IMS Bearing ALMOST failed
01-22-2016, 10:53 PM
#16
Pro
Thread Starter
This is the key sentence here for me: "Since it has 75k miles and has sat in storage several times, sometimes going many months in a row without being driven"
Drive it often like you stole it, change the oil frequently and the factory double rows will be fine. I truly believe that. Glad your engine was saved.
Drive it often like you stole it, change the oil frequently and the factory double rows will be fine. I truly believe that. Glad your engine was saved.
Regarding Mr. Raby's concern, the builder is not reusing the intermediate shaft.
Thanks for chiming in on the thread Jake!
01-23-2016, 12:12 AM
#17
Pro
Thread Starter
I'd be interested to learn from the OPs mech what was left in the sump when the oil was drained and a picture of the pleats of the oil filter. Also a pic or two of the cam lobes?
This pretty much makes my decision to add a remote particulate oil filter to my engine mandatory.
This pretty much makes my decision to add a remote particulate oil filter to my engine mandatory.
01-23-2016, 12:17 AM
#18
Pro
Thread Starter
...With the bearing at stage 3 failure damage to the IMS shaft assembly may have already occurred. The rear most drive sprocket is lightly staged with 1/4" of engagement, so the vibration and trauma of the bearing failing can create runout on this sprocket and that can make the drive literally fall off later down the road (MOF 24), or it can have enough runout to compromise the drive chain (especially the early duplex units like this one in the video).
Worry more about the damage that can't be seen.
Worry more about the damage that can't be seen.
01-23-2016, 10:42 AM
#20
Rennlist Member
From the photo, it looks like your mechanic has the case split already. That's a good sign that he's going to go "all the way" with the re-furb/re-build and not just blow smoke up your butt...Do you know if he's going to do an Ultrasonic cleaning of all the engine parts like FSI would do? Also, how are they going to address the wear in the bore for the IMSB flange? It seems that area might want to leak regardless of a new seal. Any more photo's you (your mechanic) could provide as the process progresses would be great!
Last edited by dporto; 01-23-2016 at 11:16 PM.
01-24-2016, 11:41 AM
#22
Rennlist Member
Interesting thread, thanks for posting. This reminded me to order my replacement water pump, which I did.
I'm going to perform all sorts of maintenance to the car, but to be on the safe side, I'm going to stop driving it for good. Think how good I will sleep!
I'm going to perform all sorts of maintenance to the car, but to be on the safe side, I'm going to stop driving it for good. Think how good I will sleep!
01-24-2016, 04:48 PM
#23
Pro
Thread Starter
I've been using the 951 as a daily driver since the 996 water pump went out, and the 951 has been a blast, especially since I added a few shims to the wastegate a week ago. I gained almost 4psi with the shims, and boost builds much faster! It was the original wastegate, and it was WEAK.
Last edited by jmj951; 01-25-2016 at 12:36 AM.
01-24-2016, 10:39 PM
#24
Three Wheelin'
The only reason it lasted that long is because its a dual row bearing... But... If you look hard enough you'll find collateral damage that came from the wear debris suspending into the oil. This is usually seen on the cam journals in the cylinder heads, and their caps.
The big issue with a dual row bearing is it can take too long to fail, and it has twice as many wear components to generate debris than a single row. Regardless, that bearing was at Stage 3 failure. It had failed, it just hadn't came apart yet (stage 4).
The big issue with a dual row bearing is it can take too long to fail, and it has twice as many wear components to generate debris than a single row. Regardless, that bearing was at Stage 3 failure. It had failed, it just hadn't came apart yet (stage 4).
Would UOA see higher metal content (if so what metal type?) ... also would cutting open the filter at each oil change reveal any symptoms or clues?
01-25-2016, 01:48 PM
#27
MY 99 is definitely a dual.
MY 00 and 01 are like a boxes of chocolates.
MY 02+ is 99.99% single, but Jake mentioned an 03 with a factory installed dual that he came across once.
Last edited by gnat; 01-25-2016 at 02:33 PM. Reason: I was corrected about MY 00
01-25-2016, 01:54 PM
#28
Race Director
To my knowledge, holding the dirty bearing in your hand is the only foolproof method of determining whether it's a single-row or dual-row.
01-25-2016, 02:01 PM
#29
Rennlist Member
Originally Posted by gnat
By engine number? Not that I'm aware of.
MY 99 is definitely a dual.
MY 00 I believe is also 100% dual, but I'm not entirely positive.
MY 01 is like a box of chocolates.
MY 02+ is 99.99% single, but Jake mentioned an 03 with a factory installed dual that he came across once.
MY 99 is definitely a dual.
MY 00 I believe is also 100% dual, but I'm not entirely positive.
MY 01 is like a box of chocolates.
MY 02+ is 99.99% single, but Jake mentioned an 03 with a factory installed dual that he came across once.
01-25-2016, 02:32 PM
#30
Don't the variants have different flanges? I seem to recall reading or seeing a pic that the "cup" of the single row flange is deeper. If so they you don't need to actually have it out, but you still have to have the transmission out so it doesn't really save you much.
