Cracked Head.

[Nick-palmer1]

Gday Everyone!

Well my Nav has cracked the head, between the glowplug hole and the valve seat in every cylinder. got it all apart and new bits have arrived so i'm getting it all back together now.
What i want to know is has anyone heard of why they crack like that and if there is a way to prevent it from happening again?
After $1200 bucks on parts and alot of time spent pulling it apart im not very keen on it happening again so any info would be good. Kind of at the point where once its all back together i'm going to decide if i should keep the vehicle or not. for an 06 model with 190000ks im not very impressed.

 

[Dave]

Do you glow it long ?

I only glow mine in the morning, otherwise I just start it.

Is it chipped ?

 

[Nick-palmer1]

Gday Dave,
Nah not chipped all i have done is blocked off the EGR like you i just glow in the morning, i did read somewhere, maybe on here that the glow plugs stay on for a long time after the light goes out but i havent checked yet.

 

[Dave]

How many km's ?

All the cracked ZD30 heads that I have seen, crack in the same spot.

Toyota 1KZTE heads are known for cracking, wouldn't be suprised if the do it in the same spot.

 

[Nick-palmer1]

From the intake valve seat to the glow plug hole and from the exhaust valve seat to the glow plug hole, One of the blokes i was talking to when i was trying to find a new head said all the ZD30 heads he has done crack in the same spot, I'll attach a photo you might be able to make out the crack if you zoom in.

 

[Nick-palmer1]

about 195000 kms too

 

[Dave]

All the cracked ZD30 heads I have seen all do it the same spot as your's.

Fatboy works for a Nissan dealer, he may have some inside knowledge.

 

[Nick-palmer1]

Awesome thanks, hopefully i can find an answer. something has to cause it.

 

[Krankin]

RECALL time.

 

[Dave]

Oh and have a good read of www.patrol4x4.com

There is alot of good ZD30 info on there.

Ignore the turbo related stuff and the MAF as the D22 ZD30 run's a MAP sensor and they give little trouble.

 

[Krankin]

From the intake valve seat to the glow plug hole and from the exhaust valve seat to the glow plug hole, One of the blokes i was talking to when i was trying to find a new head said all the ZD30 heads he has done crack in the same spot, I'll attach a photo you might be able to make out the crack if you zoom in.

thats just poor design....there's not enough 'meat' there

 

[Nick-palmer1]

Yeah Just had a look on the patrol forum, thats where i must have found the info on the glow plugs, apparently they stay on for 5 minutes for emissions. maybe sticking a timer of some sort in the circuit to turn em off after 30sec or so might help? you can imagine how hot they would get after 5 mins and on such a small area..

 

[ben85]

just done mine about a month a go, spent $4500.

be keen to know if you find out anything on why they crack, and if a glow timer is going to help.

 

[charlie strayarc]

Gday Everyone!

Well my Nav has cracked the head, between the glowplug hole and the valve seat in every cylinder. got it all apart and new bits have arrived so i'm getting it all back together now.
What i want to know is has anyone heard of why they crack like that and if there is a way to prevent it from happening again?
After $1200 bucks on parts and alot of time spent pulling it apart im not very keen on it happening again so any info would be good. Kind of at the point where once its all back together i'm going to decide if i should keep the vehicle or not. for an 06 model with 190000ks im not very impressed.

What parts did you have to buy?
Complete head or did you use old cam,valves etc?
New or second hand and where did you get them from?
I'd be interested in learning more about glow plug timers too.
Cheers.

 

[Nick-palmer1]

Bought brand new head, valves, head bolts and a full gasket kit from all car engines in qld, found em on eBay. Just have to use my cams, valve springs and buckets. After postage it was about $1300 still the cheapest one I could find, the local engine reconditioners wanted $1800
I'm not exactly sure about the glow plug thing just read something about it on the patrol forum, I know you can get timed relays from jaycar dunno how well they would work or mate you could wore it up to a switch on the dash via a relay.