Hello Z32 Drivers and Gurus,

This is my first post on the website, but I've been browsing around informing myself for about 2 weeks now. The amount of knowledge I've gained from reading these boards these past weeks awes me.

So far most of my questions have been answered through researching these boards... But I've got a few left that are unsolved...

I ask for your friendly help and advice, and any responses are greatly appreciated!!! Hopefully others who have similar questions can use this as a starting point for their research.


Here's my story.


I bought my 1990 300ZX N/A 2+2 about 3 weeks ago. Everything was going fine up until a few days ago. Nothing is going wrong really... I'm just trying to take preventative measures for future problems. My Z32's got about 92K Miles on it now, so obviously it's got wear and tear.

These are a few things that have been popping up that concern me:

THE BIGGEST CONCERN
My car's oil pressure (when the car is hot) while idle is ALMOST ZERO. It literally sits right above the 0. I hear no ticking noise, or overheating, the only thing i notice is strange vibrations all around my seats, shifter, and handbrake areas..

When I engage a gear the oil pressure rises to about 40-60. When I first bought the car the oil pressure was rising to about 70-80, sometimes even up to 110ish. I'm wondering if it could be a faulty sensor? Faulty Oil Pump? I'm still a rookie at diagnosing, so any help here would save a headache.

I don't know if it's just me, but the car does seem to lack some power... Sometimes I feel like my Honda Accord 2.3L was faster! (I'm ashamed!!)

Other Concerns
- While driving on the freeway, the car seems to roll in fine. My clutch is simply ready to go, but aside from that I have no issues getting in. My concern is when I start to hit 55-70. The car's interior begins to shake violently. My handbrake is vibrating like an expensive woman's toy, and so is my shifter. My passenger seat is like a massage chair, but the engine purrs along... Once I get out of that speed range and into the 75's the car shuts up and kind of glides along... It's really strange!

- When I try to switch into 4th gear quickly I often hear a grind. I'm not sure if this is because of my dead clutch, or maybe something more serious? Obviously theres no way to tell until I replace the clutch.... right?

- While the transmission is dropped from the engine, is there anything I should take advantage of and replace? I hear it's wise to change out the throw-out bearing while the tranny is dropped...


No lights ever come on (Check engine, Oil Light, Super HICAS, etc.) so this leads me to believe that these are not a severe problems? Again, I'm still a rookie at all this.



Everyday with my Z32 is a learning experience, I hope everyone is enjoying their Zcar as much as I'm enjoying mine. I understand that the Z's are expensive cars to maintain, so rest assured that only quality products will be going into this Blue Beast.

Thanks for your help in advance everyone, and thank you for letting me on these boards!

The factory gauges are hopeless. Get an after market one

Is it running on 6 cylinders?

I assume the revs have risen slightly then?

Unlikely but possible if it hasn't had good oil / changes

Is it a TT or NA? Is it running on 6 cylinders?

Centre driveshaft hanger bearing worn? Rear gearbox mount failing?

Common syncro problem ...... change the gearbox oil to Redline MT90 (there may be others)

See above

Or have the bulbs been removed to mask problems?

Nzniggles thank you for your response,

I'm not too sure how to answer that. It's a V6.. Do you mean if all the spark plugs are working? It's also an NA.
From what I can tell.. No. When I turn the car on all the bulbs come on.

I was reading about the MT90 Oil today, I'll definitely be buying me some.

Low oil pressure at idle could be the oil pressure sending unit (a common problem on the Z32), a bad oil pump, or worn bearings. If you don't want to do an aftermarket gauge, get a new sending unit and see if that resolves your problems. If that doesn't, put the car in neutral, rev to about 3000 rpms and hold them constant - if you hear a rattling/knocking sound, it's your bearings. Else, possibly the oil pump.

Your vibration issue sounds like it could be a misbalanced tire, loose suspension component, or misfire. For the idle vibration, while idling, disconnect the spark plug coil back connectors one at a time to see if they have an impact on how the car idles. If the sound changes, the cylinder you just disconnected is properly firing. If pulling a specific plug does not change the sound, you likely have a bad injector (or spark plug if you're lucky). Have the tires balanced and check the tightness of suspension components by jacking the car up and trying to shake the wheels and other components by hand. Also, check the condition of the center support bearing on the driveshaft - if it's worn, it will cause vibration at speed.

Gear grinds are common - replace trans fluid with Redline MTL or MT-90.

So i found out the normal oil pressure of the 1990 300zx NA 2+2 is 4-9 psi idle. So it looks like the oil levels are fine.

The dragged performance of my vehicle resulted from my clutch. Turns out it was so worn out that I couldn't even make it to 50 properly...

I also replaced the rear main seal, the master slave cylinders, and some other minor stuff. The vibrations on the freeway are now gone. Also my tires need balancing and alignment.

Now my next problem: I keep finding small puddles oil underneath my car every time I pull out of parking spaces.... I get to find out what that's about!!

Welcome to Z32 ownership.

Are the drips at the front or rear of the motor? Since your RMS was replaced, it shouldn't be leaking from there. Hopefully the oil pan seal was replaced too. It comes in a 3-piece kit with the seal and a retainer gasket.

I would suspect that your front crank seal and/or your cam seals are also leaking. Since you're at the 90k mile mark on a 19 year old car, you may want to go ahead and perform the 120k maintenance. This will include a new timing belt, cam/crank seals, and water pump amongst other part. It'll be worthwhile if you plan on keeping the car for a bit. Do you even know if the T-belt was changed at the 60k mark? There should be a sticker somewhere in the engine bay if it was done.

Valve cover gaskets are also a common source for oil leaks.

When I've seen these, I've always seen the oil burn off from the heat of the engine, not leave drips.

What's up there funny guy. Do you remember the guys hiding in the drainage culvert?

I have seen the oil running down the back of the block. The OP never did say where the drips were at.

I do remember the culvert....


OP where's the oil dripping?

Im going to assume youve changed your clutch out by now. Normally a throw out bearing is included in the kit.

If youre pulling the transmission out, you should throw a set of headers in. One of the least expensive "mods" for the car, and also beneficial from my experience.

The vibration, I would say its the driveshaft as well. Z1 makes a nice single piece one.

Make sure the 60k was done as well. Will definitely save some headaches in the long run.

Welcome to the Z world. Its far from a cheap one. I hope youre ready for it.

Post rejected because of a score of: 60 Rejection set to: 30.

I cant type anything???

https://www.zdriver.com/forums/showt...161#post264161

Ahhh, I see. Sorry I haven't been able to post.

Well it looks like i cant put any quotes into my posts yet.... So i'll just put them in quotation marks..


"OP where's the oil dripping?"

It's dripping right under my engine, just about dead center. There was loads of oil all over my exhaust pipes and oil pan. Much of it was burned off by the heat, exactly like Napoleon explained. I checked the silicone gasket and it's literally crumbling off. So I'm going to be working on that whole area.... Draining, cleaning, replacing, etc.

I'll keep you guys updated.

"
Im going to assume youve changed your clutch out by now. Normally a throw out bearing is included in the kit."

Yes, just replaced the clutch a few weeks ago along with bearing and cylinders. It was also the source of my highway vibrations... The clutch just couldn't hold a gear anymore. Poor poor clutch..


New Problem: Check engine light turned on. This just gets better and better!! Haha

Okay so it turns out my EGR is super dirty, so my light turned on. I gotta change it out and get it cleaned.

And my oil situation is almost done, just need to clean up.

It seems my Wallet and I are getting a divorce... She's taking the Z, along with all my money...

remove the EGR.... can be done with the engine in as long as you have the most important tool in your tool box... patience... and if you remove the tranny, and un bolt the motor mounts and take all the stuff off like your going to remove the engine, you can tilt it forward and get a good extra 6 inches to get in there to the back of the engine.

That was a damn mission. Holy cow... Finally got it out and clean. Yeah I got about 6 inches of space, the relief that came over me after I got that much more space is indescribable. Lol.

Engine light is gone, car is running strong. I'm happy.


I just saw some Stillen Headers for 200 bucks, used with no 02 sensors. Are these good? I've been reading mixed reviews.

Did you remove the EGR? or just clean it?


I have a set of NA headers i'll sell you for 50 plus shipping. Can't remember the brand. Good shape, not sure on O2 sensors, will get pics saturday when I'm at the garage if you want.

And if you've been reading mixed reviews (or reviews about them at all i should say), then why are you asking? you know as much about them as we do..

And good luck getting headers on with the engine in. You thought the EGR was hard... I'd say headers are impossible. especially trying to get the old gasket off and new studs in etc etc.

I have a set of JVT headers. I got them for about 180 shipped. they have the o2 sensors and I am really happy with them.

Not sure where I got them from, but I can find out if youre really that interested in them.

and like napoleon said, theyre not easy to do at all. mine were put in with the tranny out and that was still a bitch to do. expect to either pull the tranny or the motor. or like i said, when you got your clutch done.

I did both.

I asked just to see what review you guys would give, I'd trust this group of people over any random website any day.

Anyway, yeah shoot me some pictures I'm definitely interested.

JVT? I think I've seen a few of them on eBay. Are they carb legal?

youd have to ask them yourself. im from jersey.

jvtracing.com


im pretty sure I got mine through them, ebays shady, if you do get them through ebay they say JVT etched on them, i wouldnt be surprised to see some fakes getting sold.

im sure that this can easily be done by someone who is making them but either way, the jvts are pretty good. it was between then and amz for me, im happy with my decision, can definitely feel the gains.