My DIY Nightmare

[Boxsterfahrer]

My DIY Nightmare.

My Boxster is a 2003 S with 40 k miles on the odometer. During my last drive I noticed a change in the clutch actuation. The pedal pressure changed during a downshift to about halve the force required before and the engagement point moved from about 1” from the floor to close to the top. When moving the pedal from disengagement to engagement I also noticed a rough travel. The rough travel disappeared when the engine was shut off and the clutch activated. After analyzing all possible scenarios, I concluded that the pressure plate spring must be at fault. I purchased a clutch kit from Sunset Imports and also new bolts for the flywheel. After I removed the transmission in my garage I was proud that my conclusion was spot on, since about half of the pressure plate’s finger springs were collapsed. Since there was almost no oil visible from the RMS I decided to remove the flywheel anyway and replace the RMS with the newest version to ensure that a future leak might be prevented. The IMS housing was right in front of me and because of the bad reports about IMS bearing failures; I felt that inspecting the bearing was a prudent choice, adding at most and hour of labor to the task. I removed the bearing holder after loosening the chain tensioner for the chain from the crankshaft to the IMS. I was the able to rotate the bearing and also check for looseness or axial play. The bearing was perfect!! Now it gets UGLY real fast. The IMS was slightly off center to the right side and I was unable to get the bearing holder back in to place. The Bently Manual had absolutely no information to offer. I thought that by turning the crank slightly I might take the tension off the IMS to let it be centered and allow me to replace the cover. I just turned the crank about 15 degrees in the normal direction of travel when I heard and felt a sickening click as if the chain from crank to IMS jumped a tooth. I removed the spark plugs to check if the engine could be turned over without interference from the valves and found that a turn of only 120 degrees was possible before the piston contacted a valve. I knew my goose was cooked. What was about 3 hours of labor left to complete the clutch job now turned in to a major nightmare. I was truly disgusted with my stupidity and after two sleepless nights made the phone call to my Independent Repair Shop, Marque Motors in Portland Oregon, telling the owner Kurt Leipzig that a true basket case was on its way. A retiming of the cam shafts seemed in order and required the removal of the engine. The front engine mount and CV boots were found to have tears and were replaced along with a set of new spark plugs. Brake fluid and coolant also were changed. Marque Motors did an outstanding job of rescuing my Boxster engine.

The lesson learned is best expressed by one of Clint Eastwood’s phrases from Magnum Force: “A man's got to know his limitations”.

This experience was costly but I consider myself lucky, at least the car did not fall off the jack stands and crush me. Future DIY will be carefully evaluated prior to starting the project.

Edited October 4, 2009 by Boxsterfahrer

[pk2]

Very astute on the pressure plate. Did you happen to ask them how they maneuvered the bearing holder back/ims back in line.

Regards, PK

Edited October 4, 2009 by pk2

[Boxsterfahrer]

Very astute on the pressure plate. Did you happen to ask them how they maneuvered the bearing holder back/ims back in line.

Regards, PK

I figured it out myself but it was already to late. One must remove the chain tensioner on the back right side leading from the IMS to the cam shaft as well as the chain tensioner from the crank shaft to the IMS. Most importantly do NOT under any circumstance turn the crank when the chain tensioners are removed or when the IMS Beraing cover is removed. With the chain tensioners removed, the bearing cover can easyly removed and the condition of the bearing checked. Reinstallation of the cover will the also be easy. Total time involved should be less than 1 hour. Just be aware that any mistake might cost you about $ 3,000.00. :angry:

Edited October 4, 2009 by Boxsterfahrer

[pk2]

That would all certainly make sense. A pretty painful lesson. Thanks for the tip off.

Regards, PK

[manolo]

I was going over the LN Engineering IMS retrofit install the other night. It explains this and to use the Porsche tool to lock the engine at TDC.

From LN Engineering:

Prior to removing the IMS hub flange, it's best to lock the engine at TDC using the Porsche lock tool, pull the cam plugs and lock the cams, and then remove the three chain tensioners from the engine, prior to pulling the IMS hub flange.

[JeTexas]

I feel your pain, but credit is due for trying and for learning. You're not alone, and God only knows how many thousands of dollars I spent and respent on my last project car because I either broke something while trying to fix another problem or I made the mistake of rebuilding things to stock only to replace it all again six months later (i.e. spending $1200 to rebuild the drum brakes only to discover how terrible drum brakes are and had to spend another $800 to convert to discs when that would have been a cheaper solution in the first place.)

Eventually we all learn to do plenty of research first, and the experience that teaches us the lesson is priceless - although yes, it still sucks paying for it.

[Cloudsurfer]

There are 3 tensioners on these engines, one each for the chains from IMS to the heads, and one for the chain from the crank to the IMS. If you had loosened the tensioner for the IMS drive chain, this would have been pretty easy. Using the pin to lock the crank at TDC and locking the cams isn't a bad idea, but the engine is not going to rotate when doing any of this unless you actually rotate it yourself. If you had had an early Variocam car (2002 and earlier) they likely could have re-timed the engine in the car, but with the vane type Variocam (2003 and on) that's not possible.

Unfortunately, lesson learned :(

[Jake Raby]

Where you goofed up was not pulling the chain tensioners to remove the load from the guide rails to the IMS..

It doesn't matter where the crank position is when the IMS flange is pulled as long as the flange is removed with the tensioners pulled and the engine isn't rotated AT ALL until it's fully reasssembled.

The total lack of real information about these engines is the issue. I really need to finish my DVDs.

[JFP in PA]

Where you goofed up was not pulling the chain tensioners to remove the load from the guide rails to the IMS..

It doesn't matter where the crank position is when the IMS flange is pulled as long as the flange is removed with the tensioners pulled and the engine isn't rotated AT ALL until it's fully reasssembled.

The total lack of real information about these engines is the issue. I really need to finish my DVDs.

Jake, do you have a decent source for the two locking pins (tool #9595) required for the IMS refit; or the flywheel lock (#9538/1 engine in the car)? Having one Hell of a time sourcing these................

[Jake Raby]

Where you goofed up was not pulling the chain tensioners to remove the load from the guide rails to the IMS..

It doesn't matter where the crank position is when the IMS flange is pulled as long as the flange is removed with the tensioners pulled and the engine isn't rotated AT ALL until it's fully reasssembled.

The total lack of real information about these engines is the issue. I really need to finish my DVDs.

Jake, do you have a decent source for the two locking pins (tool #9595) required for the IMS refit; or the flywheel lock (#9538/1 engine in the car)? Having one Hell of a time sourcing these................

I am making more tools... Forget trying to get the stuff from Porsche, they don't even know what engine the tools fit!

[JFP in PA]

Where you goofed up was not pulling the chain tensioners to remove the load from the guide rails to the IMS..

It doesn't matter where the crank position is when the IMS flange is pulled as long as the flange is removed with the tensioners pulled and the engine isn't rotated AT ALL until it's fully reasssembled.

The total lack of real information about these engines is the issue. I really need to finish my DVDs.

Jake, do you have a decent source for the two locking pins (tool #9595) required for the IMS refit; or the flywheel lock (#9538/1 engine in the car)? Having one Hell of a time sourcing these................

I am making more tools... Forget trying to get the stuff from Porsche, they don't even know what engine the tools fit!

Let me know when you have them ready..............and thanks.

[artero]

Boxterfahrer, you are not alone. I had a similar experience, I just got lucky.

Several months ago I decided to order the LN Engineering kit, to retrofit my IMS (Inter Mediate Shaft) bearing (single row) with the LN Engineering bearing and IMS flange (cover) in my 2002 911. This way I wouldn’t have to worry about the IMS problem as much.

Working with Jack stands in my garage was ok. I purchased some 6 ton jacks from Harbor Freight for the rear of the car and regular car ramps (installed sideways) for the front. Finally, I purchased a transmission puller adaptor for my 3.5 ton jack from Autozone and I was all set. Pulling the transmission was uneventful (that thing is heavy), removing the pressure plate, clutch and flywheel was also straight forward. I then loosened the two chain tensioners (the Crank-IMS one and the IMS-Cam one, on the transmission side of the engine). I left the tensioner on the opposite side alone, as this would do little to loosen the tension on the IMS bearing area. I did not remove the tensioners completely, as I did not want to mess up timing. Removing the IMS flange at this point was easy, however, as expected, I found the IMS shifted to the right and up a bit, about ¼ inch. I proceeded to remove the IMS bearing with the LN Engineering supplied puller, and I then installed the new LN Engineering bearing (with the LN Engineering supplied tool). Next, I had to install the IMS flange, which was tricky, since, without removing the tensioners completely, the IMS was still way off center. Well, I noticed that Porsche was selling the alignment tool. Since that alignment tool would no longer work for me (due to the fact that the new IMS bearing stud was upgraded to a thicker one and the thread would not fit the tool), I drove down to Home Depot and purchased $8 worth of metal peaces and the alignment was done without any problems at all – the new LN Engineering IMS flange was installed.

[attachment=18648:IMS.JPG

Here is where my nightmare almost came to light: LN Engineering mentioned that the new IMS flange may interfere with the flywheel. To test this, I installed the flywheel and proceeded to crank the engine by hand. As soon as I cranked the engine, I felt something like chain skipping across teeth. It is at this precise moment that I realized what may have happened – I forgot to tighten the two tensioners! GAME OVER. I immediately fainted and, as I came to, I was sure that the timing was messed up. I quickly tensioned the two tensioners and proceeded to crank the engine by hand some more, expecting, at any moment, to have the valve hit the piston. To my surprise, however, the engine still turned and the chain skipping across teeth feeling went away. As I turned the engine some more, a full 360 deg. the chain skipping on teeth came back. I was puzzled, as the symptoms were there for 180 deg and disappeared for the other 180 deg. Finally, I remembered that LN Engineering did mention that the flywheel may interfere with the IMS flange. I immediately removed the flywheel and the chain skipping across teeth feeling went away completely. I just had to grind a little spot on the IMS flange and the interference went away. I re-assembled everything and, knock on wood and a prayer, the car started. Thus, I realize how lucky I was – one just has to pay attention 100% at all times, think things through and not get too eager.

[artero]

...continuation...

Here is where my nightmare almost came to light: LN Engineering mentioned that the new IMS flange may interfere with the flywheel. To test this, I installed the flywheel and proceeded to crank the engine by hand. As soon as I cranked the engine, I felt something like chain skipping across teeth. It is at this precise moment that I realized what may have happened – I forgot to tighten the two tensioners! GAME OVER. I immediately fainted and, as I came to, I was sure that the timing was messed up. I quickly tensioned the two tensioners and proceeded to crank the engine by hand some more, expecting, at any moment, to have the valve hit the piston. To my surprise, however, the engine still turned and the chain skipping across teeth feeling went away. As I turned the engine some more, a full 360 deg. the chain skipping on teeth came back. I was puzzled, as the symptoms were there for 180 deg and disappeared for the other 180 deg. Finally, I remembered that LN Engineering did mention that the flywheel may interfere with the IMS flange. I immediately removed the flywheel and the chain skipping across teeth feeling went away completely. I just had to grind a little spot on the IMS flange and the interference went away. I re-assembled everything and, knock on wood and a prayer, the car started. Thus, I realize how lucky I was – one just has to pay attention 100% at all times, think things through and not get too eager.

[txhokie4life]

...continuation...

Here is where my nightmare almost came to light: LN Engineering mentioned that the new IMS flange may interfere with the flywheel. To test this, I installed the flywheel and proceeded to crank the engine by hand. As soon as I cranked the engine, I felt something like chain skipping across teeth. It is at this precise moment that I realized what may have happened – I forgot to tighten the two tensioners! GAME OVER. I immediately fainted and, as I came to, I was sure that the timing was messed up. I quickly tensioned the two tensioners and proceeded to crank the engine by hand some more, expecting, at any moment, to have the valve hit the piston. To my surprise, however, the engine still turned and the chain skipping across teeth feeling went away. As I turned the engine some more, a full 360 deg. the chain skipping on teeth came back. I was puzzled, as the symptoms were there for 180 deg and disappeared for the other 180 deg. Finally, I remembered that LN Engineering did mention that the flywheel may interfere with the IMS flange. I immediately removed the flywheel and the chain skipping across teeth feeling went away completely. I just had to grind a little spot on the IMS flange and the interference went away. I re-assembled everything and, knock on wood and a prayer, the car started. Thus, I realize how lucky I was – one just has to pay attention 100% at all times, think things through and not get too eager.

I know it may be painful to do -- but I highly recommend pulling the cylinder head covers and inspecting that the cams did not jump teeth

If you don't know how to do this --- email me # mike@lonestarrpm.com and I can walk you through it.

Why? -- well I know from experience that you can be off a few teeth and still not have interference when cranking by hand -- but you may have trouble starting.

I got lucky and no damage occurred -- cheap tuition.

Also if you are off in the direction that the vario cam increases -- you could then put you valves in harms way. I don't know if you could actually get that

far -- but who knows.

I know you have been through a lot -- but an hour or two -- plus 24 hours of drying time for the cam covers maybe worth the alternative.

Mike