Just wanted to double check before I go out an buy some... does the Z350 use the same radiator as the 2003 G35 sedan? I need to get 2 O-rings (one for the drain plug and the other for the air relief plug) and possibly a radiator cap.

I want to get everything from a Nissan dealer due to cost difference (for example, jug of coolant $20 from Nissan and $27 from Infiniti... redicilous!).

I tried searching the forums but couldn't find this specific info.

Thank you,
Alex

 

I don't buy Nissan coolant. Overpriced. Get Prestone. Use some Water Wetter if you are worried about running hot. Up in canada I wouldn't think you are.

350Z radiators are slightly different. rad cap and o-rings should be the same though.

Upgraded rad cap would be a 300ZX cap from the twin turbo engine if you want to get a better cap.

 

Cool, thanks for letting me know.

Temp wise.... in the Toronto area it can get very hot. This spring/summer it has been on the cool side (apparently coldest in last 15 years) but it's not unusual to have daytime temps in the 30s (90s F) for extended periods of time in the hotter summers.

 

Ya, thats not very hot. I'm in phoenix arizona. Its like 115 during the day right now. Its over 100* all the time around here right now. Makes for LONG summers.

 

Yikes! I take back my "it can get very hot" comment.

 

Have a few other questions before I get to changing the coolant.

Steps 6 and 7 say the following in the FSM:
6. Warm up until opening thermostat. Standard for warming-up time is approximately 10 minutes at 3,000 rpm.
* Make sure thermostat opening condition by touching radiator hose (lower) to see flow of warm water. Caution: Watch water temperature gauge so as not to overheat engine.
7. Stop engine and cool down to less than approximately 50 C (122F).

So in regards to step 6, would I rev the engine at 3000 rpm for 10 minutes or do I drive the car for 10 min around that rpm level? As for step 7; how would I know the temp has reached 50 C since the gauge inside the car doesn't actually tell anything? Also, is the "water temperature gauge" that the FSM is referring to the one on the dash board?

Sorry for the noob questions.

 

Don't drive the car, just let it idle. Watch the needle til it moves up til almost normal position. Then check for hot fluid in the lower radiator hose. At that point you can rev the engine to like 2500 for 10 sec, off for 10 sec a few times. Then let the car sit and cool down.

After car is cooled open rad cap and refill following same procedure until there is no more air to fill. Make sure to keep the reservoir to MAX line.

 

Thanks for the info, it's greatly appreciated!

 

btw, it won't take 10 min for the car to warm up. Unless you are in like 40* F weather.

 

Friday I tried 3 different Nissan dealers looking for drain plug O-Ring (presumed Z drain plug is same as G) and not one of them had 'em in stock I told the parts guy that the FSM states "replace O-ring" and asked what their techs do when the drain and/or flush radiators (thinking they would have a surplus of o-rings), I was told "they just loosen the plug and let let the coolent run out". I guess they dont follow the FSM...

Also, none of them had the 300ZX TT radiator cap... had to order one.

 

I ran into the same issue at both, Nissan and Infiniti dealers. Had the exact same thought. I ordered 2 o-rings for the Z350 as they should be the same as the G’s; I should get them today. Going to skip on replacing the radiator cap as mine seems fine. And I'm not surprised at all if the techs don't follow the FSM to the letter... we'd probably be paying a lot more and the jobs would take a lot longer than they do when you drop the car off at the dealer.

 

I talked to the parts manager at Infiniti and they have a o-ring for the radiator drain plug but not one fort the bleeder valve.

OCG35 - you have a 6MT or 5AT? Where did you get the idea for the 300ZX TT rad cap.

 

bleeder valve and drain plug should be the same size o-ring - the plugs look identical… fwiw, my bleeder valve o-ring was fine but the drain plug could have benefited from replacement, I just didn’t have time to order and wait so I re-used… it doesn’t leak so I’m okay with the old one.

DaveO did some tests back in the SportZ magazine days... he did an article called "How to Keep the VQ Cool"... he mentioned the 300ZX TT cap there (and to me personally)... it's a higher psi cap but more cost effective than Nismo.

 

Right. I was talkin to Dave on the phone the other day. We were talking about it.

I don't even see an o-ring on the bleeder valve. I just took it off to check for replacement...NOTHING THERE. It should be attached to the screw that comes off right?

I have the 350Z thermostat in my G (170*). I talked to a few people who think that part of the reason that I am running hot is because of the thermostat opening early and not allowing the coolant in the radiator to cool enough. In talking to Dave, he completely disagrees as have most people that deal with the VQ. However, I wonder if it would have something to do with my ECU being different from most peoples?? I don't have the newer (and assumably better) ECU. Early 2003 suck for that reason.

 

This is the part # you guys need.