On a 93 4cyl. is there any harm in letting a valve cover gasket go un-repaired? Mine is showing that that there might be a little oil around this one becasue I can see where dirt has collected. A dealer told me about
6k miles ago that it should be replaced at some point. I never have to add oil but then I change it every 3k miles or so and it's pretty clean whenever I check it. I was quoted $150 at one dealer and $200 at another.No harm, engine might get a little dirty. you could try tightening the big hold downs on the cover to snug it up a bit.. These are what the plug wires go thru.
I had exact case. I did not notice it early and resulted in:
1) Car O2 sensors became sluggish due to some oil vapor getting to it over time. O2 sensors need to breath so avoid oil, water, and cooling water from reaching them. 2) Carbon deposits built up in EGR and Throttle Body once O2 sensors became sluggish. I had to replace EGR Valve and clean Throttle Body and Air Intake Chamber.I would say fix it now before you get further failures.
Your problems were unrelated to a small valve cover oil leak. Sounds like you had excess oil going into the combustion chambers getting to the O2 sensor in the exhaust system. Oil dripping from the valve cover is on the outside of the engine. Replacing that valve cover gasket is about the easiest and cheapest repair that the owner could do himself.
Oil and dirt overtime reached wires and outside surface of one O2 sensor, read what auto tap has to say about O2 sensors:
"The outside of the bulb is exposed to the hot gases in the exhaust while the inside of the bulb is vented internally through the sensor body to the outside atmosphere. Older style oxygen sensors actually have a small hole in the body shell so air can enter the sensor, but newer style O2 sensors "breathe" through their wire connectors and have no vent hole. It?s hard to believe, but the tiny amount of space between the insulation and wire provides enough room for air to seep into the sensor (for this reason, grease should never be used on O2 sensor connectors because it can block the flow of air). Venting the sensor through the wires rather than with a hole in the body reduces the risk of dirt or water contamination that could foul the sensor from the inside and cause it to fail. The difference in oxygen levels between the exhaust and outside air within the sensor causes voltage to flow through the ceramic bulb. The greater the difference, the higher the voltage reading."
"The sensor can also be damaged by environmental factors such as water, splash from road salt, oil and dirt."
what auto tap has to say about O2 sensors: "The sensor can also be damaged by environmental factors such as water, splash from road salt, oil and dirt."
Maybe you had the 6 cylinder and it is closer to the valve cover? Maybe the original poster had a 6 cylinder motor too? He may not have been specific..I assumed 4 cylinder. Not sure he said what year either..
Ok, I just looked at my 97 4 cylinder. It has the original O2 sensor with 4 vent holes on the body. The wires have a loose fitting rubber cover on them. The vent holes are almost
24 inches from the closest part of the valve cover...Just cant see where oil is gonna spew that far to hit the sensor..If you got a leak that bad, by all means get it fixed! RobMotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.