Used oil in the fuel tank

MULLEY · Post by **MULLEY** » Sat Mar 14, 2009 11:00 pm

Apologies to bring this up again, i can't seem to locate the original thread on this, probably went off on a tangent

All i can remember is that David R mentioned that he regularly puts some in a tankful of diesel with no ill-affects.

My question was, does this only work with mineral oil or can you use semi or fully synthetic as well? And what is a safe amount to use in a 66 litre tank without causing loads of smoke out of the exhaust or potential damage to the fuel system?

Does the oil need to be filtered at all to remove any potential metalic particles in it? If so what do you use to filter it with?

Cheers guys

ed4ferrets · Post by **ed4ferrets** » Sat Mar 14, 2009 11:17 pm

Used oil

MULLEY · Post by **MULLEY** » Sun Mar 15, 2009 1:18 am

Cheers Ed. My question at the end of the above thread remains unanswered though. Any ideas?

mike st gilles · Post by **mike st gilles** » Sun Mar 15, 2009 10:45 am

Only my opinion Mulley but if there are metallic particles big enough to think about filtering out then there is something so drastic wrong with the engine that you might as well put anything you like in it. Its a bit like the argument/ talking point re magnetic sump plugs/bolts ie what good are they, apart from telling you the things fooked as if there's any metal there its already too late....

mountainmanUK · Post by **mountainmanUK** » Sun Mar 15, 2009 11:15 am

For a bit of extra "peace of mind", there would be no harm in filtering the oil before shoving it in the tank. A bit like I do with my wife's old chip pan oil. Double layer of Tesco's Finest Value Kitchen Roll!

cauchoiskev · Post by **cauchoiskev** » Sun Mar 15, 2009 7:20 pm

What about LHM then ? Must be a damn sight cleaner than old engine oil.

rob-81 · Post by **rob-81** » Sun Mar 15, 2009 7:34 pm

Didn't marty have problems after putting LHM in the tank of a BX (or was it a ZX)?

mountainmanUK · Post by **mountainmanUK** » Sun Mar 15, 2009 11:44 pm

Yeah, I remember Marty telling me that his BX (or was it a ZX?) would burn pretty much any type of oil....except LHM! He tried it once, with unsatisfactory results!!

MULLEY · Post by **MULLEY** » Mon Mar 16, 2009 12:16 am

Thats a bit strange as i thought lhm was infact mineral oil? perhaps theres something in it which doesnt suit combustion? or Marty put in too much?

Good point Mike, just asking questions to see what others do or don't do as the case may be. I was presuming that as engines wear over time, metal particles are present in the oil at all times which exacerbates engine wear if oil changes aren't done.

I guess filtering certainly wouldnt do any harm, i could buy a powerful magnet to see if it attracted anything in the gloop as well.

Anybody know if you can use semi & fully synthetic oil in various viscocities in the tank like mineral engine oil?

mike st gilles · Post by **mike st gilles** » Mon Mar 16, 2009 1:42 am

As you said Mulley there is a chance of this but then I would also think that the diesel filter itself would probably deal with the majority of crap in the fuel. Just for peace of mind as MM says might be worth letting it filter overnight through some kitchen paper or some old sheets or the like.

DLM · Post by **DLM** » Tue Mar 17, 2009 6:17 pm

All i can remember is that David R mentioned that he regularly puts some in a tankful of diesel with no ill-affects.

Well, some of the potential for ill-effect seems to have been covered, but what is the reason you want to do it? Extra diesel pump lubrication to prolong pump life on low-sulphur diesel?

Personally speaking, the only addatives I've ever put in diesel are the fairly dear ones for injector cleaning, whih I always begdrudge a bit as there's no way of telling exactly what you're paying for. It has been suggested to me that paraffin could do the same job.

Whatever you may choose to put into your tank should you choose to do so, you could take a rough guide from the volume of those commercial injector-cleaners (pretty small), which are intended for a full tank in most cases.

MULLEY · Post by **MULLEY** » Tue Mar 17, 2009 10:10 pm

The ultimate form of recycling, no other reason to be honest, oh, & the potential extra lubrication might be beneficial.

Father Ted · Post by **Father Ted** » Wed Mar 18, 2009 3:55 pm

mountainmanUK wrote:Yeah, I remember Marty telling me that his BX (or was it a ZX?) would burn pretty much any type of oil....except LHM! He tried it once, with unsatisfactory results!!

LHM fine

Hydraflush - FTL

Hydraflush pretty much carked the 1.9NA - has no lubricity at all. Burned though and took the pump seals with it.

Post by **mat_fenwick** » Tue Mar 24, 2009 11:50 pm

At the weekend I added about 2 litres of used oil to half a tank of diesel. The constituents of the oil were mainly old engine oil (some 10W40 semi synthetic, some 15W40 mineral), gearbox oil and a little heating oil when we were tring to prime the boiler.
No noticeable difference in performance or smoke, and the (Bosch) pump hasn't seized yet...

Still another 20 or so litres to go, although I'll spread it over several tanks!