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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: cbluez on July 27, 2013, 06:04:06 PM

Title: Help..K75S oil pressure switch thread stripped.
Post by: cbluez on July 27, 2013, 06:04:06 PM

I thought I'd change the oil pressure switchthat is 25 yrs old while changing the oil and filter..ordered the appropriate one that fit's an old 318i..

Still not sure what happened but I stripped a bunch of threads while using the torque wrench..There's still a couple three at the mouth of the hole..
I have the old one back in and it's snug but am afraid to give it much more.

Any ideas?? This sucks big time, was going on a bit of a trip..lol

I was looking at the Permatex thread repair kit, but seeing as it's an open hole and I cn't cover the inside with tape or something, I'm not sure on that.

Jim

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: cbluez on July 27, 2013, 06:15:51 PM

....Well I amend that,,the threads are totally screwed.. :dunno

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: Scott_ on July 27, 2013, 08:28:38 PM

You may have a couple of options.
1. I don't know if (a) a Helicoil would fit or (b) if they are available in metric thread.
2. You could try and find a decent used pump.
3. If you know of a good reputable machine shop that could build some aluminum back in the hole and then re-tap it.( I'd really consider this as a very last ditch option.)

I'd also have your torque wrench checked. Sounds like it may be out of calibration.

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: cbluez on July 27, 2013, 08:35:17 PM

Thanks Scott..well I was looking at TimeSerts on here...that looks like a viable option..they have a LARGE selection of metric thread options..

The torque wrench is fine,,,although I checked the threads against each other and they sure looked the same, the new one seemed stiffer than normal going in, which i thought odd...Sure was odd..turned a nice little filter/oil change into a nightmare and bike off the road in middle of summer..lol :musicboohoo:

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: Chaos on July 27, 2013, 11:02:02 PM

I used the sender from an '84 328i on my k75 with no issues, maybe you got one with bad threads cut in it, bummer.   good luck resolving it  :dunno

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: cbluez on July 28, 2013, 12:13:19 AM

Yeh it's a real bummer..i have a hole with no threads.
 :falldown:

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: wmax351 on July 29, 2013, 01:42:32 AM

option A would be a timesert. I'm not sure if a helicoil would do the trick.


Option B is a larger threaded oil switch, with a machine shop making it fit.

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: mystic red on July 29, 2013, 09:49:42 PM

Quote

The torque wrench is fine,

but was the torque value used the right one? I find Clymers to be unreliable in this regard.

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: cbluez on July 30, 2013, 01:04:50 AM

I don't know if the torque wrench screwed up, but it did feel kind of stiff putting the new one in, so I took it out and tried the old one..it went in fine, so tried the new one again..They both have M12x1.5 threads...the new one went in stiff again...

It's all moot point I guess,,I have ordered a perma-coil kit and a 31/64 good quality bit..

I guess i will have to take the oil pump assembly off to do this..
 :popcorm

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: wmax351 on August 01, 2013, 03:27:46 AM

Sounds like a solid plan. Make sure you use a fresh Al or Cu washer, which will seal the sensor, removing the need for the helicoil to be sealed.

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: cbluez on February 26, 2015, 10:18:52 PM

It's all good coming into the next spring!...drilled out and used a helicoil...not a drip.

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: TimTyler on February 27, 2015, 12:52:43 AM

Thanks for following-up, Jim.

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: cbluez on February 27, 2015, 03:54:18 AM

Hello to Olympia Tim!!! :mm

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: F14CRAZY on February 27, 2015, 06:19:50 AM

If anyone has ever used this:

http://www.scribd.com/doc/36822210/K75-Torque-Specs#scribd (http://www.scribd.com/doc/36822210/K75-Torque-Specs#scribd)

The value for the oil pressure sensor is waaaaay too high. The temp sensor is a fraction of that

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: cbluez on February 27, 2015, 01:32:45 PM

Yup..that's the one I used... :musicboohoo:

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: TimTyler on February 27, 2015, 01:34:47 PM

Here's the PDF.

Title: Re: Help..K75S oil pressure swith thread stripped.
Post by: cbluez on February 27, 2015, 02:00:25 PM

yup..29.5 ft lbs for the oil pressure switch.....oops...was a bit of unexpected work..on the bright side..resealing the whole unit stopped that persistent oil drip from somewhere along the housing.