06 4.4 Surge at start, profuse smoking
 

My wife's 06 4.4 (80K miles) started bucking or surging when starting to move slowly from idle a while back. It only did it sometime, so of course I ignored it and hoped it would go away. Well, I just had it in the stealership for service for the first time since the warranty expired and they wanted to do more than $7K worth of work. I told them to just do the basic service and I would think about the other things. The major parts they wanted to replace are the vacuum pump (leaking oil?), the oil pressure switch, and the front CV joints. I own several German cars, and one Italian car. I considered this price in the Italian repair stratosphere, so I decided to repair those parts myself. I have the pump, etc, but have not gotten around to fixing it.

Now, for my question. Today I was driving it through a drive-thru and it started bucking and smoking profusely. It drives perfectly above about 3 or 4 mph, but jerks starting off. Can this jerking and smoking be somehow related to the vacuum pump leaking oil? If not, what could it be other than the obvious very bad things?

Thanks.

Sounds like a fouled plug and or the oil separator?

Thanks for the reply. I'm leaning towards the oil separator. It seems to occur when the car idles for an extended time in the 100+ degree heat. Does this make sense?

The separator will usually cause a plug or two to smoke.

Hi Big "J"

I have a 2004 4.4i X5 and need some help with the location of the oil separator and what it looks like.....any help would be appreciated.

Thanks

Hey zazoo!

Not sure if you have the N62 or the M62 V8 engine in your 2004?
I know my 4.8 has the N62 and it doesn't have an oil separator like the M62 does. It has breather valves (i forget the actual name) on top each valve cover that does the job.

The M62, I believe has the separator at the back of the engine, firewall side and is a PITA to get to. I could be wrong....

Good Luck!

Big "J"

Mine is the N62 and your correct about the two breather valves. Just changed those a couple of weeks ago so should be ok there for a while.

Thanks

Zazoo

Ok, I found the problem and thought I would post it for those that need this info. I do have the N62 engine with the two breather valves on the cam covers. When this car would idle or surge it would really smoke. I ordered the two breathers and installed them this morning. Please see the attached pic. The rubber diaphragm was completely compromised so oil was easily getting back in to the intake system . The replacement took about 10 minutes..
http://img.tapatalk.com/d/12/10/08/vudyjuzu.jpg