Very informative post on this infamous Y Pipe. I believe mine is cracked too and spilled the coolant all over the place. If only an indy shop in NY would do this install I'd rather pay for this version of the pipe that holds up to the heat then the oem way.

 

I'm not a DIY guy by any means and now having regrets as many of the surrounding parts seem to be pretty dried out old hard plastic (2016 Macan ~95K miles).

Was all set and completing the last steps, attaching the new silicone hose to the bottom connection of the bleeder valve when the top hose on the bleeder valve above it broke off that was connected towards the front of the car. FML!!!

I'm frantically searching online to see what that is now and how to replace it. Any help would be tremendously appreciated.


NOTICE: Subsequent posts related to the radiator vent tube have been moved to their own thread. Santirx has agreed that it deserves
to be in its own thread, since the procedure is not really a part of this thread's discussion - rather a potential complication which may be
experienced by some subset of DIYers.

See the following for the vent tube discussion:

https://www.macanforum.com/threads/diy-thread-radiator-coolant-vent-tubing.194163/

Good luck!

 

I wonder if you can take wire key out with a pick tool and then try to get the connector from the side with a screwdriver or something… being careful not to damage the radiator.

 

Has anyone put together a kit to bypass this line? I thought I saw mention of one...

 

I mentioned and again think a “Kit” would sell well…

 

Thanks for making this post Santirx! I bought the same 1/4” hose line, stainless tee, oem line to rob the fittings from.

I was curious if you have a link to the 3d print file for your clamp? Did you just use one or two of the clamps? How is it holding up to the engine bay temps?

 

Now working with a design prototype of the coolant vent line connector. The idea here is that once the design is completed and tested, it can be manufactured out of aluminum. This will complete the solution with a connector that will last the life of the Macan. I’m not sure how I’ll make this available once done, but I have been in conversations with @tallkyle (potentially through Radhaus) so that they can offer it as part of a full kit (clamps that I designed previously included).

On the left, is a 3D printed prototype, and on the right is the original. The 3D print is produced to confirm dimensions. Next step is getting a prototype manufactured in aluminum.

 

Additional potential designs, using AN6 connection. I think this will be probably more robust…

Long neck to ensure no collision with the E10 bolt…

Short neck in case there is no collision…. Testing required…

 

Reduced size to AN4, better size for this, and printed a sample…

Prototype on left…

Looks really good. Test fit to be done soon with this PC printed prototype… just to make sure of dimension accuracy…

 

Forgive my ignorance. Been reading about this hose for a while and have no problems replacing it with some silicone heater hose, t-fitting and some clamps. Is it 1/4" ID hose? Unreal work being done here. Very impressive. I don't mind spending for the OEM hose for the fittings, as mine is 7 years old now and I want to get it replaced. @Santirx. would you be willing to share the CAD file (STEP) for the hose separator? I have a couple of 3D printers I use for proto work and can print these out here. Found the parts list with the video.

 

Also, just for clarity, the new hose is simply a tee from the front two fittings on the heads to the purge valve on the side of the air filter??? that's it?? Leaving the rest in place to crack and wither on its own? No connection to the hose at the bottom of the coolant reservoir? It can't be that easy😟

 

For anyone in Canada looking to do this repair (using the knockoff hose from China for the fittings). Parts can be had for about $100 including 2 x 5ft lengths of hose. I will try to reuse the original fittings if these seem of lesser quality.

 

I got the OEM vent tubing, but also got this Amazon vent tubing. I did install OEM. The Amazon knock off seems to be a bit more flimsy, including the connectors. Not sure if that will help with extending life… but in the end, I got it to get fitting dimensions as we will be manufacturing these fittings out of aluminum based on my design. I will be testing these soon.

 

Do you have a timeframe for the aluminum version? I'd like to redo mine sooner rather than later, but could wait for the aluminum version if it's pretty quick.

 

I'm curious about the timeline for availability as well.
Super appreciative for your efforts, @Santirx . Though I think going with AN fittings might be a bit of an overkill for this.
Your silicone hose solution is more than robust for this application. If the ends could be aluminum like you propose, that would make the hose solution **** near failure proof.

 

Thinking about where and what this hose does, while it seems way overengineered (shocking, I know), there may have been some reason to bring it around the back to improve bleeding the cooling system after a refill. Otherwise a very expensive solution to a problem that doesn't exist. And definitely a huge thanks for modeling the parts. Not worth replacing it like the original though,.

 

Getting ready to do this mod on the weekend. Hoping to just cut the hose off the fittings and not remove them from the heads, then push the hose down and use a spring clamp to hold things in place on the two fittings. The rest will get Oetiker clamps. Drew up a clamp to fit on the big hose to hold the little one in place. The first 3D print turned out quite well. Happy to share the STEP or sliced file if someone wants to print their own.

 

Getting ready to do this mod on the weekend. Hoping to just cut the hose off the fittings and not remove them from the heads, then push the hose down and use a spring clamp to hold things in place on the two fittings. The rest will get Oetiker clamps. Drew up a clamp to fit on the big hose to hold the little one in place. The first 3D print turned out quite well. Happy to share the STEP or sliced file if someone wants to print their own.

View attachment 289061 View attachment 289062 View attachment 289063 View attachment 289077

Hmmm… Looks eerily similar to my design… 😉

What material did you use for printing these?

 

Not adviseable... the fittings will be just as rotten as the tube

 

I suppose the material will be aged like the hose, but I haven't heard of any failures of the fittings, just cracked hose. I do have new fittings coming, but not before mid November and it can be too cold to change the hose by that time. I'll probably get it done on the weekend and check the condition of the fittings. If they look in bad shape, I'll change them out in the spring. Winter is coming and the garage isn't heated.

 

The same clamp in ABS:

 

Following this thread closely and waiting to operate with the latest techniques

 

Will tackle it this weekend and grab a few pictures. I am actually thinking of trying the silicone hose direct into the purge valve on the side of the airbox without the 90degree fitting, if it works. Throw an o-ring into the locking slot on the nipple, pull the hose over the o-ring and clamp it behind. Gets rid of the 90degree angle coming out of the valve. We'll see if it's feasible or a failure point. I've got all the parts now except the spare hose with the fittings so will re-use the originals if it doesn't arrive today.

 

Many folks have use this approach of clamping directly to valve with success. You’ll have no issues going this way….

 

Got it done this weekend. I had to reuse the original fittings, but all of it was actually in really good shape. you have to understand we live in a very temperate climate with a lot of cold weather so the heat action on the hose and fittings is less than a lot of places. They seemed new once I cut the hose off. I have new ones coming and will make up a spare hose with fittings to swap out should it become necessary.

I suspect this Macan we bought has been thoroughly babied as well. When I park I can still smell the exhaust coatings like on a new car. Anyway, it took a bit longer than I expected, but I was in no rush and took my time. I had all the right tools and it worked out fine. The only pitfall was the inability to remove the hose fitting from the valve so I cut the hose off it and clamped the new hose onto the fitting. I also used the PVC 3D printed clamps. I have some nylon ones printing today that I may swap into place. Drove it for about an hour afterwards and sucked the residual coolant out of the old hose with a vacuum brake bleeder and it all seems good. Pics attached.

 

Well done man!

 

Got a Nylon version printed. This material requires an extrusion temperature of 270C (518F) to bond properly. It has a service temperature of 199C, theoretically. It should be fine clamped to the insulated coolant hose without any deformation regardless of under-hood temperatures.

 

I experienced a catastrophic failure on the freeway of the t line and fixed using this mod. Dash showed overheating in large red letters, I pulled off as soon as I could and called triple a. Now that everything’s buttoned up, I think I may have bubbles in the coolant but would like some feedback as to what my issue might be.

Couple things: 1. I’ve done the recoding fix to show actual coolant temp, so the following should be accurate; 2. No oil in coolant or vice versa so hopefully I didn’t do any serious damage to the engine during that overheating stint; 3. I’ve vacuum filled the coolant twice with an airlift, with the key in the on position and heater maxed on high.

Pre-failure: the coolant temp would climb to about 221-225f, then (presumably) fans would kick on and it would drop down to 205ish and cycle back and forth

Now: no longer overheating, I’ve taken the car on a few local and 30 min freeway trips but it doesn’t seem to be behaving the same as it was before. Temp drop and gain seems more erratic. I was idling parked for 10-15 min to test stuff out and it was steady at 225f, sometimes when I’m at a light it’ll drop.

What’s really strange is that it seems like the coolant circulation is weak if that’s even a thing. I’ll periodically stomp on the throttle to try to work the bubbles out, but I’ve also noticed that the temp reading will immediately drop after I go hard on the throttle. Even when I was idling, after blipping the throttle it dropped from 225f down to about 221f before climbing again after 30 seconds or so. When I do a quick pull on the street, it might go from 220s down to 200.

1. initially I thought I had bubbles in the system, with a hotspot forming near the temp sensor. However, the sensor seems to be very low in the system, so I don’t think this is happening. I’ve also run the airlift twice (holding 25lbs of vacuum after 10 min).

2. could this be a thermostat / water pump issue?

3. is this even an issue? Honestly, I’m just relieved I didn’t blow up my engine. At the end of the day, the car isn’t overheating anymore even after 30 min on the freeway. It’s just weird to be cruising on the freeway, seeing 225-227f hold steady with no change unless I floor it for a bit, then seeing it go back down to low 200s.

 

I experienced a catastrophic failure on the freeway of the t line and fixed using this mod. Dash showed overheating in large red letters, I pulled off as soon as I could and called triple a. Now that everything’s buttoned up, I think I may have bubbles in the coolant but would like some feedback as to what my issue might be.

Couple things: 1. I’ve done the recoding fix to show actual coolant temp, so the following should be accurate; 2. No oil in coolant or vice versa so hopefully I didn’t do any serious damage to the engine during that overheating stint; 3. I’ve vacuum filled the coolant twice with an airlift, with the key in the on position and heater maxed on high.

Pre-failure: the coolant temp would climb to about 221-225f, then (presumably) fans would kick on and it would drop down to 205ish and cycle back and forth

Now: no longer overheating, I’ve taken the car on a few local and 30 min freeway trips but it doesn’t seem to be behaving the same as it was before. Temp drop and gain seems more erratic. I was idling parked for 10-15 min to test stuff out and it was steady at 225f, sometimes when I’m at a light it’ll drop.

What’s really strange is that it seems like the coolant circulation is weak if that’s even a thing. I’ll periodically stomp on the throttle to try to work the bubbles out, but I’ve also noticed that the temp reading will immediately drop after I go hard on the throttle. Even when I was idling, after blipping the throttle it dropped from 225f down to about 221f before climbing again after 30 seconds or so. When I do a quick pull on the street, it might go from 220s down to 200.

1. initially I thought I had bubbles in the system, with a hotspot forming near the temp sensor. However, the sensor seems to be very low in the system, so I don’t think this is happening. I’ve also run the airlift twice (holding 25lbs of vacuum after 10 min).

2. could this be a thermostat / water pump issue?

3. is this even an issue? Honestly, I’m just relieved I didn’t blow up my engine. At the end of the day, the car isn’t overheating anymore even after 30 min on the freeway. It’s just weird to be cruising on the freeway, seeing 225-227f hold steady with no change unless I floor it for a bit, then seeing it go back down to low 200s.

This is odd. I do remember having a similar issue when I first changed the thermostat in my Macan and refilled with coolant using vacuum. The temperature in my initial test drives was swinging a lot (similar to what you describe), but the issue went away on its own after a few drives…

Not sure what to recommend. Maybe you should keep driving it as long as it is within range and keep close observation. Hopefully it will sort itself out.

As far as root cause, my thought was also bubbles in the system that were released on its own.

Have you actuated vent valve while car is on and at temperature? Maybe that will help.

 

I replaced my hose a couple of weekends ago. I also had some bubbling sounds immediately after the hose replacement during the first few minutes of the test drive. I didn't have an overheat warning as it was a pre-emptive replacement. I did actuate the vent valve when I got back from the test drive with the temperature up on the dash display, but the hoses still felt cold so the thermostat probably wasn't really open yet. I would suggest getting it all up to temperature and then open the vent valve on the side of the driver's airbox and see if it helps. Just lift the bar in the picture:

 

Thanks for the replies - I’ve gotten the car up to temp (15-20 min drive with both water and oil 200+) and noticed that the vent value is already loose. Unsure if this is how it’s supposed to work, but the value was already “pushed out”, with the metal handle loose.

thinking about it now, if there was 0 air in the system, maybe there wouldn’t be any expansion from the liquid at all and the value would remain closed despite being up to temp?