:wtfr:
My wife's '01 hit 4400 miles since I changed over to Mobile 1. Yesterday, I took it to have the oil changed. Pulled out the dipstick and nothing registered but a wad of sludge on the tip. I had a full engine flush and refilled with Mobile 1. As noted by others in this thread, there was no sign of oil burning or leaking over the past few months.
I immediately checked the '99. 3000 miles since change over to Mobile 1. Again, only a drip on the tip of the dipstick. I took it in today and had a minor oil flush (they did not have enough product to do the drain/flush/drain procedure). There was a different manager there today. He told me that the Isuzu 3.5 was known to need frequent PCV valve changes to prevent excessive oil burn. He told me there were several oil starved Isuzu engine failures he knew of and one instance where Isuzu had to replace the engine (No news to us but it was interesting he knew of the problem and history). I changed the PCV valve right away and came home to search our site to confirm his advice. First hit was this thread. Thank you VehiCROSS.info. It appears that this oil burn problem is common and another issue for me to monitor. As a result of this new education, I have a few questions for the community.
1. Is one brand/design PCV valve better than another? The oil change manager told me that he heard that there was one design that would fit/was specified for our engine but did not perform properly, but he could not be more specific.
2. I thought that Mobile 1 would not break down and create much sludge. Would the sludge be coming from left over petroleum oil in the engine?
3. If our engines are running fine, show no signs of oil burn out the exhaust, no leaks, or even plug fouling, where is the oil going? Several quarts synthetic carried through the PCV seems hard to imagine?
4. A few members have recently made some very long trips in their VXs. I was wondering if they experienced noteable oil burn - or is this problem more common with stop and go driving?
Thanks in advance for any replies.