hi all

just a quick question i get asked at my work for 1.8t cylinder heads regularly usually ary or bam codes but would like to know if this is an issue on all 1.8t or just select code????

also what causes the initial cracking and what can be done to avoid it

To be honest I have never heard of 1.8 t heads cracking but when the timing belt breaks it makes a mess of the head,maybe that's the reason you get asked for heads.

Heat cycling causes cracks between the valves.It's a problem on quite a few engines but having 5 valves per cylinder means that there is less meat there and it cracks easier. Higher boost and higher temps makes it more common I suppose.

Seen it on 20v corollas too

Mk4 Astra GSi's are quiet common for it aswell, friend had 2 heads on his before he got rid of it

crazy so how can we keep the temps down?

crazy so how can we keep the temps down?

Apart from not modding the ever living snot out of it, you mean?

Yeah that would be it. Lower boost means lower temps but if you do increase the boost make sure the fueling is perfect and that the intercooler is up to the job.

A wideband is always a help so you can see what's happening.

Mk4 Astra GSi's are quiet common for it aswell, friend had 2 heads on his before he got rid of it

Not seen or heard of it being a major problem with the z20let. Cracked manifolds and generally funked turbos are their common issues

cool run thermostat worth a buy and those funky gaskets??????

Not seen or heard of it being a major problem with the z20let. Cracked manifolds and generally funked turbos are their common issues

Yeah hes had a couple of turbo's on his latest one as a reconned one lasted less than 12 months