Nissan 300ZX Engine Overheating – Head Gasket Leak?
Reader Question
Austin,
I was wondering if maybe you could help me out. I recently purchased a 1986 Nissan 300ZX non-turbo for use as a beater/daily driver. The car has been overheating since I bought it. So far I have flushed the system 4 times, replaced the thermostat, radiator, radiator cap, and a ruptured lower radiator hose. The car is still overheating, even after having done all of that! I’m at wits end with this monster! What could possibly be causing it?? The previous owner believed the car has a blown head gasket.
However, there is no transfer of fluid between oil and coolant, and no smoke coming out of the tailpipe, and other than getting hot, it runs like a champ. I don’t know where to look next and it’s driving me nuts!
Joe
Hey there Joe,
Get a cooling system pressure test first Then check the electric cooling fan operation or fan clutch if you have one.
Also make sure you have bled the cooling system and there are no air bubbles in the system. Turn on the heater so the heater core fills with coolant just to make sure there are no air pockets in the system.
Blessings
Austin Davis
Reader Reply
Austin,
Thank you for your prompt reply. No wonder so many people ask for your help! I actually fixed the problem last night. It was definitely air in the system. I had to reposition the thermostat with the jiggler valve up (should have read that in the shop manual!) and manually burp the system by squeezing the lower hose to get the air out of the block. Drove it around for over 20 miles of mixed driving, and even having to stop for the world’s longest freight train and it now sits dead center on the gauge.
Thanks Again!
Joe
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Tagged with: 300zx Engine • 300zx Turbo • Air Bubbles • Air Pockets • Blown Head Gasket • Coolant • Cooling System • Electric Cooling Fan • Fan Clutch • Fan Operation • Freight Train • Gasket • Head Gasket Leak • Heater Core • Nissan 300zx • Pressure Test • Radiator Cap • Radiator Hose • Reader Question • Wits End
Filed under: Over Heating
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Austin,
I am at a loss. I drive a 1984 300zx.
I have changed the thermostat, radiator cap, and bypassed the heater core as it was leaking all my coolant onto the passenger side floor board. Now white smoke comes out from the passenger panel, as well as from under the hood (looks like it is coming from the engine). The coolant is leaking but cannot find the leak. There is no oil in the coolant from what i can tell, nor is there coolant in the oil. My only guess is that I have a blown head gasket. For someone who CANNOT afford the 1500-2000 dollar repair job, do you recommend a product like “Steel Seal” to temporarily get my car driving again?
Chad
Get an inexpensive cooling system pressure test FIRST, this is most likely an external leak not a head gasket leak.