BMW N42/N46 Valve Stem Seals Replacement PART #3: Replacing the seals

[@Valden23]

BimmerZen, this video series is helpful in so many ways. Thank you. I'll be doing this job in a couple of days. From the tech info I've studied I'll be trying to avoid rotating the engine the wrong way. When ready to compress a valve spring I'll turn the crankshaft pulley bolt until the piston in the cylinder I'm working on is just past TDC and starting to move down on the power stroke. This way, all valves will be closed and importantly, air pressure pumped in via the spark plug hole will be pushing the engine in the normal rotation direction. Should work.

[@BimmerZen]

Sounds like a good plan. Just be carefull when applying air pressure - too much and the crank will rotate. You can lock it with a wrench against line support bar in the engine bay just to be sure.

[@binkhalifa2004]

Instead of pressuring the cylinder, you can use a rope, such as a bungee cord or a vacuum tube, to keep the valve from dropping. This is an age-old mechanic's trick. I used this trick while replacing the valve stem seals on my X5 with N62 engine. It's very easy. Just before TDC of the cylinder you're working on, insert the bungee cord into the spark plug hole, filling up the remaining space before TDC, then continue turning towards TDC and you can feel the cord getting squeezed, at which point you stop, and this holds the valve up firmly. Test by trying to press the valve down. Adjust accordingly. Works great and you can take your time as opposed with the risks of using compressed air (engine turning, losing air, rushing through the job, etc). To remove the rope when you're done with the cylinder, just slightly turn the crank counter-clockwise to release the rope. Make sure to keep the chain in tension/moving as you turn the crank. Pull the rope completely out. That's it! This technique is demonstrated in the video here kzbin.info/www/bejne/pn6cfIt7rMSKmpo

[@singlechannelstuff8666]

Have just done this job, many thanks for these videos. Removing the old seals on my car was very difficult. Levering with screwdrivers took a long time and put a lot of sideways pressure on the valve stems. I found an easy and quick solution to this by finding an old piece of pipe (electrical conduit) that's a snug fit over the old valve seal and cutting saw slots from one end for 20 or 30mm or so. Making eight 'fingers'. Fit a hose clamp over the fingers at the very end. Gradually tighten the clamp a bit at a time. Then knock it jujuover the old valve seal. Until it grips enough to come loose when you twist it

[@BimmerZen]

Yes, this is an older video now and I now use a 14 mm socket wrench to remove them. I have a video that describes this method ready to be published soon. This was suggested by a subscriber and it works great. Thanks for another good suggestion.

[@singlechannelstuff8666]

@@BimmerZen thanks again for your excellent videos, my engine is running fine now with no smoke at all. Cheers

[@AleksAleks-eh7hg]

Берёшь трубку по внутреннему диаметру 14-15 мм , длинной 4-6 см разрезаешь её на пополам в длинну. И сваркой крепишь к концам плоскогубцев. И получается инструмент для доставания мск. И не каких отвёрток )

[@BimmerZen]

Good idea. You can also use long hex socket of similar size.

[@jevoncooper295]

hi there just out of curiosity how much psi air pressure do you use

[@mrhodl58]

when you replaced the spring you looked at it on mine i can see an arrow and a line painted on the spring how do you orientate please

[@ConesuelaLadyTailor]

Hi. Good video. What size air pressure are you applying to the cylinders?

[@BimmerZen]

ConesuelaLadyTailor 6-8 bar. I basically just open the valve on the air compressor all the way.

[@BimmerZen]

Update: I tried applying just 1 bar of pressure and it worked just as well as with higher pressure, so you don't really need much.

[@andrewclarke9467]

@@BimmerZen will 100psi not damage anything and does the air escape anywhere apart from passing the piston rings? Thanks great video... This is going to be my next big job on my N46. So i will be buying a set of your 3d printed compressors.

[@BimmerZen]

@@andrewclarke9467 100psi wont damage anything, just make sure you have crankshaft secured against rotating. Lower pressure is just a bit safer for rotation. In TDC some air will get past the piston rings.

[@andrewclarke9467]

@@BimmerZen thanks for the reply, i will lock the crankshaft out like when i did the timing chain. I managed to fit the locking pin into the flywheel.

[@hubertm89]

Great video! I have one question though. How to you determine mutual position of the camshafts and main shaft (crankshaft). I am asking because you removed locks from camshafts and you also rotate the crankshaft when looking for the TDC position of the particular pistons. Is is also necessary to find TDC of each piston when applying the pressure? Thanks!

[@BimmerZen]

Hubert Mitura You have to put the piston in TDC for each cylinder that you are working on. When you are finished you must put the first piston back in TDC and then reinstall the camshaft locking tools, making sure the cams are oriented correctly. Make sure you read the service manual (link in description) for timing procedure.

[@germangalarce109]

@@BimmerZen if piston 1 is already at tdc, can you start with piston 1 & 4 first instead of 2 & 3 ?

[@BimmerZen]

@@germangalarce109 yes you can.

[@emilsbernans7308]

Hi. Thank's for useful video. What was air pressure you use?

[@BimmerZen]

1 Bar should be enough.

[@bengt1758]

Hey! Would you mind giving me the measurements for the tool to push down the spring. How long it is, where the holes are ? Thanks 😅

[@BimmerZen]

I no longer have the tool - I gave it away to a subscriber - but you can buy a much improved tool kit on my website (bimmerzen.com/store). There is also a similar tool here: www.schmiedmann.com/en/product/1966337-new?product=SCM4246VSCT that has some drawings attached.

[@gerardg1853]

Great serie of videos!!! A question: Can keep the locking pin in place (fly wheel) when working on cylinder 1 & 4 seals, so that they stay on TDC?

[@BimmerZen]

Yes, 1-4 and 2-3 have same TDC. Good point, it's time to make a new video on VSS and put in all the useful tips I have learned since:)

[@rosscarstories]

How much bar should apply in combustion chamber to keep lifted the valves?

[@BimmerZen]

1 Bar should be enough.

[@hyouzhe]

BimmerZen, thanks for your videos and detailed explanation, very helpful and I have successfully replaced all the seals of my N46 engine after watched your series. Thanks a lot! I have two questions. The first one is cylinders 1 & 4 TDC position can be easily locked by the locking pin underneath, and when I move to cylinders 2 & 3 TDC position I found I can't insert the locking pin into the same hole. Is that any other better way to secured the crankshaft against rotating? Second, those valve Stem seals are full of engine oil make them not easy to grip even I used valve stem seal pliers, as you mention before the 14 mm socket wrench could do the trick, could you explain a little more details about how to use it? Thanks!

[@BimmerZen]

Hi, good to hear that! There is only one hole in the flywheel so you cant use the locking pin for cyl. 2 and 3. I put normal ratchet handle with 22mm socket on to the crankshaft bolt. The handle then rests on the plastic bracket that holds the hydraulic lines. I think i show and mention this in my latest timing video (N42 broken valvetronic spring repair). To get the old valve seal out you just tap the 14mm pipe socket on to the seal untill you feel it grips the seal. Then you just pull it out using some circular motion: kzbin.info/www/bejne/eH7OaJetqc-Sn5I

[@hyouzhe]

@@BimmerZen Thanks for your reply. Already found the answer in the video "Using the 3D printed tool to replace Valve Stem Seals on N42/N46 BMW engine". Every time I watched those old videos always can learn some new knowledge. I'm looking forward to see more repair videos about your art of BMW maintenance in the future！

[@FranciscoGonzalez-gh2ws]

Hello , im working on my Bmw N42/46 BMW 120i 2008 right now, no turbo 4 cilinders, and I´m in this stage or step , before I remove the vanos my crankshaft turns well very easy and soft , I follow every step you have in yours videos. My doubt is ,when I remove the crankshaft and the vanos valvetronic, I want to turn the piston to put tdc, but I can´t turn more tan 5 or 10 degrees, It is Normal?? I take the chain very carefully for no stucks, but my pistons didn´t turn more than that, I can take only 1 and 4 piston on tdc, when i try to put 2 and 3 piston on tdc ,I can´t turn more tan 10 degrees or something like that, and this pistons won´t be on tdc, just in the middle, I hope you Understand me, sorry for my English I´m from Mexico, thanks for your replys

[@BimmerZen]

Did you put the transmission out of gear (if its manual)? Did you remove all of the spark plugs? Did you remove both of the camshafts?

[@FranciscoGonzalez-gh2ws]

@@BimmerZen thanks for your Replay, yes I removed the spark plugs and both camshafts , yesterday I think that I turn the pistons to much carefully, today I apply a little more force to move the pistons on tdc and it works! ,Hopefully works when I reinstall all back again

[@FranciscoGonzalez-gh2ws]

@@BimmerZen do you have the measurements to make the seal valves remover tool ?

[@BimmerZen]

@@FranciscoGonzalez-gh2ws Great to hear that! Maybe it was just camshaft lobes compressing the valve springs:)

[@matas1024]

Can this be done without pressurising the cylinder? The valve should rest on the piston eventually when compressing. Or the problem would be to put the spring back in place?

[@BimmerZen]

I have heard that it can be done by putting every piston in TDC and compressing the springs all the way down. I haven't tried this method myself, so I can't recommend it. I use 3D printed compressor tool now and it's not designed to withstand such force.

[@KingAlex9two]

I love your vids and have been subscribed for a long time now - I'm currently doing this job with rope and is going well but I'm having difficulty on the exhaust valve - right at the back at the firewall putting the collets back on - do you have any tips??

[@ramidcareandmechanicalserv8684]

Hi bimmerzen, how to order your valve spring compressor?

[@BimmerZen]

Check out my webstore: bimmerzen.com/store

[@thomasdeng1182]

what is perfected to replace the old ?the original OEM or supertech after market?

[@BimmerZen]

I dont know and I could not get any recomendations for aftermarket, so i use OEM from Elring. My thinking is that they should be good for another 150.000 km and at that point, the car will likely be at end of life...

[@nestorvalcarcel4226]

I have a doubt, when the springs are disassembled, should the piston be in top dead center?

[@BimmerZen]

Sorry for the late reply! I'm not sure if i understand your question... When you compress the valve springs you have to apply air pressure to that cylinder or use the rope method to prevent the valves from dropping. That's why it's best to put the piston in TDC on that cylinder.

[@p24garage53]

Bimmerzen i have some question. How much air pressure for input cylinder 2&4? (Psi or lb)

[@BimmerZen]

about 1 Bar (15 psi) should be enough.

[@reseth]

Why do you TDC pistons when aplying air pressure? I am no expert and you know what you are doing so I am just curious. I would naively prefer BDC since engine will not try to turn itself in BDC.

[@BimmerZen]

You have a point. Crankshaft wont rotate in BDC when you apply air pressure, however in case the valve drops, you may have a very big problem if it falls all the way in. I'm not sure if that is physically possible but i prefer to be on the safe side:)

[@edmachado9373]

GOOD EVENING! WHERE TO BUY THIS TOOL TO ABOLISH THE VALVE SPRINGS?

[@hasveenbeelur9299]

Mate i have now changed the seals but now i am stuck as i have difficulties to put back the collets on the springs. Please can you help?

[@hasveenbeelur9299]

@jurgenhop1 thanks mate but i did it long time ago i actually did exactly when you just said

[@rohantait205]

Hey mate, my first piston is TDC and my inlet side camshaft is aligned and locked in the lock. However my exhaust side camshaft is sideways and isn’t aligned upwards!! What do I do???

[@BimmerZen]

Did you check that the exhaust camshaft is locked in proper position with the exhaust VANOS unit? Read the service manual regarding this procedure: workshop-manuals.com/bmw/3_series_e46/316ti_n42_comp/2_repair_instructions/11__engine_(n42)/31__camshaft/1_ra__checking_camshaft_timing_(n42_n46)/page_587/

[@rohantait205]

BimmerZen Cheers. I think the exhaust cam skipped a few teeth on the timing chain by accident. All sorted now. When do you think the 5th episode will come out?

[@BimmerZen]

Great to hear that! Part 5 (timing) will be up in a couple of days. I'll try to produce the video on Saturday or Sunday.

[@kinimod5]

How many valves has this engine?

[@BimmerZen]

@@kinimod5 16

[@kinimod5]

@@BimmerZen I have 1.4 16v from VW , it will be same? How much time does it take?

[@BimmerZen]

@@kinimod5 That is a totaly different car and engine. I can't realy answer that:)

[@DameAndThatGame]

ZZ, can I pick your brain for a second? I just bought a new car, it has a misfire in cylinder 1. I changed the plugs, coils, and injectors. In your expertise, what else could it be? (misfire in cylinder 1 / misfire multiple cylinders from ISTA) It will misfire under load, but if I drive softly, I can take it to 4k RPM where it misfires again and cuts to 3 cylinders. I drove it at 5k RPM, resetting the engine light, so it would trick the cylinder back into working. I would get a tiny boost of power, lots of clicking, then back to 3 cylinders and engine light again, have you ever cam across this? ECU? mechanical? only the misfre codes nothign else.

[@BimmerZen]

Could be mechanical. Did you check the rough running parameters in idle? It could be an issue with valvetronic/rocker arms/lifters on cylinder 1.

[@DameAndThatGame]

@@BimmerZen i think that myself, i cant it being rings as very little smoke (bit of valve stem smoke) the VVT/rocker arms is a good shout, just order a raker cover gasket, so when that comes, ill dig into head a little more, cheers bud

[@DameAndThatGame]

Ok, so i unplugged the VVt actuator, the misfire is still their, but 90% better, still throws a light, but i can rev her up bit now. also, some "clanging" i can hear somthgin metal, soudn liek a small piece, as i rev it, so beforei get into he head, does that point towards the vvt trouble?

[@jernejmencin4617]

@@DameAndThatGame Sounds like a valve opening problem. An issue with intermediate lever and spring/rocker arm/lifter. If you remove the valve cover you could probably see what the issue is.

[@filipbarac1733]

Nice video! Hoe much nm do you use to put back the camshaft?

[@BimmerZen]

filip barac first 5nm, then 10nm. Check torque specs in service manual in description.

[@filipbarac1733]

BimmerZen when is part four coming? I going to do this job in a couple of days

[@BimmerZen]

I hope soon, couple of days:)

[@andriu_6l]

and now is not burning oil?¿?¿ nothing?¿? or less

[@tomasnirmox8317]

How many mileage has this engine?

[@BimmerZen]

If I remember correctly it had 275.000 km, but the seals can go bad much sooner.

[@tomasnirmox8317]

@@BimmerZen How much? I have approximately 110 000 km. How does it manifest itself?

[@BimmerZen]

@@tomasnirmox8317 First sign is a high oil consumption, usually more than 0.5l/1000km, then blue smoke on acceleration after idling (like pulling from a red light on an intersection). The seals also deteriorate over time, so even if you have low miles, but the car is older than 10-15 year, it still can happen. The problem is in long service intervals. If you don't change the oil every year, and/or you drive short distances (heat cycles) the seals dry out and deteriorate faster.

[@tomasnirmox8317]

@@BimmerZen I have about 110 000 km and if I going to change timing chain, there is dont need to change stem seals if my oil consumption is abou 0,5l/10 000 km?

[@BimmerZen]

@@tomasnirmox8317 0.5l/10 000 is OK. Engine normally burns some oil. I don't think you need to change them. However I have to point out my personal experience with N42 and valve stem seals. I had about 185.000 km and normal oil consumption like you. I did not have to add oil in-between oil changes. Then I took a 5 hour road trip and my oil light turned on. After that I suddenly had to add about 0.7l/1000km. I had the car at the mechanic multiple times without any resolution... Eventually I learned about this problem and replaced the seals myself. This was the start of my YT channel:)

[@SanDoval201970]

wait a sec you suppose to press in the valve stem seal, you just put in on with your hand,, no way !!!!!!!!!!!!!!!

[@BimmerZen]

Yes, they are not that tigh. In any case, valve spring then pushes the seal in place.

[@SanDoval201970]

@@BimmerZen oh ok I got you cool thanks for the vid

[@TitaniumBMWGarage]

Bravo

[@bushygun8464]

Потрібно блокувати колінвал бо від тиску його може провернути і клапан може впасти у низ.

[@самоеинтересное-з7т]

Чувак рассухариватель 3000 на озоне стоит.

[@vedran.z]

I have problem to this with both exhaust valves on the 3rd cylinder. I have found TDC but as soon as I compress the spring just a little, I start to lose air pressure. I tried rotating engine few times but nothing helps. All other valves done with no issues. Any ideas?

[@BimmerZen]

Did you try tapping the spring plates with a socket and a hammer. Usually the valve keepers get a bit stuck on the spring plate and tapping them slightly helps to release them. If that does not work, try applying a bit more air pressue (up to 3 bar). Lastly, you can always try the rope method to prevent valves dropping too deep.

[@vedran.z]

@@BimmerZen Tnx. I used the dog leash rope eventualy hah. I think the keepers were to tight, heard a little pop when compressed the spring. Btw, the printed tool did the excelent job + long needle tip tweezers for removing/inserting keepers.

[@BimmerZen]

@@vedran.z Glad to hear that you managed to get the job done and that my VSC tool worked well:)