350z Overheating.. HELP!! - MY350Z.COM - Nissan 350Z and 370Z Forum Discussion

Notices
Maintenance & Repair 350Z up keep and diagnosing/fixing problems

350z Overheating.. HELP!!

Old 01-14-2019, 01:06 PM
  #1  
Dano417
Registered User
Thread Starter
 
Join Date: Jan 2019
Location: Colorado Springs
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Default 350z Overheating.. HELP!!

So my 03 350z is overheating. The radiator, thermostat, and waterpump were all replaced. New head gasket and bleeder valve. Also, bleed the car for like 2 hours but once driving the car overheated again.. The fans still work and heater blasts but why is the car overheating..? Please help

Also, side note: S.E.S. Light is on and before the overheating the car when lump and the engine cut but all electrics work. The TCS OFF and SLIP lights both cam on afterwards as well. Upon checking codes this popped up: P0340- Camshaft Position Sensor A Bank 1. Does this mean the camshaft sensors and the crankshaft sensors are bad?

Last edited by Dano417; 01-14-2019 at 01:29 PM.
Dano417 is offline  
Old 01-16-2019, 04:59 PM
  #2  
jan.w
Registered User
 
Join Date: Jan 2019
Location: Alberta
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Almost identical issue on my 2003 Infiniti FX35, also has the VQ35DE, I was actually going to make a post but you seem to have somewhat similar symptoms. Here's my story:

Just replaced the head gasket (2 weeks ago), problem went away for 500km and came back today. For me, gentle driving seems to keep the issue at bay, but if I give it any more than 30-40% throttle, the following will happen:
  • Lose cabin heat (starts blowing cold).
  • Coolant level slowly start to rise in overflow.
  • Lower rad hose cools down.
  • Bypass hose on the front of the engine slowly cools down.
  • Engine temp slowly rises until coolant boils over and sputters out of overflow tank.
  • I *THINK* I smell exhaust gasses in overflow tank.
The fact that this issue went away completely for 500KM (regardless of how hard I pushed the car, and don't worry - I pushed it hard), leads me to believe that the components related to the cooling system are functional. Thermostat is opening when it's supposed to, fans are kicking in properly, water pump is functioning as it should, and the system is airtight under testing pressures (system tested overnight at 15psi, no leaks).

When I replaced the head gasket, I didn't get the heads machined, so my current theory is that the heads were originally warped, causing the gasket to be placed under high stress in a specific location, which led to the subsequent failure after only a few hundred KMs with the new gasket. As was the problem originally, I think this is a microscopic, or semi-failed gasket which only leaks exhaust gasses into the coolant under high loads (higher cylinder pressures). When the exhaust gases enter the coolant system, I assume they travel into the water pump which causes the pump to stall (or "slip" in the gases) and cease proper operation. This then leads to the loss of coolant flow and subsequent loss of cabin heat, cooling of lower rad hose, cooling of bypass hose on the front of the motor, and overheat.

My plan as of now is to pull the heads, get them machined this time, install a new head gasket, and pray that this adventure is over.

Did you get your heads machined when you did the head gasket?
Does anyone else have any other ideas? I'm getting pretty close to buying a crashed up FX at an auction and swapping in another motor.

Last edited by jan.w; 01-16-2019 at 05:02 PM.
jan.w is offline  
Old 01-16-2019, 06:32 PM
  #3  
phreaktor
~[;::;]ᵒᴥᵒ)
iTrader: (22)
 
phreaktor's Avatar
 
Join Date: Jan 2007
Location: The Marketplace
Posts: 28,315
Thanked 30 Times in 22 Posts
Default

Something like this?


If your heat is blowing cold, It's likely got air in the system because the coolant isn't passing through the heater core. . As much as you think you got it all out, I bet you didn't. Are you bleeding it with a Lisle funnel or just lifting the front and cracking the bleeder?
phreaktor is offline  
Old 01-16-2019, 06:37 PM
  #4  
phreaktor
~[;::;]ᵒᴥᵒ)
iTrader: (22)
 
phreaktor's Avatar
 
Join Date: Jan 2007
Location: The Marketplace
Posts: 28,315
Thanked 30 Times in 22 Posts
Default


Fast forward to 19:50. This solved my symptoms and they never came back. i think the air got in the system when i installed my Throttle body spacer or plenum spacer.
phreaktor is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
06Roadster
Maintenance & Repair
14
05-21-2014 07:39 PM
Divine
Maintenance & Repair
7
03-02-2014 08:56 AM
FairladyCT
Maintenance & Repair
6
05-02-2013 01:47 PM
Jamielue
Maintenance & Repair
2
03-12-2013 10:58 AM
HoomanR
Maintenance & Repair
18
11-28-2010 09:23 AM


Thread Tools
Search this Thread
Quick Reply: 350z Overheating.. HELP!!


Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: