4AGZE - should I use head studs?

**nick.parker** · 23-09-2009, 08:49 AM

Hi,
I suspect my 4AGZE has a blown head gasket...some time ago (two and a half years ago) I changed the gasket (standard composite gasket) and re-used the old head bolts(they were re-torqued after a couple of months).

1. I have heard that the 7AFE metal shim gasket works for 4AG(Z)Es and is cheap. Can anyone confirm this?

2. Given I have 18psi of boost on tap, would I potentially benefit from using head studs? Are they less prone to stretching than bolts?

Thanks, Nick.

**Cuzzo** · 23-09-2009, 09:20 AM

If you can afford it go head studs but new headbolts would be fine enough.

**.T.** · 23-09-2009, 12:57 PM

on a turbo motor i think you would be much better off using the arp headstuds.
run a tap through the block to clean up the threads so you get even loading.

apparently you can use the 7a headgasket, but i'm yet to try it myself.

try using hylomar on the headgasket as well.

**feral4mr2** · 24-09-2009, 09:16 AM

do you need to re-torque the arp studs? i love hylomar, but you do need to re-torque when useing it on headgaskets.

you used to be able to buy 0.8mm and 1.5mm metal shims to suit the 4age through acl, hylomar is needed on them. though i would prefer to have the HG as a weak spot in a boosted engine than say a piston.
IMO genuine gze HG and arp studs should be a winning combination.

**mullett** · 24-09-2009, 04:15 PM

Good to see you around again Nick, is the AW11 back on the road now?

-RM.

**nick.parker** · 24-09-2009, 06:53 PM

Thanks Feral. G'day Robin.
Yeah the MR2 is now complied for use in NZ and fully legal with all the mods!
The custom ECU even passed emmissions! Haha.

Anyhow I ended up buying a TRD 0.8mm metal gasket today and some ARP head studs. So I'll see how this goes. I used hylomar last time with the stock gasket and even with some accidental detonation at times (for optimistic tunes) and abuse over two years with 18psi etc the stock gasket and hylomar proved itself.
Nick