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Vauxhall Astra 1.4 DOHC 2004 - Intermittent misfire, code P0304 cylinder No 4 #

Posted by Peter Igo on February 25, 2010, 2:01 pm

Year of Manufacture *: 2004
Engine Code or CC *: 1400 DOHC
( Optional ) Scanner Used: socio

The above vehicle suffers from an intermittant misfire when drive from cold. I have a P code of P0304 cylinder number 4 misfire. I have changed the coil pack and the spark plugs and the dayafter the vehicle was fine, however the fault has reocured this morning and the fault code is back.
Any pointers please.
Thanks

Re: Vauxhall Astra

Posted by Dave Harney <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2603' width='330' height='300' border=0 style='border:none;'> on February 25, 2010, 2:06 pm, in reply to "Vauxhall Astra"
Dave Harney

Hi Peter,
Have you checked the mechanical "efficiency" of cylinder 4 - compression etc
Does this engine have the EGR adjacent to cylinder 4 ? possible EGR fault !

Regards
Dave

You can trim a sheeps wool many times, but you can only fleece it once !

Re: Vauxhall Astra

Posted by Peter Igo <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1886' width='330' height='300' border=0 style='border:none;'> on February 26, 2010, 7:01 pm, in reply to "Re: Vauxhall Astra"

There is no EGR valve on this vehicle (or we can't find one) and all compressions are fine, it does (so the customers says) consume some oil.
Any thoughts?
Perhaps I should check the coolant temp valves on warm up as the misfire only occurs on the first journey of the day?

Re: Vauxhall Astra

Posted by Tony Sefton <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5581' width='330' height='300' border=0 style='border:none;'> on February 26, 2010, 7:27 pm, in reply to "Re: Vauxhall Astra"
Tony Sefton

Sticky Valves.

Give it a good engine flush and carefully suck some brake fluid into the manifold through a small vac pipe. ( about half a litre or so )

give it a good hard test drive and if it hasn't blown up by that time, and the smoke has cleared it should be ok.

H.T.H. Tony.

Re: Vauxhall Astra

Posted by dave cheesman <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1314' width='330' height='300' border=0 style='border:none;'> on February 27, 2010, 2:52 pm, in reply to "Re: Vauxhall Astra"
Dave Cheesman

Hi Peter
What is the vac doing? I have had a couple do this, 1 was a sticky inlet valve and the other had a pin hole in the servo pipe. I found both by using a vac gauge.

Dave

Re: Vauxhall Astra

Posted by Duncan Ferguson <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=ukat3008' width='330' height='300' border=0 style='border:none;'> on April 12, 2010, 9:44 pm, in reply to "Re: Vauxhall Astra"
Duncan Ferguson

It will be related to the EGR valve and your car will have one fitted somewhere! If its the X14XE its tucked down under the inlet manifold. Changing it (held on by 2 torx head bolts) is a bit of a pain, quite tight against the manifold.

Am I right in assuming the car has a light misfire/shudder if driven about 40mph in top gear too?

The EGR valve carbons up enough to allow a minor leak which the lambda sensor picks up. As the engine heats it seals up the gap.

Had a few like this. Usually driven by elderly drivers who cover low mileages at low revs. Causing the carbon to build up.

Sticky valves tend not to throw up codes (although the fuel system cleaner method mentioned above does help if it were that)

Re: Vauxhall Astra

Posted by roy ritchie <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5115' width='330' height='300' border=0 style='border:none;'> on April 13, 2010, 10:33 pm, in reply to "Re: Vauxhall Astra"

(Sticky valves tend not to throw up codes)

Since when?? Sticky valves do throw up codes.

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