2001 BMW 320I M54 Engine trouble

[bmw328]

Hello to all,
We recently bought a 2001 BMW E46 320I with the M54 Engine for an very very cheap amount (Cars body all around in very good condition, everything works that should work)

The reason the previous owner sold the car was because he’s got 3 cars & a stay home wife & because he apparently spent in the region of R16 000 on engine overall & EWSII reprogramming the BMW was the 1st too go.

The Engine trouble:
I knew when I saw the car for the 1st time that the car had a slight blue smoke coming out of the back of the exhaust on acceleration & white puff of smoke on startup, inspected the engine for leaks (Everywhere) for some weird reason 2 dead plugs, checked the CCV and found that it was totally messed up (Rubber diagram torn into pieces – therefore explaining above mentioned symptoms.) – Couldn’t let this bargain pass me up – we bought it!
Changed the CCV – The oil leaks stopped & the startup white smoke stopped immediately afterwards.
BUT: After doing an oil change & changed the sparkplugs we test drove it for about 100KM & it started to smoke with a vengeance! But after killing 2 spark plugs the smoking stopped? WTF. Replaced the 2 sparkplugs again, it started smoking again.
Did Cylinder compression test, Was NOT impressed with the results at all:

Cylinder 1 800KPA (Dry) 1200KPA (WET)
Cylinder 2 650KPA (Dry) 850 to 1200KPA (WET)
Cylinder 3 850KPA (Dry) 1250 (WET)
Cylinder 4 750KPA (Dry) 1200 (WET)
Cylinder 5 850KPA (Dry) 1250 (WET)
Cylinder 6 900KPA (Dry) 1300 (WET)

I had to test cylinder 2 couple of time (WET) every time the reading ranged from 850 to 1200KPA. I've read and the recommended Minimal for the M54 engine seem to suggest range between 1000KPA and 1200KPA.

Now the question:
Does this Compression results suggest worn cylinder rings (Cars got 250 000KM on the odometer) or more like broken rings and or worn cylinder walls?

Does anyone have any recommendations or experience in a matter like this? (I know I MUST redo the engine block from scratch, just want to know what to look for.) - PS- Cylinder head was totally overhauled (New valves, valve guides, seats & stems seals) have the invoices to proof.

 

[Ricky318i]

Do you know what the compression values range for the M54 should be?

 

[bmw328]

Do you know what the compression values range for the M54 should be?

Hello Ricky,

From what if "heard" so far, anything from 1000KPA up to 1300KPA.

More accurate information will be appreciated?

 

[Ricky318i]

I have the info for other engines, but the internets must know.

Have a look around and ask guys who have a Bentley manual. Also ask on other forums.

Also have a leak test performed and do a boroscope inspection, or a cylinder head removal and visual inspection - if all else fails.

 

[Gizmo]

Chances are the engine may have overheated, alu blocks warp and the cylinders go oval, compression numbers will be all over the place. I have also seen rings collapse on the M54 before.

Leak test is you next job though.

 

[SP33DYV]

From the Bentley Manual:

Compression pressures
Minimum 10 - 11 bar
(142 - 156 psi)
Maximum
difference between
cylinders 0.5 bar (7 psi)

 

[bmw328]

From the Bentley Manual:

Compression pressures
Minimum 10 - 11 bar
(142 - 156 psi)
Maximum
difference between
cylinders 0.5 bar (7 psi)

Hello SP33DYV,

Thanks for your info, I actually downloaded the above mentioned manual as preparation when I'm going to strip that engine & too compare the M54 to M52 components (I know a-lot about M50 & M52 engine and do have a bucket load of extra spares for the m52 -(Complete engine to be more precise).

I'm not sure about how compression RATE should wary according to engine capacity? The above mentioned Bentley manual covers the 2.5 & 3.0L M54 Engine? Are the 2.2, 2.5 & 3.0L M54 engine Compression Rate's the same?

I know from above Minimum Compression Pressures indicate that compression is lower than its suppose to be, My biggest concern is why 2 cylinders are even lower than the others.

---

Chances are the engine may have overheated, alu blocks warp and the cylinders go oval, compression numbers will be all over the place. I have also seen rings collapse on the M54 before.

Leak test is you next job though.

Hello Gizmo,

Thank u for your input. The car is second hand - Any thing is possible, my only way to know for certain is to open it up and see what is cooking.

I really HOPE that its only collapsed rings and not broken rings or worse warped alu block.

I actually have one or two projects I'm busy with, so the diagnose on this car must wait until next year. Will keep u guys posted