Pete L

While doing coolant change this eventing, removed the 13 MM drain plug from block (seemed pretty stuck). Attempted to replace and would not tighten up (found some aluminum in threads of plug upon removal). Darn, stripped at block

Threads are M12 x 1.5. What is a good fix?

1. So Helicoil and if so do i use a 12 x 1.25 or 1.75 (can not find 1.5 thread). Concerned not enough room to do this too

2. Buy a striped oil drain plug with 12 x 1.75 thread and "force it in"

3. Buy a longer M12 x 1.5 in hopes still some serviceable threads further in their?

4. Epoxy thread fixer

5 ????

Appreciate any help!

Mrmerlin

I would try option 3 with some PTFE thread sealant on the bolt dont overtighten

Don Ashe

5 rubber expansion plug, similar to those used on freeze plugs. Most marine supply stores have a wide range of sizes.


HTH,
-don

SQLGuy

After 3, I'd consider 1,

or maybe 5: find the next diameter up plug (14 x 1.75?), drill, re-tap, and use that.

GlenL

As you've noticed, 12x1.5 isn't a standard size.

12mm is just a little bit less than a half inch. Just sayin'.

fraggle

Don't go in too far, you'll risk cracking the barrel. I'd go with a drill and retap but I hope you've got the motor on the floor.

Since it sounds like the motor is still in the car, I'd go with the epoxy option.

blown 87

Any shop that works on European cars should have a TimeSert that size.
I would not trust a Heli-Coil there.

Or order it here.

http://www.timesert.com/html/mtrcsert.html

jon928se

While I am a fan of helicoils (they work great on waterpump bolts and I have used them succesfully on TT flange bolts in to the transmission in the double length version (12 threads) I'ld back blown87 on using a Time cert for these pllugs - It's a very shallow thread length and you can't afford to get it wrong all you'll be looking for some bizarre size of timecert/helicoil or finding someone with the requisitie rare skiils to weld a plate on to the block that can then be tapped to an approprate sized plug.

dr bob

It might be blasphemy, but...

A 3/8 NPT plug might work directly or with a little help from a tap first. This opens the option for glueing a reducer bushing in there, and using either a 1/4 NPT plug, or even a petcock there so it never needs to be removed again. This is an "if" you can't get the hole drilled and an insert installed, of course.

For those playing along at home, I use some teflon thread sealing paste on the bolt threads, and tighten to ~~16 lbs/ft (same as an 8mm bolt would be into the block). That's enough tension to keep the bolt from falling out, enough to shrink the leakage path through the threads to just one side where the thread sealant can do its job, and still be loose enough to remove again someday. The WSM recommended torque is probably OK with the teflon paste, I just don't appreciate the amount of pull needed to loosen that plug when it's been pulled too hard and become one wiith the block. YMMV of course, use at your own riskm etc.

AO

A Fumoto Valve expoied in might be a great solutiuon. They have a 12x1.5 application (F-109)

http://www.fumotousa.com/

Pete L

I purchased a M12 x 1.5 drain plug from NAPA that has a 17mm head (not 13 as factory) and threads that are perhaps 3 or 4 mm longer. I reamed out the drain hole with a tap then inserted the new plug into the hole and walla, fixed! (well not fixed but apparently enough threads deeper in the block to engage the longer plug threads)

Thanks to all who replied. If it starts to leak etc I will post

borland

for others.....Dwayne's writeup....... note the thread lubricant, new seal, and torque wrench usage....

https://rennlist.com/forums/928-foru...re-w-pics.html

BIMMERMIKE

Everything holding okay with fix?

Mongo

Wow and I went the less surgical way of taking the thermostat out when doing a coolant flush with a garden hose and distilled water since mine are in the same condition. I may roll the dice and give those suckers a twist down there.

jetson8859

I went thru this with the 93 GTS, IIRC the correct M12 x 1.5 is also same thread for several BMW oil pan drain plugs and they are 4mm longer. I picked a couple up at NAPA and along with a little Teflon tape, it has held for 2 years.