water in oil part 3

[Andy]

This is a follow on to the water in oil problems further down the list.Yesterday a lab did some tests on the fluid out of the sump to determine what it consisted of. They spam the mix in a centrifuge at 4000g to seperate the suspected oil/water mix but no water apparent, then span it up to 15000g and then a minute seperation was found which apparently had a pink tinge.This is starting to point towards red diesel in the sump!!! Today the lab is using samples of fresh oil , diesel out of the tank and sea water to create the same fluid as found in the sump and in the mean time i will look at the fuel pump seals...any more ideas????

 

[claymore]

Ideas

I think you should be on the Queens Birthday Honours list for your persistence - beyond that diesel doesn't sound as bad as water and maybe you've still got a little leak in a cylinder somewhere? If the injector is squirting diesel into the cylinder then that is surely the only place it can get down to the sump from?

 

[summerwind]

This is getting to be like a Sherlock Holmes story! I wish I could skip to the last page to discover Who dunnit.

 

[vyv_cox]

Diesel in oil part 3

A very common source of diesel in oil is a perforated diaphragm in the lift pump. This was probably mentioned in Part 1 or Part 2 (not by me). Also check that the return line from the metering pump back to the tank is flowing, blockage of this will overload the system and fuel may transfer to unwanted places.

Overall I would prefer to have diesel in the oil than water, so it's not entirely bad news. Don't operate the engine with all this diesel in the oil, the reduced viscosity may damage the bearings.

 

[miket]

I had this with an old Freeman 32, 2 x Ford Thornycroft 108hp diesels.

I'm not particularly mechanical but was told the eventual cure was some seal between the fuel injection pump and the engine block. Went through lots of other things first.

 

[Trevor_swfyc]

The lab are not the only ones getting in a spin over this problem!

What happened to the crackle test result? this would have told us, is it wet yes or no. Centrifudge may not break down the emulsion. Another fact Lubricating oil including multigrade when mixed with red diesel even 50 : 50 will still give a Clear and Bright mixture. The oil dissolves freely in the diesel and visa versa.
To get the sort of turbid suspension you were talking about would take something like 10-20% water to oil ratio. As previously posted hope you are not running the engine on the mixture you have in your sump? or you could end up with bigger problems or to put it another way big end problems.
We continue to look forward to the "Answer"
Don't spin us any more yarns - please
All the best
Trevor

 

[claymore]

Maybe it would be a good thing if you blew the engine and bought a new one - then we could have a thread on choosing a new diesel and another on installations!!
AMC diesels at Longton Nr Preston are brilliant with BMC's
regards
JS

 

[davel]

Can't wait for part 4!

Have you approached YBW about serialisation rights?

Dave L.
Location: 50 51.0 N 1 18.6 W

 

[ParaHandy]

Re: Diesel in oil part 3

It was…..I don’t think any stone has been left unturned and while we’re waiting for Part IV I thought this little true story might keep us amused…

The BMC diesel cylinder heads were forever having blocked waterways. Many are the (almost) brand new London taxis which shuddered to a halt with steam pouring out and that nasty smell of too hot rubber/oil/etc. The problem was how they cast the heads. You plugged the waterway, most often from both ends, and when the plug withdrew a very thin web of metal closed the passageway. To get rid of this web, the cylinder heads were passed through extremely high pressure water jets. The pressure was sufficient to cut through mild steel plate. Unfortunately, when these webs detached and then disintegrated under the water pressure the slurry so formed did not always get blown out of the head. After a few miles of normal use, this slurry would collect around the old plug marks and block or partially block the waterway hence boiling taxis.

Anyway, we had invented a surfactant with a metal-attracted head and the usual water-loving tail. On a small scale trial all looked good. The solution gobbled up the metal particles. A desperate BMC welcomed us with open arms and a full scale trial was organised. On the day (actually late evening as the power consumption was such that BMC ran it on the “white meter”) the operator in his armoured cab duly ran the pumps up and we waited. Suddenly there was an almighty eruption as a cascade of foam erupted out of every gap in a machine as big as a football pitch. There were many gaps and rather quickly the control cab had to be evacuated. We hadn’t tested the surfactant (really a fancy detergent) at high enough pressure and at these pressures, the molecules became super-active. We quickly collected our kit and beat a hasty retreat.