996 Nightmare -Thrust Bearing Failure
#1
996 Nightmare -Thrust Bearing Failure
Just purchased a 2003 4S 3 weeks ago. 30K miles, great shape, clean car fax, clean PPI. Everything I could possibly due to avoid buying a huge problem. I drove it for 3 weeks off and on and then took it in to have the IMS upgrade done and new clutch.
When we pulled the clutch and flywheel we noticed a couple of odd marks on the inside of the flywheel and then looked at the bell housing and it was obvious that the flywheel was rubbing on the bell housing. We dropped the oil pan and a large piece of the thrust bearing was laying in the bottom!! NOT the IMS, but the crank shaft thrust bearing.
That is where it sits today... Now what?? It did not make any noise, smoke, or drop oil, so I have to assume it just happened. No idea how much damage it did yet.
Any suggestions other than drop $20K on a rebuilt motor? I only paid $32 for the car.
When we pulled the clutch and flywheel we noticed a couple of odd marks on the inside of the flywheel and then looked at the bell housing and it was obvious that the flywheel was rubbing on the bell housing. We dropped the oil pan and a large piece of the thrust bearing was laying in the bottom!! NOT the IMS, but the crank shaft thrust bearing.
That is where it sits today... Now what?? It did not make any noise, smoke, or drop oil, so I have to assume it just happened. No idea how much damage it did yet.
Any suggestions other than drop $20K on a rebuilt motor? I only paid $32 for the car.
#2
Race Car
Hi there, welcome, sorry to hear your first post is not a very nice story! Legit sucks
I'm sure more experienced members will chime RE details but usually the options are:
- Rebuild current engine
- Purchase second hand engine
- New short block from Porsche
- Sell as a roller (which seeming you paid a decent price bit wouldn't make sense)
I'm sure more experienced members will chime RE details but usually the options are:
- Rebuild current engine
- Purchase second hand engine
- New short block from Porsche
- Sell as a roller (which seeming you paid a decent price bit wouldn't make sense)
#3
Former Vendor
Mode of failure #17... I just finished a build for an RL member (INRANGE) following this exact same scenario.
This one being caught early is a key, before it become a symptomatic.
I see this failure 5-6 times per year, and all too often it leads to collateral damage of a separated IMS shaft, or a broken main timing chain. Why? As the crank dances fore and aft, longitudinally, the chain and IMS drive catch pure hell, as they are now the new longitudinal control surfaces for the thrust loads of the crankshaft.
This one can be saved, but it probably needs a crankshaft. I'm instructing my hands on rebuild class later today, and I have these exact failed components that have failed due to MOF #17 here at the training facility. They came from INRANGE's engine and clearly show what to expect. I'll post some pics.
Why do these fail? The early thrust shims have one less oil groove in their face than the later units. This leads to less lube at the crankshaft/ thrust shim, and that leads to more heat and wear. The shim wears thin, and simply falls out of the carrier and into the sump.
OR the thrust shim was installed at the factory backward... Then it sees greatly reduced oil volumes to the wear face. It overheats, wears, and falls out. Yes I have caught this in process- robots suck.
This one is only a "996 nightmare" if you choose to restart the car before repairing it, or if the wrong person repairs it that is not familiar with the exact fauktbpath of the failure, and how to overcome it.
As it is now you have a best case scenario.
This one being caught early is a key, before it become a symptomatic.
I see this failure 5-6 times per year, and all too often it leads to collateral damage of a separated IMS shaft, or a broken main timing chain. Why? As the crank dances fore and aft, longitudinally, the chain and IMS drive catch pure hell, as they are now the new longitudinal control surfaces for the thrust loads of the crankshaft.
This one can be saved, but it probably needs a crankshaft. I'm instructing my hands on rebuild class later today, and I have these exact failed components that have failed due to MOF #17 here at the training facility. They came from INRANGE's engine and clearly show what to expect. I'll post some pics.
Why do these fail? The early thrust shims have one less oil groove in their face than the later units. This leads to less lube at the crankshaft/ thrust shim, and that leads to more heat and wear. The shim wears thin, and simply falls out of the carrier and into the sump.
OR the thrust shim was installed at the factory backward... Then it sees greatly reduced oil volumes to the wear face. It overheats, wears, and falls out. Yes I have caught this in process- robots suck.
This one is only a "996 nightmare" if you choose to restart the car before repairing it, or if the wrong person repairs it that is not familiar with the exact fauktbpath of the failure, and how to overcome it.
As it is now you have a best case scenario.
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#11
Pro
Good luck with it, on the positive side, as Jake points out it looks like you might have had a narrow escape.
I'm in a similar situation and will be rebuilding my engine, more for peace of mind more than anything else. Really don't want to buy a second hand engine and find out I have "issues" again.
I'm in a similar situation and will be rebuilding my engine, more for peace of mind more than anything else. Really don't want to buy a second hand engine and find out I have "issues" again.
#12
Nordschleife Master
Join Date: Oct 2015
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BJ, Sorry to hear about your engine trouble. At least you didn't decide to drive into the ground. I hope you're able to reconstruct the motor and get you back on the road asap. What part of the country are you from?
That really sucks having this happen just three weeks down the road. Did the group that carried out the PPI, drop the oil pan or just examine the oil filter?
That really sucks having this happen just three weeks down the road. Did the group that carried out the PPI, drop the oil pan or just examine the oil filter?
#13
Former Vendor
At 30K miles you don't need a "rebuild"... You need a repair, with updates, as long as collateral damage is limited.
At our level, this can be an easy (very easy) repair to make. Its like a dream come true.
If the car had 90, or 140K miles, the story would be different... At 30K, this car either had a "clutch rider" for a driver, or the thrust shim was installed backward at the factory.
You have more options than you may think.
At our level, this can be an easy (very easy) repair to make. Its like a dream come true.
If the car had 90, or 140K miles, the story would be different... At 30K, this car either had a "clutch rider" for a driver, or the thrust shim was installed backward at the factory.
You have more options than you may think.
#15
Sorry to hear that and it really sucks. Since your engine has only 30k miles, it could be worth saving. Definitely discuss with Jake. None of the options will be cheap but if you sell it as-is, it'll probably be $12 if that. So if you can fix it and address the other inherent weaknesses of this engine for $20k you will "break even" given what you have lost already.