the highlight of the video, is that air comp.

I'd quickly leak test the other cylinders, just for comparison.

A wise man once said "don't mend it, send it"! 😄

Was funny blocking off the oil cap when the valve cover is smashed to bits 🙈😂

Some things don't add up, allow me to theorize a bit here.... The only way you could be leaking compression into the exhaust would be valves and/or valve train problems, not piston rings. Rings would leak into the sump, which does have a path back to the top of the head(under the valve(rocker) cover) through the oil return passages - there are 5 return passages that allow oil pumped up to the cams to drain back down into the oil pan - if your rings were leaking, that "could" result in hearing some air leaks at the oil fill cap and that big custom widow you've got in the side of your VC, but not the exhaust. As others have stated, there's also the hydraulic lifters. Gunked up intake valves could also be leaking into the valve cover(you'd hear this at the throttle body if your VC didn't have holes in it), as well as leaking valve guides. I'd pull the intake manifold and turbos to have a look at the intake and exhaust valves, a bit surprised you haven't done that already. Might as well pull the valve cover off, as well. Forget the leak down tester for now, rig up a hose and fitting to pressurize the cylinder without all of those leaks in the fittings and o-rings. Use the pressure regulator on the compressor if you need to, but you shouldn't need to - either way, you've already got a leak down tester built into the compressor, just need a way to plumb the hose into the spark plug hole. Pressurize the cylinders again once the intake manifold, turbos and VC have been removed. Make sure you're at TDC on the compression stroke. Unfortunately, it looks like you're on a path to pull the head, regardless. At that point, you might as well re-ring the cylinders and stick new rod bearings in it, at a minimum. It would still be good to keep digging into this and find the root cause of the loss of compression. Good luck. Hope the above made some sense. Don't forget injector seals could also leak compression. Also curious where the broken bits of the VC ended up - could a piece be lodged somewhere keeping a valve open?

At TDC and with tester/air in cylinder you should be able to rock the crank back and forth to let it leak either way, then set to the middle of the two.

Interesting outcome. Good to see you take the time and effort to explore and document your process, and share it! These cars are fun. Understanding how they work is very helpful. Being able to have a solid, 500+, grocery hauler, that you understand and can maintain, just makes it better. Thanks to you and your fellow content creators.

Sticky valve perhaps from sitting a long time in a slightly open position, also cold be a faulty/damaged valve spring. maybe whip the exhaust manifold off and stick a light in the spark plug hole and see if something shines when its TDC, other that, start by taking the valve cover and cam tray off and inspect the valve. also, never attempt to push a gas/air gauge past their stop point, you can damage the internals and make them read higher due to bending the insides!

Love the reaction to the compressor, so good

This made me remember why I bought the AEG silent compressor

Even with brand new rings you gona have leak to the sump, is just cold and the gap is big, well at least is just valve, just remove the head grind all the valves, and you are ready to go.

Hi the left gauge is on 0 the right should be at 100% you should not go over 18 psi on left and set right on set if you put to much psi the right gauge will bend the spring in left one. If you think it is rings squirt a small amount of oil in the cylinder and if the psi rises on a compression test it is rings if not probably valves.

17:30 the intake ports have a hole from the valve cover. I can’t remember if all of them do or just two of them do . They are there for the PCV . I’m wondering if carbon buildup is causing your valves to stick open .

listen for the sound of air as the cylinder is rotated to TDC. If you hear air as the cylinder moves up you are on the compression stroke.

Take the rocker cover off and loosen of the rockers or the cam so no tension on the valves at all then put the compressed air back in the cylinder and that will tell you whether the valves are seating if there not remove the head and hand lap them back in it will get you out of the shit for awhile

I have the same "quality" leakdown tester. These cheap ones all work the same. However in my N52 all cylinders were reading 8 - 10% leak except for one cylinder with 14%. That one was also slightly lower on compression.

Remove your turbos and inspect the valves! Remove your valvecover so you can open one valve independently so you can exclude which one is leaking. You probably also can block of the exhaust port too see how much is leaking from the piston rings.

Hi. If you research engine rings and it seal, you understand that rings need heat and lubrication to seal properly, so you will have a leak on a cold engine, and compressor test will be in accurate

Compressor cuts in, that scared the shit out of me hahahaha you were concentrating hard and boom

I would change those 2 guages on the leak down tester for 100-120psi universal gauges. You can pick them up for 10 bucks each. What you want to see is 100psi in = 100psi out in an ideal situation. Granted you're most likely going to get some leakage. Anything more than 20% is a no go. Air out of the exhaust valve could be a valve not closing all the way, probably due to the fact the motor hasnt been run in a while. Try put a new o-ring on the spark plug end of the leak down tester and it should yield better results.

A messy valve is far better than having to pull the bottom end appart... that air out the rocker cover seemed resonable to me (blowby) looks like all your comp is escaping through those exaust valves... yank the head of clean and inspect the valves give em a lap and re assemble with a fresh gasket would be the quickest way to get it back on the road... or leak down test the other engine if that head passes yank it of that engine and slap it onto the one you just tested with a fresh gasket then the other stuff can be used for the build 😊 hope you can come up with an easy fix man 😊🤘

Ive had a similar scenario where i had low compression on Cyl 6. My injector was stuck open just leaking giving the Cyl 6 low compression. So if people are having this problem this may help.

Set it 1100 psi then measure your leakdown.Make sure to keep crankshaft from turning. Measure at TDC and BDC to determine how bad the taper is. Have fun.

Leak down on cold engine would leak as rings won't be expanded so you should expect some leak down, I would remove rear turbo and inspect the exhaust valve to see if its stuck, on the other hand make sure the valve cover broken parts are not inside the engine somewhere which blocking anything.

The air compressor starting was fucking funny!😂😂

I have the same Chinesium leakdown tool, and can confirm that once it's set, and you connect the spark plug tube to the main unit, leakdown gauge goes to about 65%, But if you press the valve in the main hose before connecting the spark plug hose, it goes all the way to 98%. So in the setup the spark plug hose is a further restriction. Next thing I noticed is you should be seeing a huge difference in TDC between one 360deg and the next - one should have the exhaust valves very open. I'd try again but on a different cylinder of that engine, maybe another known good engine altogether. Those leakdown tools are a bit shit, but they can be used as a comparison tool. Oh, and you absolutely need to nail all the leaks (including the spark plug) before you start, you'll get random results otherwise

You did ad air pressure after the needle had stopped. You may have damaged the gauge

This channel has confirmed to me that my n54 is never going to stop giving me issues 😔

Lmfaooo that compressor having you a bit scared Lmfaooo

You can't wind the pressure up on the right hand "Leak down Gauge" past the set the set point. You will kill the gauge every time.

Take the rocker cover off and give the exhaust valves a couple of taps with the pressure in the cylinder and see if it gets better

Me: talking Compressor: Boo! Me: Jesus christ you can't just scare me like that you'll give me a heart attack! Compressor: Haha I go Brrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr 🤣😂🤣😂

That sucks mate. I did exactly the same thing with adding pressure and broke my leak down tester gauge. It looks to be the same as yours. Keep up the good work.

I also have a e90 car with a e92 n54 engine I’m swapping into just getting some information on KZfaq to understand how this swap is going to go

Pull head off both. See whats wrong. Fix with parts you have. Do it for free. (need cam holder thats a few hundred) Re use head gasket go for it.

Refresh the head, lapp the valves. Cheap enough if you do it yourself or just send it and see if it comes good.

Check Ur timing chain as well we have seen a couple n54s with stretched chains which cause low compression because the valves aren't properly seated during a compression/leakdown test

I think there are two types of leak down tester, one of them you have to set the pressure at 100 then connect it to the cylinder, the other one you connect it then you set the pressure. Get a high quality for such as this purpose, just saying.

The piston rings need a gap for when they expand (of course) so that amount of blowby on those not running temperatures could be normal, I don't know, but the valve is supposed to seal when it's close, no matter what. That's an issue for sure. If you take it apart check really good the threads of that stuck spark plug hole for any damage while you're there. :)

You’re always going to get some bleed off into the crankcase especially being a cold engine, with more air coming out of the exhaust side that’s likely where a issue is. I’d pull the turbos and see if any exhaust valves look damaged or burnt

Ide pull rocker cover off and make sure your testing on the rock ie valves closed. If you’re still getting air passed exhaust valve then open the exhaust valve and stick camera down I’m. May have a build up of carbon that’s not seating valve correctly.

the compressor was hilarious, scared me too ha

20% is normal, i wouldn't worry about it, even brand new engines have about 10% leaks, as long as you are in the green and not yellow you are doing good. Just make sure you keep your gauge at zero when you do the measurements. Don't bother removing the heads, I have done over 200 leakdown tests and that is normal for a used engine, as a matter of fact, this engine is super clean for a used one. Repeat the test for the the other cylinders and if they are the same, you have a good engine. The 20% drop is from the carbon built up on the values nothing to worry about.

I have the same tester. Works fine. Some hissing from the valve cover is normal for all cars. No cyl is a perfect seal. Especially cold. Aslong as its consistent between cylinders. Engines fine. Run it !

Pull the exhaust side off the head and have a looksee. If the valves don't full close at tdc you've found your issue, or part of it

Right before your on screen message popped up I was like um, doesn't the rocker cover have a fist size hole in it? 🤭

Burnt exhaust valve, only option and I have heard of it happen a few times with the n54s.

I think the E92 is the important thing to focus on. I think it'll help you decide what to do once you know exactly what's wrong with it. I get the feeling you don't want to pull it apart, which I totally get, but it's not like you're going to drive it in that condition anyway. Worst case, the E90 engine runs, part swap over rocker cover etc. and run that gently whilst you sort the E92 at your own pace? Best case, you find what's wrong and fix it and you're back and you can build the E90 engine instead?

Pull head off. Upgrade gasket/head studs. Check for other possible damage while apart.

9:06 😂 same thing happened to me this weekend. Started a project and left the compressor on. Went back into the garage and grabbed something and the damn compressor kicked on and scared the shit out of me.

Leak down is not the most scientific way of doing it but it is useful and you have to compare cylinders that are good vs not good. You might have 15%leakage and this is normal for some engines as the rings require cylinder pressure to energise properly. Possible with the "lean it out" or the "factory has it too rich for power" might have caused an overheat on the exhaust valve and burnt the seat of both perhaps. Maybe #4 has the most air and runs the leanest therefore is sensitive. You have to monitor both cat and port or turbine in temps (whichever is higher) when tuning as this is what can die if there is no knocking to claim your pistons. Either sort out the leak down tester and do a full comparo or or pull off the manifolds and do a vac test perhaps. I think you can get your engine in the car back up and going before you mess with the replacement.

Pull the turbos and rocker cover. May be a stuck valve and bad stem seal

Burnt exhaust valve, great call Joel, saw it on the first pops.

Bit the bullet on the GT6 style "Brembo" calipers, just for the front and 355mm since I'm running 18 inch wheels. 👌

Test other cylinders to compare , fix leaking spark plug hose, also if anything pull the head see why the valves aren’t seating properly go from there keep wrenching brotha 👍🏼👍🏼

The air compressor was gold Check the other cylinders to see if they do anything similar?

I think if it were my car/engine I’d pull the valve cover off and look at the springs and see if any lifters are spongy and then just fit the engine in the car and run it and see what happens as I recon it will come good after a few heat cycles

I love how this guy buys the cheapest tools then hates them 😂

Hey man, I am in NSW and have a 335i that I am about to get rid of because the injectors have gone and a few other things. You can have it for $1,500 and freight. If your interested let me know and we can talk.

Hey @Zero To 60, - I have the same issue with that sh!tty gauge, not much you can do about it :-( - Personally, I would re-test the leak down in the following manner: -- Put on TDC with screwdriver -- Pour some oil in the cylinder -- Set leakdown tester between 60-100PSI and hook it up -- Rock the crankshaft a little bit back and forth with the ratchet so that you can distinguish the airflow and overlap between in- and exhaust-valves. This way you can make sure that you're piston is on TDC, if there's no distinguishable difference between intake or exhaust then you probably have a bent/burnt/broken valve... Just my 2 cents :D

Been nail biting waiting for the out come. Team N54 stay up.... & p.s. DO NOT REUSE N54 HEAD GASKET 🤯 😂

Set input pressure to 80 psi the second gauge should read at least 70 psi. Your gauges seem not right. You are reading a pressure drop accross an orifice. Talk ti an airplane mechanic to show you how to do the test. Aircaft piston engines are leak down tested every 100hours. If exhaust valve is leaking past the seat you can stake the valve by striking the valve stem with a hammer and drft to knock the carbon off of the valve.do this while pressure is applied. Usually done on a warm engine. Sqirting oil in spark plug hole will verfify if it is the rings.

Build the engine give it a port job, valve lap and put another piston in from the other engine. New bearings fixed!

The hole in the rocker cover lol

Sup guys sorry I’ve been slacking on the videos. Hey I’ve been looking at e90s and if I find one 6speed I’m gonna pull the trigger on it. Gonna need your help 🙏🏻

You'd need a leak down tester for your leak down tester 🤣

Just came to check if you have uploaded something yet. Uploaded 2 mins ago, hahahah

The HF leak down tester is awful. The leak percentage gauge on there is useless and the pressure gauge on the left is only showing 20psi going into the tester. What you want is the OTC leak down tester, which has two identical pressure gauges, one showing the pressure going into the tester and the other showing the pressure in the cylinder. Then you do some simple math and get an accurate result. 100psi going in and 90 psi in the cylinder is 10% leak. Alternatively, you could convert your current leak down tester by swapping another pressure gauge where the leak percentage gauge is located. Perhaps a tire pressure gauge would work or even the one from the compression tester.

If the leak down air pumped into #4 was coming out the exhaust, wouldn’t that just mean the exhaust valve is open? Watching this at 1.75x so may have missed something.

If air is coming out the exhaust wouldnt the exhaust valve be open

i have a e90 335i coupe as well while you have the engine out pull the exhaust manifold and clean all the carbon from all the valves exhaust and inlet there are spray cleaners out there for this exact job if you have just a micron of carbon on the valve face or seat its gunna leak if the motor has done over 120k i would suggest cleaning the valves and get rid of the carbon build up its a big problem with direct injected cars in general at least taking off the exhaust manifold you can get a real good look at them peace of mind anyway you also need to take into account it has vanos it could also be a sticky valve, drain the oil if it looks like shit put cheap oil in it and a bottle of engine flush run till hot change oil again cheap stuff run till hot again drain then put good synthetic in it.i would suggest you pull both vanos solinoids at the front of the motor and clean the filters on the end of them as well. before you pull the e92 engine clean the vanos filters and see if it fixes your leaky valve you might be getting oil starvation on the valve train couldn't hurt 10 minutes to pull the solinoids and clean then if there is carbon build up on the e90 n54 then there is a possibility the e92 n54 has the same problem plenty of youtube video's on how to clean them hope this helps

hey mate, on a different note where did you get the china spec intercooler from + did you have catless dumps? I'm tryin to get my hands on them from vrsf but its like playin cat and mouse with them. theyre in stock, you order em, they get put on back order for another month, repeat. It's a joke so I'm gonna go chinese

I don't know anything about leak down tests, could it be sticky valves? Could have tried on the other cylinders just to see the difference?

When that comp starts up lol

I feel for you mate. Go borrow some decent gear and seek advice on how to do it correctly. Even tdc is a bit of a guess really, either side and your results will be off. Keep the content coming though 👍

I think you can just install a 0-100 psi gauge on the right side of the tester and then find the difference between the gauges and calculate the percentage from there. The OTC gauge literally has two 0-100 psi gauges. Check out this procedure for the it: www.otctools.com/sites/default/files/0001-000-3898_5609_label.pdf I think you need a good amount of pressure to do the test. The 10 psi or whatever the leak down tester originally said 0% leakage was isn't enough I don't think. The OTC table lists 75-100 psi. I think enough pressure needs to be delivered to emulate combustion pressure to better seal the rings. Also why don't you take the turbos and intake manifold off to make it easier? You could clean up the intake and exhaust ports and maybe be able to isolate which valve is leaking. You could stick a microphone into the port and see which valve makes more noise from the air rushing out. I tried CRC Intake Valve and Turbo Cleaner last time I walnut blasted and it works really well. I used it in addition to the blasting.

Try Teflon tape

Bought the ms a 335i, I'm scared. Need to do a comp press before I do anything?

Why haven't you added a little oil in tbe cylinder yet?

I think smoke test is the best easier.

your turbo outlets looks like RHD?

Hi you could of taken the head off by now lol. I still stick to a burnt valve or valve seat has come loose from the head ;)

When the compressor came on you thought the engine got you

I can tell by your accent you are from Texas, Right?

TDC but on which stroke?

Sorry should be 100 PSI repeat 100 PSI

Dude test the other cylinders for comparison.

15:28 😂😂😂😂😂😂😂😂😂

O man this vid was tough to watch 🤦🏼‍♂️

Read the manual HAHA

So in conclusion, don’t buy a cheap leak down tester!

Your funny

Ha! "Not what I was hoping" thumbnail...is that what "Johnny 5" (from 80's movie 'Who's Johnny' fame; infamy? -Pictured-) is sayin there a week after that auction and some "tuning/suspension"...'mods' (CLEARLY!) in tryin for that 2.9 sec 0 - 60?? HA...j/k!! Idk, to me...assuming the gages are his eyes, k i n d a... maybe...MIGHT...almost l👀k like some kinda robot/brobot?? I COULD HOPEFULLY be hallucinating also?? Hmmmm...that WOULD explain the purple king cobra singing Tom Petty's "Free fallin" at my footboard i reckon!!

what do i think?, you have god damn bad luck

🤔🤔🤞