Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: lee4206 on 23 August 2007, 21:50:16

Title: VERY LOW MPG
Post by: lee4206 on 23 August 2007, 21:50:16

Does anyone have any ideas why my 98 2.0 gls manual only does abouut 18-20 mpg around town after head gasket change.  Its done 104k serviced every year had new cat and exhaust head was skimed new valve stem seals etc lambda sensor checked and working emmisions well below mot standard at idle and 3000 rpm.
Any help or advice very welcome  

lee
sorry should have mentioned that before head gasket went i was getting 28-30mpg

Title: Re: VERY LOW MPG
Post by: TheBoy on 23 August 2007, 22:04:23

Cams properly timed?

Title: Re: VERY LOW MPG
Post by: lee4206 on 23 August 2007, 22:09:16

Quote

Cams properly timed?

all marks lined up exactly as it was before

Title: Re: VERY LOW MPG
Post by: JamesV6CDX on 24 August 2007, 01:08:28

Low MPGs following the head re-fit... I would check

1) Cam timing is spot on (But you've already done this)

2) Vacc setup ok? No air leaks?

3) All appropriate sensors plugged in correctly. Including the o2 sensor, and especially the coolant temperature sensor, at the rear driver side of the engine. The CTS tells the ECU how hot the engine is, so if the engine is not getting a signal from this sensor, it will run rich

4) Crankcase breather system clear?

5) look at the condition of the plugs. Do they appear to be black and dry?

6) Do you have any fault codes stored?