Who has done an IMS change (New Oil Fed Design Idea)

[feelyx]

Originally Posted by showbiz

Hello Tim, Good to see the testing is going excellent! when can I buy some stocksjust picked up a 2000 C4 Cab,Girls want a new autocross Porsche looks to have a IMS brg problem dealer did a service 1000km ago ? and when I took the oil filter off and lots of metallic bits (BRG) in filter,runs fine but want to do a IMS inspection..before it starts again .and retro fit with yours or ? it has 114000Km on the clock was serviced from dealer since new. all the best and great work on the IMS fix Greg

Hi Greg
Yep, the girls in my house seem to always get their way also The 2000 could have a single or double bearing, you will need to find that out first. Once we know what you have we can proceed from there.

[PorscheMallorca]

Hello to all board members

I´m from Palma de Mallorca, Balearic Island SPAIN, I really love Porsche engineering boards, I found this topic looking for information about IMS.

This from far, one of the very best topics about IMS, so I want to give my deepest thanks to his creator Feelyx.

I have a lot of information in this issue, and if you want I want to help as I can

Thank you very much for share all this very interesting information

Best regards

Ernest

[feelyx]

Welcome Ernest...
Thank you for the comments. Please do share with us what information you have on the IMS issue. We are always interested in learning more about the issue.
Would it be possible for me to order your club shirts for me and my wife?
Kindest regards
Tim

[PorscheMallorca]

Hello Feelyx

Thank you so much for your warm welcome

Well I started, two years ago a project related to this issue, my problem was that I had a double row bearing in my 2001 Boxster, and I wanted to replace it for a new one after 80K

After a deep search of the well known "special size bearing" 23,8 x 47 x 20 C3 clearance and steel cage, as you said here I found that bearing was a special production for Porsche.

Talking with NSK thy told me that I can buy it but minimun order 5000 units, at 60$ each, so I realized that I had to think in other way.

[PorscheMallorca]

I start research about the system bearing first with double row, here you have all data of NSK double row bearing.

It´s very interesting that double row bearing is an angular contact bearing and single row is deep groove bearing for the same operation ?
















If you compare dynamic and static loading ratings of double row bearing and single row bearing are almost the half !!!! for the same operation again!!!

[PorscheMallorca]

Sorry forget to mention that of course you can order shirts, please PM me

Well I don´t want to disturb your post, because I thought in other way than you, your idea it´s more much interesting !!!

Of course, faillure is about lubrication problem, but if you want this information about bearings I can also continue with them as well

[feelyx]

Bravo Ernest ! Please continue...
I will pm you about the shirts, Thank you

[feelyx]

Also did you get any information from NSK on the type or if any grease in the bearing? How about seal configuration?

[PorscheMallorca]

I didn´t get info on grease type, but about seals they are made from NBR and 2RS, as you know NBR it´s not the best option working under hig temps and oil, it will be better VITON.

I allways get a lot of info from SKF site, here is a chart about grease types

http://www.skf.com/medialibrary/asset/0901d1968005eb08

Bytheway I ever though that there are more single row bearings broken than double row, in fact, double row bearings loading rates are higher.

Some pics of single row bearing explosion

[PorscheMallorca]

I have a question for the board members

This is the 5 chains timing system ¿Do you know if all systems like this uses double row bearings?

[harrisracing]

Per your request, here is what I found. I finally got some time off of work (despite the fact that it was the 4th of July) and I yanked the engine and trans out of the car.

Doesn't take an expert to tell you that the missing nut and stud are going to be an issue! I am willing to bet mine looks just like the one pictured just before this.

I will be pulling the heads as well to see how bad this engine is before deciding on a used one or to rebuild this one.

[harrisracing]

Just for information.

[feelyx]

Ernest, keep comin' with the info, what is your design ideas?

Patrick, that doesn't look good, please post more pics as you go through the process

Update... I have been doing alot of stop and go traffic.... still no issues, running like a champ.

Onward.....

[harrisracing]

Yanked the heads and looked at bearing today.

started breaking down the driver side head first (4-6). Got the cams off and noticed 2 caved in lifters. Didn't look promising and SURELY I thought the timing being off jammed valves into them. I have NEVER seen lifters like this destroyed...is this normal? Decided to keep going and pull the head. Good news is the pistons and cylinders look perfect. 24k miles perfect - no dings from valves at all which got me totally concerned about the lifters?!?!

Pulled the other head on the passenger side (1-3). This time lifters looked good, but I kept with it since I already had done the other side. Yep - 6 tiny dents in the pistons from the exhaust valves "kissing" them. I didn't pull the valves yet, but I'm sure they are bent at least to some degree. Again, cylinders look perfect.

Now the bearing. Yep total trash just like what was posted above - what a shame. Now I'm sure I'm looking at a total rebuild despite the fact that the bottom end looked so nice.

So I'm just debating now whether or not to send it all off to have the complete longblock rebuilt, try it myself, or look for a used engine.

But...as promised here are the pictures.

[harrisracing]

Also notice the dinged lifters are on the INTAKE side of the engine and only on 1 lifter of both cyl 5 and cyl 6.

Just wanted to point that out if anyone was curious. Looks like I will need a new shaft totally and/or have this one rebuilt.

Patrick

[feelyx]

WOW!!
Have you filled the combustion chambers on the heads to see if they hold water? Even though it looks totalled.... it might not be.
I am curious if the clapse of the lifters saved the intakes valves, and gear slippage on the IMS saved the exhausts valves.
Were there any signs of damage to the cams (bent)?
You might be a lucky one and just have lifters and a shaft to replace.

[feelyx]

She was pulling into a parking lot...? <1500rpms?

[feelyx]

....and if the shaft isn't bent, that might be a good canidate to bore out for your bushing idea then press back together and pin the gear.

[harrisracing]

These are pictures of pistons 5 and 6...where the bent LIFTERS are. Observe that there are NO signs of the valves hitting the pistons there (and this would be even stranger due to the fact that only ONE valve in each cylinder would have hit to dent the lifters). And as "perfectly" domed as they are, it is completely apparent to me that this not done in only a few rotations after the timing slipped...

Recall that this engine literally had 10 seconds of run time (maybe) after it died on my mother-in-law in a parking lot literally pulling into a spot. She tried to restart and it wouldn't. She called me and told me to come see it. It DID restart for me (after some hesitation), and actually cranked up semi-smooth, but sounded like MAJOR destruction as soon as it came into the revs.

This is what I think happened:

1) Looks to me like the lifter damage was unrelated...maybe low rpm service (and only 24,8xx miles) does these in as well?? (low oil pressure operation, etc?)

2) Then I think the IMS finally gave out totally and the chain from the IMS to cylinders 1-3 jumped time by just a few teeth (enough to bend the exhaust valves and shut the engine down). This made the engine give a big cough and stop running as she was parking.


I am willing to bet the valves in the cylinder head for cylinders 4-6 valves are perfect and if not for me having to split the case to replace the IMS shaft, I could have left this bank intact (despite what the lifters looked like).

I am going to confirm this by removing ALL valves from the heads one-by-one and testing them for straightness on my drill press. Replace/lap valves and prep heads/cams for reinstall.

Then look into my options for splitting case and replacing the IMS shaft.

As "lucky" as I may be, remember this engine has only 24,8xx miles on it - and if having to split the case and put this much time and money into this repair is as good as it gets, I don't feel too lucky.

[harrisracing]

Originally Posted by feelyx

....and if the shaft isn't bent, that might be a good canidate to bore out for your bushing idea then press back together and pin the gear.

I re-read this thread a couple of days ago. Your pictures where you indicated having "case flex" could really be another major issue. If that joint doesn't keep the bearings rigidly inline with the shaft then we are all at a major loss. This case flex would put too much torque on the bearing and cause it to point load and fail too quickly. Could this have been a cause of the wear that you had when testing your "bushing" idea?

I may be reaching with the case flex concerns, and the lack of lubrication may really be the source of all of our problems, but either way it's a design flaw for sure.