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2G Unsettling engine noise after BSE

aaronth777

Proven Member
76
16
Apr 12, 2015
Roseville, California
Please excuse the long post. This is a bit of a newbie question, but I did a balance shaft delete about 300 miles ago and the engine seems to be making a lot more noise than it should be. Here's the details:

Balance shaft belt broke and threw the timing, had the head rebuilt because of bent valves. Left the front bs in place with no belt, and installed the stub shaft in place of the rear bs. Lubed up the oil pump and reinstalled everything. Used Royal Purple 10w-30 synthetic oil for the first time (used to use penzoil high mileage conventional 10w-30). Engine was naturally loud on first start up but quieted down after a good drive.

When I have my windows down and drive past a wall, it sounds like I have an exhaust leak but I spent hours searching and I'm 95% sure I don't have one. At idle, the engine sounds fairly normal, maybe slightly noisy. But if I rev the engine from the throttle body while right next to the engine, it is noticably loud and rpm dependent. It's not really a whine or rattle, it's hard to describe. I removed all accessory belts and timing cover and nothing changed. Using the hose-to-ear method, it seems like it might be coming from the oil pump/rear bs area. The factory oil pressure guage is reading normally and the car runs fine otherwise, but the noise concerns me. I'm unsure if the noise has been there since the rebuild or if it's gotten worse over time.

What would the symptoms be if the stub shaft is backing out or fell off altogether? Also if I used too much assembly lube in the oil pump could that be causing issues? Maybe I'm being paranoid, but i can't afford another catastrophic engine failure.
 

aaronth777

Proven Member
76
16
Apr 12, 2015
Roseville, California
I left the front shaft in and just took the belt off, but replaced the rear balance shaft with the stubby shaft. It's a good one too from stmtuned, not an ebay one
 

aaronth777

Proven Member
76
16
Apr 12, 2015
Roseville, California
Did you follow this:
You must be logged in to view this image or video.
.

Notice at 15:35-17:44 (especially 17:05) and 25:10-27:50.
That's a very helpful video, I wish i had found that before I did the bse. I have the correct stub shaft with the oil groove in it, however i didn't use threadlocker... also i don't know if I used enough grease in the right areas. Maybe it's time to bite the bullet and get a new front case and oil pump, it's at almost 200,000 after all
 

Kryndon

Proven Member
674
357
Jan 10, 2014
Bulgaria, Europe
My thinking is, if somehow the stubby started unthreading itself, it would move *into* the block and at some point the groove will stop being aligned with the two oil holes, thus you should see a slight increase in oil pressure, if anything. Likewise, if the stub shaft completely fell off into the sump, you'd see a significant oil pressure decrease, since it would be pissing oil out of that supply hole. I've ran an engine without one of the front balance shaft supply holes (which is just slightly bigger in size) and let me tell you, the thing barely got oil pressure and started rod knocking a little bit (don't even ask about how I got in that situation). Also if it fell off into the sump, you can use a magnet to check if it's at the bottom. But I highly doubt either of these two cases happened, so you should focus elsewhere.

On the topic of oils, keep in mind that each oil brand and each weight have different additives and properties. Some oils make your engine run noticeably louder, some make it quieter, others make your lifters tick when they shouldn't. Now, I don't like jumping to conclusions, but given that you yourself said this is the first time you're running a new type of oil, I'd be inclined to say it may be that. Additionally, just to make sure, even though your factory oil gauge reads normal, that's the reading right at the oil filter housing, in other words the bottom end. What you're getting at the head might be a whole different story IF THERE IS an actual problem with your oil pressure. So remove the oil cap and confirm you got adequate oil squirting out of the oil jets onto the cams. Rev it up to 3-4k and see if it changes abnormally. Lack of oil pressure or no oil at all leads to increased friction between the metal parts, thus more sound and more heat.
 

pauleyman

DSM Wiseman
6,631
1,773
Nov 19, 2011
oklahoma city, Oklahoma
My thinking is, if somehow the stubby started unthreading itself, it would move *into* the block and at some point the groove will stop being aligned with the two oil holes, thus you should see a slight increase in oil pressure, if anything. Likewise, if the stub shaft completely fell off into the sump, you'd see a significant oil pressure decrease, since it would be pissing oil out of that supply hole. I've ran an engine without one of the front balance shaft supply holes (which is just slightly bigger in size) and let me tell you, the thing barely got oil pressure and started rod knocking a little bit (don't even ask about how I got in that situation). Also if it fell off into the sump, you can use a magnet to check if it's at the bottom. But I highly doubt either of these two cases happened, so you should focus elsewhere.

On the topic of oils, keep in mind that each oil brand and each weight have different additives and properties. Some oils make your engine run noticeably louder, some make it quieter, others make your lifters tick when they shouldn't. Now, I don't like jumping to conclusions, but given that you yourself said this is the first time you're running a new type of oil, I'd be inclined to say it may be that. Additionally, just to make sure, even though your factory oil gauge reads normal, that's the reading right at the oil filter housing, in other words the bottom end. What you're getting at the head might be a whole different story IF THERE IS an actual problem with your oil pressure. So remove the oil cap and confirm you got adequate oil squirting out of the oil jets onto the cams. Rev it up to 3-4k and see if it changes abnormally. Lack of oil pressure or no oil at all leads to increased friction between the metal parts, thus more sound and more heat.
The shaft supports one of the gears. It can't fall off or the pump would sieze.
 

Kryndon

Proven Member
674
357
Jan 10, 2014
Bulgaria, Europe
The shaft supports one of the gears. It can't fall off or the pump would sieze.

I was referring to the shaft that attaches to the smaller driven gear. It's Bolt > small driven gear > Stub shaft (or standard balance shaft). There is nothing else physically retaining the stub shaft other than the bolt and cylindrical bore. Even Jafro says it could fall out at the 25:30 minute mark in the above video. Unlikely scenario, but still possible.

But upon thinking more about it, you're right. Even if the stub shaft somehow went to Canada, it would make the small gear rattle about and pretty much reduce all oil flow, which he would have noticed by now for sure.
 

motomattx

Proven Member
3,342
1,225
Dec 9, 2010
wampum, Pennsylvania
If that shaft fell off the pump would lock up, there would be no bearing surface keeping the gears supported and away from clashing with each other.
 

DSMPT

DSM Wiseman
1,432
977
Jun 12, 2014
Japan / Mexico, Arizona
Please excuse the long post. This is a bit of a newbie question, but I did a balance shaft delete about 300 miles ago and the engine seems to be making a lot more noise than it should be. Here's the details:

Balance shaft belt broke and threw the timing, had the head rebuilt because of bent valves. Left the front bs in place with no belt, and installed the stub shaft in place of the rear bs. Lubed up the oil pump and reinstalled everything. Used Royal Purple 10w-30 synthetic oil for the first time (used to use penzoil high mileage conventional 10w-30). Engine was naturally loud on first start up but quieted down after a good drive.

When I have my windows down and drive past a wall, it sounds like I have an exhaust leak but I spent hours searching and I'm 95% sure I don't have one. At idle, the engine sounds fairly normal, maybe slightly noisy. But if I rev the engine from the throttle body while right next to the engine, it is noticably loud and rpm dependent. It's not really a whine or rattle, it's hard to describe. I removed all accessory belts and timing cover and nothing changed. Using the hose-to-ear method, it seems like it might be coming from the oil pump/rear bs area. The factory oil pressure guage is reading normally and the car runs fine otherwise, but the noise concerns me. I'm unsure if the noise has been there since the rebuild or if it's gotten worse over time.

What would the symptoms be if the stub shaft is backing out or fell off altogether? Also if I used too much assembly lube in the oil pump could that be causing issues? Maybe I'm being paranoid, but i can't afford another catastrophic engine failure.
A video with good sound would help a lot to distinguish this kind of issue.

I was referring to the shaft that attaches to the smaller driven gear. It's Bolt > small driven gear > Stub shaft (or standard balance shaft). There is nothing else physically retaining the stub shaft other than the bolt and cylindrical bore. Even Jafro says it could fall out at the 25:30 minute mark in the above video. Unlikely scenario, but still possible.

But upon thinking more about it, you're right. Even if the stub shaft somehow went to Canada, it would make the small gear rattle about and pretty much reduce all oil flow, which he would have noticed by now for sure.
What Paul meant is the shaft is holding the driven gear in its position very strictly (the driven gear to wall clearance is around .010" max), so in case if the shaft fall off, the gear would contact the case wall and would mess up inside of the case. The pump wouldn't spin smoothly anymore.
For some reason if the shaft has gone, I imagine that the OP would probably see a lot of aluminum flakes/chunks in oil already or can check it by removing the castle plug.
 

luv2rallye

DSM Wiseman
7,976
846
Jun 7, 2003
Minneapolis, Minnesota
If you have everything off to the point where it’s easy to remove the timing belt, I’d remove the tbelt. Then put an impact on the oil pump gear and spin it to see if noise is there. I take it you didn’t measure the clearance for the oil pump gears.
I don't know if you want an impact. I used a variable drill with a socket on it - allows different speeds and you can start off slow.
 

TK's9d2TSi

Supporting Member
4,845
2,095
Sep 11, 2017
Cincinnati, Ohio
That's a good idea. Those oil pump gears can start making a racket when they have a lot of mileage on them. And didn't he say he thinks the noise is from that area?

He did say he thinks it’s from that area. The only thing would be can he spin it fast enough to replicate the noise if in fact it’s loose/worn gears/case.
 

aaronth777

Proven Member
76
16
Apr 12, 2015
Roseville, California
Wow a lot of good information here, thank you everyone for the replies! I was tired when I was taking the car apart and didn't even think about pulling the timing belt and spinning the oil pump with a drill, but thats a great idea. Also i like the castle plug idea, a quick way to check it without having to remove the front case or oil pan.
 

mikyrc

Proven Member
197
4
Nov 18, 2003
Spain, Europe
Hi, I had the same issue (like vibrating sounds arouns 2-3k) when I did the BS delete just like You. Also took out the front belt, and put a stuby shaft on the rear. But finally I ended leaving back to stock.
I would say that the noise was caused by the front BS vibrating due to not having anything that was holding it tight. Probably if I had done it properly and removed the front balance shaft, there would not be any weird sounds.
 
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