Any special oil concern after a misfire?

[JohnSaints]

My car was running on 3 cilinders/misfiring for around 2 days/100 miles due to a faulty ignition coil. I was wondering if there's any special care I should take regarding the oil. Does the unburnt fuel contaminate the oil in any way? Should I change it sooner than normal? Any other special precautions?

 

[ahoier]

If it was running rich, you may have carbon build up on the intake, etc.......technically possible that some gasoline has leaked past the rings and got into the oil I suppose....

 

[zyxelenator]

Shouldn't fuel burn off when oil heats up? You may want to change your current oil little sooner than you planned. But I don't think it is too serious. Which oil do you have? Guys might be able to answer you how good or bad it can take fuel dilution.

 

[eljefino]

If it was a dead miss I'd change the oil. If it was just feeling a little off from a weak spark probably not. You could always give the dipstick the sniff test for the strong smell of gasoline. If it's overfull, you "made oil" with gas and want it out.

 

[JohnSaints]

I will check the oil for gas smell. One of the spark plugs wasn't working at all. Don't know if it was a "dead miss" or not. I could feel the car vibrate more than usual and it started choking in rpm ranges where it didn't choke. I made a mistake and stated I covered 100 miles but I meant 100 km (60 miles). My current oil has only 300 miles on the engine (my OCI is at 6000 miles/1 year). The car also burns oil - around 1 quart every 2000 miles (I don't know if it's relevant). The oil has the following specs: CASTROL MAGNATEC 10W40 ACEA A3/B4 API SL/CF VW 501 01 / 505 00 MB-Approval 229.1 Meets Fiat 9.55535-D2 Density @ 15ºC ASTM D4052 kg/l 0,863 Kinematic viscosity (ASTM D445 mm²/s) @ 40°C cSt - 96.0 @ 100°C cSt - 14.3 Flash point, v.f. ASTM D93 °C 200 Sulfatated Ash ASTM D874 (% of weight) 0.96 Total Alcalinity, TBN ASTM D2896 mg KOH/g 8,0 Pour point ASTM D97 °C -33 Viscosity Index - 155 ViscosiTY, CCS -25ºC (10W) ASTM D5293 cP 6800

 

[zyxelenator]

I think if you keep topping it up with fresh oil- you will be fine. But it is just my personal opinion.

 

[GumbyJarvis]

The third cylinder in my truck earlier this year kept misfiring and I figured out it was a bad coil, needless to say I couldnt replace just ONE coil I had to replace all 4, of them. cost me a pretty penny too, because I had just thought it was maybe the PCV, Spark Plugs, Spark Plug Wires, Air Filter, it coulda been a number of things, went the cheaper routes before I concluded it was the expensive coil pack LOL, then I kicked my truck and cursed it as a Distributor Cap would of been helluva more convenient and cheaper, but No, I had to have a coil pack. Should be fine, I went roughly 100miles on 3 cylinders, just when you do it dont forget the 2 cycle engine oil! LOL JK

 

[mechtech2]

If the oil was fairly fresh, I wouldn't be concerned unless I smelled raw fuel in the oil.

 

[artificialist]

Originally Posted By: GumbyJarvis

The third cylinder in my truck earlier this year kept misfiring and I figured out it was a bad coil, needless to say I couldnt replace just ONE coil I had to replace all 4, of them. cost me a pretty penny too, because I had just thought it was maybe the PCV, Spark Plugs, Spark Plug Wires, Air Filter, it coulda been a number of things, went the cheaper routes before I concluded it was the expensive coil pack LOL, then I kicked my truck and cursed it as a Distributor Cap would of been helluva more convenient and cheaper, but No, I had to have a coil pack. Should be fine, I went roughly 100miles on 3 cylinders, just when you do it dont forget the 2 cycle engine oil! LOL JK

Sometimes an entire distributor has to be remanufactured or be brand new, and some of them cost $800, depending on application.

 

[TFB1]

Originally Posted By: mechtech2

If the oil was fairly fresh, I wouldn't be concerned unless I smelled raw fuel in the oil.

Agreed...

 

[45ACP]

Originally Posted By: eljefino

If it was a dead miss I'd change the oil. If it was just feeling a little off from a weak spark probably not. You could always give the dipstick the sniff test for the strong smell of gasoline. If it's overfull, you "made oil" with gas and want it out.

MOST engines smell at least a LITTLE bit like gas as gasoline is extremely aromatic. If there is a STRONG scent, it means there is some sort of fuel issue, or leak-down. I usually give the dipstick a sniff and sometimes i ask myself am i expecting to smell fuel.. but some cars i do some i dont.. its variable. (And yes there have been cars wiht no gasoline smell on dipstick. One car it smelled like a gas pump on the dipstick. That car did fail, too.)