Esters make oil more electrically conductive?

[nel]

I've been chasing down the cause of ignition misfire in my wife's 1997 BMW 328i for a few months now. The most recent UOA with German Castrol can be found here: 1997 328i UOA

I've gone through spark plugs, a new battery, camshaft position sensor and ignition coils (the last two due to OBD-II fault codes). I thought I had the problem licked and then it returned after a week or two.

Finally, I was in the midst of swapping ignition coils from one cylinder to another to see if the problem would follow the coil when I saw that there was some oil in the spark plug hole. Not a lot, just a very thin film. What appears to be happening is that everytime I did something, the problem would go away for a week or so. Then the oil film would return because of a weeping valve cover gasket and the car would start misfiring again. BTW, I can't detect any change on the oil dipstick over the course of 7,500 miles. This misfire first started back in December when I put German Castrol in the car, now that I think about it. Before then, everything was fine.

So, do esters being polar in nature, cause oil to be more electrically conductive? It would appear so in this car.

 

[seotaji]

i dunno if that's true. it happens a lot on mazda 626 with weeping valve cover gaskets using regular oil.

 

[Dan4510]

i doubt its that, anything will conduct electricity in the presence of high voltage. Oil will provide the carbon trace to let the voltage go elsewhere.

Sounds like you need a new gasket more than anything else.

The problem you are having is exactly why i still drive carb cars with no computer. Misfires are easy to find and fix...And it doesnt take $300 of diagnostic work to find them.

Dan

 

[MolaKule]

nel,

Nope! The PAO's and esters are used in Transformer oils for heat transfer and Insulation.

 

[Pablo]

I was just gonna post I'm working on disposing 4000+ plus oil filled caps....I could be wrong, but they are filled with a synthetic ester: Di(2-ethylhexyl)phthalate....which interestly enough is from Sunoco.

As "they" say: "...it's not the (________) (water) that conducts, it's the crap in the (______) (water) that conducts...."

 

[MolaKule]

Caps? As in Ball Caps?

Di(2-ethylhexyl)phthalate? Great as a PPD and laxative!

 

[brianl703]

Used oil / engine grime is likely to be more conductive than clean, fresh oil because of all of the fine carbon particles in suspension (which is what makes used oil and engine grime dark).

I had a misfire in my car which I finally tracked down to the sparkplug socket which I used to install the plugs--it was filthy with engine grime, was transferring it to the insulator of the new plugs, and they'd start misfiring after a while.

I cleaned it out with q-tips and solvent, made sure it was real clean, then I replaced the plugs AND the wires (since the misfire had started carbon tracking down the inside of the wire boots), and no more problems.

 

[MolaKule]

On the older Chevy S-10's, the Isuzu engine's spark plug boots would become conductive. Add to this the corona electrical field which collected dust and carbon between the boot and ground portion of the sparkplug, and the net effect in wet weather was a severe reduction in Hp.

 

[Pablo]

Caps = capacitors (oil filled AC caps)

We won a lawsuit against the cap manufacturer (our supplier at the time,-defective product, bad internal ribbon bonds)....but along with zero dollars for our company and the lawyers getting millions, we now have to dispose of the bad capacitors. If the supplier paid any more he would have been bankrupt so the lawyers got most of their money from insurance.....all WE wanted was:

a) good product
b) field replacement for remainders
c) $ coverage for our expenses

Point: lawyers are....bad even when they are "on your side" and ester oil is just not conductive (within reason)

It gives one the ****z? So do waffles in my case..

 

[Geoff]

My wife had a mid 90s Mazda MX-6. The boots for the plugs went deep into the heads. It started missing, eventually to the point where it felt like it was running out of gas.

Turned out the boots would short against condensation in the plug hole, and once shorted, stayed shorted. The only way you could tell was to pull the boot and look at the bottom. You could see the tell tale white scorch marks from the shorting at the end of the black boot. Replaced and problem solved.

 

[Gerret]

Esters, being polar, tend to squeeze between gasket and sealing surface more than non-polar oils.