Missfire hell - Astra 1.4 2001

h57xiucj2z946q

Im posting with very little mechanical knowledge of cars:


In 2006 near winter time my car started to missfire. It caused a light do come on, on the dash board. Some times then it could missfire badly, the light would flash.

After a week or two of this, I took it to an Opel garage. They hooked it to their computer and said they need to replace the coil or "plug bar" as they called it.

Everythings grand for a few weeks, then it starts to missfire again, bring it back, and they load some treatment into the fuel and say drive around hatrd in 4th gear for a while. Week later - missfire, bring it back, they now say they have to take the head of the engine to clean gunk around valves, say it'll be at least €500 to take the head of alone, as you can imagine I said no. I got a bottle of fuel treatment that apparently frees up "sticky valves" and it didnt erally make a different. Eventually the problem resolved itself, the car stopped missfiring around mid February 2007.

Now January 2009 missfiring came back, in February I got sick of it and because I have no mechanical bacground, I was afraid I could be doing more damage so brought the car to another private mechanic. Read a missfire in cylindar 2+4. He assured me it was the coil gone again. Replaced that and replaced plugs. more €€€, few weeks later, car miss fired again. Brough it back and he read with computer and says it reported a missfire in cylindar 4, cleared fault and said to come back when it miss fires again. Now the car hasn't missfired again until now (September 2008)!!

I have begun to notice a pattern, like if you drive the car hard without the engine fully heated, like when I leave work, I have to enter a dual carrigeway/motorway.

Another funny thing I noticed is that if my car is missfiring when I accelerate, If i turn of the ignition for about 10-20 seconds, start it again and accelerate, the car wont missfire.

Does anyone have any idea how to solve this, I already have spent so much money on this with no results...





Happened again this morning.

Driving around 60mph without the engine been warm.

Fault Code is always P0300

pyramuid man

dont worry. You have another 3 months till Jan 09.

You could try googling the error code

furtzy

Simple google turn up this

http://www.obd-codes.com/p0300

few things to look at listed there

h57xiucj2z946q

I have already googled the code. but i dont know what to do.

garage man already said it was p0300 multiple cylinder miss fire. replaced coil twice and set of plugs.
I dont know what else to try. Im thinking Coolant Temperature Sensor.

E92

Surprised nobody has looked at the EGR valve, it seems to be a fairly common problem with petrol Opels.

EGR valves and coil packs seem to be the most common problems with the 1.4 for some reason.

VAG 1.8 turbos were notorious for coil problems too.

h57xiucj2z946q

What would you try next E92?

Esel

Lucifer is the man for this! I'll PM him.

h57xiucj2z946q

Thank you esel.

Lucifer

Hi, only seeing this now as I'm just in from work.

Ok, about 95% of missfires on your engine are caused by coil packs but seeing as you have replaced yours twice for the time being we will rule this out (although it is possible that it is the coil pack could be giving trouble this time,but by the sounds of your problem I doubt it is)

EGR Valves do give trouble but the usual symptoms of this would be hard starting, irractic idle, power loss. Does your car do any of these things? I doubt it is EGR trouble as you should have the trouble code P0400 when you have these problems.

I would doubt it is the coolant temp sensor as I have never seen one give trouble on this engine.

Sticky valves could be possible as the astras do sometimes suffer from this and could cause a missfire/lumpy idle. This could explain why it resolved itself for a while after you used the fuel treatment but has eventually come back. To completely cure this it would be necessary to remove the head and have it overhauled and decoked. Another solution that may help cure it that we sometimes try is by using a treatment that is injected into the inlet manifold while running the engine. Can sometimes solve it but not always. You could also try another fuel additive, BG are a good brand.

Its also possible that this could be caused by an injector sticking. They dont usually give trouble but its always possible. This could be diagnosed by checking the emissions when it is missfiring.

Let us know more info and we will try to help more.

Darragh29

I'd check the connection plug & cable to the coil pack. I had an annoying problem with the same car as yours about a year ago. The customer was complaining of a misfire initially but kept driving the car and eventually the car wouldn't start. It took a while to diagnose this one, this Astra we had was the type where the cat is vertically located just immediately below the exhaust manifold. What had happened was the cat had started to disintegrate and lumps of the active charcoal like material inside the cat were coming out of the matrix inside the cat and falling down vertically, eventually blocking the flow of exhaust gases leaving the engine. This effectively stopped the engine being able to breath, after a few misfires, the engine would just shudder to a stop.

We identified this by removing the lambda sensor and then the engine ran fine, no misfires and no cutting out but the exhaust gases were leaving the engine via the hole for the lambda sensor, so we had to replace the cat and that sorted out the problem.

I'd check if your car has this type of cat and also maybe remove the lambda sensor and check the engine with the car stationary to see if it is still misfiring...

Johnathon

Make sure all of your plug wires are good. Also check that they are on the coil pack securely and on the spark plugs good. Also make sure they arn't mixed up and are going where they are supposed to go.

Dirty_Diesel

The main problems I've heard of those 1.4 engines is coil packs, fuel pump and crank sensor.