I just use large heavy duty zip ties.

 

dude, it's a frigging cable tie ... That's like guys over here at the Belgian BMW forum asking if their engine will be toast if they use coolant that doesn't come from the dealer.

 

I never even thought about it ... zip ties are what most use here.

 

my friend with a concourse quality restored Z31 (very quirky choice) is someone who would go as far to find the OEM manufacturer of the exact cable tie and then find the last bag of 1984 date coded bag of them to keep it period as well.

but yes, any will do for that spot

 

not fair.

So, I bought a 2002 a long time ago because it was inexpensive and fun to work on. Went through a few,
had a good time, but then parts got hard to find and expensive. And the donor pool of E21's dried up.

So then a friend gave me an E30. The first one's always free, you know, so I drove that for a while,
ended up with a few parts cars, and that was good. Sometime in there, the 2002 crowd started
worrying about what was written on the hose clamps, which way the roundels on the wheels
were oriented from the factory, etc, etc, so I kinda faded away from THAT scene.

E30 parts started to get scarce, and an E36 came my way, so I started driving THAT,
and kept the E30 as a second car. Nothing against the E36, but the particular car I got
was a turd. The E30 crowd went all hipster, got worried about what was written on the hose
clamps, lowered the things so far that they sparked on level ground, and I wandered off.

So we got an E46, drove it for a number of years, ended up with a second one, and that's been
good for quite a while now. But parts are starting to get dumb, and now it sounds
like we're worrying about the color of the zip ties that BMW copped out with.

Crap. I'm too old to start working on E90's and E120's and such.

t
ennui

 

Should be one of these parts #1

https://www.realoem.com/bmw/enUS/showparts?id=BN12-EUR-04-2001-E46-BMW-320Ci&diagId=61_1711

 

Zip ties are available for exterior use. They are built to handle UV and frequent temperature swings. They are very common, but so are the ones for interior use so just make sure you use the right ones. You do not need BMW ones. If you're concerned about longevity, use a stainless steel hose clamp.

 

Zip ties are available for exterior use. They are built to handle UV and frequent temperature swings. They are very common, but so are the ones for interior use so just make sure you use the right ones. You do not need BMW ones. If you're concerned about longevity, use a stainless steel hose clamp.

The zip ties you speak of are rated for 185 deg F. Engine coolant is much above this limit in a running engine and I believe the original zip tie is rated higher to handle the temperatures. Stainless steel would not dissipate the heat as well as the nylon zip tie, it may damage the wire insulation. That is why I am interested in the specifications or the BMW part number of the zip tie. Any information would be helpful.

 

Ah, a true engineer speaking. I like it!

So from your initial picture, from the factory, the knock sensor wiring insulation is already in intimate contact with the hard coolant pipes. So we can assume the wiring insulation easily sustains whatever exterior temperature of the hard coolant pipes are. Therefore, a stainless steel clamp, which would be at the same temperature as the exterior of the hard coolant pipe, would not affect the knock sensor wiring insulation.

Your statement that stainless steel would not dissipate heat as well as the nylon zip tie is incorrect. Heat transfer coefficient is the same whether you're adding heat or removing heat. If your premise is that stainless steel would get hot faster, it would also dissipate heat faster (at the same rate) as heat flux goes both ways. At equilibrium, the exterior of the hard coolant pipe, stainless steel clamp, zip tie and the knock sensor wiring insulation would all be at the same temperature. It took stainless steel less time to get to this temperature compared to the zip tie. Similarly, it takes less time for the stainless steel to drop temperature compared to the zip tie. Therefore, the heat dissipation rate of the zip tie is actually longer than stainless steel.

While normal engine coolant is roughly 96 degC, you cannot assume that the external surface of the hard coolant pipes are at the same temperature for all times. You have multiple effects here including radiation cooling to the surrounding environment and limited coolant flow to the heater core. You don't run full coolant flow through the heater core all the time unless you want the interior to be like a sauna. As such, the exterior temperature of the hard coolant pipes is not constant and may not be the same as the coolant temperature at the head (where the coolant temperature sensor is located).

 

I found this blue genuine BMW cable tie. No idea if it's the correct one or not.

Only 8 bucks each!

https://www.ecstuning.com/b-genuine-bmw-parts/wire-tie-blue/61137711799/

 

I think that's the wrong shade of blue. ECS Tuning said it does NOT fit my vehicle.

 

We have severe OCD, and we approve!

 

Didn't see any mention of removing zip ties in TIS when disconnecting the knock sensor. Are those ties for sure OEM, or did a previous owner replace the sensors and those might not be original?

 

Are those ties for sure OEM

They are OE, all M54 engines have them.

 

This thread is awesome.

 

Those ties must be something special

 

Blue coolant, blue knock sensor harness zip ties, blue on the roundel, when will it stop???

 

those are the old 2001 era blue zip ties

there is a TIS somewhere that they switched to black zip ties in 2002 due to the dye factory not being able to reproduce the blue in the exact paint spec

 

 

As sad as this sounds, it could be a problem for me when I need to replace mine. I'm not a professional restorer, and my car isn't "show quality", but I've always tried to use original parts. Not a true restoration, but something close. I went over the car a few years ago, specifically looking for missing or damaged items--mostly hardware, connectors, plastic bits/pieces, and smaller items that would be required to compete in a real restoration event. I think I would do well, overall.

 

I have a 2001 330ci and I have replaced the cooling water pipes on the engine. I need some information about the 2 blue cable ties that attach the knock sensor wires to the cooling pipes. Does anyone know the the specification or the BMW model number for these cable ties? I think the cable ties are a high temperature type. Any information would be helpful.

You don't need to have new blue cable ties -- just unlock and remove them without cutting off. Lift the little barb up and pull the tie out. I still have the factory blue cable ties after replacing the hard pipes.

 

McMaster Carr sells high temperature cable ties. Polypropylene rated to 230F and Nylon 12 rated to 240F. Not too much money, and you can use the left overs for other jobs. They only come in black though. I always try to keep things as original as possible, but sometimes have to compromise. Could check the dealer as you only need 2. I would bet they don't stock them, but might be able to order them. Good luck and have fun with your project.
McMaster-Carr

 

Having a brother in law that has show cars, improper zip ties would definitely lose you points in the competition.

He spent more than 40 hours just putting on a manifold back exhaust system to get every piece perfect.