[Efthreeoh]

I've not seen anyone post a DIY for replacing the plastic hose bib on the Thermostat-to-Head coolant hose for the N52 and N54. The same hose bib is used for either engine.

This is a DIY for removal and replacement of the E9X N52 Thermostat-to-Head coolant hose aluminum hose bib. Cutting the band clamp securing the hose bib risks compromising the hose. Breaking up the old, week plastic hose bib is a better in-car solution using the right tools and does not require complete removal of the hose from the engine. I used a large Channel Lock plyers (it is a Stanley tool actually) and I used a Craftsman water hose clamp plyers. This DIY is based on using similar tools. The procedure breaks up the old hose bib inside the hose end and has risk of leaving old pieces of plastic in the cooling system, which could jam the water pump, so you must be very careful to ensure no small broken plastic falls down the hose.

Please see attached .pdf file for detailed instructions.

[CTinline-six]

I'm actually doing this today.

For your other coolant hose DIY, what is the best thing to use as a lubricant for the O-rings in the snap-lock fittings? The Bentley manual doesn't seem to have anything on that and I've read some people use coolant.

[Efthreeoh]

Originally Posted by CTinline-six

I'm actually doing this today.

For your other coolant hose DIY, what is the best thing to use as a lubricant for the O-rings in the snap-lock fittings? The Bentley manual doesn't seem to have anything on that and I've read some people use coolant.

I used spit...

BMW says not to use anything on the O-rings.

I hope the hose bib DIY works for you.

[arkie6]

I had to do this repair on my car last year in the parking lot at work when that plastic hose end sheared completely off. I used a small pair of needle nose vice-grips with the jaws wrapped in duct tape to clamp the hose shut below the broken plastic end piece.

[arkie6]

Originally Posted by CTinline-six

I'm actually doing this today.

For your other coolant hose DIY, what is the best thing to use as a lubricant for the O-rings in the snap-lock fittings? The Bentley manual doesn't seem to have anything on that and I've read some people use coolant.

Undiluted anti-freeze / coolant (the concentrate that you mix 50-50 with water) works good as an o-ring lubricant on cooling system o-rings.

[Efthreeoh]

Per the BMW TIS regarding coolant hose O-rings

[Efthreeoh]

Originally Posted by arkie6

I had to do this repair on my car last year in the parking lot at work when that plastic hose end sheared completely off. I used a small pair of needle nose vice-grips with the jaws wrapped in duct tape to clamp the hose shut below the broken plastic end piece.

I used this exact tool to pinch the t-stat hose:

[Phil325i]

Useful guide OP. Is there anything externally to suggest imminent failure of the OEM bib? Mine's done over 100K yet from the outside it looks in perfect condition. Mind you I do regularly clean the hoses and joints and also do regular changes of coolant...

[arkie6]

Originally Posted by Phil325i

Useful guide OP. Is there anything externally to suggest imminent failure of the OEM bib? Mine's done over 100K yet from the outside it looks in perfect condition. Mind you I do regularly clean the hoses and joints and also do regular changes of coolant...

Those plastic hose ends degrade from the inside out. Mine looked fine on the outside. Mine is a 2008 335i with around 100,000 miles at the time of failure.

[Phil325i]

Originally Posted by arkie6

Those plastic hose ends degrade from the inside out. Mine looked fine on the outside. Mine is a 2008 335i with around 100,000 miles at the time of failure.

Thanks. So what are the symptoms of failure? Coolant leak? Pieces of plastic in the coolant header?

[CTinline-six]

Originally Posted by Efthreeoh

I used spit...

BMW says not to use anything on the O-rings.

I hope the hose bib DIY works for you.

It worked great. I did this on my 2006 a few years ago, and now with this car I just looked through it to find the torque specs. It also helped refresh my mind on using the bolts to draw the bib in so it wouldn't strip the threads.

I ended up using straight BMW coolant on the o-ring for the upper radiator hose (I also did my OFHG this weekend) and just cleaned everything else really well with no lubricant. Seems to be doing well so far, and no leaks after doing the coolant bleed procedure. I plan on checking for leaks again tonight.

[Efthreeoh]

Originally Posted by Phil325i

Useful guide OP. Is there anything externally to suggest imminent failure of the OEM bib? Mine's done over 100K yet from the outside it looks in perfect condition. Mind you I do regularly clean the hoses and joints and also do regular changes of coolant...

I replaced all my cooling system hoses at 8 years and 231,000 miles. I didn't inspect the t-stat hose bib at that time because failure of them had not become an issue back then, or at least for the N52. So, the current T-stat hose has been in for a little over 4 years and 144,000. I'd say the plastic was "soft", but still pretty sound. I don't think it was close to failure, but it didn't take much to break it apart.

I also have a Z4 with the N52. The T-stat hose is original, 11 years old with 95,000 miles on it. I plan on swapping the hose bib out in the next few weeks. I'll report back on the condition of that piece.

[arkie6]

Originally Posted by Phil325i

Thanks. So what are the symptoms of failure? Coolant leak? Pieces of plastic in the coolant header?

The hose end broke clean off and most of the coolant dumped out. Low coolant level was the first indication something was wrong. I was at work in the parking lot and had just started the engine in the afternoon getting ready to go home. I tried adding some water so that I could get home, but I soon realized it was running out as fast as i was pouring it in. Then I saw the hose just laying there with one end not connected to anything.

[CTinline-six]

Here is a pic of mine on the car.

[PichaDis11]

Well I guess I have to spend more money now huh? Thanks. Ha

I've been meaning to swap this out for quite sometime and now seeing your post I'll go place an order and place it with extensive repairs that's already being done on the car.

good stuff

[Explorerlyon]

Originally Posted by Efthreeoh

I've not seen anyone post a DIY for replacing the plastic hose bib on the Thermostat-to-Head coolant hose for the N52 and N54. The same hose bib is used for either engine.

This is a DIY for removal and replacement of the E9X N52 Thermostat-to-Head coolant hose aluminum hose bib. Cutting the band clamp securing the hose bib risks compromising the hose. Breaking up the old, week plastic hose bib is a better in-car solution using the right tools and does not require complete removal of the hose from the engine. I used a large Channel Lock plyers (it is a Stanley tool actually) and I used a Craftsman water hose clamp plyers. This DIY is based on using similar tools. The procedure breaks up the old hose bib inside the hose end and has risk of leaving old pieces of plastic in the cooling system, which could jam the water pump, so you must be very careful to ensure no small broken plastic falls down the hose.

Please see attached .pdf file for detailed instructions.

The .pdf won't open. Can you reattach? Your .pdf in other posts (replacing coolant hoses) opens fine.

[Efthreeoh]

Originally Posted by Explorerlyon

The .pdf won't open. Can you reattach? Your .pdf in other posts (replacing coolant hoses) opens fine.

Weird... Try it again. I just re-uploaded it. I down loaded for me once I re did it.

[Explorerlyon]

Originally Posted by Efthreeoh

Weird... Try it again. I just re-uploaded it. I down loaded for me once I re did it.

Thank you for the DIY. Did it this weekend and all went well. I was surprised how mushy the original fitting was when I removed it.

[roadkillrob]

I did this yesterday and did not drain the coolant, just made a cap for the new fitting pulled the old fitting and put in the new one to stop the coolant from coming out, held the hose up so it didn't leak, removed the old fitting and put the hose on the new fitting. Then ran the air purge procedure and topped up coolant, lost less than 1/2 liter total and just jammed an old towel below the fitting when I removed to catch it all. I was actually surprised how little coolant came out and how slowly it was coming out once the fitting was removed. Maybe a shortcut for anyone like me that had done coolant recently, made the whole process take less than 30 minutes including the purging of air.

[Gamb1t]

Just wondering is draining the radiator coolant necessary to do this job?
From the videos I've seen there was no need. Will there be coolant gushing out when pulling the hose/bib out?

[Efthreeoh]

Originally Posted by Gamb1t

Just wondering is draining the radiator coolant necessary to do this job?
From the videos I've seen there was no need. Will there be coolant gushing out when pulling the hose/bib out?

I don't know, I drained the coolant to a level below the cylinderhead, which assures there is no coolant mess.

This car is so easy to refill and bleed, there is no reason not to just drain the coolant for a minute or two. You have to bleed it anyway, since opening the main coolant passage into the head will introduce air into the cooling system.

[clegg]

I was looking to buy one of these billet pieces to replace the plastic one. Does the supplied o ring fit in the head ok, or was the oem o ring used? I was reading reviews that the supplied o ring was too large to fit properly.