s52 m42 radiator hoses

[brads2002]

I can't find a clear answer on this one. Anyone have the information handy on what to use for the top and bottom main hoses?

Thanks.

[pazi88]

Use the s52/m52 ones and cut to them to fit.

[brads2002]

Judging by your builds you know what you are talking about. Thanks!

[brads2002]

So I ended up going with Gates 21794 or Dayco 70440 for top and bottom. They look just like an L. Pepboys has them for 7.99 after coupon. They fit really well.

Here is a pic of the top. I would be happy to take additional for anyone thinking of doing the same.

https://www.flickr.com/gp/153835794@N08/14263Y

[She loved E]

Thank you! This is just what I needed... I'm just about to swap to an M42 radiator on my swap car and was wondering what I'd need to change.

I also need to hook up my heater core. Can you share what hoses you used for them? Part numbers would be a big plus if you have em.

[brads2002]

You bet. I found this accurate.

https://www.r3vlimited.com/board/showthread.php?t=416162

[She loved E]

Rockin that's exactly what I needed.

If you don't mind I'll keep the threadjack going. ;P

Do you also have an E36 spider hose, or will you use pn 11 53 1 703 844 instead? Looking under the hood I see that my expansion tank runs to the metal hose under the intake manifold, which is what I thought would connect to the heater. In other words, does this need a T-joint to connect all 3 (exp tank, metal hose, heater)?

[brads2002]

For sure. This is good info for all. My expansion tank runs to the center of the metal line.

One heater hose runs from the back of the metal line to the core (follow above link instructions on which goes where). The other from the head to the core. I am not running a spider hose. I am not sure but I thought those were for engines without the metal line. I am getting heat and the engine seems to be cooling properly.

Let me know if that makes sense or not. I can try to take some pictures but it will be difficult now that the engine is in the car.

[She loved E]

Sweet I feel like I'm getting close. Threw this together to get everything straight... still not quite understanding what to use for #6 and #8...

Mind telling me if I'm right so far? Bear with me as I haven't pulled the intake manifold yet to clean everything up... I'm trying to order parts in advance if possible before diving in (I have quite a list of things to clean up while I'm in there).

Assuming this is right so far, here are my questions/assumptions...

- I also need #6 metal pipe
- I need to cap the nipple between #14 and head (which is currently routed to my expansion tank)
- I'd also need to cap #6 where it usually connects to TB hose #13
- Not sure what to use for #8. Obviously this is specific to M42 rads since placement is not as shown in the diagram

Thanks again for helping me sort this out.

[Dagamus(NM)]

I have been looking for info on this. Sub'd

[brads2002]

If you have the metal line (mine was from a 99 m coupe) 6 hooks direct into the back of the water pump. There is no hose.

From your prior post I thought you had 8 sorted running direct from your expansion tank. 8 connects to 10, 12 is crimped and welded. That’s how I have mine. I used an expansion hose from a 325e that I had laying around. Cut one end off to make it a smaller fit on the metal line. It is tight but it works. I am sorry don’t have the p/n for that one.

Shoot me a pm if it’s easier to talk. Happy to send my phone # to talk through.

[Dagamus(NM)]

Why not just keep 12 and 14?

[She loved E]

Thanks brads2002. I updated the diagram, how are we looking now? Only part # we're missing is the 325e hose you used. I'm sure I'll be able to figure something out with leftover parts and will try to update this when done for others to use.

Dagamus(NM) - If you want to keep the TB heater you can keep #13 and 14 AFAIK.

[Dagamus(NM)]

I get that, or you could just run a length of hose from pipe to port.

But what benefit does deleting it offer?

Seems like pulling the s52 metal pipe out to crimp and weld it along with placing a cap over the port on the head would be more work/hassle than just leaving the hoses to the throttle body. I get that heating a throttle body is dumb and unnecessary in almost all usage scenarios.

[brads2002]

My engine came deleted and capped. I don’t think it’s necessary though. Just cleanes it up a bit.

Great work on that diagram. That will be a big help for future installs. My stock m42 reservoir hose looked like it would have fit too but the bends didn’t work as well as the 325e hose.

If I can find a pn on the hose I used I will report back.

QUOTE=Dagamus(NM);4855653]I get that, or you could just run a length of hose from pipe to port.

But what benefit does deleting it offer?

Seems like pulling the s52 metal pipe out to crimp and weld it along with placing a cap over the port on the head would be more work/hassle than just leaving the hoses to the throttle body. I get that heating a throttle body is dumb and unnecessary in almost all usage scenarios.[/QUOTE]