tekk

Hi guys. I have a 04.5 G 6MT but I figured this would be a good place to seek help.

My car has 28k miles. I noticed my coolant was low, just under the Min mark, but the temp gauge was on one tick below the middle level, which is where it always has been since I got the car new. So I figured I'd add coolant when I got to my next oil change.

Well today I was letting the car idle while I was washing it, listening to music, etc. After I was getting done, I noticed it seemed really hot near the front. I went inside and looked at the temp gauge. It was showing one tick over middle. Not near the top, but definitely a tick or two above normal. I immidiately shut the car off and popped the hood to check the coolant. I wondered if was all gone but instead I saw that it was near max!

This didnt really make sense to me so I left the car off and packed things up. I came back to it and noticed the level had declined, and continues to decline.

Any ideas on what might be going on and how I might fix this?

Thanks

ericjackson

iTrader: (2)

there is one problem, it doesnt need to sit and idle for an extended period of time. there was a guy who melted his plenum like that(i dont want to search for the thread)

thats why it got so hot that time, other than that it just seemed like your car was at a normal temp, it needs to be at about 40% or so on the gauge

you can just turn the key over one click to listen to the radio, it wont run down the batt unless its for like 10 hours or something

tekk

i went back out to look at the car again. its cooled down a lot now that its been off for a few minutes. the coolant level has gone down to just above the min mark.

im tempted to add more but the fact that the coolant level has increased has worried me.

btw- not sure if it matters but when i noticed the coolant was low i checked the radiator in the morning and found it completely full to the top.

roast

iTrader: (2)

You left your car idling while washing it??

tekk

so its not safe to let the car idle for an extended period of time?

btw i was doing this because my batt had drained not too long ago. i have a computer w/ amps etc in the car so i know i cant let the car sit for too long like that.

tekk

yes... is that a big mistake? i normally dont do it (never done it before in fact) but as i said before the batt was low and before i get it fully charged i figured id give it some idle time...

ericjackson

iTrader: (2)

ah, i didnt know about that. i just use my ipod.

yeah its not good to let it idle. because there is no airflow cooling off your rad, only the fan. and also all that heat builds up in the engine bay because it has no where to go.. someone correct me if im wrong

ericjackson

iTrader: (2)

https://my350z.com/forum/showthread....=melted+plenum

roast

iTrader: (2)

yeah that's a big mistake... I knew a guy with an s2000 who did something similar....he left his car running and went inside to get something and got side tracked and forgot about the car and left it running for about an hour and came back to a pegged temp. guage.

If you had a low battery(even if not), the hot ticket would have been to leave the car off. Playing your stereo while the car is idling isn't exactly letting it charge up either.

I seriously doubt you hurt anything but I would not do that again.

tekk

oh i see. that makes sense. but then i wonder why the coolant level would increase to max?

thinking aloud here,
im not very knowledgable on this, but assuming its a closed system, that coolant had to come from somewhere... and im guessing it came from the radiator... which doesnt make sense to me... why the coolant would leave the radiator and go to the reservoir tank thing if the car is running hotter than normal

tekk

well apparently i made a huge newbie mistake

i hope i didnt damage my car.
the fact that the coolant increased has me wondering.
any thoughts on what i could do/check?

ericjackson

iTrader: (2)

well honestly ive seen the reservoir tank fluctuate in mine so if it is a problem.. i cant help with that

roast

iTrader: (2)

nah that's not a problem... when things get hot they expand.... the hot expanding coolant has to have some place to go (the overflow reservoir).

Ztalker

always a good idea to make it a habit to pop the hood in the garage to let the engine cool down after driving.

Black_Sunshine

Like most materials, it expands as it's temperature increases. Nothing abnormal here.

bacalhau16

iTrader: (32)

wow thats the weirdest thing. I'm sorry but i run my car all day long sometimes, and at times it may be idling for over 15-20 minutes. I have forgot about a few times also while i was on break at work. I have never had a problem with any of my cars idling while i wash it, listen to music, play playstation with my friends, or just stop for ice cream with the lady!

by all day long i mean, i have never shut it off from 11 a.m. to 8 p.m. while doing my deliveries!

350Zenophile

iTrader: (20)

Pretty straightforward really.. When molecules are heated they bounce around and expand...when cooled, the opposite happens, the molecules slow down and contract. The "reservoir tank thing" is also known as an expansion tank, get it?

Now, I'm sure you like your car stereo, but that's got to be the most wasteful and irresponsible way for you to listen to music. Think about the fuel you're wasting, the pollution, and the unnecessary wear on the motor.

Other alternatives would be to purchase a battery (or second battery inline) designed for extended play while not being charged, run an external trickle charger, or even do something crazy like buy a portable or used stereo just for the garage.

tekk

thanks for the comments guys.
i drove the car, high speed low speed stopped at lights etc and everything looks and feels ok. the temps are back to normal.

i didnt mean to belittle any of the components here when i said reservoir tank thing. i am an enthusiast and i try to read and learn as much as i can.. i just wasnt sure how exactly the entire cooling system works, correct terminology, etc. i will make it a point to read through the howstuffworks and the ESM tonight though.

what got me was the degree to which the coolant level in the reservoir increased. it went from minimum to maximum. it made me wonder if there was any left in the engine! i know things can change size with temperature, so a slight increase i would understand, but going from min->max seemed like a big change.

i feel a little uncomfortable now though because i was thinking about adding coolant to bring the reservoir up to the max line. but if i do that, and something like this were to happen, it seems like something would break since the reservoir would fill to the top fast? any thoughts on this?

superchargedg

iTrader: (4)

^^^ this is the right answer,dont worry nothings wrong.if your still worried have the dealer look at it under warranty.

Ayankees2772

thats why they have the max line...if u fill it up to there...it wont overflow..lol!