Posted: Jul 23 2012 at 4:58pm | IP Logged

Greetings Frontier owners/enthusiasts,

I own a 2003 Frontier w/extra cab, 4WD and supercharged V6 engine. My truck has 84,000 miles and it has never leaked a drop of oil until this weekend. I went on a long drive to southern CO over a very high mtn pass. Once I reached my destination I noticed it was dripping black oil from the eng/trans area (not a constant drip, but enough to stain the driveway). I called the local Nissan dealer to see if they could pinpoint the leak. I wasn't sure if/how much they would charge to diagnose so I haven't taken it in. I confirmed the oil is not running down from the valve covers. The dealer service manager said the rear main seal rarely fails in this engine, but they would have to examine it to tell. The lower bellhousing area is now coated with oil so I can't really determine the source. Has anyone had a similiar experience (sudden oil leak from lowest point of bellhousing), if so, please what was the source? I'll get some degreaser to facilitate better diagnosis. Thanks for any suggestions.-Tim

Posted: Jul 26 2012 at 8:12pm | IP Logged

Hi thanks for the reply, I plan to thoroughly clean the lower bellhousing area this weekend. I'll try to confirm whether the oil is engine oil or trans oil. If it turns out to be engine oil, hence, failure of either the engine oil pan gasket or the rear main seal retainer, are those parts I can replace without removing the entire engine?

Thanks,

Tim

Posted: Aug 09 2012 at 8:12pm | IP Logged

Hi again everyone, I degreased the engine/bellhousing/trans area a couple weeks ago. There is residual oil still coating the upper part of the transmission (where I couldn't scrub). This leads me to believe that the oil may in fact be trans oil leaking from above. I have not found any more oil dripping from the bellhousing/trans area since I degreased. If my suspicion is correct and the leak is trans oil from somewhere high up on the transmission, is this a leak source someone else has experienced? In other words, what seal on the transmission would have failed to allow oil to run down the side of the transmission to form a drip at its lowest point?

Thanks for your help,

Tim