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5 minute diesel purge

695 views 9 replies 6 participants last post by  Cook90 
#1 ·
1984 300SD with 150,000 miles. Prior to my purchase the vehicle hadn't been driven in the previous 4 years. Today I performed a Lubri-Moly diesel purge with a single 500ml can. The engine consumed the fluid in five minutes at mostly idle power. There was little exhaust smoke and no contaminants in the return fluid. All the accounts I read online told me to expect the purge to last between 15-30 minutes. What, if anything, can I learn from this procedure? Is this a healthy motor? (6 liters per hour!). Thanks.

Dan
 
#2 ·
That does seem like a super rapid fuel use. I'd be worried that it's going someplace... like into the oil from an internal leak in the injection pump.

Stupid question time: Sounds like you did unhook the fuel tank from the fuel pump, right? Both the feed and return?

There should be no smoke from the tail pipe at idle when running a diesel purge.

-J
 
#4 ·
I just did a Diesel Purge on my 1982 300D with the same engine. Took under five minutes for it to consume the whole can running at varying speeds. I don't think there's anything wrong here.

And there's no way a single can of diesel purge would last 15-30 minutes, even with the engine running at idle.

Dan
 
#5 ·
Hmm. To be fair, I'm thinking back to my 4 cylinder TDI VW... I imagine those use less fuel at idle.

If you have any questions about oil contamination a $20 blackstone oil test will answer them :)

-J
 
#6 ·
I did a purge on my 300CD last spring. I was astonished at how LONG it took to consume that one can.

If the oil is good and the level hasn't risen you can probably rest easy. I'd be very interested in knowing what kind of mileage (and smoke) you're getting out of the engine. That would give you a good idea about consumption.
 
#7 ·
Thanks, everyone, for the discussion. I checked my oil and the level hasn't increased. It smells slightly gassy but it's not overwhelming. Unfortunately, the car isn't roadworthy (motor mounts are shot) so I don't have any mpg data. I do have white smoke from the tailpipe which I've read could be any number of serious problems; however i haven't run this engine enough to get a feel for its health.

Thanks again for the input.
Dan
 
#9 ·
Polei has white smoke at start. I am chalking it up to dead glow plugs, as the starter has to work to get her to spin up, and idle is rough until there is enough heat built up to warm the colder cylinders.
 
#10 ·
The car idles rough due to the bad engine mount. I threw caution to the wind this afternoon and took her out on the highway. The car runs great, especially during acceleration from 50-80mph. I did see grey smoke trailing the car during heavy acceleration but after returning home there was very little smoke and the exhaust didn't smell like unburnt fuel. I hope the car sorts itself out as it accumulates more miles. Thanks for helping out everyone.
 
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