1992 300ZX N/A M/T 180K Miles?!?! Help!

[VengeAllez]

So I just received this car for free from my cousin's ex bf and its not bad, needs paint etc.

That's not the issue. I don't trust this car, because it has SO many miles!

I don't talk to my cousin's ex bf much but he keeps insisting that it's fine to drive etc. but due to recent events I don't trust him at all.

I discovered what appears to be an oil leak and constant check engine lights indicating a knock sensor needs fixing.
I love the car, it's absolutely beautiful, but I want to fix it so I can trust it to race around and have fun.

I'm new to cars, so I have no idea what to do to bring this car back to brand new.
I keep thinking that if I just swap the engine to the vg30dett that I wanted that it would fix the problem but I'm pretty sure there are other factors for restoring performance.

Could someone give me a brief to-do list for my own reference? Any advice is appreciated!
Also could you tell me what I should have a professional do and what I can do myself?
Is this car even worth it to fix? The tires are balded and I'm trying to decide if I want to fix the car or get rid of it before I get new tires.

[VengeAllez]

Oh, and is TIEN suspensions good? I don't know if they are or not.

[NolimitZ32]

Tien is generally a respected company yes. As for the issues you are having, you need to give us a bit more, how is the car behaving, what codes do you have, what is the general history of the car, the more details you provide the better we can tech support you.

[Z-owned]

Knock sensor code isn't uncommon and most just bypass the sensor till they can get to it later. The oil leak is likely a valve cover or rear main seal. But like said we need more details. These engines are quite robust and can easily go past 200k without issue. Big things to worry about at that mileage is the 120k kit (timing belt, water pump, seals) and with the older style injectors at that mileage I wouldn't be surprised if they are starting to go.

[VengeAllez]

Thank you for the fast reply!

The car is driving alright when I drive passively. It's just that I'm afraid to drive aggressively because I don't know much about the engine history. The mechanic told me that the knock sensor needed replacing and didn't give me a code.

The oil leak is coming from some part of the engine in front of the passenger side, my friend swears it's a "cam seal" because apparently that's 99% oil leaks in this car??

If I'm planning to replace the engine should I still do the timing belt change? It looks like one of the accessory belts is going bad but only that one.

So is it true that all I need to replace make this car like new is the engine?
Thanks again

[VengeAllez]

Tien is generally a respected company yes. As for the issues you are having, you need to give us a bit more, how is the car behaving, what codes do you have, what is the general history of the car, the more details you provide the better we can tech support you.

I confirmed with the mechanic that I received a code number 34 on the engine light check. Does that agree with the knock sensor advice he is giving me?

[NolimitZ32]

I think you should spend some time reading through the troubleshooting portion of the FSM (factory service manual) and messing with the car, a he said she said approach to diagnostics or working on a car in general never end well.

[Ace2cool]

^This. The FSM is an invaluable resource. If you're running to your mechanic all the time, you're gonna have an empty wallet quick in a hurry.

But yes, code 34 is knock sensor. Could be the harness, could be the sensor, could be both.

[DCaff300ZX]

My NA went 234K before a rod bearing went out, so as mentioned 200K+ ins't out of the realms of possibility for an NA with decent maintenance.
FSM is your friend as there's not many people can afford the costs of a professional going over your entire engine and drivetrain, you are best off to do anything you can yourself and save the big jobs for a pro.

[VengeAllez]

Did not realize that the FSM had a troubleshooting section. I will take the week to read through it. Learning a lot from the search function as well. Jjst one more question is there some section that has write ups for DIY jobs like replacing said knock sensor? Thanks for the replies!

[NolimitZ32]

There is a sticky in the Z32 Tech forum called "Everything you need to know about your 300zx" or something like that, there is a ton of information in there. Also there are tech pages on other sites such as tt z of dallas with a plethora of DIYs and other helpful info. I'm not certain about the knock sensor as I changed mine during the rebuild but I am sure the information is out there. Start off with these two resources as they have about 80% of the information you will ever need.

[DCaff300ZX]

IIRC the knock sensor delete/relocate (preferred to keep it myself) isn't that bad, just that you need to have the plenum off to relocate the sensor to the block valley area, and also to upgrade the harness (Z1, CZP) when doing that work. If you are that far in, then cam seals and more is in your best interests for long term happiness and best engine operation.

[VengeAllez]

My NA went 234K before a rod bearing went out, so as mentioned 200K+ ins't out of the realms of possibility for an NA with decent maintenance.
FSM is your friend as there's not many people can afford the costs of a professional going over your entire engine and drivetrain, you are best off to do anything you can yourself and save the big jobs for a pro.

Been busy with school, haven't even touched the Z since.

I have yet to touch the FSM,

Regarding the "big jobs" could you maybe list a couple jobs that I should leave for the pro?

Update:
I've been working on the headlights, got some 8k HID on the low beam and just finished drilling into the back of the fog light housing to accommodate room for the 3k hid kit I'm going to use!

Bought front and back brake pads from stoptech for the new Michelin pilot sport a/s tires i just got, going to install this coming weekend.

Trying to save up for a timing belt/accessory belt change, is that the 60k or 120k service? Can anyone give me an update on ~how much it will cost for a professional to do it, and whether or not if its worth it to do it myself?

[VengeAllez]

The bigger question in my head right now, however, is:

I'm planning to do a TT swap in the far future!

Yes, I've been looking around at the forums, JDM no-no. Right now I'm just trying to fabricate a number of how much it should be to have someplace buy the engine and make the swap, so I can start saving up for it.

Another question would be:

What can I upgrade while waiting for the time to do the engine swap? Like can I change the exhaust? Like the exhaust pipes and what not. Can I have a cold air intake installed? Basically are there any mods that I can just take from the old engine to put on the TT engine when I do the engine swap?

Thanks again

For those in the BAY AREA of California, is there any advice?! I saw a couple of 300zx around Milpitas, give a shout-out if you're here as well!

[Ace2cool]

Go ahead and budget $10-15k, if you're not doing the work.

[DCaff300ZX]

IIRC there is a pretty large Z32 group in the SF bay area, don't have their name off the top of my head though.

If you are thinking TT swap, then there really won't be anything for a pro; you will need to become a pro.
So many people think that the TT swap is like swaps with other cars, and it is not. Too much to go over here and a subject with TONS of play over the years, so research there will get you in the ballpark I speak of and will surely be the final decision maker. Ace gave a great price range, which may even be close to the $10K if you do it yourself if you go the smarter route and buy a front cut, or get a good condition TT donor car for ALL of the stuff needed.
The TT engine and NA engine are quite different in many ways such that for "waiting" mods, probably only the cold air intake will swap over as exhaust is different for the turbos, and there aren't many power mods you can buy for an NA anyway.

The age-old saying around here is and always will be "Just buy a TT", and is true 99% of the time.

[evildky]

These cars are expensive and difficult to maintain and repair. If it needs mechanical and paint work, sell it and buy a better car, it'll be cheaper in the long run.