Replace Heater Hose to Upper Plastic Coolant Pipe

[staggerwing17]

Hello Everyone!
Wow a whole different world today when compared to a couple of months ago. Hope everyone is staying healthy.

I have a leak at the joint of the upper plastic coolant line (11531705210) and the heater hose (64218377673). Both are new after a complete cooling system update and intake manifold upgrade a few months ago. It is just dripping, only when running. I figured out the problem spot by following the heater hose to that joint with my hand (after moving wire harness out of the way). It is very tough to get a hand in there I'll tell you! I confirmed my suspicion with a wifi borescope. Shows leak are clearly but no way to know which hose/pipe it is. Maybe the o-ring in the rubber hose?

Has anyone ever managed to replace this heater hose without removing the intake manifold? I am loathe to take apart that manifold. My son suggested possibly removing the air intake from the front up to the plenum, unscrewing the motor mount nut and slightly lifting the motor - maybe get a couple of inches?

Any help appreciated! Thank you and be safe!!

 

[colb]

I assume its part number 4 in the oem diagram here https://www.realoem.com/bmw/enUS/showparts?id=CL31-EUR-01-1999-Z3-BMW-Z3_20&diagId=11_2343
Probably best to lift the manifold so you can at least get a good look at the joint, I would suspect the O ring part number 5 has gone bad or pinched, if you replace it lube it with vaseline before seating it to insure it seats ok.

 

[staggerwing17]

I assume its part number 4 in the oem diagram here https://www.realoem.com/bmw/enUS/showparts?id=CL31-EUR-01-1999-Z3-BMW-Z3_20&diagId=11_2343
Probably best to lift the manifold so you can at least get a good look at the joint, I would suspect the O ring part number 5 has gone bad or pinched, if you replace it lube it with vaseline before seating it to insure it seats ok.

Hi colb! Thank you for having a look at my post! I may not have explained clearly where exactly the leak happens. So I have attached a diagram I created when replacing the cooling system. It is part oem and part hand drawn but it helped me a lot during the overhaul.

For sure if it was indeed as you described, the manifold would need to be removed. But the leak is at the other end of that cooling pipe where it attaches to the rubber heater hose. I have circled it in red on the diagram. I think I probably will need to remove the manifold but I am hoping someone might have figured out an alternate method for repair. Thanks for your reply and please let me know if you have any additional thoughts. Have a great day!

 

[colb]

Not sure what that joint is actually like I assume its some sort of round tube that the hose fits over to continue its run to the firewall, how about wrapping the end of the plastic pipe with PTFT plumbing tape to achieve a better seal and a jubilee clip to retain the firewall hose to the joint, not sure how that joint is retained normally to achieve a leakproof joint.

 

[Rodders67]

I know this is old post… and I have entered my LC88677 VIN and cannot find cooling system diagram for my ‘99 S52 M Roadster, as I try to confirm coolant pipes needed. Everything seems to indicate I have only 1 vs others with 2? Help???

 

[Althulas]

I would try using Realoem but manually inputting your vehicle details then looking through the subsystems.

 

[Rodders67]

I had tried that previous, but found it now… too many ads. Had to keep scrolling down. Cheers

 

[Delk]

The heater hoses have a plastic fitting that pushes onto the pipe from the engine. The fitting has an O-ring inside and should be greased up to seal correctly.

I dont know the S52 but on the M52 you can get the heater hose off with some determination.

 

[Rodders67]

S52 from 1999 has only single 4 way rigid pipe with o-rings. Was confirming this with diagram. Seems they changed the S52 in subsequent years to an upper and lower 2 pipe version. As such, I ordered the Vaico Aluminum version of plastic OEM pipe and all hoses that are under or around the intake manifold. I plan to change them all with intake manifold removed.