Bigz38b

Hi guys. Can anyone help. Starting to get stressed now. Here are my 350z symptoms.
Car overheating within 2 to 3 miles of driving.
I have done the following.
Burped the coolant system using a funnel with the car on an incline.Bled the air purge nipple near engine bulkhead.The coolant level in the radiator looks good and the exspansion vessel is around the max level.The radiator cap looks like it'should working correctly.
When burping the system after 10 mins or so when the fans start up soon after the funnel starts to bubble and boil and coolant to the point it will over flow. The oil is good and clear with no white sludge and exhaust gases look pretty clear and not really paticularly white.Could this be a thermostat sticking closed or could this be more sinister like a head gasket. I am waiting on a dye kit off amazon to help diagnose if its hydrocarbon gas in the coolant and the head gasket could be the problem. Any tips or advice would be appreciated.

travlee

iTrader: (8)

feel the hoses. is the top one hot and bottom one cool? if so, tstat

eZg

iTrader: (5)

turn the heat on high.......

Squeeze hoses carefully while the leslie funnel is doing it's thing, trying to loosen air pockets. These thing are a ***** to bleed so just keep at it.

When filling the coolant it is best to go very VERY slowly.

Bigz38b

YES.You are correct the lower hose to the stat is 12 degrees c measured at the rubbr hose with a laser gun. The upper return to the rad is measuring about 50 degree c at the rubber hose.I hope you are correct there. I have myou fingers crossed this is the fault. I am hoping that as the stat is shut the water pump is pushing the water out of the rad.

Bigz38b

Lovely thanks for that. I have been trying this for a few days though. I will however hope it is the stat and keep your thoughts in mind. Really appreciate both replies guys. Fingers crossed.

CK_32

iTrader: (1)

A trick I found too is tab or hit the top of the rad.

I found a crap ton of air gets stuck in those lines and bends. Do it I bet you'll bring up a bunch of bubbles.

Bigz38b

All excellent tops guys. Thanks for all your swift responses. I will let you know the outcome.

Bigz38b

Just an update on the overy eating and boiling saga.Tested last night with a radiator pressure tester. Pumped to 15 psi and held relatively well for 15 mins. Maybe 14.8 psi after.Then started the car and when up to temp the pressure gauge was reading 12 psi and fans starting and stopping yet bottom hose still cool and when revving a small pulse of 1 psi so to 13 psi which I think is the water pump spinning creating pressure. Removed old stat and boiled in the kitchen to 90 degrees stat only partially opened. Then tried new stat and opened fully. Fitted new stat and coolant. Burped car with funnel and when up to temp fans kick in and bottom hose is hot. GREAT NEWS.Then as before engine rev increase to 3000 revs but this time no over boil at the funnel. I can only guess that the old stat was partially opening and the volume from the water pump was too much for the radiator to handle hence the over boil in funnel. Car only tested for 30 mins but very consistent needle temperature fans coming on and off and after some extra bleeding at the bleed screw I have very good heat in the car. Well worth trying before panicking about HG. Thanks guys for all the online tips. Helped quite a bit. Anyone suffering similar conditions or symptoms feel free to post and I will try to support.😀