4.8is Misfires

[Abid]

Hi All,


I have owned a X53 4.8is 54 plate since 2010, soon after buying the car I noticed that from time to time I would see the engine management light flash on when started in the morning and it would judder for a while but once it was driven 100yrds the light would disappear and all is fine.

I then had the car checked by some indy's a few times with no problem found except misfire registered on certain injectors. But again the fault was and is intermittent and they couldn't force the fault so no repair was ever carried out.

The car has since been gas converted and has done 40000 miles in 2 years on gas no problem before being parked up, only thing I noticed during the 2 years of daily use was that the car would smoke whilst at the lights or stationary.

I am now looking to sell the car and would like to see if anyone on the forum knows what could be causing the misfire which was there before the gas conversion and hasn't become more often or less since the conversion.

Also is the smoke caused by the gas conversion or is to related to the intermittent engine management light that appears some mornings?


Thanks

[kkx5]

Misfire-valvetronic
Smoke-valve seals

[Abid]

[quote="kkx5"]
Misfire-valvetronic
Smoke-valve seals
[/quote]

Thanks

Is that an expensive job?

[kkx5]

Yes, very...

[Turks]

I had all mine replaced under Warranty. I had exactly the same issue. It solved the problem but it can sometimes be rough on first start-up on a cold damp morning.


Turks.

[Raj]

On start up on these cold mornings mine does judder White badly and the engine light flickers on. A little more refs for about 10seconds as soon as I start it usually keeps it at bay and then all fine.

The smoke is the valve stem seals most likely. A big and costly job for sure at around £2.5-3k