# 2017 X5 battery ground strap replacement - why so expensive?



## Househouse2564 (7 mo ago)

Hello!
As part of my general maintenance service, the BMW dealership informed me that the battery ground strap is corroding and that I would need to replace it. The quote they gave is $660.
Is this part something that can be replaced by a general (but respected) auto store? The price seems way to high in comparison to the cost of the part itself (seems to be $40 online for a genuine part), so not sure why the labor is so high - is it a difficult piece to replace? 
Thanks in advance!


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## Doug Huffman (Apr 25, 2015)

Upsell. Ignore it. Ground straps are commodities, not specific to BMW. They are made of tinned copper braid and the copper corrodes green naturally and normally.

Don’t fix what ain’t broke. for goodness sakes do not have a parts store change parts. They are in buisness to sell more parts


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## HotGrbg (Apr 23, 2021)

👆 ignore that.
Your engine ground strap is hugely important and can cause all sorts of issues from bus communication to no start problems. I literally had one towed this week due to no start. When attempting to spin the crank over by hand to verify the engine hasn’t locked up I could hear the arching of my ratchet against the metal cross brace as I was proving a ground and completing a circuit.
X5 is on drivers side of engine compartment and is a thick braided metal strap made of woven steel. It is the only thing that grounds your engine to the chassis on this model. The price does seem pretty high. They are kind of a pain on X5. On the frame side it’s a simple 13mm bolt but in the engine side you need 3 hands almost. One to hold the cable, one to spin the nut on and one to hold the 13mm bolt that lines up from the bottom. It’s a stupid design.
The 40$ part is probably not 40$ in the service dept but probably over 100$. The labor is somewhere between 1-2 hours but I would ask for a breakdown on the price as this gives you better negotiating power.


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## Househouse2564 (7 mo ago)

Thanks for the detailed answer! 
I do have an issue with my entertainment system that keeps rebooting every 5 mins, so seems like that could be the cause? 
What would be a reasonable price to negotiate/pay for this work (Greater Boston Area)?


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## jaye944 (Jul 5, 2015)

HotGrbg said:


> 👆 ignore that.
> Your engine ground strap is hugely important and can cause all sorts of issues from bus communication to no start problems. I literally had one towed this week due to no start. When attempting to spin the crank over by hand to verify the engine hasn’t locked up I could hear the arching of my ratchet against the metal cross brace as I was proving a ground and completing a circuit.
> X5 is on drivers side of engine compartment and is a thick braided metal strap made of woven steel. It is the only thing that grounds your engine to the chassis on this model. The price does seem pretty high. They are kind of a pain on X5. On the frame side it’s a simple 13mm bolt but in the engine side you need 3 hands almost. One to hold the cable, one to spin the nut on and one to hold the 13mm bolt that lines up from the bottom. It’s a stupid design.
> The 40$ part is probably not 40$ in the service dept but probably over 100$. The labor is somewhere between 1-2 hours but I would ask for a breakdown on the price as this gives you better negotiating power.


^^^^ THIS ^^^^
On some BMW's the earth straps look good and they are trashed, replacing them fix's a multitude of problems, there are a couple of engine grounds on the E series
of course if your car is good not a problem.


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## HotGrbg (Apr 23, 2021)

I doubt it has anything to do with your infotainment system rebooting. No/poor engine ground is more likely to cause starting problems, driveability issues and warning lights. 
I suggested a breakdown so you can see the parts cost and ask about the service markup. Also Almost all labor is negotiable and usually the more you buy the more wiggle room is available. I don’t live in Boston so I can’t comment to reasonable prices but the time should be between 1-2 hours. Once you get the labor price you can calculate per hour what your being charged.
These steps provide a customer will more information and therefore more ability to negotiate pricing.


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## Househouse2564 (7 mo ago)

Thanks again!
Last one - do you know if this part should be covered under warranty? Or is this wear and tear and hence would not qualify?


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## dukedkt442 (Feb 12, 2013)

It’s a simple piece of wire connecting engine and chassis to complete the circuit back to the battery. A simple $10 4ga insulated 12” battery ground cable, with the eyes already crimped on, from your local FLAPS will more than suffice. Uninsulated braided straps oxidize within a couple of years due to their placement on the underside on BMWs. My ‘84-86 GMs and even my ‘70 VW have their original ground straps in place, yet my ‘08 E83 is on its 3rd engine and exhaust ground cables (it wasn’t until the 3rd one that I went insulated). I also have added an extra 2 of various parts of the engine. 

Without proper ground, charging systems won’t operate properly and you’ll get red herring DTCs as noted above. You may also risk electrical component damage as the car finds a path to ground any way it can; on the VW last summer, a faulty headlight switch was causing the battery to ground through a taillight, causing it to illuminate when the drivers door was opened. Took me a while to figure out that one. 

Here’s my my exhaust strap replaced last Fall. 










The braided cable was green but a little manipulation severed it. The DME is so sensitive to voltage that even a standard check for resistance across the cable is inconclusive, a voltage drop test works better. 

















4-6ga negative cable with eyes crimped on and installed. Note how much cleaner its bolt is compared to the other one; the cable was the sacrificial metal in that galvanic circuit and the bolt didn’t oxidize.


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## HotGrbg (Apr 23, 2021)

The one pictured above is an exhaust ground which is a lot smaller than the engine ground. It’s the same style braided cable though but not copper like the exhaust ones. As previous poster mentioned any ground cable will work but preferably a 0/1 gauge cable with protective coating.
As far as warranty goes if your under new vehicle warranty then yes, if your under CPO or ESC then I doubt this is covered.


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