Hi all. We’ve had our LR4 for about two years now. I had a problem with an oil leak that I was trying to track down, and then we would get intermittent HUGE plumes of smoke. Particularly when going down a steep hill, but other wise it would never happen.

I saw a bunch of different references to the vacuum pump leak somehow sucking oil into the exhaust.

I have no idea how this is possible.

Is there any truth to this? I guess I’m looking for a “oh yeah that’s a known issue!” or “he fell for the vacuum pump story.”

Thanks. And yes I just replaced it.

+APPA+

 

Never heard of that one. The vacuum line does go from the pump to the booster and intake, but theoretically it always has engine oil covering the back side of it.

we've had old genuine pumps fail causing either a fuel pump timing chain skip or tabs on the end of the fuel pump cam to break off.

also, beware of cheap pumps, they can fail and do the above mentioned failures.

 

Thanks for the reply abran.

I had wondered at first if the vacuum pump leak was just filling up in the guard plate, and then at speed the airflow was sucking it out onto the exhaust. I’ve tried to concoct a variety of ways to figure it out.

I can say it’s been 3-4 days now and my oil level stays the same, and no more smoke show.

My guess would be oil pressure shoots up when you apply the brakes, and the gasket in the vacuum pump lets oil past and into the intake?



+APPA+

 

You’re welcome Appa.

If you take off your throttle body you will see pools of oil resting on the base. My assumption has always been that comes from the PCV system.