Author Topic: Missing bolt, oil leak (Read 3698 times)

erupert66 · « **on:** January 20, 2013, 07:43:56 PM »

I picked up an engine from a club member to swap in for my son's first car( 91 318is). I just realized that a bolt is missing in the front of the engine. It's on the bracket that holds the tensioner. I've got a ton of bolts from stripping the old engine but they all seem to be M10 or M8. M8 is too small and M10 is too large (M10 fits in the hole but the threads don't start). Before I go buy some M9 bolts, is there a way to find the spec for that bolt?

irish44j · « **Reply #1 on:** January 20, 2013, 08:49:29 PM »

having just redone an M42 entire timing case/oil pans/etc, I can tell you that I don't recall running into any M9 bolts (nor have I EVER seen an M9 bolt used on any car.) BMW is extremely consistent with the bolt sizes. Damn near everything on the front of the engine is M8.

All of the bolts associated with the alternator adjuster/brackets are M8 (I also checked on RealOEM to confirm), as are all of the bolts associated with the PS adjuster/bracket and the AC bracket.

Or do you mean the timing chain tensioner? Be more specific about the part (or take a pic of location) and I'm sure we can find all the specs on realOEM, if you haven't looked already.

or I can check my spare M42 sitting in my garage.

Also, are you sure that the bolt and/or bolt hole aren't stripped or cross-threaded? Could explain why it won't start.

erupert66 · « **Reply #2 on:** January 20, 2013, 09:46:29 PM »

I'll take a pic tomorrow. If you are looking at the tensioner pulley on the bottom of the engine, it's the bolt right above just to the right of the A/C compressor. I have heard of realOEM recently but have never used it. I'll check there as well. Worried that it was cross-threaded but if I find what it's supposed to be, I have a full tap set.

erupert66 · « **Reply #3 on:** January 20, 2013, 09:48:58 PM »

Confused, don't see an E30 choice in the pick list. Starts with E36

erupert66 · « **Reply #4 on:** January 20, 2013, 09:50:49 PM »

Found it. Had to switch the catalog from current to archive

DesktopDave · « **Reply #5 on:** January 21, 2013, 08:23:11 AM »

http://www.realoem.com/bmw/showparts.do?model=AJ93&mospid=47318&btnr=64_0552&hg=64&fg=50

Looks like all M8 or M6 fasteners...but I'm not sure what bolt you're referring to exactly. Note that #7 is pretty long - maybe the bolt is too short to engage the threads?

bmwman91 · « **Reply #6 on:** January 21, 2013, 09:25:59 AM »

Was it the really long one? A LOT of guys that have removed the AC system have that bolt missing (since it is too long w/o the bracket) and have an oil leak there.

erupert66 · « **Reply #7 on:** January 21, 2013, 09:36:07 AM »

Quote from: DesktopDave;119452

http://www.realoem.com/bmw/showparts.do?model=AJ93&mospid=47318&btnr=64_0552&hg=64&fg=50

Looks like all M8 or M6 fasteners...but I'm not sure what bolt you're referring to exactly. Note that #7 is pretty long - maybe the bolt is too short to engage the threads?

Bingo! #7. I think you are right about the length. I have a ton of bolts so I'll look for the longest one that I have and try it. Too bad it doesn't show length in the schematic.

ti_tony · « **Reply #8 on:** January 21, 2013, 11:53:33 AM »

#7 is 110 mm long or about 4.33 inchs.
Look to the right in the diagram @ 8mmx110.

erupert66 · « **Reply #9 on:** January 21, 2013, 12:34:53 PM »

Quote from: ti_tony;119461

#7 is 110 mm long or about 4.33 inchs.
Look to the right in the diagram @ 8mmx110.

Yeah, went to show my son the RealOEM page and saw that the length was listed. Doh on me.