possible blown engine or loss of compression??

[Guest]

car is a 92 RS Legacy

car revs like its missing..turbo spools at around 5g...with very little boost and has lost power in lower revs

I have just spent the week checking all hoses and wires....fuel pump, injectors, cleaned IACV, checked turbo for cracks or play...

I havnt changed coils or plugs but can they do this much damage if it was these 2 things...I understand they can cause engine to miss...but can they cause turbo to start spooling at high revs??

anyway I have tryed almost everything I can do for now apart from coils and plugs but just wondering if the above can be symptoms of a blown engine??....

[DRFVDR]

A quick check for me is usually the balloon check

get car warm

remove oil cap

fit balloon/rubber glove/condom

rev engine

see how fast the balloon blows up

if quiclkly then yup u got heaps of blow by

also check exhaust gaskets

could be burnt valves causing low compression

I know that when I sent my Legacy heads away they said that the exhaust valves were only sealing at 20%

[BC5RA]

1992-RS

I've got a free day tomorrow, I'm happy to pop over and check the car out if your keen?

[Guest]

yeah mate im keen as if you dont mind coming out to manukau...I can drive the car but its real risky...anyway will pm you the details.

cheers DRF ill give the trick a go. Now that exhaust gasket is mentioned im thinking the gasket from off the turbo to front pipe may be blown...not sure hopefully if BC5RA comes around he can see if it is or not.

[Guest]

Early Ej20 had rocker arms that can jump off when overreved

If low on compression and engine doesn't have heaps of blow by remove R/C and check rocker arms on that cylinder

[Guest]

ok so I tried the quick compression test but with a plastic bag and rubber band to seal around the the bag....wondering if thats ok to use??....but anyway reved the engine and it doesn't blow the bag up at all and when down revs it sucks it in...so I will check rocker arms....if they are ok my next question would be what cylinder heads to use??...would be good to use some wrx ones but which ones???.....

[Guest boostcut]

v3 v4 wrx ;D

[BC5RA]

1992-RS If your still running the standard RS EJ20 and you change your head's you'll also need to use WRX pistons.