Questions about valve lifter replacement

o my car has been running great for several years. i autocross and track the car about 4 or 5 times a year and daily drive it. the best car ever and i will never get rid of it . however recently the car started misfiring after hard pulls. would get the car almost to redline all the way up to 4th or 5th gear and she would work perfectly until i let off the throttle. a little after it would start misfiring slightly but only for a few seconds. if i left it at idle it would come right back and keep going. but last week the car completely gave out on me. all cylinders were misfiring but cylinder 6 was the worst one by far. i do all the maintenance on this car myself and checked everything and nothing was wrong. engine oil perfectly clean and a good caramel color. spark plugs are brand new with less than 1k miles on them. coil packs are around 30k miles and i tested them all no problems, fuel pump also pushing strong pressure. but when i did a compression check only cylinder 6 was not holding compression at all. i feared bore scoring but after using a small camera to look inside the bores looked like new. so my deduction is i need to replace the valve lifters in the car and/or the valve springs. so sorry for the long read but basically i wanted to know if i should just replace the valve lifters and not bother with the springs or just do both since i have the cams off already. my gut feeling from working on cars for years is telling to do the springs as well but if its not needed i would rather not unless it's necessary. i also plan on just replacing the Valvetronic solenoids since everything is already off and i keep reading that they tend to fail. also if anyone can recommend me all the parts i would need to do this job it would be greatly appreciated. if i do just the lifters i know i will need new bolts for the cam cover along with the sealant for it, the valve lifters for intake and exhaust (obviously), and some new oil to press the lifters into before going in. besides that idk what else to get and just want to make sure i got everything. and if i do the springs ill need the removal tool along with new springs but i don't know if i will be needing the retainer or retainer keepers since I'm using the same valves. any and all recommendations would be welcome! this is the first time i do this on this car and its my baby so i want to do it correctly with the best stuff. thanks in advance for the advice!

Did you scope the cylinders from the top (spark plug hole) or the bottom (through the sump) ?

If the heads are off, buy new lifters and send off the heads to Hartech to have them re-done. You might have a burnt valve in #6. Really the only way to do it perfectly. How come you didn't hook up something like Durametric to verify your conclusions? Or Foxwell? See about these misfires?

I recently had a forum member contact me about his 996.2, he has had three failures of valve springs !! First was an original spring, the next two were NEW springs going out within a few months on different cylinders, on completely rebuilt heads... It's worth the trouble to check the springs....

Do a leakdown test and listen where the air is leaking in that cylinder and ONLY THEN figure out what the next steps are. Right now you are still just guessing.

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A friend of mine had a �blown up� Boxster engine that was replaced. We tore it down for a PCA tech day event, and low and behold, what was thought to be bore scoring or cylinder cracking, was none other than a broken valve spring. Valve contacted piston, and lost compression.

My persistent misfire that was caused by valve lifters noted in the thread below. It fixed the issue and I haven't had any misfires since. https://rennlist.com/forums/996-foru...estions-2.html

Hi Formerfrost I would say if you have no compression at all on that cylinder it's probably going to need the head off, you probably have a broken spring or valve seat, sounds like you have a partially open valve , take the lifters off and look at the tops of the valves , does one look slightly further down than the others in that cylinder, I don't think it's bore scoring myself as I know engines with scores bores can still run decent compression and if you have no compression on 6 I think the scoring would be really bad and you would see if from the top, I might be wrong but seems more like the head to me !

Maybe it's too late now, but I would have done is Compression test followed by a leak down test to see where the compression is leaking... then I decide what more to do. If I were to take the head off on a car that I take to the track, you can bet that the while-in-there list would be longer than valve lifters. lifters, springs tested, any questionable valves, variator, chain ramps, and tensioner pads.

thanks for all the responses guys. and with all this i guess ill just replace it all with lifters and springs. and i did not do a leak down test because the tool i had for it was old and leaking. and when i went to get a new one no one had them in stock (just my luck) but either way i already know a valve is stuck open because of the compressions test so either way the leak down test won't tell me anything i really need since I'm gonna end up doing all the lifters and springs anyway. and i can get to both with the engine in the car and just taking off the cams. now once i get there if i notice its not a lifter or spring and it is a chipped valve or leaking head then at that point it's just doing the entire head, and with the cams off half the job is already done. with that said, i don't think it's gonna be a head gasket that's why I'm gonna try and just do the valves and springs. because i haven't found any other evidence that it could be the head. i literally did every test i could to make sure (besides the leak down test since i could not do it) and quite honestly i don't think the head gasket is the problem. even the way the spark plug was full of fuel when i took it out and the smell the car is making makes me think its gonna end up being one of the exhaust valves that's open. plus after sticking a camera through the spark plug tubes and the oil drain plug i saw nothing to show any mixing of oil and coolant or any damage at all to the piston in cylinder 6 to show a valve hit it. in all honesty, from what i saw the engine was remarkably clean and healthy inside (all my OCD with preventative maintenance paid off) and showed no signs of anything so it seems whatever it is it's likely just a valve that's slightly stuck open but with all the stuff you guys are telling me i think ill just wait and order a leak down tester online and do it to find out exactly where the leak is. because quite honestly if it is the head i would rather send it to a good indy to do it. although i really doubt it is. any other ideas and advice is still welcome here guys. could use all of it!

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was reading your thread and these are almost the exact same symptoms i was getting with my car. so it would seam that it is actually a stuck lifter in mine just as you had. only time i had major problems was at high RPM and it would go away after the revs dropped and engine oil cooled down a bit. also the comment about not telling the wife about the major work on a car you just got was just gold. i have the same problem now lmao

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OE head gaskets are metal, they only fail from excessive corrosion.

You don't need a leak down testing tool. Just use the end of the compression tester and connect it to a air hose. Thread the end in the spark plug hole and listen where the air is escaping. You need to know where the problem is before you rip it apart or you can easily miss it and think the problem is somewhere else.

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I'm pretty sure the gaskets are stainless and don't corrode.

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ill give it a try later and see thanks for the tip this is why i don't think its a head gasket problem. worst leak this engine has ever had was spark plug tubes and there's almost no corrosion anywhere on the engine.

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so i did this and from turning the engine it seems that its one of the intake valves for cylinder 6. from doing the best i could to get it to TDC i never heard anything coming out from the exaust or the head but the intake always had a little air coming out or at least it sounded like the air was coming from there when i could get all the valves to closed at TDC. and all 4 valves are opening and closing when i turn the engine from what i can tell since the airflow varies as i turn the engine. so it seems either one valve is not completely closing because of a spring or lifter or one of them got chipped or is not sitting properly. considering the symptoms i have been having with the car before i think its gonna end up being one of the springs or lifters for the intake.

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Now you know where to look. When you remove the cams, re do this leak test again. If the intake valves seal up the problem is not a chipped valve seat but either the hydraulic lifter or something is causing the intake valve/s to come up too far in the head.

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thanks for the advice! ill start taking the cams off sometime next week to test everything and once i know ill order all the parts and fix it. ill take pics of the process for everyone to see in case anyone in the future could use them.

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Might want to verify before posting.

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I will, and sorry if I'm mistaken.

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The engine case & heads are aluminum

alright so here is a slight update. finally got some time to do the work but ran into a problem. i noticed that in the oil filter cover was very small amounts of metal in it. and when i mean small it mean microscopic. no metal pieces in the pan i used to collect the oil, the magnetic plug i have was clean of anything as well, but the filter had some very small magnetic pieces on it. went through the whole thing after cutting it open and only found 3 pieces so small they fit on a pin head. besides that completely clean. oil came out caramel like before. only thing that worries me is the stuff in the oil filter cover that looks like metallic soup but its not that bad. bottom was reflective but very little. i don't think its the ims since i put the LN one when i bought the engine and its only been there for about 3 years and 30k miles. im just a bit worried it mite be something more serious but there's really no sign that it is. i am wondering if maybe with the misfires something was rubing a little and cause it to happen since there so little in there that i did not notice it before. so anyone got any ideas of what it could be?

Send a oil sample with a few flakes off to LN Engineering to be analyzed !

All engines shed metal as they age. Minor amount in the filter and the housing is normal.

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i am really ****ing hoping lol. i figured it mite of shaken a few bits off because of the misfire. UPDATE: cam cover is off. took off the muffler and its bracket along with the headers to get enough room and had no need to take the bumper or tire off. then dropped the engine off the motor mounts on that side for a little more room. quite an easy job to take it all off and straight forward. will take the cams off in a bit but as of now, the entire inside looks spotless. even the oil pump was super clean inside with no flakes so maybe its nothing serious. but as of now the entire inside looks healthy and clean. exhaust valves on cylinder 6 looked dirtier than the others but its prob because of the misfire. will take pics and post later.

so last update for today one of the intake lifters was for sure gone. the rest could be compressed well enough but one of them would not move at all even when i tried with a hammer. and even the ones that were good were a little harder than i think they should be so they were prob on their way out as well. also, it seems i will need to take the head off of that bank as well. hooked up the compressor to cylinder 6 with the cams off so that all the valves are closed and it was leaking from both intake and exhaust on one side. from what i can tell with a light the one on the exhaust is not coming all the way closed and is staying a bit open. i tried cylinders 4 and 5 and 5 was perfect while 4 was leaking just a little from the exhaust. i could see small bubbles coming out from one valve. so at this point im just gonna take the entire head off tomorrow and send it to a shop to inspect the entire thing. if the head is not warped or cracked then ill just resurface it and get new valves along with it. im sure some valve cleaner would fix my problem for cylinder 4 but deff not cylinder 6. there seems to be a combination of problems there prob caused by the lifters. hopefully i wont need new heads for this so fingers crossed and please pray for me lol

I think you have some carbon built up on the valve seats. If I were you, before pulling the head, I would remove the springs (one at a time) and try to "lap" the valves in with a cordless drill and a rubber hose. Don't use anything abrasive on the valve seats other than maybe some WD-40 something similar. Then re test it for leak. You've got nothing to loose and everything to gain. Also, if you pull the head and it is straight and the mating surfaces are not corroded, don't re surface it. There is no need. All you are doing is removing the chance that if in the future the head really needs a resurfacing, it might not have enough material left to do it.

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Please do.

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yeah i figured it could be when i post the pics in a bit you will see cylinder 6 has more buildup on it than the rest that look much cleaner. its probably from all the small misfires i had every now and again and that's what caused the buildup. problem is however that i can only really see the exhaust valves so its gana be a lot of guess work for the intake. ill try lapping them both to see if that helps. also from what i can tell the exhaust valve is sitting just slightly open. i don't think its the valve spring but it could be that that valve is slightly bent. if i tried i could prob fit a thin paper through it but nothing else, that's how close to closing it is. ill let you know how it goes later today.

If you need valve lifters do a few searches, I think I posted the details in one of my posts. I think if I remember right if you have a 996.1 they the intake and exhaust is the same part and its exactly the same as a BMW part which is way cheaper than the Porsche part. If you have a 996.2 it has a different inlet and exhaust lifter, one being the BMW part and the other Porsche. Either way the saving is significant.

so here is a pic of the exhaust valves before i took off the cams. you can see their dirtier and have some build up on them compared to the bottom pic that has the calves for cylinder 5. goona try and clean them up and seat them before i pull the head like imo000 recommended. the one on the right is the only one letting out air when i put air through the spark plug hole bellow is a pic of the cam cover. was really easy to take it off after hitting it a few times with a rubber mallet to get the sealant to let it go and it only poured out a small amount of oil when it came off. no wear or anything on it at all and it had no "glitter" from what i could tell on it either here is a pic of the cams on the car looks good for a car with almost 130k on the odometer you can really see the normal wear the cams have been getting over the years on this pic bellow valve lifters for cylinder 4 and 5 are here bellow no real wear on them and same went for cylinder 6 heres a pic of cylinder 6 with one lifter removed the one on the right is the one that's giving me problems but the lifter was still good on that one and here ad the intake valves without the lifters. the right side valve is the one that had the bad lifter and the springs for all 4 seam to be in good shape but im prob just gonna replace them all anyway since im already going this far to seat them and all

Should he consider new chain guides since he is this far into the motor?

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I test fitted a lifter from a 2005 VW Passat TDI when I had my heads off and it dropped right in as if it was meant for it. I didn't; measure the height or the diameter to see if it is the same part but I wouldn't be surprised if it is.

That engine is really clean, must have had regular oil changes. I don't see the cam hold down tools on or at the ends of the camshafts. You need to either get some made or to buy them before you put the valve cover back on. You don't want to brake a cam. Also, as suggested above, this is the time to replace the Vario Cam pads too. If you do, you should do the other side pads too. They are cheap.

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will keep this in mind when i go searching for the lifters. and yes you are correct the 3.4 in the 996.1 uses the same lifters for the intake and the exhaust. idk what the previous owner did but when i got the engine it looked like it was well taken care of, and i do liquid molly oil changes every 6k miles on the dot since i first started her up. about 40k miles later and she still looks good. as for the chain guides, i don't think i will be doing them i looked at the ones i have and they actually look really good with minimal wear. the ones for the vario cam guides look really good too, perhaps the previous owner did them at some point. ill take a pic tomorrow and show you guys the guides so you can give me a second opinion i do plan on probably doing the solenoids for the vario cam since im already here. and i did have the tool inserted already but for some reason the intake valve does not have the little slit to fit it in place and hold it and only the intake exhaust valve did. so i could only lock the exhaust camshaft. the cams did not move much to be honest so i think ill be ok as long as i am careful when i put it back in and align it properly.

so here is today's update guys. when i took the lifter housing out i also went and checked all the lifters just to see and ALL OF THEM BUT 2 on cylinder 4 for the intake were seized. i had only looked at cylinder 6 before and did not realize how softly these lifters should be able to be pressed down. so now i know this job for sure needed to be done and will for sure be doing the other bank after this. all the springs look really good in the car in fact im willing to bet they mite be new considering the condition and that i can still see the part numbers painted on them, maybe the previous owner also did them at some point. since im going to take off the head anyway (you will see bellow why im going on and doing it) ill prob replace the springs just on this side only. sp bellow are pics of the culprit for the one valve in the exhaust that was slightly stuck open. once i got the spring off and opened it a little i found this little guy looking back at me. not sure what it is but its stuck right on to the seat of the lifter and that's why its not closing completely now. it looks like a very small and thin piece of metal and only the tip of it is on the seat. i tried getting it off with a thin flathead but it wont let go and is prob welded on from the impact of the lifter while the car was running. i was able to wiggle it very easily so i doubt there's much damage. also looked at the lifter and it was surprisingly clean where it meets the seat and was not warped or chopped or even scratched. i also tried sticking a camera inside to see if i can see the intake lifters but could not curve the camera enough so the heads will have to come off for me to check properly and to clean our little friend here off. and this was about as far as i got today before it started raining and i had to stop so hopefully tomorrow i can try and get the head off. still trying to figure out how im going to get to the chain tensioner on this side because its the one in the back right of the engine that is stupidly hard to get to. will prob have to drain the coolant and take some hoses off to get it. and here is another thing i noticed. the cam for the exhaust seams more worn out on that one bearing closest to where it meets the chains. not sure if maybe its because most of the tension is there and that's why but the rest of the guides were more or less spotless and the intake one was also spotless. i rubbed my finger on it and it was just as smooth as the rest and on the cam there is no wear at all on it so maybe its nothing to worry about. and again the deeper i go i still cant find any glitter or anything anywhere so maybe nothing is going on at all but ill still keep an eye out. also if anyone can recommend some good lube for the cams for when they go back in and i start the engine that would be great. or should i just rub a little engine oil on it? i dont want it to get more wear than it needs when i turn the car on and its dry for a few seconds. and if anyone has any ideas on how to get that tension out on that side i would REALLY appreciate it lol. i dont want to drain he coolant just to get it. or if you think i can get the head out without it then let me know ( i doubt you can though to be honest lol) i also wanted to know if you guys think i should replace all the internal bolts for everything. im deff going to replace the bolts for the cam cover but not sure if i should also do it for the housing and the cams and vario cam

The hold down tool is different than the timing tool. You can make one easily, or they are not expensive. Uses the back of socket head cap screws to interface with the recess in the end of the cams. And bolts to the threaded boss in the head. Should be able to do a search for an easy template. Not worth the risk imho to not use one. Looks like your little friend in there may be aluminum. Maybe got dropped down its throat when someone was working on some part of the intake. I'd weary of the valve seat getting knocked loose from the uneven forces on that valve seat (from the FOD on the valve). They are known to come loose on some of these motors. In any case good luck with the fix! The gold colored tool: https://www.pelicanparts.com/More_In...CABEgLNGfD_BwE

I would use assembly lube. I currently use Redline, but have used several brands over the years. Driven has assemble lube, so if I didn't already have the Redline I would consider getting theirs. Next time I buy some DT40 I'm going to pick up a tube or two of their assembly lube.

FWIW,, the same bore scope that fits in the cylinder ,, will slip right down the intake to look at the valves. Your way deep than that now but thought I'd point it out. I've also used them to look through the drain plug on a transmission just to look for issues.. Cheers

Just use regular engine oil for assembly. If I'm not mistaken that worn cam bearing has an independent top half that isn't part of the valve cover. If that the case then, someone installed it the wrong way and caused the excessive wear. I made this mistake with mine on the passenger bank when I first had the heads off and ended up with the same results and a ton of aluminium in the oil when I first changed it after the head work. After that the oil changes were normal and didn't notice the screw up until I had to pull the engine for main bearing replacement.

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Very likely. In fact, the last time I was installing my head (a week or so ago) I couldn’t remember which way the caps went, so I took a picture and planned on posting here to ask.. Then I forgot, so it still isn’t torqued down. Is this correct?

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You have the caps on the wrong cams. E= Einlass , German for Intake A= Auspuff, German for exhaust

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Doh, I knew E & A. Luckily they’re just setting there and aren’t torqued down. What about the direction? Which way does the printing go?

I double checked. The E is on the intake and the A is on the exhaust cam. Now I just wonder which direction the printing goes. Jakes M9x engine rebuild DVD set should arrive from the Pelican Parts Group Buy tomorrow, so I‘ll be tearing down this engine again soon I’m certain.

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i had marked almost everything with a marker before i took anything off. as for how the printing goes on my car it was with the letters looking normally and not upside down. in other words just like you have them. and did you buy new bolts for those or used the same ones? i was thinking of getting new bolts for everything but figured only the valve cover bolts would need to be replaced. been looking online and I've seen some people say they are all ok to be re used along as you torque them correctly. also if anyone can tell me what sealant to use to reseal the valve covers i would really appreciate it. been looking online and there's a lot of diff stuff. and the locktight that's on there the 5900 or whatever seams to get bad reviews because its starts leaking eventually

so just a slight update for you guys. i haven't been able to do much because its been raining almost none stop down here in Miami. i did manage to get the chain guides looked at and there was only very slight wear on the vario cam tensioner and none on the one for the belt that goes to the crank. so it would look as if the previous owner had done all of this before or at the very least was meticulous with his oil changes just like me. anyhow as for the head, i will need to drop the engine in order to take it off. managed to take all the bolts off and got it loose as the car is but then i realized i forgot to take the intake manifold bolts off (im stupid like that apparently ) and that's the only thing still holding the head in place. and because its bank 2 for cylinders 4-6 there's too much cable and hoses in the way for me to actually get all the bolts off and back on later on with the engine still in the car. i looked at bank one and since there is almost nothing there you should be able to take out the bolts for the intake with the engine in the car by simply taking the coolant tank out (just my luck it was bank 2 and not bank 1 that had something stuck in the valves). so for anyone trying this in the future the head for bank one should come out with the engine still in the car but your going to have a super hard time with bank 2 and its not even worth it. from here im just going to order all the parts i know i need and try to get the valve lifters for bank 1 out and replaced if this rain ever lets up. after that im going to attach the tow hitch behind the license plate in the back of the car to see if i can use my engine lift to lift the car up while leaving the engine on the ground on an old car wheel and tire i have. once its out i should be able to get this done quickly. so lets pray the rain man stops dancing long enough for me to do it P.S. i also found the original repair manuals for this little teardown and saw Porsche does not need new bolts for the head when you do this job unless its the old bolts from engines from 97-99. 2000 and up have reusable bolts. and for the valve cover bolts they also do not need to be replaced with the exception of one special self-sealing bolt on each cover. that special bolt is the only one that must be replaced and the rest are reusable as long as they haven't been over-torqued.