Ive just been to look at my sisters Z10XE corsa. The complain was a scratchy sound when accelerating and feels like its going to stall so ive just been to look at it.
First thing was a code check - no codes on pedal test - didnt have laptop with me
Checked oil - just below minimum so ive added another litre
Started the car and its probably best described a a clackety sound when you rev it. Now the chain been rattling for years and although you can hear the chain rattling this is a slightly different noise to the normal rattle from it. There is no rattle when driving at constant speed or idle -other than normal rattly camchain. The noise only comes when you either rev it to drive off or rev it when stationary. The noise only lasts a second or 2 and its gone. It sounds like its coming from the back of the motor more towards the chain.
Ive had a feel of the motor and it appears to have maybe a slight missfire although it is a 3 cylinder so I might be going down the wrong path with this. exhaust note also doesnt feel 100% smooth when you hold your hand in front of the tailpipe - could someone confirm if it should feel smooth. My feeling is it should.
Ive pulled the plugs out and they all looked pretty black and old - the car never gets warm and does 2 mile each way to work.
After a quick drive its apparent that its reluctant to pull away which may back up my ideal of a slight missfire, its abnormally slow. Its more airbox noise they go lol - Maybe timing issue
Ive ran a compression test on it on a cold engine with WOT and results were:-
Cylinder 1 = 160
Cylinder 2 = 175
Cylinder 3 = 185
So compression is a bit low but it was a cold engine. (spec is 203psi min)
Ive performed a basic coilpack test using a test lamp and all 3 were capable of jumping the spark 15mm+ but the battery started to go flat so didnt try any further.
So this is where I am at with it now. Ive asked her to drop the car off tomorrow where ill have a few hours on it tomorrow with my tools and hopefully come up with some answers.
I think ill also throw a vac gauge on the inlet and check for a clogged cat/timing
I think ill repeat the compression test on the engine with it hot @WOT. If compression is still low I think im going pull the camcover off and check the timing hasnt jumped a tooth.
If timing looks good then im gonna pull the scope out and see whats happening with primary ignition just to rule out the missfire. Im thinking that maybe the noise when you first accelerate could be a missfire which is causing the chain to abruptly slap the casing creating a different noise than normal. Maybe im barking up the wrong tree with this one but a easy check.
Ill obviously be checking out the MAF as this is the original from new with 100k on it.
Ill get some live data from it tomorrow when she drops it off and see if anything jumps out at me.
Ill throw a set of plugs in it too because ive got them in stock lol
Any more suggestions gratefully received.
First thing was a code check - no codes on pedal test - didnt have laptop with me
Checked oil - just below minimum so ive added another litre
Started the car and its probably best described a a clackety sound when you rev it. Now the chain been rattling for years and although you can hear the chain rattling this is a slightly different noise to the normal rattle from it. There is no rattle when driving at constant speed or idle -other than normal rattly camchain. The noise only comes when you either rev it to drive off or rev it when stationary. The noise only lasts a second or 2 and its gone. It sounds like its coming from the back of the motor more towards the chain.
Ive had a feel of the motor and it appears to have maybe a slight missfire although it is a 3 cylinder so I might be going down the wrong path with this. exhaust note also doesnt feel 100% smooth when you hold your hand in front of the tailpipe - could someone confirm if it should feel smooth. My feeling is it should.
Ive pulled the plugs out and they all looked pretty black and old - the car never gets warm and does 2 mile each way to work.
After a quick drive its apparent that its reluctant to pull away which may back up my ideal of a slight missfire, its abnormally slow. Its more airbox noise they go lol - Maybe timing issue
Ive ran a compression test on it on a cold engine with WOT and results were:-
Cylinder 1 = 160
Cylinder 2 = 175
Cylinder 3 = 185
So compression is a bit low but it was a cold engine. (spec is 203psi min)
Ive performed a basic coilpack test using a test lamp and all 3 were capable of jumping the spark 15mm+ but the battery started to go flat so didnt try any further.
So this is where I am at with it now. Ive asked her to drop the car off tomorrow where ill have a few hours on it tomorrow with my tools and hopefully come up with some answers.
I think ill also throw a vac gauge on the inlet and check for a clogged cat/timing
I think ill repeat the compression test on the engine with it hot @WOT. If compression is still low I think im going pull the camcover off and check the timing hasnt jumped a tooth.
If timing looks good then im gonna pull the scope out and see whats happening with primary ignition just to rule out the missfire. Im thinking that maybe the noise when you first accelerate could be a missfire which is causing the chain to abruptly slap the casing creating a different noise than normal. Maybe im barking up the wrong tree with this one but a easy check.
Ill obviously be checking out the MAF as this is the original from new with 100k on it.
Ill get some live data from it tomorrow when she drops it off and see if anything jumps out at me.
Ill throw a set of plugs in it too because ive got them in stock lol
Any more suggestions gratefully received.