Hey guys so I got a 05 g35 coupe that’s having a problem with overheating. It started couple months back when temp would go up all the sudden and after I pulled over and turned car off and back on it would go back to operating temp and then it would drive fine for a week or so, until it happened again. After about a month I was going tothe gym when it went all the way hot out of nowhere I shut it off and back on and saw temp was staying at hot, so I parked it and popped the hood coolant in the resovoir was bubbling and coming out from overflow. So my thought was hesdgasket but it could’ve been just air so we bled it drove fine for 3 or 4 days when again it started overheating. I noticed car would not blow hot air so after I changed thermostat and radiator cap and bled it again and after that heat finally came back, so I was like omg my cars fixed I took it to sacrmento for a exhaust deal and I’m all the way from Modesto so I thought that would be a good stress test to make sure it’s fixed. Once I entered Sacramento ,while I was driving I saw the temp go up slowly and I immediately pulled over. The coolant in the tank wasn’t bubbling this time but it was all the way past the max line and again my car stopped blowing heat so I had it towed to my friend who’s a good mechanic. He ran a pressure test on it and a compression test and everything is really healthy, so it’s not my headgasket. I’ve checked oil too, so what can be causing this I’m also changing my water pump right now. so if that was the cause I’ll let you guys know but just in case it doesn’t work suggestions would be helpful.

 

It was probably the thermostat. But u replaced that and now u probably have air in the system. Ive heard many stories about G35s having trapped air in the cooling system and its a bìtch to get out.


Let us know if the water pump fixes it. If not, its probably just trapped air like I mentioned.


BTW, use some periods when u type so its less annoying to read.

 

You are kind to actually read and reply. I motor right past unreadable posts like that....

 

Can trapped air cause it to be irregular like that? Like it drove fine for a good 50 miles and then all of the sudden overheated. If there was a problem, shouldn't it be constant and not when it wants to. Also, sorry about the periods.

 

A lot depends on the ambient air temperature, how fast you were going, were you going steady or sitting at stop lights, etc., etc., etc. Have you checked that the fans are working as they should? The driver side runs on low side heat. The passenger side kicks in when demand gets high. Your issue could be that you were going along fine, got to Sacramento stop and go traffic, she started to heat up, and the second fan never came on and bingo -- it's time to get out the ingredients to roast s'mores over your red hot block!

PS: Thanks for the periods!

 

Hey man, So I hadn't thought about that. The entire journey was highway and it wasn't until I got into the stop and go that it started doing that, but when the temp did rise I was moving for a good 20 seconds or so beforehand.

 

Once heat starts to build in, 20 seconds isn't going to make any difference. Not enough air flow through the radiator. You need the fans.

 

I just forgot that had my fans checked and they are running fine do you think a clogged radiator can cause this because along with changing my waterpump im having my radiator flushed out completely right now.

 

yeah, clogged radiator could definitely cause overheating issues. good call on getting it flushed. while you're at it, might want to check the thermostat housing for any cracks or leaks. those can be sneaky sometimes.

 

Alright thanks ill let you know if that fixes it, but what I hate is that its going to drive fine for a little when i get the car back like it always does. It usually takes a day or two and then bam overheating.