Ok so I am hoping this is not the start of a gearbox problem.....

(2004 4.4V8 Petrol vogue - 90K miles on the clock)

At low'ish (less than 2K revs) speeds and only very occasionally I am getting a judder like going over rumble strips etc - if I put my foot down and accelerate the rumble goes (to be replaced with a very pleasant V8 rumble).

No problems at all with gear changes or an delay in selecting gears or drive.

Car just feels ...sluggish (sorry only way I can describe it) - Engine just feels like its not having a good day. When its good its smooth as silk and at the moment it is not smooth.

Thought it might be a failing MAF so have replaced that - car is regularly serviced at main dealer.

Not had the gearbox oil changed but other than that what would you lot recommend I check to try to narrow down the issue.

thanks
Simon "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

Had similar problems.

First thing to do will be to get it on a diagnostic tool to check which fault codes it show.

In my case it was p0174 - a misfire on cylinder 4. We found that the spark plug coil on no 4 was fubar and after replacing that, she is as smooth as ever, if not better.

In addition we also replaced the petrol filter, air filter and spark plugs, which due to the misfire and lean running, caused the plugs to wear out much faster than it should have. The vehicle was serviced 3000 kms before the misfire started.

Thanks for that - one question - do I have to go to the dealer to get the codes read or can they be read via the OBDII and a suitable app? (app recommendations welcome)

-Si

EDIT - answered my own question as I had forgotten I already have an RSW Allcomms.....just don't use it often. "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

Does it surge when held on rake at lights etc?

No it doesn't surge. It behaves itself in every way apart from the feeling it is running lumpy occasionally. "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

Right just got an app to read a code whilst the car was idling.

P0160 oxygen sensor 2 bank 2 no activity detected.

What's that then? "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

http://www.obd-codes.com/p0160 ... - .- -.




Y. O. L. O.
.

Hooked up AllComms and read all stored codes - cleared them and rechecked with the engine running. Now there are no errors appearing. Will have to run the car around tomorrow and see what turns up. "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone

Its whats sometimes referred to as a lambda sensor. Some vehicles have them before & after the catalytic converter. The one before the cat (No1) monitors whats coming out the exhaust & sends this info to the cars ecu & alters the mixtures. The No2 sensor is after the cat & is used to monitor the condition of the catalytic converter by allowing the ecu to see the difference in the two readings. It does not affect the running of any vehicle I know of apart from possibly putting the engine management light on with a fault code alerting you to the fact the cat is knackered Worse things happen at sea! Well thats what swmbo said when WRENS came to sea!!!

Not had any engine management lights ever on this car. "On first name terms with my local Dealer......now."

'61 Plate 5.0SC Autobiography - in Black ——— Gone
'53 plate 4.4V8 Vogue Bonatti Grey inside and out. ----- Gone