oil drain plug issue
02-19-2013, 06:22 PM
#1
Rennlist Member
Thread Starter
oil drain plug issue
Dear 928-colleagues,
I was recently estonished since I wantend to replace the oil drain
plug of my Porsche 928 4.5l (M28.01 engine) of 1980.
So I ordered an original Porsche oil drain plug with magnetic tap
at the dealer in Germany.
Guess what : it did not fit. My thread was M22x1.5, and the original Porsche plug had a thread M20 ?!?
I checked if perhaps my thread in the sump had been overhauled/drilled larger, but no trace of this at all.
Could it be that older engines had different oil drain plugs?
Can I fit a drain plug from other cars, such as BMW, since oil drain plugs have the same measurements.
Kind 928-Regards,
Gerrit
I was recently estonished since I wantend to replace the oil drain
plug of my Porsche 928 4.5l (M28.01 engine) of 1980.
So I ordered an original Porsche oil drain plug with magnetic tap
at the dealer in Germany.
Guess what : it did not fit. My thread was M22x1.5, and the original Porsche plug had a thread M20 ?!?
I checked if perhaps my thread in the sump had been overhauled/drilled larger, but no trace of this at all.
Could it be that older engines had different oil drain plugs?
Can I fit a drain plug from other cars, such as BMW, since oil drain plugs have the same measurements.
Kind 928-Regards,
Gerrit
02-19-2013, 08:12 PM
#2
Team Owner
post a picture of the new plug you want to fit
02-19-2013, 09:04 PM
#3
Former Sponsor
Originally, the oil pan had a 20 x 1.5mm stainless helicoil in the pan. That got damaged and someone removed it...or it came out on its own. The "remaining aluminum" threads were 22 x 1.5mm. So, they obtained a 22 x 1.5mm plug. This is common.
You can get one of these, with a magnet, from by ordering a drain plug for a late 928 transmission. It will have an internal allen, but will work fine.
Your other choice is to obtain a 20 x 1.5mm helicoil kit and put a new insert in. I've done this several times....but you will need to cut down some of the coils from an insert to get one "thin" enough to work...and they are very difficult to get started.
You can get one of these, with a magnet, from by ordering a drain plug for a late 928 transmission. It will have an internal allen, but will work fine.
Your other choice is to obtain a 20 x 1.5mm helicoil kit and put a new insert in. I've done this several times....but you will need to cut down some of the coils from an insert to get one "thin" enough to work...and they are very difficult to get started.
02-20-2013, 06:19 PM
#5
Rennlist Member
Thread Starter
Hi guys,
Guess what, I found the correct oil drain plug @ BMW dealer
Apparently it was the same plug, also used for a BMW 635csi of 1980 !
Besides the ecu, it is not the only part that is shared
Grtz
Gerrit
Guess what, I found the correct oil drain plug @ BMW dealer
Apparently it was the same plug, also used for a BMW 635csi of 1980 !
Besides the ecu, it is not the only part that is shared
Grtz
Gerrit
02-28-2013, 02:42 AM
#6
Inventor
Rennlist Member
Rennlist Member
My '88 has done some off-roading at some point - the oil pan is from an earlier year.
Not only that, it had a non-Porsche drain plug with only ~6mm of threads.
Of course, when I went to change the oil, all 6mm of threads came out with the plug, leaving ~6mm of threads at the bottom of the hole.
Luckily, I was at my friend's shop, where I found the 22mm BMW plug, with threads enough (w/gasket) for the entire depth of the 928 pan plug hole.
I cleaned out the debris and carefully screwed the plug in. It held!
11 131 250 089 - 22mm BMW (Pretty much all BMW before '80.)
944 107 197 01 - 20mm plug
Not only that, it had a non-Porsche drain plug with only ~6mm of threads.
Of course, when I went to change the oil, all 6mm of threads came out with the plug, leaving ~6mm of threads at the bottom of the hole.
Luckily, I was at my friend's shop, where I found the 22mm BMW plug, with threads enough (w/gasket) for the entire depth of the 928 pan plug hole.
I cleaned out the debris and carefully screwed the plug in. It held!
11 131 250 089 - 22mm BMW (Pretty much all BMW before '80.)
944 107 197 01 - 20mm plug
02-28-2013, 03:24 AM
#7
Rennlist Member
Thread Starter
My '88 has done some off-roading at some point - the oil pan is from an earlier year.
Not only that, it had a non-Porsche drain plug with only ~6mm of threads.
Of course, when I went to change the oil, all 6mm of threads came out with the plug, leaving ~6mm of threads at the bottom of the hole.
Luckily, I was at my friend's shop, where I found the 22mm BMW plug, with threads enough (w/gasket) for the entire depth of the 928 pan plug hole.
I cleaned out the debris and carefully screwed the plug in. It held!
11 131 250 089 - 22mm BMW (Pretty much all BMW before '80.)
944 107 197 01 - 20mm plug
Not only that, it had a non-Porsche drain plug with only ~6mm of threads.
Of course, when I went to change the oil, all 6mm of threads came out with the plug, leaving ~6mm of threads at the bottom of the hole.
Luckily, I was at my friend's shop, where I found the 22mm BMW plug, with threads enough (w/gasket) for the entire depth of the 928 pan plug hole.
I cleaned out the debris and carefully screwed the plug in. It held!
11 131 250 089 - 22mm BMW (Pretty much all BMW before '80.)
944 107 197 01 - 20mm plug
well I think I had a likewise issue (perhaps in the past the previous owner had changed the thread from 20 to 22mm). So I also used same plug from BMW but added a magnet. Here are some pics :
https://rennlist.com/forums/attachme...7&d=1362035852
Kr
Gerrit
Last edited by GerritD; 09-23-2013 at 03:44 PM.
