IMS upgrade then CAM timing off first start

IMS bearing replaced preventively, AOS, Clutch etc... while in there. After install first start up check engine light. CAM Chain timing. Invoice from shop states engine drop and re timed. Coincidence or poor install of IMS caused this. Is this a red flag. 2002 C4S

Yeah that sounds like they didn't do things properly and lock the timing like they were supposed to Assuming the timing has been fixed I don't know what, if any, long lasting effects there could be, but that would make me question everything that shop did.

Wow...did they actually give the car back like that?

No. After IMS install first start in shop check engine. I am not the owner. I am considering buying the car and going through the service records found the note from the shop on IMS install and saw the notation. I have a call into the shop to see if they can shed more light on this.

Read though some of the engine rebuild threads (Asai/Cringley and or AWDGuy I think) - there's a condition that when locking the cams at TDC (inserting the cam lock tool) it's possible to have the cams 180 degrees out of phase - evidently the cam lock still fits in the slots, but not properly/straight. I think the result of this may be one of the timing error codes...

Thanks dporto. The shop provides a two year warranty on the work so i am not overly concerned. I am just wondering if any long term damage might have occurred. Sounds like the check engine light was right away on first post IMS install start so little run time in this condition. I'll post up more once I get a call back from the shop.

Bad work is bad work. What else that they did was done wrong or at least with sloppy? Might consider moving on to another car.

Forgot to lock the crank and cams? Hmmm...installed the bearing with a sledge hammer because it almost fit? Unless you get a full PPI including current cam deviations values...move on from this one. That is just shoddy work by an inexperienced shop. There is an established methodology for bearing replacement that they did not follow. Makes you wonder what else they screwed up.

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Warranty to anyone during the two year period?? Usually just the guy who pays for the work gets the warranty. Probably should check.

There maybe some who would dismiss these comments as alarmist. Indeed ,there may be no lasting damage but you won't know until something fails. This IMS work is not ideal for the "slap it in,get 'er done" mechanics. Exhibit #1 is the LN Installation Instructions. This runs to 17 pages ! On Pcar Forums you'll find threads on IMS jobs that show inadequate cam locking (per old,incorrect Pelican Instructions !) that go horribly wrong. http://imsretrofit.com/ims-retrofit-procedure-overview/ http://lnengineering.com/files/IMSR-...n-Warranty.pdf

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Depends how much the cam timing is off. It wont take much deviation that causes valves hitting the pistons. If the valves bend just litle, engine will still run, but risk that valve will break after some time is high.

$hit happens, they mus have fixed it since the light is not on anymore and the engine is running well. I wouldn't worry.

Hi all- can anyone provide insight into the condition described by the OP occurring approximately 100 miles after IMS replacement, rather than on the first startup/immediately after the repair, as the OP experienced? I had the IMS/RMS/AOS done and drove 100 miles with no issues. Then while driving at highway speeds I lost all power and the dashboard lit up. The mechanic said the oil pump seized, causing cam timing to jump, cracked cam sprocket, and damaging valves on one cylinder head, pretty involved valve job on one cylinder head to fix but unrelated to the IMS repair. I think the timing is very strange as there were no obvious issues before the work was done, but I don�t know enough to be sure, and it didn�t happen immediately after the work was done which would make it more clear that this was the cause. The condition described by the OP seems very similar to what I experienced, except for the immediacy with which it happened in that situation rather than 100 miles later as I experienced. Any insight would be greatly appreciated!

Ask your mechanic to open up the scavenge oil pump and see what's in it /why it seized (oil pumps usually don't just seize for no reason).....ask him to show it to you, take a picture of it and post it. What year model is your car ? What is the mileage ? Is the seized scavenge oil pump on bank 1 or bank 2 ?

I will ask for that. Thank you and thanks for the quick reply. It�s a 2000 996 with 72K miles. I believe he mentioned bank 1 but will have to check my notes.

Used too much silicone sealant. Some of it breaks off and blocks the oil passage to the scavenge pump and it seizes after 100 miles. That is just a theory.

Thank you for this theory. I will try to press the mechanic on that as well. As I�m not very technically inclined and I want to be as clear as I can with him- can you be specific on the various places the silicone sealant would be applied, so that I can be really clear with my questions to him? What would you say the likelihood is that this is the cause? What are some other possible causes for the scavenge pump seizure, and are they also potentially related to the work that was done (IMS/RMS/AOS/Clutch)? I�m at a disadvantage here because the car was towed back to the same mechanic (a Porsche specialist) who did the original work 100 miles ago, and he�s not exactly incentivized to take the blame for what went wrong� Thanks again!

I feel your pain and wish you good luck in dealing with this. Check out the engine assembly videos on Finn's channel (he posts on rennlist too) to see where sealant goes: https://youtube.com/@ManinaGarage Incomplete list: both case halves, each cam cover and oil sump cover. Get a picture of the scavenge pumps BEFORE removal too. You want to be convinced they were fitted the correct way around as a sign of professional workmanship

Nothing he says he had done would necessarily require any sealant or removing the scavenger pumps. If is related to the work done then my guess would be damage to the ims or improper installation of the bearing. There was also someone recently that found the metal ring of the RMS in their engine from improper removal.

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He said " After install first start up check engine light. CAM Chain timing. Invoice from shop states engine drop and re timed." Retimed means the valve cover comes off ...

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That is the OP from 6 years ago. We are discussing the person who had an issue and revived this thread in post #13. I understand sometimes people don't read the whole thread.

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Yes, you are at an extreme disadvantage, both in terms of experience and who is incharge/first to observe.. My advise is to be inquisitive, but do NOT be accusatory...be very specific that you just want to know what seized the oil pump, but do NOT give any theories as to what you suspect... , AND very willing to pay for the answers you seek... I think most people and Mechanics are honest with good intentions..and inquisitive. He may think he did nothing wrong, and when he opens up the oil pump and see's whats in, he may not even recognize what it is or where it came from..That is to YOUR advantage... Post the findings/picture here.... Correct, the commonly used ( and Porsche approved ) procedure to remove the RMS is to drill a 3mm small hole in the old RMS and screw in a sheet metal screw you can grab to pull the seal out....there is a small tension spring around the inner lip of the seal that CAN be popped off when drilling the hole. There is no mention of the possibility of this spring popping off in the approved instructions......IT MUST BE REMOVED FROM ENGINE IF IT POPPED OFF.....I have found pieces of this small tension spring in oil pans years after the RMS was replaced.....It can flop around harmlessly on the crankshaft for years before the timing chain grabs it and chews it up sending metal bits everywhere..Like "Pickup Stix" it is just luck in how the bits fall and make their way to a safe place in the oil pan by gravity as to if they go through an oil pump or not...If they go into an oil pump it will surely seize it.. I didn't want to put out a theory/hypothesis/SWAG/guess but you did ask for them and will get many different ones Good luck !!!

Thank you all for your feedback and ideas. I�ve pieced together the theories and here is the plan of action I�ve come up with, open to any other ideas or corrections if I�ve misunderstood anything above: Ask if the seized scavenge oil pump was for bank 1 or bank 2. Ask for a picture of the scavenge oil pumps before removal (if possible), to make sure they were refitted correctly after the work was done. Ask for a picture of inside the seized scavenge oil pump to try to identify what may have gotten in and seized it. Possible causes: Too much silicone sealant was used and it broke off after 100 miles, blocking oil passage to the scavenge pump and seizing it. I reviewed the Pelican Parts IMS installation guide and flagged anywhere silicone sealant may be applied in the process: A. Intermediate shaft bearing cover: �With both single- and double-row installations, you will want to use a new seal on the cover. If your cover is the older-style one with the small black O-ring, you will want to upgrade to the newer-style cover and improved seal to guard against leaks. I also like to place a small bit of Curil-T sealant on this seal when I'm installing it, just as an added measure of oil-leak protection. � B. Set screws for IMS shaft cover: �With the cover fully in place, you can now remove the set screws. Replace them with new micro-encapsulated bolts included in the Pelican Parts kit� � It's okay to reuse your old bolts, but be sure that you coat the threads in a sealant like Curil-T or Loctite prior to installation or they will leak. Tighten the bolts down to 8 ft-lbs (11 Nm).� C. Center shaft O-ring: �With the cover installed and the cover bolts tightened down and sealed, install the O-ring on the center shaft (Photo 20). I recommend putting a thin layer of Curil-T sealant around this O-ring in order to help seal against leaks. With the O-ring in place, now install the spacer. Finally, install the 12-point nut on the top, tightening it to a maximum of 24 ft-lbs. I also recommend placing a bit of Curil-T sealant underneath this nut. D. Camshaft end caps: �After you're done checking the camshafts, install new camshaft end caps as shown in Photo 27 of Pelican Technical Article: Porsche 911 Carrera Camshaft Swap and Valve Train Repair. Although I like to use a bit of sealant everywhere, these end caps don't tend to leak.� Theoretically, too much sealant in one or more of the locations above could have broken off and blocked oil from getting to the scavenge pump causing it to fail? 2. Improper removal of old RMS may have resulted in the small tension spring around the inner lip of the seal to pop off, and pieces of it could have been rattling around the crankshaft until, after about 100 miles, it got sucked into the oil pump. 3. Improper installation of the replacement IMS bearing. Note- this is the first thing I asked the mechanic and he said that the replacement IMS bearing itself looked fine upon inspection. Additional questions: 1. Could the oil pump seize as a result of no specific debris/oil starvation? In other words is it a wear item or a known weak point on these cars that may have just worn out after 23 years / 72K miles? 2. Are there any common issues that could cause the oil pump to seize that are completely unrelated to the work that was done? Thanks all for your input.

Too much sealant on the parts specifically mentioned in the instructions above (good thinking on your part to go through them!) will not end up inside the engine but in the bell housing or outside the engine in case of the cam plugs IMHO. I would ask the (open) question of which type of sealant he used on your repair. Anaerobic ones like curil-T have the benefit that any excess squished out between the parts when fitting is dissolved into the oil. Do tell us please if the mechanic timed your engine too as mentioned in post #1, or not.

Update- I am told it was the scavenge pump for bank 1. Also, the mechanic has not yet opened up the oil pump to determine what if anything got in it. (Is it possible to diagnose that the oil pump seized and caused the damage that occurred without opening the pump up to see that something is inside)? I requested a photo of the inside when available.

Pkease tell us: Did he re-time the engine like mentioned in post 1?

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You realize that post 1 is not the same person we are discussing now right? This person revived an older thread.

Yes, I am aware and that's precisely what is triggering my question.

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Sorry I reread your question and I do see what you were asking. Why would the engine have been retimed for the work he had done. Don�t understand why this question is relevant to the current discussion. The op only had the engine jump the timing. They retimed and I would guess he was good. This person had a big failure. Doesn�t sounds like anything been done to it except the initial diagnosis.

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Can you (or anyone) tell me what Finn�s username is on Rennlist? I would like to contact him in reference to a video he has posted ( You Tube ) where he references in the description a timestap for �Oil Pump IMS problem� but it doesn�t match the video. Any help reaching him would be appreciated! It�s at the bottom of the description on YouTube it says 11:09.

I'll tell you when you've answered my question I asked you in this thread...

Hi, I appreciate your question, and I�m trying to get answers from my mechanic on this and other things. Unfortunately the mechanic has not been very communicative and my main concern is it getting to the bottom of what happened here, before he is in 100% control of the narrative. To do that I am trying to figure out what I can on my own, if possible, to present him with questions or theories as to what happened. Any help in getting in touch with Finn would be very helpful to me. Thank you.

If you have not yet found out what is inside the "seized oil pump", you are loosing your opportunity to find the "smoking gun"...

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I suspect you missed the fact that since post #13 it is a different case from the one in post #1...

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https://rennlist.com/forums/members/...-a-garage.html If the cams and crank have only heen locked in your case then no sealant has been required as only the cam plugs had to come out. Any excessive sealant would end up outside the engine and could not have locked a scavenge pump. However, If timing has been checked/measured then the cam covers have had to come off and sealant be used upon reinstall. Too much sealant in that case could clog up the scavenge pump. So you really want to know what has been done.

Smoking gun= Shops lot has more than Porsche's and Maybe Audi's in the lot. (If it has 2 of every German marque.. Oh well.. ) All the Porsches in the lot are Air cooled. You want someone focused on your car.. If you can find one any more. .

Well, here is a picture from a component within the scavenge pump. The thin strand of metal on the right side of the photo got sucked into the pump and is now fused on to this ring piece. The mechanic said had no idea what it was from�

That's definitely NOT a piece of the tension spring from the RMS, it looks to be the size and shape of a piece of the lock ring for the early dual row IMSB. Get the old IMSB ,see if it is a dual row and that ALL of the lock ring is accounted for.....They often break into pieces when extracted, but not always..

I know it was dual row, but unlikely I will be in able to get the old IMSB as the initial IMS/RMS/AOS/Clutch work was done last December and I didn�t ask for it at that time. Any chance someone can provide a photo of what the piece you reference looks like? Thanks for all of the help!

Here are some more photos�

You can easily search the archives here to find pictures of the dual row IMSB. The retaining lock ring is indeed a round wire of about that size, I'm 99% positive that is where that came from. It is way way to small to be a piece of a valve spring and I know of no other wire in the m96 engine that would be that size or likely to be broken..

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Looks like this. I would also agree that's the culprit.

understood on photos of the IMSB, was hoping someone could point to a photo of the specific retaining lock ring you are referencing. Would it be the ring in one of these photos? The first photo is from a single row to dual row ims retrofit kit and the second is a dual row to dual row retrofit kit. the piece looks a lot like the ring in the first photo, but less like the ring in the second photo. did the original retaining ring for the factory dual row ims bearing look more like the one in the first photo? thanks again for your help.

HBDunn- i had not refereshed and seen your reply, but I guess we were thinking the same thing! thank you.

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The one I posted is what comes out when extracting the original dual row, it's round. The second is a snap ring, which is flat. Those are used with the single row and some retrofits.

So....I guess the mechanic hasn't retimed the engine but the locking spring shard locked the scavenge pump which caused the timing chain to jump?

hardtailer, i think that is right, he told me he did not remove the cam covers when i went down that line of questioning.

can someone expand on how or why the retaining lock ring would break into pieces when being extracted, could this be the result of improper tools used (i.e. not specialized IMSB removal tools), incorrect technique, etc., how common is it, any additional information on this issue would be very helpful to me for when I go back to the mechanic as I am otherwise outmatched, though the picture now is pretty definitive. thank you.

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What bearing did they use as a replacement? Some use the same locking ring. I could see reinstallation maybe going wrong without the proper tools to compress the ring.

Hbdunn- my invoice says 106-08.4 for the part number which I believe is the part number of the LN Engineering retrofit kit, with a flat ring piece. Another question- what is the path connecting the IMSB to the scavenge pump, is it the IMS itself that connects the two? Trying to figure out if more pieces of this ring piece could still be floating around between the IMSB location and a new replacement scavenge pump, or, if once this was all disassembled to be diagnosed and fixed any other pieces would be visible and removed.

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The path would be it was carried by the timing chain up to the cam which drives the pump. The sump should be inspected for more parts and possible debris. The chain should also be thoroughly inspected for damage.

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There is no way to "pick" the ring out of the groove once it is installed in front of the bearing. The way to remove it is to use a special puller sold as a removal kit with the LNE install kit. The puller screws on to the shaft on which the bearing is installed and pulls the shaft/bearing out of the bore. In the process, the small retainer ring is squished and deformed in order for the bearing to slide out. Sometimes the deform is severe enough for it to break into pieces.

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Thanks for your reply. Replying to your last question, you ideally want to have all the pieces of the securing ring in front of you to make up a complete ring of the same size as an original one. Only then you can be sure. Ask the mechanic if he still has everything he's taken out (long shot, I know) and check if the piece you've found is the only bit missing of the snap ring he shows to you.. In my personal opinion the mechanic should take responsibility if he presents you with the rest of the ring but he'll probably understand where you're going and will reply that he's thrown them away and the bin has been emptied in the meantime etc. Then it is your word against his and you'd need to prove it is indeed a piece of the snap ring that secured the previous bearing that he removed and that that bearing was the original bearing that had been fitted to the IMS at its time of manufacture.