Hi,

Ok, I’ve searched and can’t find a simple straightforward guide for doing a compression test on the Zed.

From what I could find out it looks to me like the best way to do it is:

 

1 - Disconnect CAS and/or take out fuel pump fuse.

2 - Take off all coil packs and remove all spark plugs (so as to allow as least resistance as possible, battery will last longer)

3 - Connect pressure gauge up to one of the cylinders (not sure if there is a preferred sequence or if it makes any difference)

4 -Turn engine over a few times (not sure how many) and push fully on accelerator (this is to open the throttle bodies to allow as much air in as possible)

 

Min 143 psi, max 184 psi (no more than 14 psi deference between any).

 

If any of the cylinders a re showing lower pressure (obviously check it a few time first and check the pressure tester connection) put a bit of oil in the cylinder, if the pressure looks better after this is would indicate the rings are leaking.

If the pressure is still low it would indicate head gasket (should have other symptoms for this as well, i.e. bubbles/CO2 in the water or possibly if bad enough mayo in water or oil), Valve stem seals (again other symptoms with this, i.e. burnt oil), or valve seats not closed flush (reduces performance and/or un-burnt fuel/ black smoke/backfiring if it’s the exhaust ones).

 

 

Can anyone pleases confirm, correct or add to this?

Cheers.

yup and found nothing untoward, apparently that can happen. let me know how you get on at zed world. i should have my block out by saturday end of play.

Ah, you're going for the full rebuild then?... well that will fix everything.... :)

Just turbo rebuild and fixing some annoying bits like leaky rockers and the like. Doing egr delegte and water bypass the norm

Hopefully I wont be building a new block just yet...

update.... oil in water..... BHG !!!

 

well I guess it could have been worse... (might still be.. lol)