Repairing oil leak behind oil pump housing

Hi all, I am still chasing an oil leak which ive traced back to where the oil pump housing mounts to the engine block. Im thinking either the o-rings need replacing or worse case the flange that seats into and around the IMS shaft has a crack in it. I would like to do this repair myself but with the engine in place or atleast lower it down with the engine mounts removed from the corners. I understand the rear bumper and exhaust needs to be removed to give me access Ive been looking for a guide for this but can't seem to narrow anything down. I purchased a Bentley manual hoping the steps would be in there but I can't seem to find anything in there. Does anyone know if there is a section in the Bentley manual which outlines this job? I found a post on this thread (post #5) by KrazyK who shared some steps but I was wondering if anyone knew which guide these steps are from so that I can see the photos related to it: https://rennlist.com/forums/996-foru...ff-center.html Car is a 2000 C2 2.4 manual. Can I get away with locking the engine at the pulley in TDC and removing the two easily accessible chain tensioners and leaving the one under the AC compressor? The engine has lots of fixes done recently such as UAOS, New oil cooler, New Vacuum lines while at a garage Appreciate any guides and tips to do this job. Thank you

R u talking about the cover that bolts to the block. This is sometimes called the front coolant casette. If u dont pull the tensioner under the ac compressor it will pull on the ims shaft and it wont go back together. Just unbolt the compressor and lift it out of the way (no need to break open the system). There is a metal gasket that goes under that casette. Raby suggest using the copper high temp spray gasket maket on the gasket. As far as thw repair goes....lock cams, pull tensioners, unbolt, clean and reassemble. Its fairly straight foward.

Im referring to item 22 So the tensioner under the AC compressor is the one that really needs to be removed and the other two can stay in place? Can I lock the engine at the lower pulley or do the cams need to be locked? Can the cams be locked with the engine in situ? Regarding this metal gasket you're referring to, is this for the coolant areas of this housing? Could you link me to more info on this please as it's the first ive heard of it Thanks for the help

Leaving the back 2 tensioners in place is a maybe. They will pull the shaft and it may force it out of alignmnet. The one under the ac compressor will deff need to be removed. I would lock the cams themselves. Im pretty sure u will need to pull the crank pully to remove the casette. If u r confident your leak is cominh from the pump area u will need 6 and 14. Edit ....also 3 https://www.autoatlanta.com/porsche-...section=104-00

[QUOTE=De Jeeper;20014194]Leaving the back 2 tensioners in place is a maybe. They will pull the shaft and it may force it out of alignmnet. The one under the ac compressor will deff need to be removed. I would lock the cams themselves. Im pretty sure u will need to pull the crank pully to remove the casette. If u r confident your leak is cominh from the pump area u will need 6 and 14. Edit ....also 3 Thank you! So all the gaskets and the o-rings. But the hex key too? Will I need to drain the coolant system and the oil to do this job? Do I replace the tensioners or can they be reused? Anything else I should look at doing whilst im there? Is it easy enough to lock the cams with the engine more or less in place? Thank you

Yes on the coolant oil. It will make less of a mess. Tensioners can be reused if still functioning (no chain rattle) some replace as preventative maintemance but that depends on mileage. The hex kee is not really a wear part but some have failed over the years. There r some upgraded units out there.

LN Engineering has the upgraded hex drive.

You can buy a Bondhus allen wrench and make your own hex key for about $1. I'd change the O-ring also if you take the housing off tbe crankcase. Part#2 in the Auto Atlanta picture.

The oil pump console has a snout that fits into the crankcase. It has two o-rings that seal it with the crankcase. If you are pulling the oil pump it is IMPORTANT to pull the oil pump console straight out from the case. It’s you side load it you can break the snout off the oil pump console and that will require you to then replace the oil pump console. When installing the oil pump console be sure to lubricate the o-rings prior to reinstalling the oil pump console.

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Someone did just break a console on here ....

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What ever happened here...? What was the outcome..?

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Thanks, I’ve seen some photos where this has cracked off and stayed in the engine because people have pryed it from one side. Hope that doesn’t happen to me! Will rotate it once unbolted to help Please share more info lol

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Hi! so in the end I got a second hand engine to get the car back on the road as rebuilding the old one was way out of my budget and needed the car back on the road as it�s my daily and only car Replacement came with a new water pump gasket already fitted including the piece behind the oil pump console so my thinking is that the seller must have loosened and disturbed the oil pump console to slide the gasket in behind which have caused some damaged to make it leak from there. Couldn�t see any leak from above this area so that�s why I am suspecting it�s from behind the console

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please could you share more info on this suggestion from Jake Raby please? I tried to search for it but not sure if I am searching for the correct terms

Are the cams easy to lock while the engine is in the car? From what I understand there are plugs that need to be removed to access the end of the cams to lock them? So should I buy new plugs/caps for these?

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Its in one if my threads i think but it would be from a few years ago. Not sure if i can help beyond that, it was just a comment he made as i was doing some repairs. Yes u need plugs, u can lock the cams with the engine in the car. Follow the instructions for imsb replacement.

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Cool, I will look through your threads Saw one video where they only locked the one cam on the rear end of the engine on the left side next to the exhaust tailpipe. It was only the bottom cam. Would this be sufficient enough? When I searched for locking kits, there only seems to be one plate in the kit for the cams so I was wondering if only one cam needs lock or at least one side of the engine I also have a BRS sump spacer and an EBS racing baffle both from LNE as preventative mods Anyone one have experience with these?

I would drop the engine to do this. It's not much more work considering everything you need to remove to get to this. Also, you want a lot of space when pulling out and installing this piece. The snout that goes into the block is extremely easy to break. On Raby's DVDs, he installs this piece before the block halves are put together to avoid having to push the piece in and risk breaking the snout. Also, I would lock cams and remove all 3 tensioners.

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From working with Flat 6 Innovations and LN, I've gathered from them that a broken front console is one the most common mistakes that people make when attempting to remove the console from the engine. As you can imagine, the remaining part of the "snout" stays broken off in the block. It's a real challenge to safely remove the broken off snout from the engine. Word to the wise!

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I will ry and lower the engine down as much as I can but I just don�t have the means to drop it completely plus I don�t want to go to that extent if it�s not need seeing as others have mentioned it�s possible with the engine still in position Regarding locking the cams , so far I�ve only found kits which have only one lock tool to fit onto one side of the engine. Is it correct that my engine is a 5 chain engine being a 2000 3.4? Could someone suggest a lock tool kit that would work for the job I need to do please? Will locking just the one side and then removing all the chain tensioners be okay to do?

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oh wow hope I don�t get into this trouble. Is there a trick on getting the console off in one piece then? Would unbolting it and then rotating it before pulling it away help?

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For a seasoned m96 mechanic, in the car is doable but not preferred. For someone thats had the pump housing off and on the engine on a engine stand in previous jobs its doable in car. And knows there way around the peculiarities of the m96 pump console install methods. For a rookie mechanic, the tight quarters makes this job difficult and a good way to bust stuff at worst, and not get it installed correctly, suffering from leaks/busted parts/whatnot.... Do yourself a favor. Drop engine and do this job with engine out of car. Then you can Do all the other maintenance that should of been done when this engine was installed a few months ago. Like the aos, its very brittle hoses and connections that are prone to oil leaks. Plugs/injectors/plug tubes/coil packs/ pully/tensioner/ belts, worn hoses, etc... And I'd not assume the water pump was just changed with a proper oem plastic impeller pump. I'd take that out and at the least check it along with a low temp t-stat. Not sure what any of this below quote means, but having a better look at this out of the car might be a good idea... After looking at engine out of car you might find the oil leak is not even coming from where you think it is. Oil flows downhill, with engine out you can see everything better and have room to do proper assembly work. And clean complete engine of grime and oil. IMHO dropping engine is the only way to go for you. But if you're a gambling man, like I see you are with a "used m96 second hand engine" install, then go for it... jmo

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Thanks for the info, Not sure if your trying to scare me off from doing the job or not but I appreciate your help So as per my first post, When the replacement engine was fitted an UAOS was fitted, Vacuum lines replaced, New oil cooler and seals, New seals for intakes, New water pump with a plastic/composite impeller, New spark plugs. Recently I've done the oil fill tube and seals because I thought this could be where the oil was coming from but it was not. Engine it self was clean when it went in also. Regarding the water pump gasket, There was a brand new fitted when I purchased the engine. This was the complete gasket so the tabs were not cut off for the piece behind the oil pump console. Hence why I am suspecting this may have caused an issue leading to a leak. I have checked above the oil console a few times now and I cant seem to see any oil dripping from above anywhere. Is there an area directly above the console thats prone to leak? Either way, from everyones feedback, the console will need to be carefully removed so hoping someone could advise on the best way to attempt a successful removal. If both banks of cams need locking where can I find the correct locking kit that will allow me to do this?

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No not trying to scare anyone. Just to give you all the info i have learned over the last 50 or so years building engines. This engine is very fussy in the way the front console is assembled/removed and not having the experience along with no room/correct perspective to R&R it properly, could easily lead you into more problems than you now have.... Unfortunately you now have a oil leak. And suspicious areas of your concern that might not be sealing correctly. I missed your post of maintenance work on your replacement "used m96 second hand engine". Good job on doing those things, smart move. Its great the engine is now clean, as it should make finding the leak easier. Even with all your good maint done so far, still think its in your best interest to drop the engine and double check everything done and search for the leak source unencumbered by the engine bay close quarters. You don't want to pull that console unless its absolutely necessary imo. And then if you do need to disassemble the engine front console you'll have room to remove it and assemble it properly, leak free and centered correctly. The console is a very important part of a m96 as the ims bearing/bushing that the shaft rides in is part of the console. The console does many jobs on the m96, got to get it right for sure.... If you got this engine from a dismantler/bone yard/eBay, they routinely combine multiple blown engine good parts together to get 1 'good' engine. My local bone yard gets a blown engine 996 in every few months or so. Most of their failed engine cars have some amount of other heavy wear/damage making the car a parts car. Can't fault them as they need to do something with their pallets of NG 996 engines/parts in varying stages of disassembly..

I didnt find the removal and instal all that hard but it was tight. i used this along with the tool in the kit ti lock both cams. https://www.9products.com/product/6110/cam-lock-tool

I spoke with LN because I enquired about their cam lock tool kits and they said that by locking the crank pulley at TDC and having one Bank locked then there shouldn’t be any issue with any timing loss. So question is can I lock just the left bank (looking from behind the car) and remove all tensioners to do the console job?

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Thank you! I’ll grab one of these then to go with a locking kit. Was it easy to install this on the right bank where the cam plugs are facing the front of the car?

Use the lock in the tool kit on the rear of the motor drivers side, use the tool i posted on pass side front (transmision side). U have to remove the large ground wire and use the bolt. Having both tools is nice but not 100% needed if u r careful.

Hi All, Finally got around to try and fix this today. I started to things apart and I found more traces of the oil leak but away from the oil pump housing! It seems to be travelling down from below the AC compressor somewhere and then down the side of the engine and then spreading along the bottom: I can see abit of a puddle under the AC compressor with my camera I started to remove the AC compressor but there seems to be two extra lines connected at the back of the compressor (Circle in red). Could someone tell me what these lines are and if I can safely disconnect them or do I need to reassemble the car and take it somewhere to have the whole system degassed before I can disconnect these two lines at the back? I was hoping not to disconnect anything AC related. I need to remove the compressor out the way so I can see where this oil leak is. Would be grateful if you can help me out so I can find the issue and get the car back together. Im hoping the leak is somewhere under the compressor and not the oil pump housing fingers crossed! Appreciate the help, Thank you if anyone has any ideas on where the oil could be leaking down from please let me know

Those r fuel lines for the fuel cooler. Suck out the power steering fluid and remove the resi, then u can just pull the compressor up and out of the way without disconnecting anything.

That residue looks green-ish to me. Does it smell burned? If not you may have an A/C leak. A/C oil is usually dyed green.

Pentosin power steering fluid is green also. it could be a power steering fluid leak at the pump or reservoir.

Thanks for the reply guys! Managed to get the AC compressor moved abit after removing the PAS reservoir like De Jeeper mentioned. Cleaned up any oil I could see sitting but I couldnt see anything leaking from that area. Was stumped as ive come this far so decided to keep going with the Oil pump housing removal. Managed that without any issues. The O-rings on the flange looked abit tired and there was some greyish sealant around the flange also. Cleaned it thoroughly and fitted brand new O-rings and also brand new gasket and seals. While I was there I fitted a new oil pressure valve and LN engineering hex key. Still got to finish putting the rest of the parts back on but fingers crossed this has fixed the leak issue as I really cant see anywhere else it could be leaking from. Im thinking that the oil drip down the side in the above photos might be PAS fluid overfilled and then overflowed out the pipe and then mixed with the oil that was sitting in a cavity above and maybe the oil leak was actually from the oil pump housing So confused but hope its all sorted!

Check the metal return pipe for the power stearing. It goes into the lower section of the ps resi. It just has a couple o-rings and is a quick disco. They r known to leak because the powder coating fails and the o-rings no longer seal. U wil probably have to use your endoscope camera.

Is it this line? Sorry for the unclear photo. This line is the one that bolts to the side above the chain tensioner and then snakes under the ac compressor

I cant remember by looking at that photo. Ill try to dig up the thread that i was in about this subject. One ps hose comes around to the front of the ps pump. It screws in under the pulley. This is the high preassure line. This line sometimes develops a leak at the metal to rubber crimp. The other is the return line and it snakes around to the back of the pump and pushes into the plastic resi.

I think this is a good thread to review. It also has a link or 2 to other related threads. https://rennlist.com/forums/996-foru...se-leak-4.html

Got the car back together and started it up, all looked fine. Went through the process of bleeding the coolant system semi successfully with lots of overflowing. Got that sorted and went for a drive. Made a stop to check under the car and saw that oil is still leaking from somewhere . Still in the same place of dripping from the lowest point of the oil pump housing and the lowest point of the engine case halves as per my previous photos. I looked up between the oil pump housing and engine to see if there was a leak from the flange that goes into the engine case around the ims shaft and that looked to be dry. I’ve cleaned it off for now so will need to drive it a bit more and see how it goes. The leak is a slow seep. But I’m tired of trying to chase it! I looked around the ac compressor side to see if anything leaked down from there as per my previous photos but that was all dry One new issue is that my oil gauge on my cluster doesn’t seem to show a reading when turning the car on. I did disturb the plug on the sensor while I was refitting the ac compressor. The plug seems to not click into place so I guess it’s come loose. I think the clips have probably broken off. Is there a fix for this? Does the plug only go on one way? I had to refit it by feel as I could not see down where it connects Not sure where to go from here now either. I really appreciate everyone’s help in guiding me, you’ve probably saved me a lot in just labour charges

Add some uv die to the engine oil. See if the leak glows with a uv light to determine that it is actually coming from in the crank case. From your previous pics i suspect its leaking higher up.

Yes I’ve done the UV dye before so it’s still got some effect on the new oil as that’s how I was checking after this job So this area seems to be bone dry and clean after driving yesterday so I think it’s not from that area anymore. this area is to the right of the oil pump housing Plus the leak is more localised to the lowest and centre point of the oil pump/engine I found there is a TSB for oil leaks from engine bolts on 99 engines. The replacement block I got was from a 99 so now I’m thinking this could be it as initially on first investigation it looked like the oil was seeping from the bolt heads. If anyone has further info on this then please let me know. I will look into this more but I also want to enjoy driving it and fix other worn out areas on the car. Is this normal for 996 ownership?

Hi all, been awhile since I updated as I�ve been going through everything to track this leak down. I think I finally found it so now trying to sort it so it seems to to be leaking from the front main seal behind the pulley. Found some instructions in a workshop manual which guides you to replace it with the engine still in place and this is what I found once I removed the pulley: Definitely leaking from here! Extracted the old seal and cleaned up the bore and made sure there wasn�t any sharp edges in there on the casing side: pressed in the new one: and got it all back together and went for a drive hoping it was all sorted but got back and checked underneath and it�s still leaking Used a borescope camera to check behind the pulley and saw oil had pooled on the seal just like before: now I�m pretty sure I pressed the seal in as far as it would go. I didn�t want to over do it. It�s certainly further in compared to where the old one was. I think it�s not sealing around the shaft as it�s pooling in the holes in the middle of the seal as you can see in the photos. The seal is genuine Porsche bought from FCP with part number 99911347540 I couldn�t pressing the seal further in but I�m worried it will be too far in. Does anyone have any experience with the FMS? What am I doing wrong? Really appreciate everyone�s help, thanks

In your photos, the end of the crank (where the seal rides) looks a toile rough. Did you clean, smooth that surface to remove any grooves or rough spots. Most seals leak on that surface where the crank is turning in the seal rather than from the outside of the seal which is static. I have polished the end of the crank with fine sandpaper or emery cloth. Be sure to clean out any residue from polishing prior to fitting the new seal. Good luck with the repair. Mark

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Ah no I never touched the end of the crank as I was thinking it should be fine. I just wiped it down with some brake clean on a cloth. So I should go over it with some fine wet n dry to polish the surface? Looks like I need to buy a new seal then as there�s only way to get them out lol. Is the depth I�ve pushed it in good? thank you

You need a speedi-sleeve to cover the wear marks on the crankshaft.

I dont know the part number but speedi-sleeve makes very thin sleeves that go over the seal surface and renews it. On my Cummins motor it is a repair kit and it comes with a special seal. The origional seal material can groove the crank so u want to be a little more proud or even deper then the original seal if u can feel a defect if a repair sleeve is not available or not used. This might be it but a quick search and i couldnt really find a result for the 996 front crank seal. Maybe LN-e or @Slakker knows? https://www.ebay.com/itm/306112115523

Looking at the case half, looks like you created a path by cleaning the silicone off on the bottom case half, can't see the top half I would apply silicone back in that and upper half, and use a speedi-sleeve on the crank, no one has one but if you measure the crank and go to CR/SKF who manufacture sleeves according to crank journal size.

So it�s best to just sleeve the end? I�m thinking if I end up just cleaning the surface and giving it a sand with some fine paper only to find it leaks again then I�ll need to do the job again! I�ll reach out to LN and see if they can help regarding the silicone, do I just smear some over where the two case halves come together? thanks all!

Since you put the seal deeper it rides on unworn surface that has always had oil coverage and thus no corrosion. As such you put it where it sits best. I think the removal of silicone sealant between the two cases halves is the much more probable cause for the leak you experience. Smearing some over it from the outside has little chance to work imho but since it cannot get any worse, you might want to give it a try. After that the only way to seal it would be by removing the current seal, smear sealant between two case halves and some around the outer circumference of the seal and then refit it.

Yes the plan now is to remove the seal completely again and address the issues. Don’t want to just patch up. I’m just hesitating to remove the pulley again just to measure up for a sleeve and then put the pulley back on so I can still use the car as it’s my daily lol

I did use a speedy sleeve on a 72-911 cam shaft, and it worked to stop the leak. I also used a speedy sleeve on a BMW crank shaft and it worked for a while ...

If the seal isn't perfectly square to the crank, it will leak. Here's a few steps to use as a guide... - Use very light emery cloth or Scotch-Brite to clean the bore and crank surface. You don’t want to remove material—just ensure it’s smooth and free of old sealant, corrosion, or debris. - Wipe everything down with brake cleaner or alcohol to ensure it’s completely clean and oil-free. - Apply a thin film of clean engine oil to the crankshaft surface, leave the outer edge of the seal dry to avoid it spinning in the bore. - Use an install tool to keep the seal perfectly square to the crank. Even with the tool, pay close attention to how the seal is starting—it should press in evenly all the way around. - Press in slowly and evenly. Work slowly, keeping constant even pressure.

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Appreciate your help! I did make up a simple install tool and used that to help press in the seal using the pulley bolt: It must be because I didnt clean up the crank end surface properly. Do you think thats all ill need to do? I asked LN regarding the Speedi sleeve and they couldnt help with it. Pelican sell them but said theyre suppliers do not carry one for the 996 3.4. I guess as others have suggested it would mean to take a measurement and buy accordingly but I'm hoping a good clean will do the trick

You don't need a speedy sleeve as any ridge in the crank surface from the previous seal sits outside of your newly installed seal, since you've had it sit slightly further inward.

Managed to get the seal replaced again. I cleaned up the crank surface properly this time and also pushed the seal in slightly further. So far it�s holding and sealing fine. Haven�t see any leaks underneath so it looks like it�s fixed it fingers crossed! Thank you all for the help and your patience with me on this issue. Appreciate it

Thank you for closing and updating the thread. Unlike others who don't .....