Tonight my friends 91 3000 GT VR4 started to get a knocking sound between 3-4k RPM’s. It sounds like its coming from the engines cams closer to the driver. The cars oil is dark black and very thin, but it is not low. He has to make a 400 mile trip home tomorrow but this noise sounds like the begining to a big problem.
Anyone ever own one of these cars or work on them? Im looking for the safest thing for him to do before he leaves tomorrow.
All help is greatly appreciated,
Joeknock or tap, HUGE difference.
could just be lifter tick, those motors are notorious for it, especially if he’s low on oil and its thin theres gonna be more air getting in there. i’d change the oil and see where that puts ya. cause like howie said, those are 2 completely different issues one bad , one not bad lol
thats not lifter tick. you usually don’t hear it at higher RPMs but lower ones, like idle.
I’m betting it is something worse.
my 3000gt used to get lifter tick pretty bad whenever it was near the time for an oil change. mobil 1 synthetic cured it completely until it needed to be changed. if it doesnt go away with the oil change, i might worry.
mine ticked no matter what i did. sometimes it is as easy as changing oil, but it is a design flaw, not an oil problem.
But enough about lifter tick … cause thats not the problem 
if its knoking its most likely rod knok and is going to be serious problem. he cant try to drive it home but i dont forsee the future of this motor beign well
my friend knows some1 with a black 300GT thats rebuilding his motor and i guess its a real bitch. as in he’s been working on it for a year and its not done or something crazy like that.