Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: rastiman on 15 October 2010, 14:31:35

Title: Lumpy tickover and poor low rev performance
Post by: rastiman on 15 October 2010, 14:31:35
Hi all

Another question Im afraid  :-/ My 2.5 V6 Mig has always had a lumpy tickover, which is shaking the car at approx 500-600rpm. If I switch the manual aircon on, the revs pickup to approx 700rpm and it's fine. I've had the ICV off, checked, cleaned with carb cleaner, dried, oiled and put back but no difference There is no problem with revs being held high before dropping down etc.

Re the lack of power, if I blip the throttle, the revs momentarily drop before picking up. With the bonnet open, there is a short sound from the induction system similar to escaping air being suddenly cut off. Sometimes it might backfire slightly.

If I need to pull out of a junction a bit quick, it feels like the engine is being strangled until about 4,000RPM, when the multi-ram kicks in.

Im wondering if the timing is out - it's due a replacement as the time period is up in April next year.

Any thoughts gratefully received on these two issues please guys!
Title: Re: Lumpy tickover and poor low rev performance
Post by: bigdods on 15 October 2010, 15:10:57
I have always had to switch the aircon to auto when sat in traffic to keep it ticking over. In ECO it would bounce between 300 and 500 and almost stall. Then Daz came along and changed my cambelt. Problem has disappeared. I am guessing the timing was out.

Now idles at 600RPM with Aircon in AUTO and 500RPM in ECO , smooth and even  :)
Title: Re: Lumpy tickover and poor low rev performance
Post by: TheBoy on 15 October 2010, 15:33:59
The revs are too high, which makes me think you have an airleak, or some retarded thicko mechanic has buggered about with the throttle butterflies.

I'd do a full breather clean, and at same time check for airleaks and that the throttle fully closes.
Title: Re: Lumpy tickover and poor low rev performance
Post by: rastiman on 15 October 2010, 17:24:34
Thanks guys, the "garage" (and I use the term losely) that serviced the car before I owned it obviously didnt have a clue when it came to Omega V6's.
When I get the cambelt done, I'll get the breather pipes rechecked, and that the throttle fully closes.
There were no fault codes, so it must be something along those lines....