The 300ZX TT I ALWAYS WANTED

[tfs1975]

Hi All,
I am not new to the NICO forum but new to the 300ZX section. Previous daily driver was an M35 and this forum helped me out many times. I recently got my hands on what seems/seemed to be a pretty nice black 91 TT, 5 spd. Not a swap. I would add pics but I am not a rocket scientist and can’t figure out how. Just getting old I guess. Got a good deal on some 350z wheels and had to put them on already. They look great. I would consider the mileage to be low in regards to the age at 114k. Two owner car and it looks to be mostly original with good paint and good interior. Picked it up in Palestine, TX and towed it back to Austin. It's been in my garage for a few months now and I need to get under the hood and get this thing on the road. I have wanted a 300zx since I was 18. At that time I was approved for pretty much the same car but insurance costs and being practical lead me to forego the purchase. I ended up getting a DSM car (Eagle Talon) and working that. Even though it was an AWD rocket, it never did take the place of the 300ZX I always wanted. I have gone through this forum pretty good and have read the "everything to know about your Z” section as well as a lot of posts and DIY's. I will attempt to do most if not all the work myself. I have a few questions as well as a few concerns. I have done a pretty good inspection of the car and have a parts list that is needed to get back to 100%. Big jobs needed are the 120k mile timing belt change (new bolt kit needed) and the driver’s side valve cover gasket (all valve cover gaskets will be changed at that time). Of course with those two jobs, the plugs and oil will be changed as well. Here is the parts list that I will be ordering shortly. Recommendations are welcome for any parts or supplier you feel is good. I have looked at Z1 and CZP.
-Adjustable Tension Rods
-Front Adjustable Camber Upper Control Arms
-Plenum Gasket
-New Radiator
-Exhaust Valve cover seal
-Valve cover gaskets (as referenced above)
-Silicone PCV hose kit with PCV valves
-Solid bronze shifter bushings
-Rear outer Ball joints (could just go with the HICAS delete)
-Adjustable rear upper control arms
-Power steering rack boot
-120k mile timing belt kit (as referenced above)

All seals seem to be good. After initial inspection, I thought that this would get me to 100% or what I think is 100% as a starting point. At which point I would start doing all the tests stated in the "everything you need to know section". OK...sorry for the long drawn out explanation....this leads me to my ultimate question and concern. I had noticed that the radiator is shot. Shot in the sense that the car had sat for a few years and the fluid is rusty. I would prefer to replace and that is why the radiator is on the parts list. Did an initial flush just to get it out on the road and see what issues I could find. Once I returned, I notice some gurgling coming from the coolant overflow canister and upon filling it up, on the next trip it was gurgling and coolant was leaking out. Needless to say that I am extremely concerned that this could be a bad head gasket is an understatement. I know that these cars shouldn’t sit and if they do there should not be water in the coolant system as it may corrode from the inside out. Coolant still looks OK, no smoke from the tailpipes, nothing strange under the oil cap and no temperature issues. I am wondering if there is an air pocket (don't think this is the case), a bad heater core, bad thermostat or possibly the dreaded head gasket. So the question is (finally) do I go ahead and do the valve cover gaskets and timing belt change that will include the new radiator and water pump and see if that takes care of the issue or do I test for the possibility of the head gasket being bad? I can't really do all the tests stated in “the everything you should know” section in the current condition. Is there a way to determine that it is not the head gasket before doing all this other stuff? Just don't want to rip everything apart just to have to do it again at a bigger level. Appreciate any and all suggestions. Thank you.

[Ziggy1621]

Doing those things is never a bad idea. But to test the radiator, rent a leak down tester from your local auto parts store. Pressurize it and let it sit according to it's instructions. If it is leaking, then it may be the gasket. I would be it is just bubbles since you drained the system.

Moving this to Technical forum

[solaire]

It could be bubbles from behind the rust breaking loose in the block. If there's rust that means there was poor coolant and air in the system to begin with. Could also be a bad cap letting the pressure escape into the overflow. The auto stores have a tester you can put on the radiator cap and a special fluid that will change from blue to yellow if combustion gasses meet the fluid. I'd try that before making a concrete decision. If the tester fluid doenst change then do the timing belt, covers etc but if it changes well you're essentially doing all that anyway + head gaskets.

[tfs1975]

Appreciate all the info. Will be getting my hands on a leak down tester, a radiator pressur tester and will also be doing compression testing. I will look into the liquid test for the exhaust gas in the coolant.

I have figured out how to post pictures and have included 2 pics of my new Z. I will post back with results. Thanks to all. Looking forward to getting this on the road.


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[tfs1975]

Just a few additonal questions:

1. I have always thought that coolant should be a 50/50 mix. Is that not the case wit the Z? Should it be all coolant and no water? Seems as if the consensus is that no water should be in the coolant system. Appreciate the clarification on this.

2. Can you tell me what the best way to flush the coolant system is?

3. Are the pictures that were posted seen? When viewing this site from my tablet or my phone I can see the pitctures, When viewing from my desktop at work, I cannot. Are you guys able to see them?

Thank you

[Ziggy1621]

1. I think a little water won't hurt anything. I don't think a 50/50 would damage it unless you live up north. Maybe someone with more technical knowledge could chime in

2. No clue, I did mine during the rebuild

3. Yes, the pictures are showing up... nice ride!!!!

[nissanfreak12]

Z needs a 50/50 mix. All coolant will make the car overheat and no coolant will cause things to rust and over heat. Antifreeze adds as a lubricant to the seals and also creates a higher boiling point for water. Add pressure to the system you have an even higher boiling point. You can run 30 antifreeze/ 70 water and will be fine unless you live up north or its freezes in your area.

Flushing the system is easy as going to the autoparts store and buying the coolant flush stuff. If the radiator is bad, take it to a radiator shop and have them rod the radiator, they take one of the tanks off and send a small "rod" through and it cleans the passages. Be warned, if the tank is brittle enough, it may not go so easily or break. Flushing the block is using the flush from the parts store as directed, then flush with water till it comes out clear. You will need to take out the thermostat when you flush the water through to make it clear. Its very time consuming, but not hard at all. Hope this helps.

[tfs1975]

Hey guys. Appreciate all the info so far. Today I was going to change the plugs and do the compression testing. Noticed that the coil connectors aren't looking so hot. Some seem to be held together with electrical tape. I did not undo any of them. I know I will need new connectors but, can I get away with just switching the pins to new connectors (cheaper and easier) or do I need the connectors with the wires? I have included pictures. The pictures are three different connectors. I am assuming the car was not well taken care of. She needs some love! Would you suggest changing the coil packs? Is there a way to test them?

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