Nissan ZD30, Oil Pump Problem

Problem

The problem is a poor fit of the oil pump cover on the ZD30 engine, which is mounted on the front plate of the engine and driven directly by the crankshaft. Unsuccessful fastening can lead to the process of gradual unscrewing of the cover in some resonant operating modes of the engine and the penetration of fallen fasteners into the engine mechanisms and, as a result, cause their destruction.

Causes

The oil pump cover is secured to 11 studs and a pair of bolts. The screws, made from small M6 screws with a cross-shaped conical head, are screwed, as a rule, without the use of a thread locker. Under the conditions of resonant effects that arose under certain unspecified operating conditions of the engine, these screws began to gradually unscrew one after another. In the best case, the screw simply falls into the pan, and there is a closely spaced gear in the lower parts of the teeth, causing their destruction.

The problem occurs on both the earliest machines and the latest ones from 2010, so we are not concerned about manufacturing defects or a drunken assembler.

Since the problem occurs rarely, it is unlikely that the problem can be called a congenital sore; rather, it is a blatant design flaw, because it is completely incomprehensible how such important and loaded components can be secured to screws from a children's construction set.

Symptoms

Clearly expressed symptoms of the problem, as a rule, are already fatal - metallic knocking and crackling from the side of the front plate from the operation of crippled gears.

In a more successful case, you may find a whole screw that fell out of the pan when changing the oil. In some cases, the oil pressure light coming on at high speeds can also be a symptom.

Solution

A high-quality solution is complicated by a decent disassembly of the engine with the removal of the front plate.

The screws need to be replaced with similar ones for the hexagon for normal tightening, put on the clamp, and tightened with an impact hole

To detect the problem in a timely manner, during the next oil change, you need to install a plug in the pan with a powerful magnet that will attract fallen parts.