Corsa won't start, low compression.

Strider590

Low compression could be simple bore wash, caused by lack of spark. Un-ignited fuel pools on the pistons, runs down past the piston rings, washes away the oil and boom your compression is gone.

Don't go chasing the lack of compression without being sure there's nothing else causing this.

atrixblue.-MFR-.

engines havent changed just whats around them, when you pull one out take off all electricals its an engine like all others that have been built since 4 cylinder OHC came out bar push rod to hydraulics.

a leak down test would be the way forward in looking for where your compression is going. you would need a compressor for that wich i gues you dont have and a special valve wich you can get at a local factors.

my rule of thumb with a leak down is:

if forced air is leaking through the oil check dipstick tube, its going past the piston rings (fried piston rings)

if forced air is coming out of the throttle body or oil filler cap (throttle needs to be open fully) its coming up past the valves or the valve seals. or possible a crack in the head.

if its a combination of both get a new engine/car.

if it was hydraulic lifters it would make a whole bucket of spanners in washing machine seem quiet.

im just woundering whether you had a full or partial timing chain kit fitted? BGA do the upgraded full kit to prevent the chain going again!. partial kits will fix the problem of timing chain wrattle for 12 months then your back to square one.

your compression test isnt even so the leak is not limited to one cylinder! wich could mean the HG has blown between cylinders and no water in oil or oil in water would be evident.

Wig

Get it up to temperature and check the compression again, making sure you remove all the plugs and remove the fuel pump relay - the purple one, if there are 2 purple relays it's the one closest to the drivers side.

spacey2012

Checking Compression on a cold engine is a waste of time.
This is more likely to be ECU problems, Vauxhall went through a phase of sticking the ECU under the bonnet to fry, I know Astras of this era are dogged by ECU solider joint failure.

SteveJW

Strider590 wrote: »

Low compression could be simple bore wash, caused by lack of spark. Un-ignited fuel pools on the pistons, runs down past the piston rings, washes away the oil and boom your compression is gone.

Don't go chasing the lack of compression without being sure there's nothing else causing this.

Son had a Peugeot 106 with the exact same problem, lack of compression. Car had been stood for around six weeks he tried to start it and flattened the battery. Charged battery, no compression, removed plugs, two or three squirts of oil down each bore, replaced plugs and started straight away. Clouds of smoke and took around five mile drive to clear.
Never gave any further problems until he sold it thousands of miles later

paddedjohn

Just been out for a run and shopping, done about 25 miles altold and she's driving ok and starting on he button. For now I'm going to do nothing to it and in the next 3/4 weeks hopefully trade it in for something different/newer. Thank all for your help.