Knocking

Nissan 300ZX technical discussion forum: Maintenance, performance, installations, modifications, how-to's and troubleshooting.
Killadelphia04
Posts: 2
Joined: Mon Dec 21, 2015 6:32 pm
Car: 1990 Nissan 300zx Twin Turbo 2+0

Post

Sounds a bit more than a lifter... Any input? :facepalm:
https://www.dropbox.com/s/t44d0ac2fyrvd ... 4.mp4?dl=0


nissanfreak12
Posts: 1709
Joined: Sun Jan 23, 2011 4:07 pm
Car: 92 300zx 2+2 TT
Location: Denver, CO

Post

That doesn't sound like a lifter, truthfully. Too slow for a lifter.

If you want to find out, unplug injector one at a time. If the noise goes away, its rod knock in that cylinder. If it stays after you unplug everyone of the injectors, then its a collapsed lifter, and a bad one at that.

That is the easiest way to find if you have rod knock, it will essentially make a dead cylinder. Doing it that way there will not be a combustion in that chamber, which will not create a "knock" noise.

Killadelphia04
Posts: 2
Joined: Mon Dec 21, 2015 6:32 pm
Car: 1990 Nissan 300zx Twin Turbo 2+0

Post

Thanks man I'll start process of elimination with your recommendations.

nissanfreak12
Posts: 1709
Joined: Sun Jan 23, 2011 4:07 pm
Car: 92 300zx 2+2 TT
Location: Denver, CO

Post

Also, if the noise is more pronounced under the car than while looking in the engine bay, then its a bearing. Engine bay vs under, its a lifter.

User avatar
NolimitZ32
Posts: 7042
Joined: Fri Jun 27, 2008 9:07 am
Car: 91 AG2 2+0 TTMT swap/E39 BMW 540i6/E53 4.6is Dinan S3
Location: Houston, TX

Post

Sounds Like NVCS tick.


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