hoov100

new question on page two.

NismoPick

so... you've told us what it's "not." Where is it coming from? Top end, bottom end? front, rear?

hoov100

its not a rod thats for sure though, but open to anything with this car right know, this car is a bit different from my old 240z

RodMoyes

It's probably the timing chain slapping against the top of the valve cover. Tensioners go bad, chain gets sloppy... (especially after 370K) and voila!
I've seen L28's with a third of that mileage doing the same thing.

Rod.

duowing

Even if it were rod knock. After 370K miles, I don't think I'd be that upset. I'd know that I got the most out of my car, but I'd agree with Rod. How's the car run?

hoov100

it can go 70 MPH in third while at 3k rpms and it still spins those tires. ill check on the timing chain now.

Bleach

nice.
Funny how in my car 70mph at 3K rpm is 5th gear. 3rd gear at 70mph would be about 5000rpm.

NismoPick

but are your tires spinning at 70mph? When I hit 70, my tires actually stop spinning all together.... no wait... they keep going.

hoov100

found the knock today, it appears i need new lower bearings, but with how many miles are on the car, ill just replace the engine with another stock l28 and put a t-5 in it.

WildmaN

Sorry to hear that man, but good choice on replacing it. Instead of half#ssing it. It is just not worth it, I did that with my '81 after I blew the head. And went ahead, and just did the head, not that he doesn't run good. He runs great, but if you go a higher RPM he starts burning oil. Probably bad crank bearings, but it is a tough old car nonetheless, and still runs better than my '82. Just looks like it came from a junkyard. Figure that one out, man this sucks, I just want to swap the motors, but that is plain foolhardy, and not worth all the time and money to do it. I might as well rebuild it if that is the case. But I know the '82 is more sound, inside, he just has some bugs to work out. I will get there, I am done rambling.

NismoPick

Your car is a "HE" huh?

Bleach

O I C ! So the CAR is traveling 70mph but the tires are going slow in 3rd gear and actually skidding, not spinning forward. ....are we talking about a rocket propelled Z?

NismoPick

My tires actually start spinning backwards above 70mph... it's just one of the tricks I've trained my z to do. Another is to sit up & shake... roll over, and bark.

WildmaN

Yep they both are he's, that is just the way they appear to me. I never thought them to be she's. But my '75 Firebird is defiantely a she, lots of power! Almost 400 hp, with a newly rebuilt '69 block. Anyway as if you didn't know already, my '82 is Bluestreak, like the Autobot. I was going to call my '81 Smokescreen, but I am not quite sure yet. Don't know if I will fix him later, and restore him also. I have time, to think about it, no hurry. I just want to leave him where he is, and not think about him. And concentrate 100% into my '82.

hoov100

i get the joke, what i meant by spinning, was it seems like someone welded my diff together.

NismoPick

at 70mph? thas gotta be scary!

hoov100

if only i could slap you and tell you to act your age.

NismoPick

that is what you said right? We're all just joking about it, cuz nobody knows what you meant by that comment.

FYI... Someone will always make a smart *** remark, from someone else's unclear statement... thas a safe guideline in life.

Anyway, any updates on your engine? (to get this thread back on topic)

hoov100

woops, forgot a period.... i meant it still runs strong/fast after so many miles, but how can it run so strong without being rebuilt?

NismoPick

that amazes you? I'm sure you'd feel some difference between a freshly rebuilt engine & yours.

hoov100

alrighty, took it to the dealer the said it was coming from the rockers, pulled off the cyl head cover and sure enough there where four rockers i could move up with my hand and two i could not move (i can only move them till they hit the spring) could this be a cause of high speed head knock?....i fixed the knock at idle (dist came loose)

jfairladyz

I used to get a noise from under my valve cover that sounded like a knocking noise. I adjusted the valve lash and the sound went away. When was the last time the valves were adjusted? Give it a try, it only takes a few minutes. Just need some feeler guages and a couple wrenches. I think it was 14mm and 17 mm if I remember correctly It's been a little while. If you don't know how to adjust the valves then you're going to need a manual. Trying to describe the process without pics is like...you get the point.