As my car was lacking power/hesitating acceleration & misfiring, I did an oil flush & spark plug change in my vauxhall, changing the oil from a mineral to a part synthetic 10W-40 Castrol Magnatec and the spark plugs from NGK to Bosch Super 4.
However, the problem still persists - I checked the spark plugs 2 weeks later & all were slightly sooty and one was oily.
I also added STP fuel injector to the petrol tank to clena out the fuel system.
Do u think I should do a compression test or could there be a problem with the choice of oil & spark plug?
I went to Vauxhall for a diagnostic check which was fine.
Please help.
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The choice of plugs *might* be part of the problem. There's been previous mention here of using only Vauxhall[1] plugs for the best performance.
[1]Which are/were made by AC Delco (I beleive) and rebranded with the Vauxhall logos.
My Dads Astra recently had the occasional misfire, diagnostic checks revealed nothing. A while later the ECU light came on when the misfire got worse, and the fault was traced to a couple of faulty coil packs and then several days later a faulty lamba sensor.
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Top cookies these dealers huh? As I have said before they place too much reliance on DTCs (Diagnostic Trouble Codes) rather than thorough structured diagnostic testing. Having said that I always check for stored DTCs as a first port of call and note any present and use this info as part of the procedure before erasing them from the memory.
Back to your problem, I personally dont rate the Bosch super 4 plugs, use NGK BKR6EK or the equivalent GM plug, Your problem could be a number of things from failing coil pack, open circuit HT leads, air leaks, failing Air Mass Meter, coolant temp sensor, Lambda (oxygen) sensor etc etc. Unless you are a competent DIYer with access to some test equipment youd be best advised to find a competent independant to sort it for you.
Andrew
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Simplicate and add lightness!!
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Top cookies these dealers huh? As I have said before they place too much reliance on DTCs (Diagnostic Trouble Codes) rather than thorough structured diagnostic testing. Having said that I always check for stored DTCs as a first port of call and note any present and use this info as part of the procedure before erasing them from the memory. Back to your problem, I personally dont rate the Bosch super 4 plugs, use NGK BKR6EK or the equivalent GM plug, Your problem could be a number of things from failing coil pack, open circuit HT leads, air leaks, failing Air Mass Meter, coolant temp sensor, Lambda (oxygen) sensor etc etc. Unless you are a competent DIYer with access to some test equipment youd be best advised to find a competent independant to sort it for you. Andrew -- Simplicate and add lightness!!
I've bought a draper compression tester. Would u know the acceptable compression numbers for this car? I will change the spark plugs to a vaux branded ones.
The Ignition module looks fine & unlikely to be damaged as it comes as a one-piece.
Don't the diagnostic checks point out failing sensors? I think they did a servo 2 test.
Is it normal for spark plugs to get oily when the oil is replaced?
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The Ignition module looks fine & unlikely to be damaged as it comes as a one-piece.
Looking fine is one thing, working correctly is another.
Don't the diagnostic checks point out failing sensors? I think they did a servo 2 test.
Not all diagnostic tests (in this case, Tech2) find faults. Sometimes it's down to how qualified and experienced the technician is to be able to spot faults.
Is it normal for spark plugs to get oily when the oil is replaced?
No, it's not normal. Are you 100% sure you haven't put too much oil in when you changed it?
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yes, i'm pretty sure that i drained all the oil followed by putting in exactly 3.25 litres which is the sump capacity.
i also constantly checked the dipstick which showed aaa correct reading i.e. between the MIN and MAX mark.
Only one of the spark plugs is oily - the rest r all fine.
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The choice of plugs *might* be part of the problem. There's been previous mention here of using only Vauxhall[1] plugs for the best performance. [1]Which are/were made by AC Delco (I beleive) and rebranded with the Vauxhall logos. My Dads Astra recently had the occasional misfire, diagnostic checks revealed nothing. A while later the ECU light came on when the misfire got worse, and the fault was traced to a couple of faulty coil packs and then several days later a faulty lamba sensor.
I will try and change the sspark plugs to vauxhaall branded ones. this should work hhopefully. will keep u posted. thanks.
is oil on the spark plugs a normal thing?
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Hi,
No, oil on the plugs isn't normal - there may be a more serious problem here.
For the compression test, look for consistent values first. So, if you get one cylinder with notably lower compressions than the others, you are on to something.
number_cruncher
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You're not confusing "oily" with maybe soaked in petrol are you. Change the plugs around, i.e. swap cylinders, and see if the same cylinder gets "oily" or if the plug still gets "oily" when it's in another cylinder. If the latter, then it's just a duff plug. If the same cylinder gets "oily" again then check whether it's petrol or oil on the plug. If it's petrol you could have a faulty coil pack, if it IS oil then it could be piston rings, a holed piston (accompanied by pressure in the rocker cover) or very worn valve guide or stem, which probably means a new engine.
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What is a coil pack? Does it cost a lot to replace? Thanks
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What is a coil pack?
From what I understand of it, rather than having just one coil connected to a distributor and then going off to the 4 plugs, each plug has it's own coil - hence making your Astra a distibutorless ignition system. Somone more technical will be along shortly to correct me and explain in more detail.
Does it cost a lot to replace? Thanks
Having a quick butchers on Ebay, you're looking at over £150 from Vauxhall.
tinyurl.com/4juot
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Hello aagain - i haven't had a chance to change those spark plugs as yet but this morning on the way to work the car revved uncontrollably twice for a min before settling down and i can hear a constant tick-tick noise coming from the engine when its idle.
What do u think this might be given all the recent problems? Any suggestions?
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Pleaase can someone help..
i haven't had a chance to change those spark plugs as yet but this morning on the way to work the car revved uncontrollably twice for a min before settling down and i can hear a constant tick-tick noise coming from the engine when its idle.
What do u think this might be given all the recent problems? Any suggestions?
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Hi, mishmash
Is your car a G reg or 1998?
If its 1989 G reg, then isn't it carburetor & breakerless ignition with standard distributor?
These engines seem to suffer from problems in the top end if the oil hasn't been changed often enough.
Does the ticking sound electrical (like a spark) or mechanical?
Sounds like it might be a combination of things.
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oops just read 16v. I guess it is the 98 then.
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Any suggestions anyone? Looks like the ticking sound increses when I hit the accelerator pedal. Please help. Thanks.
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Ticking sound could well be leaking exhaust manifold, either gasket or manifold itself. Common failing is the stud immediately adjacent to the thermostat housing. Another cause for ticking sound could be an HT spark jumping around, could explain your misfire. Dont leave it too long before getting it sorted or you could well trash the cat.
Andrew
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Simplicate and add lightness!!
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Ticking could also be failing hydraulic lifters/or tappets to you..Though would go with last post.
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Steve
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I have now had a look at the spark plugs, changed them around & there seems to be a leak on only one cylinder as that one makes the spark plug oily - the others being fine.
Does anyone know any good/reeasonable mechs around northwest london who can have a look at this and sort it out?
I think its a case of changing the valves or tappets (as the ticking noise carries on) and general lack of power but no misfiring.
Please help.
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Ticking noise, plus oiling up on one cylinder sounds to me like it's broken a piston ring. It might be possible to drop the sump and pull the offending piston out the bottom past the crank shaft - but you might sill be looking at an engine rebuild or replacement.
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RichardW
Is it illogical? It must be Citroen....
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