IMS Replacement... The Jager Saga

[Jager]

Put 8 1/2 quarts of Mobil One, it's the only oil I use. Also trying-out Royal Purple in the gear box.

Does anyone else have this decal on the under-side of their trunk??

[Jager]

It's like driving a new car again! The clutch grabs quickly, the gearbox is shifting very smoothly, and no more vibration at 3000 RPM. I'm sure the old flywheel was causing the vibration problem.

[Jager]

I'm reviewing some of the data I recorded. Can anyone explain why the "camshaft position deviation" is different now (both banks are closer) than before I started this project? The idle is also smoother and a little higher. O2 sensors changed the idle???

[Jager]

Originally Posted by Perfectlap

Excellent. Do you have a professional background in auto repair?

No I do not have any professional experience in auto repair, it's all been hobby. I started when I was 17, over 30 years ago, mostly played with muscle cars with V-8's.

Jager

[JFP in PA]

Originally Posted by Jager

I'm reviewing some of the data I recorded. Can anyone explain why the "camshaft position deviation" is different now (both banks are closer) than before I started this project? The idle is also smoother and a little higher. O2 sensors changed the idle???

Answer is simple: With the new IMS installed, there is now less "slop" in the cam drive system. The normal cam deviation values are an expression of how far off ideal the shafts are running at idle, and the deviation is caused by wear and mechanical +/- variances, etc. It is also not uncommon for an IMS bearing that is near death to cause the cam deviation values to swing wildly back and forth while the engine is at idle.

[Jager]

Originally Posted by JFP in PA

Answer is simple: With the new IMS installed, there is now less "slop" in the cam drive system. The normal cam deviation values are an expression of how far off ideal the shafts are running at idle, and the deviation is caused by wear and mechanical +/- variances, etc. It is also not uncommon for an IMS bearing that is near death to cause the cam deviation values to swing wildly back and forth while the engine is at idle.

Here are more interesting snapshots of before and after the project that show some improvement. The "Actual Angle For Camshaft" data I recorded before the project, on 9 April, and the data I recorded yesterday. The scales on the graphs are different (software auto selected) but on 9 April there was .50 degrees variance on bank 1, and after the IMS bearing upgrade there is now .30 degrees variance on bank 1. See attached files.

Jager

[tonycarreon]

wow. very interesting. i had to go check mine to see what was up.

at idle, no change in deviation - stays at:
1: -8.88
2: -5.64

actual angle:
1: -0.33
2: -0.28

during drive @ 3k RPM (i didn't check actual angle) the deviation moved to:
1: -8.98
2: -5.69

i love this forum - i learn something new every day! and jager, thanks for this awesome thread.

[Jager]

Originally Posted by tonycarreon

wow. very interesting. i had to go check mine to see what was up.

at idle, no change in deviation - stays at:
1: -8.88
2: -5.64

actual angle:
1: -0.33
2: -0.28

during drive @ 3k RPM (i didn't check actual angle) the deviation moved to:
1: -8.98
2: -5.69

i love this forum - i learn something new every day! and jager, thanks for this awesome thread.

More than 3 degrees difference between banks on deviation... Not sure what the specifications are for timing difference between banks are but you might want to take a close look at this. I'm sure performance is not optimal.

Jager

[tonycarreon]

Originally Posted by Jager

More than 3 degrees difference between banks on deviation... Not sure what the specifications are for timing difference between banks are but you might want to take a close look at this. I'm sure performance is not optimal.

Jager

not a lot of info out there, so maybe someone else can chime in. from what i gather the "acceptable" deviation is +/- 6 degrees on each bank, no idea as to what is acceptable difference between 1 and 2. i am sure the pads are worn out seeing as the car is 10 years old and has 85k miles on it, no work has been done in regards to the timing system.

[jaykay]

Originally Posted by tonycarreon

not a lot of info out there, so maybe someone else can chime in. from what i gather the "acceptable" deviation is +/- 6 degrees on each bank, no idea as to what is acceptable difference between 1 and 2. i am sure the pads are worn out seeing as the car is 10 years old and has 85k miles on it, no work has been done in regards to the timing system.

By pads do you mean chain tensioner pad wear giving more cam chain slop and loss of motion on cam shafts?

[tonycarreon]

Originally Posted by jaykay

By pads do you mean chain tensioner pad wear giving more cam chain slop and loss of motion on cam shafts?

yeah the ramps/tensioner pads on the variocam solenoid - though all the pictures i've seen of them show them as a brown color and the bits in the filter were black and rounded. so perhaps the chain guides as well. can't imagine both of them are fine after that many miles / years.

[Paul]

Jager, great work and great pictures!

Hope to have some time to get back to my 2001 "project".

[Jager]

Originally Posted by Paul

Jager, great work and great pictures!

Hope to have some time to get back to my 2001 "project".

Thanks Paul... I was wondering how far you had gotten on your motor issue. Since you are tearing it down, are you going to ship the IMS to LN Engineering and have them do the bearing upgrade??

Jager

[jaykay]

Originally Posted by tonycarreon

yeah the ramps/tensioner pads on the variocam solenoid - though all the pictures i've seen of them show them as a brown color and the bits in the filter were black and rounded. so perhaps the chain guides as well. can't imagine both of them are fine after that many miles / years.

I found black bits in my filter and thought they were tensioner guide material but when I put pressure on them they crumbled like carbon.....carbon deposits released by my spirited driving perhaps; they were roundish small bits ....quite a bit actually. I am not really sure what they are

....couple of green copper specs along a few silver metallic specs which were cause for concern

[Paul]

Originally Posted by Jager

Thanks Paul... I was wondering how far you had gotten on your motor issue. Since you are tearing it down, are you going to ship the IMS to LN Engineering and have them do the bearing upgrade??

Jager

No progress since the last set of pictures, have been way too busy and I'm still conflicted on whether it's worth fixing.

[Jager]

Originally Posted by thstone

Super post! Really enjoyed it. Excellent job!

Now, the real question is why this bearing was generally ok (not perfect but still working fine) after 210,000 miles when others fail at 1/10th of that mileage?

Thanks thstone

I would like to go back to the photo I took of inside the IMS. Per Porsche’s design of a sealed IMS bearing, oil inside the IMS is not per design correct? I wonder what Porsche’s forecast was on IMS bearing life if it maintained the grease seal?

I drive my car every day to/from work, and short trips on the weekends, averaging somewhere between 60 to 70 miles a day. With this amount of driving I’m sure my IMS bearing was maintaining a coat of motor oil keeping me off the IMS failure list.

Jager

[Dragonwind]

Originally Posted by Jager

Thanks thstone

I would like to go back to the photo I took of inside the IMS. Per Porsche’s design of a sealed IMS bearing, oil inside the IMS is not per design correct? I wonder what Porsche’s forecast was on IMS bearing life if it maintained the grease seal?

I drive my car every day to/from work, and short trips on the weekends, averaging somewhere between 60 to 70 miles a day. With this amount of driving I’m sure my IMS bearing was maintaining a coat of motor oil keeping me off the IMS failure list.

Jager

This is in line with what Jake as said that the more you drive it (and harder) the better off it is. From the looks of the picture your failed seal allowed enough oil to circulate through to allow some lubrication and save your engine. Hats off to you for driving your car and not just looking at it!

Chris

[boberocket]

I am new to the 986 forums and somewhat of a new Porsche owner. I found out after I purchased my 2000 Boxster S w/Tiptronic in the summer of 2015 that these engines had an IMS 'time bomb' in them. It has made me uncomfortable every since. I am a home mechanic and understand the concepts of most anything automobile related however I would like to ask for the opinions of those well experienced and/or trained in the automotive repair industry.

I have captured an image of my camshaft variance using the Durametric software and shared it with this thread. It is my hope that someone can help me understand what these numbers mean and if there is an IMS concern here. I am thankful for everyone's opinion.

The snapshot indicates the readings with the engine at an idle. I did rev the engine high a few times while logging and the numbers did not change for either camshaft more than 1/100th of a value. What I mean is the 8.47 value may have moved to 8.48 and the 7.59 value may have moved to 7.6. What do these values tell me about my camshaft tensioners and my IMS bearing?

Thank you

[JFP in PA]

Originally Posted by boberocket

I am new to the 986 forums and somewhat of a new Porsche owner. I found out after I purchased my 2000 Boxster S w/Tiptronic in the summer of 2015 that these engines had an IMS 'time bomb' in them. It has made me uncomfortable every since. I am a home mechanic and understand the concepts of most anything automobile related however I would like to ask for the opinions of those well experienced and/or trained in the automotive repair industry.

I have captured an image of my camshaft variance using the Durametric software and shared it with this thread. It is my hope that someone can help me understand what these numbers mean and if there is an IMS concern here. I am thankful for everyone's opinion.

The snapshot indicates the readings with the engine at an idle. I did rev the engine high a few times while logging and the numbers did not change for either camshaft more than 1/100th of a value. What I mean is the 8.47 value may have moved to 8.48 and the 7.59 value may have moved to 7.6. What do these values tell me about my camshaft tensioners and my IMS bearing?

Thank you

Steady cam deviation values are an indication that that the IMS is still healthy; but as the specs for this value are +/- 6 degrees, yours are out of spec, most likely due to severely worn chain pads that need to be replaced.

[boberocket]

Thank you for the quick response JFP in PA. I will research on this site as well as Pelican Parts for the procedure to replace them.