I recently wanted to buy a '93 Nissan Pathfinder with almost 100,000 miles. It looked really nice and seemed to be well-maintained. When I took it out on a test drive, I heard a slight ticking sound when taking off from a stop.
The owner said it had been making this noise for a long time without getting any worse, but he didn't know exactly where it was coming from. I didn't commit to buying the SUV because of the noise.
Your description matches a common condition when dealing with Nissan's 3.0-liter V6. The ticking sound is a small exhaust leak at one or both exhaust manifolds. The problem at each manifold is the retaining studs breaking off at the cylinder head. Several Nissan vehicles equipped with the 3.0-liter (VG30E) have been dealing with this flaw since as far back as 1984 including the 1990-94 Pathfinder.
Nissan Technical Service Bulletin number NTB94-041 dated April of '94 contains the manufacturer's repair procedure. It involves the replacement of the exhaust manifold studs with new hardware which has been engineered to improve durability. The bulletin also recommends the replacement of the exhaust manifold and gasket on the affected side.
Yes, it can get expensive. When adding up parts and labor on the left side alone we're looking at approximately $200 in parts for the exhaust manifold, gasket and updated studs. We can then tack on a labor time of 3.4 hours for the manifold replacement. This gives us a labor cost of about $220 when using a common shop rate of $65 per hour. That makes a grand total of $420 plus an additional hour of labor time per broken exhaust stud, to cover the time involved to extract them from the cylinder head. Did I mention tax or doubling the price if both sides are involved?
The Pathfinder is still a reliable SUV. Simply take this repair into consideration when making a purchase.