Which hose does 99610621002 connect to?

[Jinster]

Hi everyone.

A rubber coolant hose on top of the engine on my MY97 2.5L Tip has ruptured.

As far as I can tell, this hose runs from a metal pipe sitting across the engine to the rear firewall.

I cannot for the life of me find this particular rubber coolant hose on any Boxster parts diagram. But I have been able to ID the metal pipe its connected to. 99610621002 is the metal pipe. Except, in every single Boxster pipe diagram, that pipe is drawn alone, not connected to anything. And yet it clearly does connect to something on both ends. The description for this metal pipe is "breather pipe"... so I am think it's a coolant overrun type of pipe.

The question is, what is the part number of the rubber hose it's connected to?

The rubber hose is circled in red in the photo below. You can also see the metal pipe to its right, covered in pink coolant residue. The whole setup up sits next to the AOS and the AOS breather tube.

[Starter986]

I'd like to help, but I'd need a much larger illustration... and an arrow pointing to the hose.






















































































































































































































































































































/S

[78F350]

Starter needs a bit more coffee...

I think that the hose that you are referring to is to purge air from the cooling system of the engine. It is unique on the 1997 engines. It runs from the top of the coolant manifold on oil pump housing to the coolant reservoir. On later engines there is a fitting on top of the heat exchanger (oil cooler) to purge air.

Metal pipe location on the front of the engine:


The hose should be the one I referred to in this picture as "Coolant to oil cooler on top of the engine":



For parts, you may just need the hose listed here as (30) 99610620700, but possibly the others noted in the diagrams. I don't have a 1997 handy anymore to see the actual connections.



Possibly these, but I don't think the '97 uses this hose...



You should replace the oil dipstick tube while you are in there. It looks like yours was cracked and repaired.

[elgyqc]

Originally Posted by 78F350

Starter needs a bit more coffee...

Or a lot less...

[Jinster]

Originally Posted by 78F350

Starter needs a bit more coffee...

I think that the hose that you are referring to is to purge air from the cooling system of the engine. It is unique on the 1997 engines. It runs from the top of the coolant manifold on oil pump housing to the coolant reservoir. On later engines there is a fitting on top of the heat exchanger (oil cooler) to purge air.

Metal pipe location on the front of the engine:


The hose should be the one I referred to in this picture as "Coolant to oil cooler on top of the engine":



For parts, you may just need the hose listed here as (30) 99610620700, but possibly the others noted in the diagrams. I don't have a 1997 handy anymore to see the actual connections.



Possibly these, but I don't think the '97 uses this hose...



You should replace the oil dipstick tube while you are in there. It looks like yours was cracked and repaired.

Thank you so much for the detailed reply. It's very helpful. It's good to know the metal pipe is for the coolant air purge in MY97. Though I don't think the hose in my photo quite match the top hose "coolant to oil cooler" - my hose is actually much longer and tourtuous than what's in your photo.

But. I doesn't matter now. I decided the easiest way to tackle this would be to just cut off the section of the hose that's leaking, and fit a new generic coolant hose in its place with a brass hose joiner. Worked a treat. Nevermind where it actually ends up going.

Also, your prompt to get re the oil dipstick tube was great because: 1. I didn't know that's what it was. 2. I bought the car 22 years ago and it came like that so I always thought that "patch job" was how the factory had it 3. My dipstick hasn't been able to fit down the tube for a couple of years now and I hadn't bothered to investigate the issue. But you pointing this out made it very easy to diagnose that the "patch" had come apart a bit. It was an easy adjustment on the patch to make my dipstick fit again.

A new dipstick tube is also on the way - in my effort to "repatch" the patch, a further bit of the original tube broke. It seems like a very very brittle part....