hey, car over heats when at a stop then cools once car is in motion. We thought it was air in the system that we got out but it happens again.
could aftermarket rad fans be the cause?????

can someone please buy my car...or steal it whatever....

 

well could be the fans wired backwards

 

get a phat asz radiator. maybe burp your radiator.. did you flush it lately? maybe you have a super tiny hole in the hose or sum'n

 

that could be it I will do a leak down again if I don't hang myself first

 

There must be a leak somewhere, your thermostat is weak, your fans are functioning properly, or your headgasket is toast.

First, make sure both of your fans are coming on. Then start by pressurizing the cooling system and looking VERY closely for leaks...use mirrors and flashlights. You might have a slow drip somewhere that was undetected. If the cooling system checks out tight, I would check your thermostat. If the problem still persists, its time for a leakdown test.

 

Are you loosing coolant? Do you have to refill it once in a while? I bet the problem is with the fans...

 

coolant levels are always at the top I can't see and coolant anywhere, no smoke no power loss nothing looking bad.

I think the fans are trying planing to kill me.

 

Is your heater working full blast and full heat?

 

heater blows lots of heat, and we did the blue dye test on the rad. The colour did not change which means no exhaust gas is the rad, then the overflow tank puked again and temps started to rise.


WTF

 

you could be getting headlift and not see any residual exhaust gasses in the radiator. If you have properly bled your system and the problem persists, it is most likely headlift. Eventually your headgaskets will give way enough to see the tell tail signs of a headgasket failure. At this point, your only system could be blowing coolant due to boost pressurizing your coolant system

 

Bhg

 

this only happens at idle and then temps go down once the car moves??



I used L19 head studs, what if the engine builder did not torgue them down enough would this cause head lift??


if ur right how can I test this or should we just check the head studs torgue lbs??

 

I had this happen on my car twice. In both cases it was the thermostat. The first time it was the stock thermostat. It failed and my car would overheat at idle and then drop temp when moving. I replaced it with a Nismo thermostat. 3 months later same exact thing happened. I finally decided I was done pulling the damn housing off and ditched the thermostat all together. I haven't had a thermostat on my car since. That was years ago. Its really easy to pull the assembly and remove the thermostat. Yes it bolts right back on and the only difference I have seen is that my car takes about 5-7 minutes to get to ful operating temp when sitting there after a cold start. Aside from that no downsides and no more overheating.

 

+1...happened on a few of my cars....thermostat was sticking....

swap it out..cheap fix...if that solves the problem...you can rule out head lift.

 

Could be your radiator cap if your overflow is filling up.

 

my man you got a fan problem................one of the reasons you have radiator fans is to simulate wind across the radiator.....esp. when you are in stop and go traffic and when your idling still at a stop light or stop sign................at my service shop i see it all the time.............check those fans

 

Exactly...after dealing with all the same crap for 3 months and being paranoid about having lifted the gasket, I said this is BS, pulled the thermo out and threw the damn thing away...car heats up within the 1st mile..I dont hammer on it while its cold of course....I do have the 53MM koyo and its never gone above 205 sitting in traffic. It will cool back to 180 after taking off again..
Pull it out...purge the system again with a radiator funnel and dont worry about it...
I did install a water temp gauge and keep an eye on it...but normally the car's temp gauge stays in the middle...
Ended all those BS problems..

 

I was having the same issues..it could be a few different things so tell us what you have already fixed and maybe we can narrow it down for you. I was able to get my fans working properly so that helped but Zivman told me to put a new rad cap on and that seemed to help the most and it only cost 8 bucks. My old cap for what ever reason was holding pressure as good as it should. Also no T-Stat for me too....

 

Probably the thermostat but try this procedure too:

https://my350z.com/forum/forced-induction/356151-coolant-purge-nightmare.html

 

Evans npg+ is a low pressure system. Just another option...