Upgraded Cooling Hose Coolant Flange Connector In Cast Aluminum For VW Passat and Audi A4 1.8T B5 058121132C 058121132A 058121133B 058 121 132

Installed this in my European automobile with engine code AWM. Be extra careful to seat the hard plastic connector and clip from the cooling hose in this aluminum flange before pressurizing the system. There's one o-ring that this product doesn't supply, but it was in the best shape out of the three, seemed to be the least critical considering the mating surfaces and design of the connectors, and the original o-ring was able to be reused without issue. This product seems to have stopped the mysterious slow coolant leak I had been searching for. Good enough quality, definitely a fair price considering tooling costs and all that. Thank you for supplying enthusiasts like me and whoever reads this.

Fit great, worked great, much better than the plastic ones.

Not a bad idea to eventually replace yours from plastic to aluminum. These are expensive here on Amazon and just resold from AliExpress at 5x the price. All the kits are missing the metal supply line o-ring gasket but include the engine head to metal flange and coolant temperature sensor. Replacement is tricky due to space issues but easily done if you remove and flip the coolant reservoir out of the way and come in from the catalytic converter side with each arm. Good luck. Will update long term for how it held up.

Installed this product as a replacement to the VW factory plastic coolant flange which failed after 16 years of use! My car is a 2003 Passat 1.8T. Was a very difficult job, due to the awkward location and took almost 4 hours to fix. Watch some YouTube videos for guidance and you’ll be fine. No longer will I have to worry about this issue. Product should outlast my car’s life expectancy. No defects in part. Just some “cast flashing” that may need grinded away. I used my Dremel and was ready to install in about 20 minutes.

Perfect fit

Worked very well on my 98 1.8T Passat. The flange that mounts to the cylinder head was rough and uneven, but a few seconds on a belt sander took care of that. Don't over torque the bolts that thread into the flange. Sealed perfectly with no additional silicone needed.

Didn’t seal at the pipe connection due to there is not enough lip inside the tube of it to push the 0ring(the one not supplied) to seal it to the pipe going to the radiator like the original. Sealed to the head but caused a leak at the other connection. Had to purchase one from the dealer and new rings.

Reviewers have reported in this listing and others that these aluminum flanges may not be deburred on the inside. I used a dremel 90 degree attachment with a new dremel grinding ball (about 8-10mm wide) and had just enough length to insert it. I wore the grinding ball down to a point. I've attached a before & after photo of the lower outlet and an after photo of the back of the flange. I suggest only deburr to remove the thin aluminum leftovers that impede flow or could break off. Note I did not grind any surfaces where the o-rings sit. Grinding is probably too coarse for those surfaces. If yours is damaged in that way then I would exchange it. Believe it or not I would buy this again. It arrived in less than 24 hours with free prime shipping which was very important to me and except for the deburring issue it worked out well. The flange replacement took many hours on an 2003 Passat AWM engine. If you search youtube for video id 0qg5PeIUPpM then you can see a video (not mine) explaining the replacement. In addition to what's in the video I found coolant crust/corrosion in the area on the back of the head around where the flange o-ring sits. I used a flexible auto mirror and 2500 grit sandpaper to get rid of it. The pipe inserted into the side flange has an o-ring but it is not included and it's possible the size may vary depending on the car. For my engine it is part 058121687 which is an unusual 31.5x3.65mm. I had to special order it from an Audi dealership to get it next day. Also, the heater hose which attaches to the flange's lower outlet has an o-ring which is not included and VW doesn't sell it separately. You can use RKXtech's improved o-ring replacement which is sold on Amazon as RKX-KIT-004 (search "2X RKX Coolant Hose O ring Compatible with VW Audi") or do what I did and leave it alone if it's in good condition. edit: I remembered one more important thing. I broke the secondary air hose pipe rubber elbow (for my car it is part 058133785B) while removing the side air pipe. I read about that happening to a few other people as well. See also the thread 'Replacing the coolant flange and heater core hoses - job notes' on passatworld.