Airlock? headgasket gone bang?

[ellycully]

hey guys new here.
-06 str d22 ZD30
to cut a boring story short last week i drove about 400km with no probs. wasn't till i slowed down as i got into town that temp raised quite hot.
checked it out. coolant everywhere. upper rad hose was very pressurized.
after taking rad cap off and watching the amazing display of foaming bubbling coolant trying to make it to the moon . the engine quite quickly cooled down to normal temps again. i topped it up slowly assuming an airlock. after a few revs it would foam and id top up (did this a for a while and eventually foams and the amount of foam reduced drastically)

drove back fine. coolant still pissed out the overflow after about an hour of driving. (did this 3 times) engine temp was getting a bit hotter(not extreme) up/down/up/down for a while. car is not lacking anypower. drives fine as usuall.
i noticed the heater is making a bit of a noise when i turn it on. but i didnt notice it working or not

-no smoke out of exhaust(that i have noticed)
-no water under oilcap/dipstick
-no lack of power
-top rad hose pressurized. bottom hose inconculsive

i refuse to take my car to a mechanic without diagnosing first.
i doubt its cylinder damage(running fine)
it could be headgasket?(but no water in oil)
with engine off. i squeeze rad hoses and i can hear noise from near t-stat making a clinking/grinding/sliding noise.

what are you opinions?

 

[TigerST]

I'd take it a Mechanic and just say it broken. And let them figger it out, that way if they charge you and the problem still ant fixed you can keep talking it back antill they fix it.

 

[baylock]

Sounds like the same thing mine was doing after i cooked it a while back, i ended up getting a head kit and new gasket, when my brother and i pulled it apart, we believe only the gasket needed replacing, but i didn't have the time to replace gasket, test, and then if needed replace head, as i figured it was warped from the overheat anyway we just did the lot. Cost about $1300 for the kit, but it solved the problem.

From what i have been able to figure out, the number 4 exhaust is usually first to go on these motors, and tho it usually happened with the pootrols, it is still the same motor.

Also, dont bother with any of the 'head fix' chemicals;
1. With the thermostat being at the intake, there is no pressure to force the chemical into the crack.
2. It will fill the small holes in the gasket that are responsible for your block pressure, preventing water from flowing through them.

 

[ellycully]

what symptons occured in your experience?

 

[baylock]

Bubbles in the coolant, and when driving the cooland would overflow out of the bottle.
These are videos i made to show my brother, and a mechanic at work to confirm my suspicions.
https://www.youtube.com/watch?v=9zQkqm_AWnQ
https://www.youtube.com/watch?v=ASxIJESICgg

 

[baylock]

other than that, no other symptoms related to normal head / gasket failure. no mayo in oil, no coolant in exhaust... nothing, just the bubbling, and overflowing.

 

[ellycully]

thats interesting, was engine lacking power? missing?
did you have coolant in your oil?
this is most probably the h/gasket you reckon?

 

[ellycully]

okay thats interesting, did the bubbles ever foam up?

 

[Old.Tony]

If you suspect the head gasket (and bubbling in the coolant like that is either head gasket, a dodgy water pump or a very small scuba diver that's really, really lost) then you COULD get yourself a block test kit like the one in these instructions. Check the video on how it works here.

 

[baylock]

no more than pictured, but foaming would probably be more related to the type of coolant than the gas, as i mentioned tho, that was the only symptom i had, even with driving it nearly 2000k stopping regularly to top up the coolant to my brothers to fix it, in the middle of summer, in 40+ days.... never let it be said the motors are weak, they just have a few gremlins.
My advice, if you take it to a mechanic, let them deal with it (From all reports they charge like a wounded bull to do the job, and after doing it with my brother, they probably deserve every penny), or if you have the tools and know how, or a friend you can bribe with a carton, you ill probably be better spending the $1300 (I got this one: http://www.ebay.com.au/itm/Nissan-N...=AU_Car_Parts_Accessories&hash=item43be7e7b10 ) and doing it at home, just dont forget about the oil return at the back, and don't drop the little oring at the front.
Oh, and no i will not do this again, the next time this happens, it gets burnt, only nissan could make a simple 'take this part out, put this part in' fix so complicated.... so much crap to move before you even get to the rocker cover, let alone the head.

 

[baylock]

If you suspect the head gasket (and bubbling in the coolant like that is either head gasket, a dodgy water pump or a very small scuba diver that's really, really lost) then you COULD get yourself a block test kit like the one in ...

Problem with those tho, they are not 100% accurate on diesels, they tend to give a lot of false negatives according to reports i have read

 

[ellycully]

a very small lost scuba diver ahahahah ok cheers guys. ill do a wee bit more tinkering and sussing out and ill replace the rad cap and take her in to a mech.

would you think i'd have a cracked head?

 

[baylock]

im still yet to get my old head tested (If its ok, it would be nice to have a spare... these things are not cheap, but i would say whether it is the head, or the gasket that the problem would be around your No4 Exhaust port.

 

[Fat801]

Sky 02 had these exact symptoms last Sunday.. Currently pulling mine down to check the head and gaskets