Perspiring Injection Pump

[WRe]

Hi,
since some months I observe a phenomenon I don't understand, maybe you can help.
Usually I drive only short-haul routes means crusing via country roads with low rpms not more than 50-100 miles a day. In this situation my injection pump sweats, oil smells of gas (oilcheck 1.7% gas) and the engine leaves one drop of oil in the garage.
After our tour to Poland (2300 km mostly on side roads, some highways) or after a highway ride the engine/injection pump keeps dry, no gas smell, no drop on the ground.
Btw the engine runs very good and smooth, moderate gas (~12l/100km) and oil consumption (< 0.25l/1000km).
Any ideas would be appreciated!
...WRe

[Shvegel]

Sounds to me like an issue with crankcase ventilation.  The tube that runs from the valve cover to the throttle body is about it.  I would check both ends to make sure the vapors are getting sucked into the intake.

[WRe]

Hi,
Sorry for my late answer: Yes, i checked this, everything ok. The ventilation is free and the blow-by gas pressure is very low.
...WRe

[Benz Dr.]

What coolant temperature are you running?

[WRe]

Thermostat 79°C

[Benz Dr.]

Thermostat 79°C

That would be the coolest one you can run. Maybe try a 82C and see if that improves it.  Your condition makes me think that your engine isn't running at full operating temps and could stand to be running at a higher operating temp. Do you happen to have a infra red probe you can verify what your real temp is?

[WRe]

Hi,
some time ago I checked my internal thermometer with an infrared probe and it was pretty close to it.
My engine gets hot very fast, after a few km the thermometer shows 80°C and stays there except when I stuck in a traffic jam during hot weather but never reaches 100°C since I have installed an electric fan.
The oil temperature (oil drain plug sender) shows 60-80°C all the time except I drive with high speed.
I just changed my spark plugs (see pic) because my idle was bad when engine was hot. With new NGK BP7ES everything is fine.
...WRe

[Benz Dr.]

BP7ES is the actual spark plug that's the standard part number.  I've been using BP5ES for a number of years as they seem to come up to running temps faster and tend not to foul out if you have the correct fuel ratios.
Do you have any extra resistors in your spark plug wires? Carbon core?  Your plugs look like you have correct fuel ratio but are either too cold or have lowered voltage. New plugs can fool you into thinking you've fixed a problem that will come back slooowwwwlllyyyy.

[WRe]

Hi,
the old spark plugs are Champion N7Y which worked fine for at least 20k km. At the end idleing was bad when engine was hot.
I use a 123ignition with standard spark plug wires and no resistors.
I will check the new NGK spark plugs after a while also my IP which is dry at the moment.
Thanks for your input!
...WRe

[Tyler S]

The white deposits on the electrode look like oil consumption or some sort of fuel additive. I ran Stabil in my tank for a short period and the plugs would turn white with deposits.

[Benz Dr.]

The white deposits on the electrode look like oil consumption or some sort of fuel additive. I ran Stabil in my tank for a short period and the plugs would turn white with deposits.

I saw that too - kind of odd looking because the center electrode is quite dark by comparison.

 ( like a couple of oracles examining the entrails of owls )

[WRe]

Hi,
my oil consumption is moderate, means 1l/2500 km and I don't use any fuel additives.
I used these Champion spark plugs for nearly 10 years and more than 20k km.
Experiences from German Pagoda fans  about spark plug usage:
- NGK BP6ES for slow drives/crusing
- NGK BP7ES for fast drives
...WRe