[accordfreak]

I just got a 2007 328i 6mt that doesn't start. Currently, when attempting to start, it cranks but it sounds like it has no compression.

I did a compression test (took out all spark plugs, screwed in the tester, mash the gas pedal and had it turn over for 5 seconds. no compression. I tried pouring a little oil down the spark plug hole and same thing on all cylinders.

So now I moved on to the leakdown test. I set each piston at TDC for the test and they all pass no problem. no leaks on the gauge. 90 PSI.

I'm a little stumped as to why the leakdown test passed but the compression isn't there. Any insight? how can all the cylinders have no compression?

There are signs of neglect from the previous owner as I see a little bit of sludge.

[Tambohamilton]

Slipped timing? Valves are closed at tdc, but they only just close then, so there isn't the duration for it to build compression.

[garrethwessels]

i have a BMW E90 320i, car has about 240 000km on the clock, car was smoking when the vehicle was standing idle, grey smoke on pull off. i sent the vehicle in and they removed the head and had the head redone , acid bath, new valve stem seals, engine is reassembled. now when the car is started there is no compression, but if you turn the car over manually is builds compression very quick, try start it after that and loosing all compression, car drove in to the workshop. all old oil and sludge has been cleaned, the head has been sent back to for testing and passed. the car has been reset with the computer , any ideas

[Tambohamilton]

Do 320i have vanos (variable valve timing)? Sounds to me like the timing is set improperly, or the vanos is adjusting it incorrectly...

[garrethwessels]

Originally Posted by Tambohamilton

Do 320i have vanos (variable valve timing)? Sounds to me like the timing is set improperly, or the vanos is adjusting it incorrectly...

the workshop that is doing the repairs has a time chain kit for a e90, they have reinstalled the timing chain, we have also replaced the vanos, both of them about 10k kms ago, also replaced the valve tronic,

[iqraceworks]

Originally Posted by accordfreak

I just got a 2007 328i 6mt that doesn't start. Currently, when attempting to start, it cranks but it sounds like it has no compression.

I did a compression test (took out all spark plugs, screwed in the tester, mash the gas pedal and had it turn over for 5 seconds. no compression. I tried pouring a little oil down the spark plug hole and same thing on all cylinders.

So now I moved on to the leakdown test. I set each piston at TDC for the test and they all pass no problem. no leaks on the gauge. 90 PSI.

I'm a little stumped as to why the leakdown test passed but the compression isn't there. Any insight? how can all the cylinders have no compression?

There are signs of neglect from the previous owner as I see a little bit of sludge.

Check the instructions for your leakdown tester.....I could be wrong, but I don't think you are supposed to run 90psi into them.....more like 35psi.

Make sure you are doing the test right.......