[bennettboy]

Hi recently bought 1.2 16v with a few faults cheap, one being a misfire below 2000rpm man from AA said it was the coil packs and plugs, so went to town on it new coil pack,new plugs, cleaned throttle housing up, cleared blocked breather pipes, cleaned up EGR valve as was carboned right up but still the darned thing misfires below 2000rpm and no sign of the engine management light :thumbs_up: even though its showing historical codes on the code reader : 1405,0100,0403,0443 and today 0110 but still no management light, any advice would be great as its starting to give me sleepless nights.

bennettboy

 

[davy69]

hi

mate im stumped youve done everything i can poss think of, does the car run ok above 2000rpm.

all i could suggest would be log onto www.vauxhallmechanics.co.uk and post a thread if know-one can help on here.

 

[ash-uk]

Bent valve, water in fuel, ?

The obvious one (D'oh) - change the spark plugs

 

[bennettboy]

Yep changed the plugs for genuine GM ones and the car does go ok above 2000 rpm revs freely, thinking about doing an oil flush and filter change just in case its got a sticking valve as i dont think the previous owner had a scooby about maintenance after the state of the breather pipes and throttle housing

 

[davy69]

hi bennetboy

just seen your thread on vauxhallmechanics thought they would have an idea or two. i just hope what they suggest sorts it out mate.

good luck.

 

[ash-uk]

Yep changed the plugs for genuine GM ones and the car does go ok above 2000 rpm revs freely, thinking about doing an oil flush and filter change just in case its got a sticking valve as i dont think the previous owner had a scooby about maintenance after the state of the breather pipes and throttle housing

Plugs are usually gapped properly, but it does pay to check them out.

I used to get this on my Astra and it was always the leads or rotor arm/cap which gave up every 2 or 3 years

 

[bennettboy]

Hi Guys thanks for the help i've got another MAF and ECU on its way so fingers crossed it'll sort it, i'll post the outcome.

bennettboy

 

[bennettboy]

Well i've just done a compression test and the results are as follows :

Cyl 1: 210psi
Cyl 2: 10psi(yes ten)
Cyl 3: 220psi
Cyl 4: 170psi

So what now? another engine? head gasket? valves? or piece of rag and tin of petrol

 

[ash-uk]

sounds like a holed piston to me. If it had dropped a valve, you would see a lot of swarf in the oil as well as a lot of noise.

Are you running any type of aftermarket exhaust or filter ?

Can you not see the piston crown through the plug hole in the offending bore ?

 

[bennettboy]

Ash can see top of the piston but its well coked up and the oil is ok if a bit on the black side, got a suspician that a valve is stuck as the coking in the egr and the piston was and is heavy, i would of thought that if the piston was knackered the car would run like a tractor all the time but it don't it pulls like a train above 2000rpm and doesnt smoke at all, im going to do an engine flush tomorrow and see if there is any change as if a valve was stuck open it would not allow compression to build...but then what do i know


bennettboy

 

[ash-uk]

If it has not had regular oil changes, an engine flush may make it sound like a bag of nails.

Hydraulic lifters gum up and wear and when this is cleaned off with flush, they can end up rattling. If the valve is sticking, then the seat/valve is going to be scorched. Can you not take the throttle body off and look down the inlet ?

It doesn't sound good

 

[bennettboy]

Yep could take the throttle body off but i think i know what to expect from when i cleaned the throttle housing up earlier it looked like outer space it was that dark and every pipe that breathes was blocked solid, i don't think the kid that had it before me did any kind of regular servicing,

The top end already sounds like a typewriter so if a flush works it wont be a problem, i'll just buy my daughter some ear defenders and tell her is fine or stick some TDi badges on it....lol

 

[Clutch]

My car has a 20k gap since its last service, i used redex to de coke and clean up the engine, and yes the top end did knock, ever since iv stopped using its be quiet and runs sweet as a whistle, just thought id share that with you lol.

Yeah it sounds as if the valves are not sealing, can you tell if its burning oil or not?

 

[ash-uk]

If its stuck, I'd be surprised if its not bent. The heads got to come off to take a proper look TBH

As an aside, my Shogun failed on emissions and I used something called 10k boost to decoke it - ccost £20 a can though, but with a new filter did the trick.

 

[bennettboy]

Clutch, it doesnt appear to be burning oil theirs been no excessive usage it doesnt smoke so that rules the piston ring out( i hope) i personally think it is a valve and looking at the state of the EGR when i took it off would say its an exhaust valve but the way my luck runs it'll be both and they wont free off with flushes and the blasted head will have to come off , Ash where did you find 10k Boost and which filter did you change??


bennettboy :driver:

 

[ash-uk]

10k boost came from Halfords, and it was the air filter, but I take it offroad a fair bit and the old filter was like a hoover bag

 

[bennettboy]

Well one good thing to come out of today is that the MAF i ordered arrived and cleared the fault codes straight away....result! but the 10K boost and engine flush didnt sort the problem out so now its head off time but maybe easier to put another lump in it or even sell it and buy something else.

 

[HOT_TUNA]

1.2 16v Corsa b - MISFIRING?!?

Hi,

I have had my corsa since january. Had No problems until about 3 weeks ago when the ECU (orange) Light came on. i took it to get a diagnostic done on it and it came out saying it was just the EGR valve. Since then it's misfired and juddered under about 2000RPM, and on 'tick-over' Revs high (about 1400RPM, instead of it's old 750/800RPM). I have blanked the EGR off, hoping this would fix the problem, no luck! I've changed the spark plugs, and got a new throttle position sensor but still no luck. The problem is getting worse, really not too sure what to do. I am a student @ college so have very little money, so pouring all this money in is a right pain!

Hope someone can help

CHEERS!!!!!

Tris

 

[taurus]

Welcome to the forum. At least you have searched the old threads for an answer - you must have gone back a long way with this one.

It would be helpful to know which engine you have and how well serviced it has been. The variations across the range mean that not knowing the engine involves a lot of guesswork.

Just a few suggestions though. Firstly, make sure that the EGR blanking plate is well sealed - no leaks.

Secondly, although the fault code said it was the EGR it is worth taking out the idle control valve and giving that a good clean. Tickover problems usually have something to do with that, so it's worth checking.

The next thing to check for would be a vacuum leak on the inlet manifold or the throttle body. Look for any obvious signs of damage. One trick is to get the engine warm and let it idle - then spray WD40 slowly along the joints. If there is a vacuum leak the WD40 is drawn into the system and you will hear the tickover vary slightly.

 

[HOT_TUNA]

Thanks for the response

Tried looking at the inlet manifold and found that the stub to the brake servo was broken so leaking a bit. Sealed up now (so that is one good thing to come out of all of this) BUT it hasn't solved the original problem. But a bit more on it:

Engine is a X12XE (I think) T reg 1.2 16v
When throttle position sensor is off it seems to run fine but as soon as its back on same problem comes back:
After starting engine from cold it is fine for about 30 seconds then goes funny:
At tickover its OK but at about 1500 rpm or so it hunts. Then at higher revs its OK again.

Also, I took of throttle body to get access to sort our vacuum on the brake servo and noticed quite a bit of oil and contamination in inlet manifold. Is that normal or is it likely to indicate an inlet valve problem? Car does burn a bit of oil but not too much and no smoke out the back.

I guess, as it runs OK without the TPS I could just take the easy option and leave the plug out but I'd rather sort it if I can.

Oh yeh, forgot to mention. Car has done about 140k and has had a pretty hard life by the look of it.