Oil smoke.

[David Layton]

Sudden burst of oily smoke out the tail pipe on acceleration and an oily exhaust pipe. Lower end or valves?  At least I was close to home. 

 

Engine bay is clean. So the failure was internal. 

Edited May 5 by David Layton

[Pablo M]

From what I've found out, chasing the same issue, if its on acceleration its rings, if its on deceleration its valve guides. On mine, it was decel, and rebuilding the head fixed that.

However, many will tell you if the head needs rebuild you should also rebuild the bottom end. You'd otherwise be putting a good head on a weak bottom end. I did that though, because $$. Its fine so far. 

[Dudeland]

Is it consistent? If so, then it's time for something to be refreshed. If it happens once in a while, it may be a gas-washed cylinder. I was messing with my tune and gave it too much juice at the top end, which laid out a smoke show (happened once) 

 

 

[Son of Marty]

I also wonder if your master cyl. is leaking in to the booster, hard braking or a sharp turn can cause this fluid to get sucked back into the intake manifold and it does burn white. If the car still runs well I'd drive it some more and see if it repeats the smoking routine. 

[David Layton]

The BMW is sitting next to my TR4a which is being reassembled after some dashboard and cowling work.  My local Triumph club, St. Louis Triumph Owners Association (SLTOA) is hosting the South Central Region Vintage Triumph Register (VTR) gathering and I am spending my time doing that.  But after I come back from meeting my son's future in-laws this weekend, I will pull the plugs and do the compression.  

My brother who is a very good mechanic and has had several 02's.  He mentioned the Master Cylinder as one issue and the one-way valve on the breather as another.  

[David Layton]

Marty,

 

This what we are checking next. I had to be out of town last weekend, so I began examining this the other day.  The spark plugs did not appear to show a head gasket issue, these were not too wet with oil.  I have been losing a little bit of brake fluid but the clutch master and slave are dry.   But I did not think that little bit of fluid may be coming from the booster unit.  (It's BRAKE fluid but my neurosis has me think CLUTCH.)

 

Later today I will plug the brake boost return to see if the pope smoke stops.  If this is the brake booster, this unit will have to be rebuilt as this is a discontinued item.  Is Power Brake Exchange the best option?

[BarrettN]

Power Brake Exchange does good work in my experience with them - they powder coat the unit when they rebuilt it, so it loses a little originality. For me, having a brake fluid resistant coating is a plus, I didn't ask if there's an option for them to just paint it or leave it as-is.

 

Barrett

[jimk]

If it's passing brake fluid, it's the brake master cylinder, not the booster.  The booster is just catching what the master cylinder leaks.

[David Layton]

Yes, and brake fluid flowing into a 51 year-old booster is not good for the diaphragm.  So, if the test reveals that the oily smoke is brake fluid from the master and booster, I need to address the booster issue.   I have a new in box brake master.

 

 

 

[Preyupy]

Are you loosing brake fluid?  If you get a puff of smoke after a decel from higher RPMs when you open the throttle again it is most often valve guide seals.  This can also happen if it is sucking brake fluid from the booster, but this only happens after you have had to add a significant amount of brake fluid over the last few hundred miles or so.  

[Mike G]

Plug #1 certainly looks darker than the rest. What didn’t compression check show?