HELP! Heavy white smoke out tailpipes – smells like gas (not coolant)

[thesalboy]

2003 X5 4.4i (M62tu) automatic. It ran great before I started this 100K overhaul. At my wit’s end.

I serviced the valley pan, and while at it did valve cover gaskets, intake manifold gaskets (all internal and mating surfaces), oil separator, PCV/CCV/EGR (on back of intake), and had injectors serviced at Mr. Injector. I also changed the fuel filter, which has the fuel pressure regulator integrated into it. Also changed plugs – I used Bosch 4417 (FGR7DPQ).

Immediately on startup, light white smoke started coming out of only the right tailpipe. The smoke quickly thickened. The engine also had a miss – I think only on the right bank. Left tailpipe seemed fine – no smoke, no miss present. I let it idle to warm up the motor, revving it a little occasionally, but the smoke stayed thick and the miss was there at all RPM ranges. I shut it off after 10-15 minutes.

No SES/CE light ever came on. I checked codes and it showed only one: P0134 - 02 Sensor Circuit No Activity Detected (Bank I Sensor 1). I believe this is a symptom not a cause – the first O2 sensor on the right bank is flooded with gas and may now not operate at all. I have not since run it more than a few seconds as I tested, but there are no codes coming up, much less a SES/CE light.

There is no hint of coolant smell to the white smoke. It appears to be unburnt fuel vaporized by the catalytic converter. When I ran it for a while, the right tailpipe was moist and the moisture smelled like fuel. Oil smells a little like fuel.

In desperation, I replaced all injectors with brand new. The smoke now comes out of both tailpipes equally. As in the beginning, the smoke is light at first, but thickens quickly.

TESTS AND RESULTS

I switched the two lines on the fuel filter to make sure I didn’t get them mixed up. The car started and ran for a few seconds before dying. This is consistent with my understanding that the car would not run if the lines are switched – it ran after switching only on residual fuel pressure. I switched the lines back and the smoke returned. [Beware – there are DIY posts out there mixing up the ports on the filter. Blue lines indicate fuel flowing away from the filter – return or engine feed. The black line feeds the filter.]

I sealed off the throttle body with a plastic bag and hose clamp, pulled off the evap hose on the side of the intake manifold, connected a spare hose and blew into it to pressurize the manifold. Air only came out of the plastic pipe that goes from the intake boot to the EGR/brake booster one-way valve – once I capped that (and the hose I blew into) no air came out until I released a hose. I was concerned an intake manifold gasket had fallen out of place during install, but this seems to confirm there is no leak in any of the intake manifold seals.

I pulled the engine harness off the injectors and cranked the motor with a test light in each fuel injector port. Each acted the same – after some cranking the light started flashing, a little faster than once per second. Other cars have reacted differently, flashing more rapidly. Not sure if my results indicate a problem or not – not covered in Bentley.

Fuel pressure is normal – 3.5 bar at the Schrader valve on the rail.

As this point I have to suspect the DME, but am hoping someone has an idea of what else it could be.

[pnoyako85]

sell it....

I traded mine in.... take the Loss and Run....hate to say i spend over 23k in 2 yrs on my x5...but its time to move on now..

I do have DME for X5 and all the stuffs it needs...steering,key,obd..etc..

[thesalboy]

I decided to try to run it and hook up INPA. No errors in memory for engine. I took some video while I did this. These three links represent about 60 seconds in real time.

1. Just after startup: https://www.youtube.com/watch?v=cG3sQC9vA38

2. After running for 30-45 seconds: https://www.youtube.com/watch?v=NBIwDCIYSr8

3. Engine stopped due to smoke overwhelming the garage (my neighbor ran over thinking the house was on fire): https://www.youtube.com/watch?v=NVJMmuZFxH0

[bcredliner]

Originally Posted by pnoyako85

sell it....

I traded mine in.... take the Loss and Run....hate to say i spend over 23k in 2 yrs on my x5...but its time to move on now..

I do have DME for X5 and all the stuffs it needs...steering,key,obd..etc..

Isn't that helpful.

[bcredliner]

Oil smoke is white, a rich fuel mix smoke is black. Coolant smoke is white and has a strong sweet smell.

In the first video it looks like it is just burning off water condensation as it appears to disappear. If the last video is after it had been running for awhile it looks like the smoke is going away.

If you start it up after it has been sitting for some time does it smoke like video 2 each time?

Was there any oil in the spark plug holes when you removed the plugs? Did you

With the engine running, remove the oil fill cap to see if there is a normal vacuum. There is the possibility that the oil separator is bad. If that is the case you don't want to be driving it. It could also be related to the tube under the intake that goes to the oil separator to the back of the engine.

[X5only]

Start with the basic stuff as Bcredliner advises. Relax and approach it systematically looking at the simple stuff. The car was running fine before you did the repair. I recently learned this way of tackling repair issues the expensive way after replacing pricey components when the issue was a mere inadvertent swap of two CPS sensors.

[upallnight]

Originally Posted by pnoyako85

sell it....

I traded mine in.... take the Loss and Run....hate to say i spend over 23k in 2 yrs on my x5...but its time to move on now..

I do have DME for X5 and all the stuffs it needs...steering,key,obd..etc..

A poster with over 2000 posts on this forum must know something about owning an X.

[bcredliner]

Originally Posted by upallnight

A poster with over 2000 posts on this forum must know something about owning an X.

So that means if I make enough ignorant and incorrect posts, my posts will become accurate and filled with wisdom. I feel smarter already.

[SMOKEY53]

Subbed thread for more 'wisdom'


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[pnoyako85]

Originally Posted by bcredliner

Isn't that helpful.

From my experienxe on the Old X5 i had 4.4i

Check your coolant side valve cover area


Last time i got this issue. It was coolant leaking into engine.giving you white smoke .
Changed the valve cover gaskets and few other related to that side.of the motor.
Hope that helps