Bummer !!!

[yodawill2000]

I have a loud noise coming from the front of my J.
It almost sounds like something is banging the inside of the TBelt covers.
It speeds up with the RPM's and at about 3K it goes away.
But at Idle it sound LOUD.
Figures it happened when its 103 out !!
Will pull it apart on Saturday assuming it makes it until then.

[GerryO]

Here's hoping that it's something simple and there is no real damage. Sources of under the hood noises are often so difficult to identify, how many of them don't speed up with rpms and when isn't it 100+ in Texas? You might like CA. You aren't parking the car, until Saturday's tear down?

[yodawill2000]

Don't have a choice.
Gotta get to work and back.

[J30tChumpCar]

Can you pull back a timing cover to be sure the belt isn't ready to skip and trash the valves?

Oh soon on the lights...

[GerryO]

Owning a spare car sure makes working on any of them easier, but another J30 might not be the best choice. I could help you get this one Texas ready, but it also sounds too much like the one that you already have, if it's still running.

http://sfbay.craigslist.org/sby/cto/3099297411.html

[yodawill2000]

Using a Mechanics Stethoscope it is VERY loud when touching the Crank angle sensor.
Like a Tapping sound.
Is the outer shell of the sensor directly connected to the Cam shaft ?
Need to know if its the sensor, or sound being transmitted through it.

[GerryO]

The relatively short and small diameter o-ring equipped shaft on the backside of the CAS keys into the end of the camshaft that drives it. All other external portions of the CAS are non-moving parts.





There's not much to the CAS and if it was making a noise, I suspect it would be a squeal or small rumbling sound caused by one or both of the sealed bearings inside drying out.

How about the VTC spring under the cover of the other camshaft or a sticky lifter on that side of the engine ? Try adding half a quart of Castrol 20/50 synthetic blend motor oil.

[yodawill2000]

I will check that spring this weekend.
I did add some Marvel oil last night.

[GerryO]

Marvel is pretty thin, compared to regular motor oil, and more of a gasoline/diesel fuel additive, plus it was formulated long before more lubricious synthetic oils became commonplace?

http://eaaforums.org/showthread.php?166 ... ystery-Oil

Before turning it over by hand, I squirted MMO into the spark plug holes of my 240Z engine that had been sitting for 20+ years.

It might be time to thicken the oil up a bit, as the engine has over 200K miles on it? Adding half a quart of 20/50 synthetic really worked for me, but that my car had been sitting caused the problem.

Top-end oil starvation due to low crankcase levels, worn/weak oil pump or clogged oil pan intake screen issues would cause all of them to be noisy.

Otherwise there are these instructions, if it's a sticky lifter:

http://autorepair.about.com/library/faqs/bl565g.htm

http://www.xenonz31.com/Rebuilding%20Lifters.html

http://www.ghost-tech.com/Freeing_Lifters.pdf

[yodawill2000]

213,000
I only added about 1/4 quart.
I have added about 1/4 quart of fresh10/30 since Ive had the leaky Valve cover.
And did the full oil/filter change religiously at 3k.

[yodawill2000]

Update:
Took the drivers side TBelt cover off this morning and there is WAY too much slack in the belt.
Gonna be a long HOT weekend.
Will make sure it didn't jump time then tighten everything back up.

Would slack in the belt allow it to smack a cover somewhere ?
That's what the sound is like.
Something hitting the plastic cover with a really high frequency.

[J30inthe sun]

Good luck! Glad you caught it before major damage.

How many miles on the current belt?

[yodawill2000]

Only about 40K.
I'm guessing the tensioner gave out.

[yodawill2000]

Anybody know if Infiniti Of Scottsdale still carries TBelt stuff for the J ?
As in Belt and Tensioner ?

[GerryO]

Don't know the particulars of this set or if they offer expedited shipping, and am not familiar with the AMP brand.

http://www.ebay.com/itm/NISSAN-300ZX-IN ... de&vxp=mtr



What about Courtesy Nissan?

http://www.courtesyparts.com/bundle-60k ... 7651_7696&

[yodawill2000]

Thanks GerryO
Already had my eyes on that ebay set.
But I'm not sure if that's a Kevlar belt.
All I need is the Belt and Tensioner and Seals.
Will dig deeper.
My son and I were looking things over and noticed the front edge of the Belt was a tad worn. As in its rubbing something.
The backside was still black, as in rubber. The front looked as though it was rubbed to the cord.
I will be taking more stuff off during the week.
Got a cheap weekly rental to get to work and back.
Curious as to what it was rubbing on.
Gonna get this baby to 300K or Else !!!

[yodawill2000]

Snagged this.
http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0818389249

Some things, I think should be OEM.
Will pick up the Belt, seals, springs and pulleys from the Infiniti/Nissan place locally.
They quoted me $225.00 for the tensioner.
NOT !!

[driverdriver]

Good luck with the fix. I would hate to see anything bad happen to your J.

[J30tChumpCar]

I was worried about you driving as the noise description was a very slack belt, glad it was parked.

http://www.ebay.com/itm/300zx-Genuine-N ... 6rk%3D1%26

[yodawill2000]

Got this belt right after I ordered the tensioner.
With free shipping its about the same price.
http://www.ebay.com/itm/190618623084?ss ... 1497.l2649

[J30tChumpCar]

Update?

[yodawill2000]

Still waiting for the parts.
All is Good though. Timing was still spot on !

And after a good de-greasing of the whole drive train, I fell in love again.
Any new's on the blinker lenses?

[J30tChumpCar]

No fear they are on the hood of the race car awaiting a box.

[yodawill2000]

Sweetness.

[yodawill2000]

The rest of the parts are ordered !
The place I got the OEM tensioner and timing belt didn't ship until yesterday !
Even though I ordered last Tuesday. Holiday week and all.
Here's what I ordered locally from Courtesy Nissan.Should be here Thursday, and the TBelt and Tensioner Friday.
2 x SEAL-O RIN
13037-75T00 $1.01 $2.02
2 x SPRING-TEN
13072-45V20 $2.79 $5.58
2 x HOSE-WATER
14055-F6511 $5.07 $10.14
4 x OIL SEAL-C
13042-16V00 $9.21 $36.84

If the Crank seal appears to be leaking I will get that as well.
Kinda forgot that when I was ordering.
More time to degrease and such.

[GerryO]

It's great to read the progress reports and of your 300K miles goal.

Was it the tensioner that gave up the ghost?

Recall camshaft and crankshaft oil seals being exactly the same, even though Nissan assigns them different part numbers and prices.

Carefully removing and installing oils seals was a bit of a cold sweat experience for me, plus I may have had to slit and replace the crankshaft sprocket. And then there was my son's vinyl coated wire cable dog leash harmonic balancer wrapping trick, that made it possible to loosen and tighten the crankshaft bolt unassisted, and without removing the starter.

Continued success!

[yodawill2000]

I have a Son that helps me with the Crank bolt.
Starter is a snap to drop.
Yeah , I will be careful with the seals, don't want to scratch the mating surfaces.
I believe it was the tensioner. The part the pushes out only goes about a quarter of an inch max.
I expected it to be oil driven. There is even a channel coming from the oil pump that's capped off, And a spot on the tensioner that lines up with that channel capped off.
Must have been a revision on the early VG30DE's

[yodawill2000]

The timing belt I got is a Nissan Belt , but it came with a sticker that has a lot of Japanese words and has 100,000 Km at the end .
This must be a 60K belt and not the 105K Kevlar belt .. Grrr

[Amadauss1]

Just read your problem here, I hope it works out.

[swimshark]

hey hope its works out. i use the 300zx timing belts so i replace tb every 60k and replace the tensioner every 120k along with all the cam gear seals and front main seal.



ive had mine torn down even further with valve covers off and lower plenum off so if you got any Q hit me up. if you could remove the upper plenum you might as well redo the valve cover seals.