IMS change for next maintenance ?

[knarf]

Hi all,

i purchased a 2001 - 986S in March 2012 with 50 000 miles. the car is clean with several options (full leather, hardtop, PSE...)



i have to think about the annual maintenance (oil change) for beginning 2013, i put 7 000 miles on the car since March 2012.

i was wondering whether i should change the ims during this annual maintenance or i can postpone it for next year (when i will change the ims, i will do also the rms and the clutch replacement)

The car is running well with no strange sound. No major oil leaks, on the oil gauge, only 1 bar has disappeared since last oil change. However, the junction between the engine and the transmission is a little bit greasy

i did some camshaft position deviation measurments with the durametric tool and here are the results:

Data taken in September 2012 (engine is running at idle)
- at startup when the engine is cold : -6,64°
- when the engine is warm : ~5,88°. the value is fluctuating by 0,15°- 0,25°





Data taken in December 2012 (engine is running at idle)
- when the engine is warm : ~5,98°. the value is fluctuating by 0,15°

i know that wide fluctuations of camshaft position deviation could indicate a coming IMS failure and i don't know if my current fluctuation could be considered as wide ?!

Thanks for your help

[Meir]

im not sure which version of the durametric tool you are using, but here is how it is suppose to look like:



the cam deviation values are presented on the top right, but what is more important, is that rock solid line at idle.
the values should not change even a bit (at idle) if all is right.
it is also recommended to change the oil every 3k mils, and inspect the oil filter for any metal debris.

[thstone]

If you are worried about it to the extent that you're taking measurements only 60 days apart and comparing the data, then I'd suggest that you should replace the IMS bearing as soon as possible.

I have 120,000 miles on my original IMS bearing, track the car 25+ times a year, and never, ever, ever think about my IMS bearing except when I come on this forum and read posts from everyone else.

If you can't forget it, then I suggest that replace it so you can be at peace with the car.

[knarf]

im using durametric v5
and of course i will check the oil filter for any metal debris.

[thom4782]

My understanding is that the camshafts should have zero wobble at idle. If you're risk adverse, change the IMS. Inspect RMA and clutch and replace if needed. If you're a risk taker, leave it as is.

[Meir]

Originally Posted by thom4782

My understanding is that the camshafts should have zero wobble at idle. If you're risk adverse, change the IMS. Inspect RMA and clutch and replace if needed. If you're a risk taker, leave it as is.

there is no risk to take here.
if the cam deviation is not rock steady at idle,the IMSB is on its way out.
so basically it is more lake a death sentence then taking a risk.
the only reason i will not urge you to replace the IMSB, is because i'm not familiar with the Durametric V5, and i'm not sure what we are looking at in your first post.
assuming you did not changed your oil in the last 7K miles, you should find many metal particles in your oil, if the bearing is failing.
if i was in your seat, i wouldn't start the engine before inspecting the oil.

[san rensho]

Are you sure you are looking at the right Dur values? There is a cam DEVIATION value and there is the actual angle value of the cams. The actual value varies slightly at idle but then will go up wildly when the car is accelerated.

If you are absolutely sure you are looking at the cam deviation values, then don't even start the car without looking at the filter,as Meir said. If you were looking at the actual value, then switch to the deviation,which shoould be a dead flat line at idle.

[knarf]

Hi,

sorry for my late reply,

yes, i am looking at Camshaft position 1 deviation on durametric V5

I went to my Indy mechanic for annual maintenance yesterday.

The guy is used to handle IMS bearing change and engine swap due to IMS failure. (there was a 996 engine blown due to IMS failure)
He is a Porsche specialist and work only on Porsche car (both for regular maintenance and track preparation)

We inspect the oil filter and the oil dropped from the engine and found nothing inside. (not a single piece of metal)



i showed him my log and he checked it also with his durametric software.
Apparently nothing to worry about. The fluctuation are too small to be concerned about IMS failure.

As far as the car is running properly and no metal part in the oil, i will not touch the engine and wait for the clutch replacement to change the IMS bearing.

anyway thanks for your comments.

[thom4782]

The IMSB question gets a lot of discussion IMHO for two reasons. One, if it fails, the results are catastrophic and expensive. Two, it's very hard to know with certainty whether your IMSB is close to failure or not.

The only sure way to tell is to remove the IMSB itself and inspect it. Otherwise, the indicators are vague. Metal debris in the oil filter is one key indicator, but the metal can also come from other parts of the engine. The absence of metal isn't a guarantee the IMSB is OK. Cam shaft deviations at idle that aren't absolutely flat are another indication of a IMSB that is starting to wobble. Oil leaking between the engine and the transmission is a third indicator where the IMSB seal is failing. A ticking sound in that same area can indicate that the end of the IMSB stud has brOKen.

Your car seems to be exhibiting two symptoms: varying cam shaft deviations at idle and a possible IMSB leak. If this were my car and I planned to replace the IMSB in the next year, I wouldn't wait. While it may turn out the current IMSB was perfectly OK, I'd at least know I had a much better bearing in its place.

If you want to hedge your bet, consider adding an IMS Guardian. It might provide an early enough warning of an impending IMS failure to avoid the engine trashing itself.

[thstone]

Failed Boxster engines can be replaced for $6K including labor. Expensive? Only you can decide.

[Ckrikos]

If I knew I was getting a good engine for that price then it's not bad, but I don't think you'll know that buying from a dismantler.