| I had my 300zx TT rebuild about 30,000 miles ago and have generally been very happy with the engine. About 2 months ago it developed a tick in the upper part of the engine. Over the last month or so it has been getting slightly louder. I am thinking it is a lifter tick as that seems to be a common issue and my symptoms are similar. Watch the video and let me know what you think: 93' 300zx Twin Turbo Lifter Tick? A little background info... The tick goes away if I rev the engine a little bit, after 3-4 seconds at idle the tick returns. It is in the top half of the engine and is much quieter when under the car compared to under the hood. It’s almost like I can feel something hitting the plenum. I always run 10w-30 and have tried Greddy, Valvoline, Royal Purple (all full synthetic), and even some Marvel Mystery Oil with little or no effect. The tick seems louder and more consistent when the engine or ambient temperatures are low. No temperature makes the tick disappear but it does seem a little quieter when it’s warmer outside. Sometimes the tick is very consistent and steady; other times (especially when it idles after a rev) it’s sporadic and skipping. The engine does have a slight oil leak although I cannot seem to locate it. It does not have any oil on the underside, and does not leave oil in the garage or my parking spot at work. I have asked the pro shop that did the rebuild about it on several occasions and have just been told "these cars burn oil when driven hard." However it goes through about half a quart every 2 weeks. This is my DD so it gets a lot of drive time but there is no smoke or anything else indicating the oil is burning. On a side note I am usually watching my oil pressure (AEM digital gauges) like a hawk but there was one time that I didn’t notice it was running at 8 psi. I drove it like that for 10-15 miles before pulling over and filling it with a quart. I mention this because I know oil starvation can cause lifters to go bad. It seems that if the car gets more than half a quart low I get fluctuating oil pressure readings (pressure drops slightly before going up when accelerating hard). It’s supposed to have a modified or "race spec" oil pump and am not sure what difference if any that could make. I would appreciate any info on what I can check or what you think it sounds like. Taking it back to the shop that did the rebuild is not always a good experience. It seems they never want to do any of the "maintenance" on my Z, just the $15,000 rebuilds. *Most* of my mods are listed in my profile.
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