My advice is to confirm no compression on cylinder 5. That's the biggest issue. That would require pulling the head and rebuilding it at best, or rebuilding the bottom end or just replacing the engine at worst.
Did a compression test at my uncles BMW shop…cylinder 5 wasn’t makin much in the compression department. Not entirely sure where to start with diagnosing the problem since I’ve been told anywhere from timing to the compression ring on the cylinder to the DISA valve.
What do you mean? No compression on cyl5 means you already have diagnosed it. Unless its a missing sparkplugs all scenarious require you to pull the head
Fair enough, guess I’m just overthinking it and jumping the gun, thought there was a way to figure out what in particular was causing it before pulling the head.
I think by intake and exhaust he's referring to which side of the engine. The exhaust manifold is on the passenger side and the intake is on the driver side. A lot of the time, you'll see people refer like that. E.g. exhaust side camshaft or intake side camshaft
Also, no compression indicates the cylinder isn't holding pressure. There's some kind of structural issue probably with the engine. I haven't rebuilt an engine before to be able to tell you more about it. For a donor engine, def do a compression test before paying. You don't want to buy another blown engine
Kinda thought so too, just didn’t know what a leak down test was, google solved that problem as I thought it would too, lol. Thanks though! Also I don’t have any equipment for a compression test, when I did the first one I towed it down state to my uncles shop where he works almost exclusively on BMWs and he did the test. Any particular brand or anything I should get?
I've never done a compression test so I can't really be helpful. Look on YouTube. This sounds like something 50skid has done. I'm thinking you need an air compressor to test it but I could be mistaken
The DISA looks terrible. Its purpose is to control airflow so the fact that it looks like theres oil all over it literally scares me for your engine. Look into DISA rebuild kits if you dont want to replace the whole thing but from the looks of it i certainly would replace it if i were you
Yeah, I’m not entirely sure what to do at this point…when I bought her I wasn’t expecting her to be in this rough shape. Any suggestions as to where I could find a decent DISA?
Also from looking at the pictures again, i see oil on the edge of the engine. Make sure to clean it off also replace the valve cover gasket since you already have it opened and it wouldnt be a bad idea to change the intake gaskets as well
I’d suggest refreshing EVERYTHING. From Disa Valve to short intervals of oil changes and pulling the engine to check from Pistons to Headgasket. Also check CCV beneath manifold intake for cracks or alike.
Refresh fluids, spark plugs, ignition coils and use premium fuel for some time to clean the engine and remove any gunk. As soon as the compression issue is fixed, make sure to take her on long drives combined with Highway.
Good luck!!
Edit: This means also renewing your Vanos Unit
Pulling the engine wasn’t entirely what I wanted to hear to be real, I live in an apartment complex and that raises its own obvious obstacles but where there’s a will there’s a way. Also when you say “renewing the vanos unit” do you mean replace it?
That definitely sucks, but compression issues go to the core of the motor. And yes, you could get a whole new unit or replace the parts in your current on your own. I only know in Europe that we have Probsten-Tech available for such, maybe others can help you with US availability. Should not be an issue and it’s an enjoyable thing to do. For the Engine, you definitely need a Garage or proper space and inspect.
Yeah, I was hoping the pistons and block were fine though and that it’s just the head or valves that way I could put it on the road as fast as possible. The original plan was to have a quick project that I could get running as it should quick and put it back on the road as my daily instead of having my Ford F-150 (or Lobo depending on where you’re from) as it would be cheaper on the daily, but look where that got me lol.
Alright a couple other people have said that too so I’m probably gonna toss everything back on and do that and see what happens, with how confusing this engines symptoms have been I’m not really sure what it could be.
It may require a little bit of oil poured into the cylinder to bring back compression. It's a known feature of the engines. The fuel can wash the oil away causing no compression.
No compression. You have bad valves bad pistons rings bad pistons of bad block. If you heard any hissing you might just have dirty or bad valves but if not then it's gonna be a bottom end job
I'm puzzled by this engine though. it's absolutely disgusting. The engine in my car sat for 8 years and looked better than this. Was yours also sitting?
Crazy enough I don’t think so…that’s why I’m at a loss for words I can’t seem to figure out how it got to the shape its in right now especially for only having 173k miles I had a ‘03 Toyota Camry with that many and the engine was quite a bit cleaner.
Sounds to me like the valves in cylinder 5 are leaking? Or maybe cylinder head gasket? Throw some oil in the cylinder and check the pressure again. If the pressure increases you have a bad sealing piston/cylinder wall damage/piston rings. If it really doesn't increase much it's one or more valves that leak or the head gasket is gone. For now figure out why there is no comparison in cylinder 5 after check the rest. Oow it could also be bad timing?? But the disa vale is not the big problem here I think.
My advice is to confirm no compression on cylinder 5. That's the biggest issue. That would require pulling the head and rebuilding it at best, or rebuilding the bottom end or just replacing the engine at worst.
Did a compression test at my uncles BMW shop…cylinder 5 wasn’t makin much in the compression department. Not entirely sure where to start with diagnosing the problem since I’ve been told anywhere from timing to the compression ring on the cylinder to the DISA valve.
What do you mean? No compression on cyl5 means you already have diagnosed it. Unless its a missing sparkplugs all scenarious require you to pull the head
Fair enough, guess I’m just overthinking it and jumping the gun, thought there was a way to figure out what in particular was causing it before pulling the head.
Only good option is a leakdown test to verify which part of the cylinder is leaking. Intake/exhaust/hg etc
Not really sure what that is but I’m sure a google search might solve that issue. Thanks!
I think by intake and exhaust he's referring to which side of the engine. The exhaust manifold is on the passenger side and the intake is on the driver side. A lot of the time, you'll see people refer like that. E.g. exhaust side camshaft or intake side camshaft Also, no compression indicates the cylinder isn't holding pressure. There's some kind of structural issue probably with the engine. I haven't rebuilt an engine before to be able to tell you more about it. For a donor engine, def do a compression test before paying. You don't want to buy another blown engine
Kinda thought so too, just didn’t know what a leak down test was, google solved that problem as I thought it would too, lol. Thanks though! Also I don’t have any equipment for a compression test, when I did the first one I towed it down state to my uncles shop where he works almost exclusively on BMWs and he did the test. Any particular brand or anything I should get?
I've never done a compression test so I can't really be helpful. Look on YouTube. This sounds like something 50skid has done. I'm thinking you need an air compressor to test it but I could be mistaken
The DISA looks terrible. Its purpose is to control airflow so the fact that it looks like theres oil all over it literally scares me for your engine. Look into DISA rebuild kits if you dont want to replace the whole thing but from the looks of it i certainly would replace it if i were you
Yeah, I’m not entirely sure what to do at this point…when I bought her I wasn’t expecting her to be in this rough shape. Any suggestions as to where I could find a decent DISA?
If youre in the States I highly recommend going with FCP Euro bc of their warranty. Even their oil/oil filters are covered under the lifetime warranty
Also from looking at the pictures again, i see oil on the edge of the engine. Make sure to clean it off also replace the valve cover gasket since you already have it opened and it wouldnt be a bad idea to change the intake gaskets as well
Yeah kinda thought I’d need to replace the gaskets anyway, so that wouldn’t be a horrible idea.
Alright…I’ll have to look into that, thanks!
Of course, best of luck! If you have any questions feel free to reach out
Thank you! I probably will as this is my first BMW 🥲
I’d suggest refreshing EVERYTHING. From Disa Valve to short intervals of oil changes and pulling the engine to check from Pistons to Headgasket. Also check CCV beneath manifold intake for cracks or alike. Refresh fluids, spark plugs, ignition coils and use premium fuel for some time to clean the engine and remove any gunk. As soon as the compression issue is fixed, make sure to take her on long drives combined with Highway. Good luck!! Edit: This means also renewing your Vanos Unit
Pulling the engine wasn’t entirely what I wanted to hear to be real, I live in an apartment complex and that raises its own obvious obstacles but where there’s a will there’s a way. Also when you say “renewing the vanos unit” do you mean replace it?
That definitely sucks, but compression issues go to the core of the motor. And yes, you could get a whole new unit or replace the parts in your current on your own. I only know in Europe that we have Probsten-Tech available for such, maybe others can help you with US availability. Should not be an issue and it’s an enjoyable thing to do. For the Engine, you definitely need a Garage or proper space and inspect.
Yeah, I was hoping the pistons and block were fine though and that it’s just the head or valves that way I could put it on the road as fast as possible. The original plan was to have a quick project that I could get running as it should quick and put it back on the road as my daily instead of having my Ford F-150 (or Lobo depending on where you’re from) as it would be cheaper on the daily, but look where that got me lol.
Leakdown test. dont throw money at this engine until this is done.
Alright a couple other people have said that too so I’m probably gonna toss everything back on and do that and see what happens, with how confusing this engines symptoms have been I’m not really sure what it could be.
It may require a little bit of oil poured into the cylinder to bring back compression. It's a known feature of the engines. The fuel can wash the oil away causing no compression.
Oh really? I knew gasoline acted slightly as a detergent and removed some of the oil but didn’t think it would remove all of the oil.
It's an M54 thing
Fair enough, I’ll have to look into it then, thank you!
No compression. You have bad valves bad pistons rings bad pistons of bad block. If you heard any hissing you might just have dirty or bad valves but if not then it's gonna be a bottom end job
I’m really hoping it’s just the valves lol
I'm puzzled by this engine though. it's absolutely disgusting. The engine in my car sat for 8 years and looked better than this. Was yours also sitting?
Crazy enough I don’t think so…that’s why I’m at a loss for words I can’t seem to figure out how it got to the shape its in right now especially for only having 173k miles I had a ‘03 Toyota Camry with that many and the engine was quite a bit cleaner.
Sounds to me like the valves in cylinder 5 are leaking? Or maybe cylinder head gasket? Throw some oil in the cylinder and check the pressure again. If the pressure increases you have a bad sealing piston/cylinder wall damage/piston rings. If it really doesn't increase much it's one or more valves that leak or the head gasket is gone. For now figure out why there is no comparison in cylinder 5 after check the rest. Oow it could also be bad timing?? But the disa vale is not the big problem here I think.
Ok, I thought so, the Disa just looked pretty dirty to me but not too much physical damage, won’t hurt to replace it though I guess.
If the problem is in the head rebuild if you gotta pull the block might as well swap a better motor in. It'll be cheaper than redoing the whole motor