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2G No clue what part this is, need help identifying

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zotis777

5+ Year Contributor
41
6
Mar 23, 2018
Oklahoma City, Oklahoma
Hey guys I recently pulled the 7 bolt out of my dsm. Forgive me if it’s a newb question this is the first dsm I’ve ever torn down. When I removed the oil pan I found this guy jangling around inside it. Upon further inspection I noticed both balance shafts have been deleted in this engine and everything inside “looks” brand new. Granted looks can be deceiving but this engine has certainly been worked on before. I had no idea I thought this thing was absolutely stock. But the more I take apart the more I find.


Back on topic (sorry for rambling a bit) here are the photos of the part, I’m not sure where it came from. Is it a good thing I caught this when I did? It was trapped below the baffle, although could it not where it belongs have done any damage yet?
 

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That's an oil pump stub shaft. It's used in place of the balance shaft to allow the oil pump to be driven.


Is there any way I knocked this loose during disassembly? Would it cause the oil pump to not be driven at all? I guess I’ll answer a lot of these when I pull this engine apart further but I have not gotten to the oil pump yet. I didn’t notice any symptoms of oil pump failure prior to pulling this engine
 
Well the oil pump gear attaches to this shaft so if yours is still in place then its most likely someone dropped that in the pan at some point and installed another stub shaft rather than remove the pan and fish it out.


I will see, I’ll remove the oil pump and front case tonight when I get off work and report back. I’m not sure when or what happened. There are no signs of starvation at the head and I haven’t found shavings anywhere.
 
Like I said, the motor won't run without that shaft in there. The timing belt runs around that shaft and up to the cam gears. If that shaft comes out the timing belt stops turning and the engine dies. You would more likely have bent valves then oil starvation if that happened.

So if your timing belt was still in place when you pulled the motor then something weird was going on from the previous owner when they did the BS delete.
 
Like I said, the motor won't run without that shaft in there. The timing belt runs around that shaft and up to the cam gears. If that shaft comes out the timing belt stops turning and the engine dies. You would more likely have bent valves then oil starvation if that happened.

So if your timing belt was still in place when you pulled the motor then something weird was going on from the previous owner when they did the BS delete.


The timing belt was not In the motor when I pulled it, the pulley for the timing belt is still in place. Don’t mean to sound inept I think I overthought it a bit off the bat. Thank you I’m gonna tear into it tonight and see if I can’t get some answers
 
If the bolt came out, it probably wasn't locktited in place. Most use some form of thread locker to make sure that doesn't happen. I am looking for the stubby shaft bolt myself, as I am doing a BSE to a spare motor. Haven't had any luck with a part number for the bolt yet.
Hope the best for you!

Edit: use the bolt out of the balance shaft for the stubby or purchase a 8 x 1.25 x 16mm grade 10 bolt and use it with red locktite so it doesn't come out ever again.
 
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If the bolt came out, it probably wasn't locktited in place. Most use some form of thread locker to make sure that doesn't happen. I am looking for the stubby shaft bolt myself, as I am doing a BSE to a spare motor. Haven't had any luck with a part number for the bolt yet.
Hope the best for you!

Edit: use the bolt out of the balance shaft for the stubby or purchase a 8 x 1.25 x 16mm grade 10 bolt and use it with red locktite so it doesn't come out ever again.



It turns out it did fall out, There is a Knick on the stub shaft and a Knick on the front cover and the bolt is even still in there which leads me to believe it was while the engine was running.


It also confuses me how my car stayed running or what else would’ve caused the light damage on these parts.
 
I don't how that bolt still stayed in there, but that's pretty crazy right there. I would definitely have the head sent out to make sure there's no bent valves or anything. That's definitely the stub shaft from a BSEK. If there's a nick in the front case you might want to replace that too - depending on where it is and reinstall everything. Locktite it as mentioned above and torque it all down to spec.
 
I don't how that bolt still stayed in there, but that's pretty crazy right there. I would definitely have the head sent out to make sure there's no bent valves or anything. That's definitely the stub shaft from a BSEK. If there's a nick in the front case you might want to replace that too - depending on where it is and reinstall everything. Locktite it as mentioned above and torque it all down to spec.


My mistake the nick is on the oil pump cover, you can see it at the top photo at the 12:00 position. The reason the car came apart was a trashed head gasket so the head is going to a machine shop anyways just to get it milled flat again. The temp needle spiked hard when the head gasket let go I’m pretty sure it’s not flat anymore
 
Oh wow. I guess this is a prime example of how important it is to use proper torquing techniques and applying thread locker where needed (not blaming you OP!).

The stub shaft has a groove through which high pressure oil flows. I'm pretty sure without a shaft in there at all (either stub or balance), high pressure oil would be pissing out into the sump. God knows how much wear would have occurred if the engine was ran like that.
 
The shaft is there only to align and reduce vibration to the pump gear, but with that bolt not being blocking the hole, oil pressure could of scape.
However I would crack open the oil pump and inspect for wear/scratches which it didn’t had the shaft.

The original pump shaft is big and heavy and runs across the engine, it has oil gallery’s to feed a bearing, that shaft was removed and replaced with that small solid shaft, in order to do that the oem shaft bearings where replaced or turn around to block the oil hole so oil doesn’t scape and with the shaft being solid oil will not come off the shaft.

The timing belt will not come off with the shaft removed, the belt rides on the oil pump sprocket which is bolt on to the other oil pump gear., (oil pump has 2 gears, in one goes the belt sprocket and the other gear goes the shaft).
 
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