[e91Owner]

My e60 has been a little slow to crank lately and aside from the starter itself, every other factor seems to be good with the possible exception of the ground. I can see some corrosion, but no fraying and it seems to start better when I ground the ending to the negative lug as a test.

I know there are many out there as generic alternatives to the genuine ground straps—has anyone replaced theirs lately with one?

Autozone and advance both sell Dorman 15 inch coated copper straps for under $7.

[nsjames]

there are reasons it's a flat braided strap.
the first is that a flat strap provide more current capacity than a round wire made of equivalent amounts of metal.
the second is EMI.
the third is flexibility.

[e91Owner]

Originally Posted by nsjames

there are reasons it's a flat braided strap.
the first is that a flat strap provide more current capacity than a round wire made of equivalent amounts of metal.
the second is EMI.
the third is flexibility.

Thanks? That's not what I was asking, though lol.

The alternatives are also flat braided straps.

[mainbearing]

I would think that will work. In fact I am thinking of preventatively replacing it and was actually looking at a battery cable.

[Welcome to NBA Jam]

Originally Posted by mainbearing

I would think that will work. In fact I am thinking of preventatively replacing it and was actually looking at a battery cable.

You'll ideally want something flexible. There is some movement between the engine and the body which gets worse as the motor mounts wear out. A negative battery cable could work if it's flexible enough.

[mainbearing]

True, a heavy gauge battery cable might not have enough flexibility, even if at a longer length. It is not designed to do that anyway. Good point!

[nsjames]

Originally Posted by e91Owner

Thanks? That's not what I was asking, though lol.

The alternatives are also flat braided straps.

then any flat braided ground strap is fine as long as it's adequately sized.

but not round battery cables.

[e91Owner]

Anybody buy anything that they particularly liked? That was my original question.

[Brian86]

A round battery cable will be fine.

Just don't be stupid about how it's routed so that it can flex a minimum amount with engine movement.

BMW installed a round battery cable for a ground strap on my e36 in Munich 25 years ago and it still works.

[e91Owner]

Just picked up the dorman generic braided cable from autozone. Way too long for the normal e90 N52 location to the block, but is the same width as the original. Looks like it will be just fine for an e60 N52, though.

[ZGator]

The ground strap usually refers to a much thicker gauge underneath the car from frame to starter. This is also a ground strap - but I think it is called something like noise suppression strap, and is up top as shown in your pic. I used a the generic
dorman but frankly it's way too long - guess it does the job.

btw - For the 'real' ground strap - I actually bought from bmw parts because they had it, it fits perfectly, easy to install without awkward bends, and as others noted can flex with the car - salt does eat at them - they go green and brittle for us in the salt belt.

[e90yyc]

Originally Posted by mainbearing

I would think that will work. In fact I am thinking of preventatively replacing it and was actually looking at a battery cable.

By all means you do you, but I wouldn’t bother replacing it unless it actually needs to be.

I know you hear about strap failures from time to time but I think it’s pretty rare overall. Mine has over 220k on it and is in great shape.

[e91Owner]

Originally Posted by ZGator

The ground strap usually refers to a much thicker gauge underneath the car from frame to starter. This is also a ground strap - but I think it is called something like noise suppression strap, and is up top as shown in your pic. I used a the generic
dorman but frankly it's way too long - guess it does the job.

btw - For the 'real' ground strap - I actually bought from bmw parts because they had it, it fits perfectly, easy to install without awkward bends, and as others noted can flex with the car - salt does eat at them - they go green and brittle for us in the salt belt.

Yeah, it's actually called an Interference-Suppression Band, although some part sites still just call it a ground strap. Strangely, the N52 on my e60 doesn't have this, although the engine still has the screw to mount it. I was going to try to mount that dorman cable there until the next time I have the car on a lift, but there's no good grounded place on the chassis to attach it.

[lookalikehuuh]

Originally Posted by e91Owner

Yeah, it's actually called an Interference-Suppression Band, although some part sites still just call it a ground strap. Strangely, the N52 on my e60 doesn't have this, although the engine still has the screw to mount it. I was going to try to mount that dorman cable there until the next time I have the car on a lift, but there's no good grounded place on the chassis to attach it.

Dorman makes some real trash, avoid at all costs even if it's a ground cable. You are better off getting OEM or even quality amplifier cable over a dorman part.

[e91Owner]

Originally Posted by lookalikehuuh

Dorman makes some real trash, avoid at all costs even if it's a ground cable. You are better off getting OEM or even quality amplifier cable over a dorman part.

Unfortunately, there is no OE or OEM alternative for these that I could find, although the dorman cable is fine. Just too long.

[nsjames]

they are readily available in nearly any size and lengthf rom a number of industrial suppliers.

http://classcorders.mscdirect.com/Pa...playName&ASC=1

https://www.mcmaster.com/straps/grou...id-and-ribbon/

round battery cable does not suppress electrical interference. A large flat braided strap does,

I have a much larger than factory braided strap to the head on my n52, I replaced the primary ground with a factory one because it's not worth the hassle to make anything else fit there.

[Torgus]

I upgraded my ground strap on my e92 as it was failing. Use a high quality tinned ofc car audio cable. Super flexible. Use quality: terminals, crimper, heatshrink, fasteners, and some form of noalox etc. You will have a larger gnd cable that will not fail in the future. Also for the same price or less of a oem gnd strap.

Or just buy the oem strap, it is all small money in the grand scheme of owning a bmw.

[e91Owner]

Originally Posted by Torgus

I upgraded my ground strap on my e92 as it was failing. Use a high quality tinned ofc car audio cable. Super flexible. Use quality: terminals, crimper, heatshrink, fasteners, and some form of noalox etc. You will have a larger gnd cable that will not fail in the future. Also for the same price or less of a oem gnd strap.

Or just buy the oem strap, it is all small money in the grand scheme of owning a bmw.

Yeah, but that small money adds up. Especially on these BMWs with very little value left in them and constantly having to replace one part or another. I'm just hoping my e60 can last through one last teenager driving it before I can retire it.

I was able to find a wider 3/4'' x 12 braid for under $10 on Amazon that will do the trick, although I'm just going to use that long Dorman one on top until I have it on a lift in about 4000 miles.

Strange how my wife's Toyota minivan has retained more value and required nothing but routine maintenance in 130k and I have replaced more things than I can remember on BMWs over the same time frame.

[lordnikon]

Anyone know the OEM part number for the engine ground strap? Not the one underneath the chassis.

[StradaRedlands]

Originally Posted by lordnikon

Anyone know the OEM part number for the engine ground strap? Not the one underneath the chassis.

???
12427555222 or 12427578869
???

[lordnikon]

Originally Posted by StradaRedlands

???
12427555222 or 12427578869
???

That's the upper ground strap??

[gbalthrop]

Originally Posted by lordnikon

That's the upper ground strap??

What you are referring to as the "upper ground strap" is called by BMW:
"Interference Suppression Band", which is MUCH Smaller cross-section than the "Ground Strap" that carries Starter Current back to Negative Battery Post via the chassis to which that strap is connected.

If the Ground Strap at the Starter FAILED or were disconnected, that tiny Interference Suppression Band would burn IN TWO in short order, trying to carry the AMPS drawn by Starter Motor Cranking Engine.

There is a reason the Ground Strap is attached where the Starter Motor is attached to the Engine. However, you can test for a failing Ground Strap very simply WITHOUT getting Under the vehicle: Simply attach ONE Jumper Cable from the "Hex-pin" at the Right Wing (you know -- the FAR RIGHT of the engine compartment, otherwise identified as X166 Chassis Ground ;-) to a good metal bolt, or bracket attached to the Block/ Crankcase, and see if your Starter turns any faster. You can use a Scan Tool to read exact RPM during cranking -- much more accurate than the Tach.
George