Rough running M20 in 2002

[chrisracer79]

Hello everyone I need some help diagnosing a rough running M20b25 I swapped into a 2002. Car starts up just fine but it sounds like it’s misfiring at idle. Firing sequence is correct. I swapped in new spark plug wires and checked the fuel injectors using the screw driver test. I can hear all of them clicking but I know that’s only part of the story. Not to mention the crazy amount of smoke coming Out of the car as soon as it starts up. Any help appreciated. https://youtu.be/5k-ZMxuVH40 Sent from my iPhone using Tapatalk

[chrisracer79]

Hello everyone I need some help diagnosing a rough running M20b25 I swapped into a 2002. Car starts up just fine but it sounds like it’s misfiring at idle. Firing sequence is correct. I swapped in new spark plug wires and checked the fuel injectors using the screw driver test. I can hear all of them clicking but I know that’s only part of the story. Not to mention the crazy amount of smoke coming Out of the car as soon as it starts up. Any help appreciated. https://youtu.be/5k-ZMxuVH40 Sent from my iPhone using Tapatalk

Here’s another vid https://youtu.be/r9OhX7-e5QA Sent from my iPhone using Tapatalk

[tomstin]

What does the oil look like? Any sign of water (milkshake)? Pull the spark plugs and see what they look like. While they are out, run a compression test. Keeping it simple, how is the cap and rotor?

[digger]

Any vacuum leaks ? What colour smoke black, wahite, blue ?

[chrisracer79]

Hi everyone apologies for being non-responsive. I have a parallel thread going over at bmw2002faq.com which as become quite active. Short summary looks like a couple issues. Poor spark, and poorly seated pistons causing low pressure across all cyls and/or bad cylinder head gasket.

At any rate it looks like I've got a couple issues going on.

Issue #1 Rough idle as mentioned in this post.

I pulled all my spark plugs and they are BLACK. Possibly due to the engine running real rich. I bought the motor rebuilt back in 2013 and I'm just now getting it to fire in my 2002. I don't know if the plugs are black due to the many attempts of trying to get the engine to fire. At any rate, I have all new plugs, new spark plug wires since the old ones were not looking good and a new rotor and cap. Terminals on cap were cracked.





I have also new fuel injectors.

I have not yet installed all these new components due to issue #2 and #3 below:.


Issue #2 - Low compression across all cylinders - this is what concerns me most.

So I think my rebuilt motor is DOA. keep in mind I live at 6600' elevation. I pulled the following compression numbers: 90, 85, 80, 80, 80, 85. Altitude correction should be around 117ish.

I then performed a wet compression test per the Bentley and my numbers shot right up over 150 PSI which is why I think its the piston rings. I'm no expert so I'm getting my advice from my bentley.

Yes, throttle was wide open when I did the test.

Issue #3 - Milky oil, white steam

When I pulled the compression tester out after doing the wet compression test, I found milky oil in the tester hose. Also, I believe the smoke to be coming out the back of the car is white. I thought maybe it was a blue gray. I may be colored blind -I don't usually believe my wife.

Video of the smoke coming out of the tailpipe. Smoke is present immediately upon running.

Diagnosis

Need some advice here on what to do about the low comp #s and whether it is possible to address the issues on my own. I spent some coin on this motor that was advertised as "rebuilt with performance Shrick cams." I have no idea what else has been or has not been done to this motor. Maybe I'm overreacting. Feeling burned. Either I fix the motor, sell the motor and get another motor (devil you know vs the one you don't?) or sell the whole project car and find something else to do.

Oddly enough I reached out to the shop where I bought the motor and they have been responsive in trying to help troubleshoot. Basically they're telling me to put in a new head gasket and replace the timing chain ha. I think the motor has had about 5 minutes worth of runtime since I purchased it 'rebuilt.'

I'm not laughing.

[tomstin]

With 7 years on the timing belt, regardless of mileage, needs to be replaced. Particularly on these engines. The milkshake looking oil, typically is head gasket, not a particularly hard job, but time consuming. Take lots of pictures, bag and tag your parts. Take the head to a machine shop and make sure its flat. They can also tell you if it was rebuilt properly.

If the engine was indeed rebuilt in 2013, and not broke in properly (limited mileage), that MAY just be the rings seating in properly therefore the oil consumption.

What type of spark plugs are they? These engines don't seem to like the newer platinum plugs. Go with the basic plugs that the car was designed to use.