fan is supposed to come on?

Here's what the folks that designed the car think:

Switching temperatures:
1st stage
On: 92 - 97 C
Off: 84 - 91 C
2nd stage
On: 99 - 105 C
Off: 91 - 98 C

That's at the lower part of the radiator. Meaning, where the green coolant temp sensor is, at the hot end outlet of the cylinder head, is going to be hotter. But a quick check of that plug wouldn't hurt.

 

[03TDICommuter]

When do you think the cooling fan is supposed to come on?

Here's what the folks that designed the car think:

Switching temperatures:
1st stage
On: 92 - 97 C
Off: 84 - 91 C
2nd stage
On: 99 - 105 C
Off: 91 - 98 C

That's at the lower part of the radiator. Meaning, where the green coolant temp sensor is, at the hot end outlet of the cylinder head, is going to be hotter. But a quick check of that plug wouldn't hurt.

203F is 95C, right in the middle of the low stage range you listed. Zero airflow due to being stuck at the light is my historical reference, and lower radiator output will approach/equal head outlet with no airflow. Never seen it go above 205 at a stop light/grid locked traffic before until now.

Will jumper the connector and check for fan operation

 

[03TDICommuter]

Jumpering shows the fans work at low and high speed. Will order and replace the fan temp sensing switch.

 

[P2B]

I saw similar behavior when I replaced my radiator - fans didn't come on until the temperature reported by my scan gauge was 4-5C higher than before. I assume it's because the new radiator flows better than the 20 year old one, even when stopped at a light.