M20 finally pooped out

[f4tj0n]

a little crude but you can: remove the pan, use a wood block between crank and eng block to 'lock the crank and as mentioned use the proper heavy socket and long breaker bar. be carefull if ingine is on a stand

Thanks man, it was pretty easy to remove with the tool I made. It still required about 4' worth of leverage though.

[f4tj0n]

Was taking a look at my motor and noticed this.






Is this replaceable? Is it important?

The PO said that the owner before him had replaced the original oil pump. The original pump must have had something serious occur for that to happen, because the chain and everything was still intact when I opened it. I do notice that there are marks around the timing chain area that shows chain slappage, but I don't think there is any way that it could have happened while this incident occurred

Looks like I'll be needing one of these also:






Heres a pic of the oil pump splines



Should I look into buying Achilles Upgraded Refurb unit?


With all of these problems showing up, I think I'm still alright with paying $600 for the motor.. No discouragement yet, it's a BMW. :D

[328ijunkie]

jeebus. Worst ive seen in a while

[f4tj0n]

Can I use a S52 style lower timing chain tensioners on my S50? The newer style plastic one appears to be longer than the older.

[MyE30]

f4tj0n, i suggest you replace that bent oil spray nozzle. How'd it get bent like that?

Also, at a minimum the inner oil pump gear/shaft and sprocket should be replaced considering the condition of the splines on the shaft. You should disassemble the oil pump and see if anything else is worn as well. If the housing is good you can rebuild the oil pump yourself for less than $200.

Good call on getting another dual sprocket for the crankshaft.

[f4tj0n]

f4tj0n, i suggest you replace that bent oil spray nozzle. How'd it get bent like that?

Also, at a minimum the inner oil pump gear/shaft and sprocket should be replaced considering the condition of the splines on the shaft. You should disassemble the oil pump and see if anything else is worn as well. If the housing is good you can rebuild the oil pump yourself for less than $200.

Good call on getting another dual sprocket for the crankshaft.

I honestly have no idea how it got bent, the motor was already out of the car when I bought it, therefore I can only go off of what the PO says. I'm just going to go through the whole thing. Might as well. But only thing that I assume since everything was still intact when I took the motor apart aside from a loose oil pump sprocket nut; it had to be from a previous failure.

I actually just looked at RealOEM this morning and seen that the parts to rebuild are available. Might take that route, or just go with the Achilles unit and just replace.

and the crankshaft sprocket is toast. From what I'm guessing is that it had to be worn from a previous failure as well, and somebody cheaped out. The lower chain tensioner rail had only a tiny section of cracked plastic on the top and wear marks on the metal towards the bottom.

[f4tj0n]

Go talk to Carl Stirtz over at Stirtz Machine in Oakland. That's were I got my machining done when rebuilding my s52. The guys has been around for a loooong time and knows bmw's very well. Take the cam and caps and have him take a look. They may be ok with a clean-up polish. Same for the crank.

Stirtz Machine seems to be out of business. I found their number on Yelp, but it gets redirected when called.

[e30serg]

Really?? Haven't been there in 2 years....I'll have to drive by and see....possibly this Thursday. Will let you know.

[f4tj0n]

Bad news was found.

A couple of the cylinders have some scoring felt with a finger nail, and one cylinder has some pitting.

I need some advice.

I'm sure there is more, but I've found that the two piston manufactures that are mostly used are MaxSil and JE. MaxSil being OE replacements and JE being high performance with minimal price differences. Should I pull the trigger on the Oversized JE 11.5:1 Pistons?

http://www.ctsturbo.com/cart/products/BMW_S50B30US_KIT_86_5mm_11_5_1_85_8mm_stroke-2421-268.html

Probably on the higher side but:

http://store.bimmerworld.com/maxsil-replacement-pistons-p1129.aspx

Have people had a problem with the Glyco bearings?


Thanks.

[f4tj0n]

Took the crank out.




Look closely at the main caps...


The pump nut catastrophe can explain why the bearings are extra toasty, but what would cause axial play?

[mpowerful]

Crank walk/failed thrust bearing?

[surebimmer]

Looks like your going to need a good machine shop. Terry Tinney in Livermore does great work. He did my head on my track car with a S52.

http://www.terrytinney.com/

[MyE30]

The pump nut catastrophe can explain why the bearings are extra toasty, but what would cause axial play?

The thrust bearings on the #6 journal are FUBRed which is why you have axial play. How do the journals look on the crank?

[MyE30]

Judging by the pictures, a few of the main caps don't look too happy. The same could probably said about the crank. Have any pics of the crankshaft?

[f4tj0n]

Judging by the pictures, a few of the main caps don't look too happy. The same could probably said about the crank. Have any pics of the crankshaft?

I didnt snap any pics of the crank, but there is some good wear where it ate the thrust bearing. I'm picking up a good one up in the next couple days for a good price.

The main caps should be okay use like that?