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Discussion Starter · #1 ·
G'Day all,
i have a 2001 ZD30 which i suspect may have a cracked head.
I have owned the beast for years and have been dreading this day.
The problem i have is that it has been using a fair bit of water lately, and the radiator builds up heaps of pressure to the point that coolant is pushed out of the overflow bottle.
The engine runs fine on start up and doesnt get hot (by the standard guage only), however, when i switch the engine off, i can hear/see bubbles in the overflow and with cap off whilst idling there are eruptions of froth spewing out of the top.

i cant smell the pungent smell in the water as usually happens when a head and/or gasket has gone.

I have changed the radiator cap hoping it was that which was stuffed but the problem still persists
Can anybody please tell me if this is another Grenade down the gurgler or is it another problem perhaps
Rawlo
 

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it sounds like it buddy, but also could be the symptoms of a stuffed thermostat or a blockage in your cooling system. Is the radiator fluid really dirty? you could always throw a bottle of chemweld or bars into it and see if that helps. apparantly there is some stuff you can dump in the radiator which will change colour if you have head troubles, might be worth checking that out.
 

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I'd avoid Chemiweld at all costs IMO. Get a tk test done it will show ifthere is combustion gases inthe cooling system. Thought it doesn't sound good for ya
 

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yes ive been weary of bars and chemweld too as they are designed to create a blockage, but when i used it i figured i didnt have money for the head at the time and i needed a car so i did it, apparantly it doesnt clog until it meets air but that could be crap too
 

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G'Day all,
i have a 2001 ZD30 which i suspect may have a cracked head.

The problem i have is that it has been using a fair bit of water lately, and the radiator builds up heaps of pressure to the point that coolant is pushed out of the overflow bottle.

The engine runs fine on start up and doesnt get hot (by the standard guage only), however, when i switch the engine off, i can hear/see bubbles in the overflow and with cap off whilst idling there are eruptions of froth spewing out of the top.

i cant smell the pungent smell in the water as usually happens when a head and/or gasket has gone.

I have changed the radiator cap hoping it was that which was stuffed but the problem still persists.

Can anybody please tell me if this is another Grenade down the gurgler or is it another problem perhaps
Rawlo
These are the exact symptoms that I had back in April, word for word infact.

Yours has not grenaded yet, so get the necessary tests done to see what is happening. Me thinks a head gasket though.

With mine, once the head was removed, servere scoring of the bore was evident so I went the new long motor.
 

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Chemiweld makes an absolute mess of the inside of the motor so much so that some people once they start to repair end unjust replacing the engine. It just blocks up everything. I personally would never use it unless I didn't want that motor anymore
 

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be aware that on a ZD30 the radiator cap has no pressure release valve in it. It is just a cap. the cap with the pressure release is the one over on the passenger side of engine bay.

just check the basics before you dismiss it as an expensive problem!
 

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Discussion Starter · #8 ·
Thanks all for your priceless advice, that is not quite what i wanted to hear but atleast now i have something more than just a gut instinct about the head. i will take it to my local radiator joint and give them a squizz. Yom, i am aware of the standard cap on radiator and pressure cap on the sub thanks anyway.
Good thing i have a low Km ZD30 engine sitting on my shed floor for just such an occasion. looks like i will be stripping the head off that and replacing mine.
 

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Discussion Starter · #9 ·
Just an update on the situation. I went to a radiator specialist today and he was about as handy as an ashtray on a motorbike. i then went to a reputable local mechanic and got a TK test done. they claim that there are no exhaust gasses in the cooling system at all and it may be the fact that the ZD30 has a duel thermostat maybe it is stuffed. not convinced by this i went to another mechanic who proceded to tell me that diesel is hard if not impossible to trace exhaust gases and that the problem is the head and/or gasket. who do i believe? as i will be doing the work myself the lure of cash is not persuading them to tell me a **** n bull story but 2 diffenent opinions in 1 x day?
Help please
 

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not convinced by this i went to another mechanic who proceded to tell me that diesel is hard if not impossible to trace exhaust gases and that the problem is the head and/or gasket. who do i believe? as i will be doing the work myself the lure of cash is not persuading them to tell me a **** n bull story but 2 diffenent opinions in 1 x day?
Help please
Again, this is the problem I had, 3 mechanic shops could not detect any exhaust gases, which had them all stumped. It has to be either the head or the gasket.

Obviously, until you remove it, you won't know.

And only one thermostat.

Have you had the radiator rodded?

I do not trust the Nissan gauge, its like as useless as tits on a Bull.
 

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gday mate i am a diesel mechanic and have had the same problem with my zd30, it does sound like a blown head gasket to me, can you see any small bubbles or anything coming out of the coolant with the radiator cap removed(obviously when cold otherwise you will get covered in hot coolant) also when doing the tk test make sure they spend a bit of time when doing the check as it took up to 5 minutes to detect mine even then it was only faint but when i pulled the head off it had blown gasket and hairline cracks in number 1 and 4 pistons, hope i could help but it doesent sound very good mate.
 
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