T5 misfire - bent rod?

[Mr Tea]

Garage just phoned me, told me that my '95 850 has failed it's MOT due to emissions. They said that it has a misfire (I only noticed it about a week ago when it chugged into life and almost stalled) where one cylinder isn't combusting properly and dumping a load of fuel out of the back.

I'm hoping it is a mucky spark plug, they've tol'd me that they will do a compression/leak test to check that it is nothing serious, but I'm worried I might have somehow bent a rod - would that cause these symtpoms?

Cheers

[Skodaku]

Couple of things :

o What makes you think you've bent a con-rod ?

o If you had, somehow, I think it might just show up in other, less subtle, ways.

Look on the bright side. Probably something simple.................sincerely hope so.

[Mr Tea]

Skodaku said:

Couple of things :

o What makes you think you've bent a con-rod ?

o If you had, somehow, I think it might just show up in other, less subtle, ways.

Look on the bright side. Probably something simple.................sincerely hope so.

Nothin makes me think it, just thinking worst-cxase scenario. My hope is for a mucky spark plugs...

[Rockatansky]

They will still run with a lightly bent rod, but unless you have specific reasons to suspect you've bent a rod then I guess you won't have.

Are you running an MBC per chance, or a poorly written map? - these *could* contribute to a rod bending episode.

It might be an injector that is misfiring or clogged, as these are routinely neglected.

Get your injectors out (easy job) and send them to this guy. If you live near Blackburn then go and see him, he'll do it while you wait.

While you're waiting on them coming back, replace the fuel filter - it often gets overlooked too.

Good luck.

[Mr Tea]

The garage told me that it is running very rich (and my nose told me that too) so I do not think that injector/fuelling is the answer.

It kind of chugged into life and the idle dived, that is the only real sympton but I'm nit sure what it would indicate? It also improves slightly once warmed up...

Ta

[Rockatansky]

What engine is it?

Has it tripped the Lambda/fault light? - if so, what are the codes?

Could be so many things...

Try disconnecting the MAF to see if it runs any better, could be a knackered MAF.

Don't rule out injectors, one or more could be overfuelling (stuck open).

You could also try having a look here: http://www.volvoforums.org.uk/

[Mr Tea]

Stuck open, could be. I wouldn't expect it to be ruinning so rich with a faulty MAF, however could be a possiblilty... I have no lambda light so maybe not a MAF? I will call them in the morning to see progress and if any fdault codes up etc.

Not registerred on the Volvo forum, I thought it got shut down? (and was sneakily looking for answers for this whilst at work....)

[Rockatansky]

Mr Tea said:

Not registerred on the Volvo forum, I thought it got shut down? (and was sneakily looking for answers for this whilst at work....)

It was shut down for a while, but is now back up in all it's glory

I don't *think* you have to be registered to browse, you might be lucky and stumble over a similar thread.

If it's a T5 variant then you could also try http://forums.t5d5.org/ - not the busiest forum, but a very knowledgeable/helpful bunch.

[Mr Tea]

For completeness, cleaned plugs, checked gaps. Ran some 'treatment' through the fuel and all is tickety-boo. I think I probably clogged up the plugs by driving everywhere in 5th....

[F i F]

Well there you go, the good old Italian tune up would have worked wonders. Can't beat it plus added fun element.

[Mr Tea]

I go through two sets of fronts a year as it is, I can't afford to give it any more beans!