ryanscooby25

iTrader: (1)

iv got a 1996 impreza sport non turbo got a loss of power when accelerating so changed the coil pack today and still the same so a friend of mine did a compression test these were the results

cylinder 3 - 195lbs cylinder 4 - 160lbs
cylinder 1 - 190lbs cylinder 2 - 145lbs

im guessing this isnt right?

please help me out here guys

thanks in advance

tubbytommy

iTrader: (20)

you shouldnt have much more than 10% difference really.
the low pressure could indicate bag exhaust valve or rings

as the pressure is low in two cylinders on the same head it could also be the head gasket has failed

ryanscooby25

iTrader: (1)

whats bag exhaust valve buddy?
can the valves be adjusted in this engine? if so can anyone tell me the clearances for this

tubbytommy

iTrader: (20)

sorry bad i.e damaged .
spelling fail.....

i would think the headgasket has failed in on side of the engine but get it checked by a specialist to confirm.

The Zohan

as stated above 10% max variance between readings. If you are losing compression and it is the hg then i should show up in the coolant or even oil. check the coolant colour and also see if there is any 'mayo' in the expansion tank and oil cap. take the car to a garage and get a 'sniff test' or see if a local factors sell the sniff test kits - most do and it is a simple test to do.

Otherwise i would suspect valves are burnt/worn, maybe mixture/injector/maf fault

ryanscooby25

iTrader: (1)

no mayo or overheating issues buddy and if i remove the maf sensor the car runs alot better but i put a new maf on as someone advised me to try it and it was still the same, loss of power. if it had been the maf would that alter the reading on compression test?

thanks

tubbytommy

iTrader: (20)

no if you have lost compression it will be headgasket or valve/piston ring related i think zohan means that the problem was caused by the engine running lean due to injector/maf etc and burning out the valves

ryanscooby25

iTrader: (1)

ok buddy thanks, maybe il just change the engine would a EJ201 out of a 2000 sport fit or would i have to get the EJ20E for a straight in fit
thanks

tubbytommy

iTrader: (20)

no idea as i have new age car but i would get it checked by a specialist to confirm the problem first

ryanscooby25

iTrader: (1)

ok mate thanks for your help

ALi-B

iTrader: (1)

Firstly I need to ask: Was the battery going sluggish during the compression test? And was it during the test of no 2 and 4 ? If so you won't get accurate reading (as the engine is cranking slower). If s,o get a fresh battery and do it all again.

Secondly, Check the cam timing. Get the engine at TDC and check all the cam pulleys align, especially on the on the right hand side of the engine. Use a mirror and torch if you have to. If its a tooth out, it'll misfire and give iffy compression readings.

Finally, once ruling that lot out, as other say suspect valve issue or Head gasket (this doesn't always cause coolant/oil mixing - common misconception), or at worst broken piston ring or damaged piston.

ryanscooby25

iTrader: (1)

Thanks ali
the battery seemed to go the same on all 4 checks
would you have to hand the valve clearances for my car its a 1996 impreza sport non turbo and il check these are correct

ALi-B

iTrader: (1)

I think its hydraulic (self adjusting) up to 1997. It was on the non-STi turbos at least.

Workshop manual here: http://www.mediafire.com/?bp5js3yjgcc62#wxogqmdo5650z

(credit due to slipstream: https://www.scoobynet.com/technical-...d-updated.html )

ryanscooby25

iTrader: (1)

thanks again for the help ali

ryanscooby25

iTrader: (1)

cant access that link for some reason bud

ALi-B

iTrader: (1)

Try this one: http://www.mediafire.com/?ae5wazn5yzd

or this one: https://rs980l33.rapidshare.com/#!do...07A9176ACB|0|0


You will need to install winRAR to open the files (free...just google it)



If that doesn't work look at this thread and use the link from there: https://www.scoobynet.com/technical-...d-updated.html

But don't use any links saying "MEGAUPLOAD", they no longer work (megaupload was shut down recently)