Hello:

My son's 95 Maxima 3.0 6 Cylinder
all the suddenly is leaking anti freeze at the radiator
replaced radiator, both hoses, and thermostat
Jacked the car in the air 20 plus inches trying to burp/purge the air out
Used the funnel in the radiator to gain an additional 10 inches
I had the car running 30-40 minutes in the air
revving the engine 1500-2000 RPM
and the top of the radiator always boiled.

Notes:
only upper hose gets hot
lower hose does not get hot
Dashboard heat only comes out if cap is on and pressurizes
After the car is shut down on restart the antifreeze burps up 3 feet in the air with the cap off
tried driving for an hour and the radiator tank blew up/split from the tank from the pressure.
Replaced the radiator and thermostat for the second time.
When I go for a short drive 5-10 minutes
tremendous radiator cap pressure
and it feels like the hoses are rock hard
about to burst.

How can I be sure it is a head gasket?
What else could it be?

Thanks ahead of time

FixandFly

 

If the lower radiator hose is not getting hot, I don't think the thermostat is opening up. Since you have tried 2 thermostats, I wonder if you are putting them in backwards.

I would check to see if the thermostat is opening at the proper temperature. Put the thermostat in water with a thermometer and heat the water. At 180ºF, the thermostat should be open. See page 13 is section LC of the service manual for more info on this.

click for section LC - http://boredmder.com/FSMs/Nissan/Maxima/1995/LC.pdf

I also wonder about the radiator cap. That could also be bad. The radiator cap is supposed to let excessive pressure out of the radiator so the radiator will not explode.

Lastly, go to an auto parts store and rent a cooling system pressure tester. It is essentially an air pump that you put on the radiator in place of the cap. You pump it by hand and pressurize the cooling system to 23 psi. Carefully note the pressure reading and leave it there for at least an hour. The pressure reading should not drop. If it does, there is a leak somewhere, maybe the head gasket, maybe something else. See page 9 in section LC of the service manual.

 

I vote for the radiator cap as well. It's supposed to vent into the overflow at about 15 lbs. The overflow tank should vent to atmosphere, so no pressure should be in there. What caused that to split open?
Make sure the t-stat is in correctly, and make sure the cap is good, the overflow lines to the tank are clear and the tank vents correctly.

 

Block tester with the carbon dioxide reaactive dye

 

Pull your spark plugs, are they wet? If so, a head gasket is going same for milky tan oil

 

Block tester ------Dye failed test
Removed thermostat
Lower hose does get hot now.
Cap tested to 12 PSI
Used Thermo Gasket as a last ditch effort
http://www.rxauto.com/
I do not agree with Mechanic in a jar
After a few days I will pressure test the radiator
I do not want to do a 20 hour cylinder head job.
The car was bought for $1,100.

Thanks for the reply's

DennisMik
njmaxseltd
gruesome
and
asand1

 

Wrecking yard engine will be easier, cheaper, and quicker.

 

if you keep getting air on the top of the radiator, its probably combustion gas from a blown HG.

worst case if youre not bent on fixing it yourself, call technical schools and see if they need cars to work on. when i was in school the customers just paid parts, labour was free

 

My hoses get rock hard as well, and I've been loosing coolant, lower hose stays cool. Are the hoses supposed to get rock hard under full engine heat?

 

Yes. The cooling system is pressurized, that's why they tell you not to remove the radiator cap when the engine is hot. Pressure is regulated at 14 psi by the radiator cap.

 

Thanks Dennis. I know it's pressurized but I can't remember if n the past if they were more flexible/squishy under full operating temp.

 

yes when the thermostat opens, both hoses should be hard and warm.

 

I would first of all thank everyone for the helpfulness and input

#1 Why does the oil pan/pans have to be removed when taking off the Front/Rear timing covers?
(are there bolts that come up from the bottom?)
#2 Can only the lower pan be removed without the big upper pan removed?
#3 Can the heads be removed with only the front timing cover removed?

Thanks

Fixandfly

 

#1 -it's easier (in my opinion anyway) to install the rear timing cover without the upper oil pan installed. The oil pan seal kinda gets in the way otherwise.
#2-I think it can but my memory is kinda shot.
#3-Yes but the caulking could prove difficult to crack near where the heads meet the timing cover and it just makes for cleaner install if the timing cover is put on after the heads.
Anyone can, of course, throw any info contradictory to my own