low compression?

Hi guys, I have a 2007 535i with 283k miles. was running good and then started gradually running rough. was going to go through and replace all ccv and disa and 02 sensor and it got to where it wont start. here is my compression, 50-150-105-50-8-75. could this be due to the vanos going bad and clocking the cams wrong or something? or should I just part this thing out it out, the car is still very nice. thanks

50-150-105-50-8-75, Really? Not a typo? Motor is toast. Figure what is bad, if not multiple things and decide where to go from there.

Originally Posted by stanggt

Hi guys, I have a 2007 535i with 283k miles. was running good and then started gradually running rough. was going to go through and replace all ccv and disa and 02 sensor and it got to where it wont start. here is my compression, 50-150-105-50-8-75. could this be due to the vanos going bad and clocking the cams wrong or something? or should I just part this thing out it out, the car is still very nice. thanks

Are you sure it's 535i, cause BMW don't make 2007 535i.

I thought compression test is done when engine is off, no? so it's hard to say if vanos is bad.

Originally Posted by HPIA4v2

Are you sure it's 535i, cause BMW don't make 2007 535i.

I was thinking the same thing. Also wondering how you managed to put 283k miles on an 07 or 08 car, I had my 2005 530 for 5.5 years and only managed 60k miles - and I live in L.A.

Plenty of people drive 50k a year if they work in sales or similar roles.

OP - Inspect for carbon build-up on your valves. If your valves aren't seating, a compression test won't hold much water. Assuming you actually own a twin turbo series BMW, carbon build-up is well known. After that amount of mileage, you could be experiencing severe carbon build-up issues.

Originally Posted by stanggt

Hi guys, I have a 2007 535i with 283k miles. was running good and then started gradually running rough. was going to go through and replace all ccv and disa and 02 sensor and it got to where it wont start. here is my compression, 50-150-105-50-8-75. could this be due to the vanos going bad and clocking the cams wrong or something? or should I just part this thing out it out, the car is still very nice. thanks

If it was a cam timing problem, then you would get low compression across the board, not just a couple of cylinders.

Originally Posted by HPIA4v2

Are you sure it's 535i, cause BMW don't make 2007 535i.

I thought compression test is done when engine is off, no? so it's hard to say if vanos is bad.

Correct that there were no 535i 2007 models. Maybe he bought the 535i in 2007, as the 08s were available in 2007...

sorry,its a 525i and no its not a typo lol. I drive all over the country. made the trip back to mid-michigan from toledo ohio with it the night I shut it off then the next morning went to start it and it ran real rough and then quit. would not start after that.

Did you ever have an overheating problems, prolong drive in that condition (maybe due to bad water-pump/thermostat)? Just a wild guess.

With that many miles, it's time for a rebuild - rings are probably worn out as are the rod and crankshaft bearings. There is a big difference in a 525i and a 535i but either one would need a rebuild with those miles.

Any smoke? If there is a rough idle, and what seems to be misfiring in some cylinders, then there must be other symptoms that can help in a diagnosis.

I put a good used motor in the car and everything went together very nicely but it does not crank over like the starter is not getting the key signal. triple cked evrything and its all hooked up properly. What I did notice was that the digital idicator on dash for PND 54321 says S and 4 is high lited like its in 4th gear. shifter linkage is working fine and all but woundering if that is why it wont crank over. any thoughts.