Before the CCV replacement, you had no issues at all?

 

No issues. After the CCV replacement it ran real well. I stepped on it for a short time and let fully off the throttle and coasted through some curves. When I accelerated again it had miss , running rough.

 

I have pulled apart several M54 engines. I daily drive an E53 that I bought in need of a head gasket due to an overheat.

Significant loss of compression on a WARM M54 engines due to rings is kind of rare. The oil rings can carbon-up and that can lead to significant oil consumption, but usually not low compression. I have seen burnt or chipped valves, which can happen if too much oil gets into a cylinder...

Replacing a CCV should not have caused this.

How low is compression in cylinder 2? Is it zero? You did say you "lost" compression.
I have seen a piston essentially melt in an overheat, but that is not what we're talking about.

You can put a borescope into a spark plug hole and see if you see anything.

 

I have pulled apart several M54 engines. I daily drive an E53 that I bought in need of a head gasket due to an overheat.

Significant loss of compression on a WARM M54 engines due to rings is kind of rare. The oil rings can carbon-up and that can lead to significant oil consumption, but usually not low compression. I have seen burnt or chipped valves, which can happen if too much oil gets into a cylinder...

Replacing a CCV should not have caused this.

How low is compression in cylinder 2? Is it zero? You did say you "lost" compression.
I have seen a piston essentially melt in an overheat, but that is not what we're talking about.

You can put a borescope into a spark plug hole and see if you see anything.

#2 has zero compression. I bought a camera that works with my iphone and looked inside. The pistions are black but I didn't see any damage. I suppose I could try another the leak down test. I could tell it had laekage coming from the rings through the oil cap hole. What seems od is the gage was not showing much decrese in pressure, only a a couple PSI. With zero compression I would expect a lot of air to pass by the rings or valves. Seems like I missing something.

 

Have you scanned the car for codes?

 

Yes it shows a misfire #2.

 

I daily drive an '05 X5 with M54...I also like driving it despite US-build quality issues and its many quirks and component failures - particularly in cold weather.

2 yrs ago, I bought it as an overheat and I replaced the head. Doing an in-car head gasket is EASY on an X5...Plenty of access and the car stayed on it wheels the whole time.

I agree that if you are 100% certain it is rings, then pulling the head doesn't make too much sense. However, if you are not 100% certain, then maybe it's worth the effort to make certain it is not the valves. zero compression due to rings is rare on the M54.

On engine removal you can pull from the top or out the bottom on the subframe. I have not pulled an X5 engine although I have pulled a RWD E39 and an AWD E46xi.. I also don't have a lift. We pulled the AWD E46 engine out the bottom and slide it out the front while engine and trans were on the subframe. That's how I would do it on the X5.

Although I am not a fan, Nathan's BMW Garage pulled the engine from a V8 E53 X5 in his gravel driveway in this manner and said it was definitely the way to go. Same concept on an M54 X5.

 

Yes it really won't cost anything but some time to pull the head.
I saw how Nathan did the subframe drop in the gravel. It should go a lot better on concrete. If it were not for the front dif it might be an easy job from the top.This guy did a later model X5 from the top, but I'm sure there are differences on the first gen.

Have you had the thread inserts pull out on the head bolts? They say you can fix those in the car, but there doesn't seem to be enough room at the back of the engine to fit a drill in there. 90 degree angle drill maybe?

 

Have you had the thread inserts pull out on the head bolts? They say you can fix those in the car, but there doesn't seem to be enough room at the back of the engine to fit a drill in there. 90 degree angle drill maybe?

You're hitting my sweet spot here.

I have time-serted 7-8 M54 blocks. I have Time-sert kit 1090 which was made for the M54 and includes a jig to make the job fool- proof - even for a 1st-timer. Since I have the tools, I always time-sert the block whether it overheated or not because I view the factory aluminum threads as one-time use.

I rent out kit 1090 to forum members in good standing. Message me if interested.

Doing it in-car is only slightly more challenging. You need a 1/2 inch chuck drill to fit the Time-sert drill bit, but you need a right angle 1/2 drive drill to drill a couple of the rear holes when you do an in-car head gasket job. I usually rent one from Home Depot/Lowes for 4 hours when I need it.

While we're at it, I rely 100% on 50's kid excellent dual vanos timing video. I use it and the dual vanos timing kit (also avail for rent) every time. Never had a problem.

 

Can you hear compression loss while cranking? Have you done a relative compression test?

 

I'm not sure how you hear hear it. I did test all 6 and #2 and it is zero to a few psi. typically.
I did 2 treatments of the GM cleaner. When the engine was hot I tested #2 three times again. I got 75 PSI, 3 PSI ans 60 PSI. I might be making progress, not sure. Cylinder leak down is 2% on #2. Going to try the same top end cleaner that's in the video before taking the head off.

 

Loss of compression on one cylinder has a distinctive sound on cranking.
Relative compression test..... put an amp clamp around battery to starter cable, connect to a scope. Waveform during cranking shows low current during bad cyl power stroke.

 

That's interesting.

 

Start from the simplest and work your way up:
1-fuel rail bleeding
2-look for loose connections on all the sensors you disconnected

 

The main problem is compression loss on # 2 cylinder.

 

How many miles in your X5 M54?

I doubt that you have burned valves bc burned valves are somewhat uncommon in M54 engine with < 200K miles.

Why don't you try the BavarianE39 CCV Mod?
I wrote a detailed procedure in that thread, cost is about $30 or so for odds and ends.
And it takes about 1.5-2h, easy job.

 

That's worth considering if I can get the compression back first.

 

Please keep us informed. I just had compression loss on all 6 cylinders...gauge reads 30-50 psi...I think my 420k mile M54 engine skipped a tooth on the timing gear. Not sure why...

You know, I wonder about the sound you are hearing in the leakdown test.

The Intake manifold is connected to the valve cover through the CCV connection. If you had an intake valve leak, I think the sound might travel through the CCV into the valve cover, and out the oil fill cap?

Maybe you disconnect the CCV from the valve cover -if you haven't already - and listen to it directly (the CCV hose) when doing the leak-down test.

 

Please keep us informed. I just had compression loss on all 6 cylinders...gauge reads 30-50 psi...I think my 420k mile M54 engine skipped a tooth on the timing gear. Not sure why...

You know, I wonder about the sound you are hearing in the leakdown test.

The Intake manifold is connected to the valve cover through the CCV connection. If you had an intake valve leak, I think the sound might travel through the CCV into the valve cover, and out the oil fill cap?

Maybe you disconnect the CCV from the valve cover -if you haven't already - and listen to it directly (the CCV hose) when doing the leak-down test.

I have verified that the air leaking is coming from the crankcase and through the oil filler cap. I used some smoke to make sure. When the smoke passed over the opening it shot straight up.
You should be able to diagnose the problem by removing the valve cover and checking the chains and valve timing.

 

I knew I was missing something! I pulled the valve cover and watched the valve springs all go up and down as I turned the engine. I took my bore scope camera and aimed under the cams to look at the valve springs. Sure enough there is at least one broken exhaust valve spring on #2. The other one looked okay. The spring still has enough pressure to fully lift the valve. The pressure from the leak down test would actually close the valve tighter at TDC with the air pressure, so the valve tested good. That also means the valve did not get bent. I makes sense now why sometimes I would get some compression and other times about zero. I also used the camera and looked for any kind of a dent on the piston. There is none. The piston sure is clean now.
Now for the fix. I know I need the special kit for timing the cams. I'm thinking that the intake will need to come off to access the alignment pin hole in the flywheel. Or will removing the throttle body and DISA make enough room? Any tips for this job? I can make my own valve spring compressor, so I won't have to but one.

 

Well at least you don't have to pull the head...

You said exhaust valve right? So taking the intake off won't help you. If you meant Intake valve, taking the intake off would not be such a bad thing. It would allow you to replace plastic hard coolant pipes which are likely due.

But I think you can do this by putting rope or similar in the piston, moving piston up to hold valve in place and replace valve spring after removing the cam.. M54 valve springs don't break often, so I might not replace all valve springs.

Use 50's kid video on dual vanos timing with a timing jig. I can rent you all the timing tools.

In fact 50's kid I believe has an M54 valve seal or spring video where he uses the rope trick...have a search.

I bought this guy's custom M54 Valve compressor and it's a great tool:

BMW Valve Spring Compressor

This tool works with the following BMW engines and allows you to remove valve springs, retainers, keepers, and stem seals with the cylinder head still ...

farrow.tech

 

Well at least you don't have to pull the head...

You said exhaust valve right? So taking the intake off won't help you. If you meant Intake valve, taking the intake off would not be such a bad thing. It would allow you to replace plastic hard coolant pipes which are likely due.

But I think you can do this by putting rope or similar in the piston, moving piston up to hold valve in place and replace valve spring after removing the cam.. M54 valve springs don't break often, so I might not replace all valve springs.

Use 50's kid video on dual vanos timing with a timing jig. I can rent you all the timing tools.

In fact 50's kid I believe has an M54 valve seal or spring video where he uses the rope trick...have a search.

I bought this guy's custom M54 Valve compressor and it's a great tool:

BMW Valve Spring Compressor

This tool works with the following BMW engines and allows you to remove valve springs, retainers, keepers, and stem seals with the cylinder head still ...

farrow.tech

The reason for removing the intake would be to get access to the hole for the alignment pin that goes in the flywheel for the timing process. It's in the video @ 17:51. Kid has the intake off the engine.

The tool is nice. I work in a CNC shop, so I can put something together. The rope trick goes way back, it's pretty slick. You can also use the leak test hose and pressurize the cylinder at TDC to hold the valves. I do prefer the rope though. There's no way to lose the valve.

 

This is a good video to watch re exhaust valve.

I'd use BMW Genuine spring only.
Don't forget to replace the valve stem seal, again BMW brand only.

PS: Search Volvo forum for tricks using rope or compressed air to prevent the
valve from falling down once the spring is removed.

 

Thanks for the input. I like the 50sKid how to videos for the M54.

 

BTW, how many miles in your engine?

 

170,000. Please don't take this the wrong way, but if you think about it the part I'm replacing was genuine BMW and it broke. I don't subscribe to the OEM only parts doctrine. Thanks again.

 

No problems...

What I meant was: whenever I do a labor-intensive job such as valve spring, valve seal, engine seals, I tend to use only BMW Genuine parts simply bc I don't have enough knowledge of aftermarket parts to gamble.

Of course, BMW part may not be necessarily better, but it is the "devil I know"...lol.

PS: Of course everything breaks if they have enough miles. The factory spring lasts some 170K, it is pretty good. My 1998 528i still has stock engine.
My point is: if you use BMW spring, it should give you another 170K-200K service.
Aftermarket spring: who really knows, maybe 200K or 30K or whatever.
At least with BMW, you are dealing with the devil you know.

Mahle is the original supplier for many many BMW parts.
TRW is a good brand too.

PN 11347504268 is only $14 at BMW dealer.

 

There nothing wrong with that practice, I just don't think it's necessary. I worked in auto repair for a couple years. We never went to the dealer for part unless we had to. The only major issue we had was with rebuilt parts, especially starters. On my owns cars and trucks I've only gone to the dealer twice because at the time I couldn't find after market parts, it was pre-internet. 98% of the time there are no issues. Spring failure of any type spring is pretty rare in my 50 + years of experience. I'm getting her put back together, taking my time. Changed the spring and put the cams back in. Here's my DIY spring compressor. I didn't think I could compress both valves with one broken spring,so I rigged up a tool.

 

Good to hear....broken valve springs is not something we see all the time with the M54...

 

That's good to know. Thanks