skizot722
Well-Known LVC Member
Been a while since I posted on here, but I've got a few questions about my car. It's a 2002 V8 with about 33,500 miles on it. When I first got it, I noticed that oil was leaking out around the oil-filler tube in the driver's side valve cover. I figured that the o-ring gasket for the tube was damaged (even though the car only had 18K miles on it at the time), so I decided to replace it. That was a major PITA, and it's still been leaking since I did that. It stayed clean for a short while after I replaced it, but it didn't take long for the valve cover to start getting dirty with oil. The oil is definitely coming from where it seats into the valve cover.
On a side note, but I believe related, I keep getting P0133 (and the other 3 HO2S "slow to respond" codes) randomly. I even replaced one of the O2 sensors thinking there was just something wrong with it. But, over time I've gotten one for every sensor. I checked the service manual for possible causes, and one of them was to check the MAF sensor and gasket. I did this, and found nothing wrong with either (visually, haven't had the voltage on it checked yet). In the process of taking the air intake tube off, I noticed on the other valve cover (passenger side) that there is oil coming out of a tube that goes from it to the throttle body. On the valve cover, it is dirty with oil where this tube goes in at. And, I noticed that there was oil in the throttle body (I actually got a good dab on my finger when I felt around inside of it).
I'm thinking that oil being taken in through the throttle bottle might be causing the O2 sensors to trip up. But now, the bigger question, why is there oil blowing out of these openings on the valve cover? I know that excessive blow by can cause this sort of thing, but there's no way I should be having ring failure at 33K miles (let alone 18K when I first noticed oil coming from out around the filler tube). Now, I noticed that the V8 doesn't have a PCV valve, but it would appear that this tube going from the passenger side valve cover to the throttle body is acting as one (except that there is no one-way check valve, like you have with a PCV valve).
Can anyone give me some thoughts as to what's going on here? This is a really strange problem, and I have a hard time believing that it's blow-by, but I don't really have another explanation for the type of pressure that would be needed to cause oil to be forced out of these openings. Here are some pictures of what I'm talking about:
On a side note, but I believe related, I keep getting P0133 (and the other 3 HO2S "slow to respond" codes) randomly. I even replaced one of the O2 sensors thinking there was just something wrong with it. But, over time I've gotten one for every sensor. I checked the service manual for possible causes, and one of them was to check the MAF sensor and gasket. I did this, and found nothing wrong with either (visually, haven't had the voltage on it checked yet). In the process of taking the air intake tube off, I noticed on the other valve cover (passenger side) that there is oil coming out of a tube that goes from it to the throttle body. On the valve cover, it is dirty with oil where this tube goes in at. And, I noticed that there was oil in the throttle body (I actually got a good dab on my finger when I felt around inside of it).
I'm thinking that oil being taken in through the throttle bottle might be causing the O2 sensors to trip up. But now, the bigger question, why is there oil blowing out of these openings on the valve cover? I know that excessive blow by can cause this sort of thing, but there's no way I should be having ring failure at 33K miles (let alone 18K when I first noticed oil coming from out around the filler tube). Now, I noticed that the V8 doesn't have a PCV valve, but it would appear that this tube going from the passenger side valve cover to the throttle body is acting as one (except that there is no one-way check valve, like you have with a PCV valve).
Can anyone give me some thoughts as to what's going on here? This is a really strange problem, and I have a hard time believing that it's blow-by, but I don't really have another explanation for the type of pressure that would be needed to cause oil to be forced out of these openings. Here are some pictures of what I'm talking about:



