CK_32

iTrader: (1)

Now that my Z is up and running again. I've been driving it every now and then. Mostly then due to the rain season.

I let it sit for a couple weeks and decided to take it to work on a nice cold rainy day. Dead battery so I roll jumped it and went to work.

On my way to work (only a couple miles) and noticed it got to temp semi quick but at Op temp so I didn't think anything of it.

Took it to Carls Jr for lunch and noticed the 2 miles I drove it and sat in the drive thru it was climbing in blurps. Literally only in the car for 10 min at this point. Fans pop on and think nothing of it and it's climbing up to "H" level (see video)



Note the temp is a cold 57f at this time and I didn't have this issue a month ago at a hot 92f sunny day. Anyways I drive back to work and literally as soon as I hit 20 mph for a second then to a stop it drops down to normal OP temps while in motion... I know it will cool while driving but to drop 50-80f in a matter of seconds I don't think so sorry not that fast.

When I left the drive through drove literally one light and got back to work..


Pop the hood and notice my over flow has a little more fluid than usual and my fans are going full blast even tho the thermo says cold OP temp..


Idle is also fine which is another reason I'm thinking air isn't the cause.

I'm going to bleed the system again after work but this is kind of an odd string of events to me.. What do you guys think is going on with this?

BluestreamDE

Your issues seem similar to when my thermostat went bad. Fluctuations with normal temperatures all the way to max depending on either idle or driving normally. After I replaced it with a new thermostat the issue went away. Not saying it's YOUR issue, but an area of failure to look at. Good luck.

CK_32

iTrader: (1)

Yea that's kind of what I was suspecting my self or maybe the water pump.. hoping not to have to recplance small parts tho. But we'll have to see

jhc

1st step, eliminate the possibility of air in your coolant system. Search for the "Burp" thred.
Make sure your coolant overflow is topped off to reduce it sucking in air.

For what it's worth, I've got 104K on the original thermostat. Last time I had coolant/temp issues I took of the cap on the heater relief valve. Poured pre-mixed coolant into the heater core until overflowing. Replaced cap.

Remove radiator cap, top off. Fill overflow. Run engine until normal temp.

If you still have high temp at stand-still but not when moving, your radiator or fans may be bad.

dboyzalter

iTrader: (3)

Bleed that system... You putting air bags back in ?

CK_32

iTrader: (1)

Yea I've bled it and plan to try it again. I'm just wondering why it keeps over flowing all of a sudden. But yea I know how and just did it recently and it was fine. Until I let it sit and the battery died. I'm stumped why air would get in the system from sitting.

As for the air bag, not bags (pass side only). It's low on my priority list. I'm the only one who ever drives in the car so to invest and spend effort on one as a priority for a seat no ones ever in doesn't make much sense.

That and when I find one priced right. It's almost cheaper to just buy one from Nissan or pick up a whole new parts car than what dudes want for these used parts.

dboyzalter

iTrader: (3)

How much do they run? I have one sitting in my basement from a G35, the entire dash piece with the air bag intact and nobody seems to be interested in it... The 350z has a better set up with the air bag and dash being separated.

dkmura

iTrader: (64)

This makes me think the problem may be as simple as a defective radiator cap. If the VQ comes up to temp and the cap won't hold pressure, you'll overflow AND introduce air into the system. Depending on how old the cap is, it might be an easy fix just to replace it and bleed the system once again. You should have no antifreeze anywhere in the engine bay and no overheating problems.

CK_32

iTrader: (1)

From Nissan they are like $800.. eBay lists them for about $80 - $100 shipped but those are from authentic shops with warranties and some liability. I think a lot of parts places price off of that and want like $150 - $200 for them.

I honestly won't pay more than $40 - $70 for a bag. ESPECIALLY from a part out. Where you have to run the risk that maybe they just ripped it out, maybe it's a faulty unit, from a flood donor which is like 50/50 if it will even work etc etc.

CK_32

iTrader: (1)

It could be also something I would have guessed but the cap is literally brand new. Has all of maybe 100 miles on it.

I also have a mishimoto rad and cap sitting in their boxes I'm waiting to install. Just waiting on my boosted pref kit before I install all my go fast and stay cool parts. Also why I wanna sort allthis before I add FI into the equation.

i8acobra

iTrader: (6)

Get it to where the temp gauge goes higher than normal, then pop the hood and carefully reach down and touch the lower radiator hose. Is it significantly cooler than the upper hose? T-stat is stuck closed. Replace it.

CK_32

iTrader: (1)

Actually that's a good idea. That's how I figured out I had air in my system the first time.

Didn't even occurr to me to do it again this time lol

If it over heats again ima do that. Right now it seems to be working again since I got a couple bubbles out after burping it for about an hour the other night.


Got a nice burn tattoo from the rad on my wrist after I dropped a screw lol