Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Owen on 10 July 2007, 12:03:32

Title: Comsumption!
Post by: Owen on 10 July 2007, 12:03:32
After doing the breathers, icv, rocker gasket, multirams, oil filter and oil, air filter,  and all the gaskets between, consmption is at 18 >:(
And thats driving it grandad stylie!
Shes a 2.5 auto, and I know the auto's are a little juicy to run bit 18mpg? That cant be right. My 3ltr Elite used tol do 26 at average driving round here!

So anyone any ideas? what I could have missed, or what else might be wrong??? :(
Title: Re: Comsumption!
Post by: Marks DTM Calib on 10 July 2007, 12:14:05
I would say that you have an air leak.....
Title: Re: Comsumption!
Post by: Markie on 10 July 2007, 12:16:21
tighten everything ensure everything is sealed ( in other words retrace your steps)

Is it lumpy when blipping throttle and under bonnet is it at all gasping ( air leak)

It wont be serious, but its also not right.
Title: Re: Comsumption!
Post by: Abiton on 10 July 2007, 12:52:32
Could it be that your coolant temperature sensor's on the way out? What's 'she' like to start when hot?

If the CTS is reading a lower engine temp than reality, the ECU will overfuel and consumption will gradually get worse until the sensor reads out of range and you get fault lights coming on.  Hot starting ought to worsen as the discrepancy between reality and sensor reading widens (if it's a gradual sensor death).    
Title: Re: Comsumption!
Post by: Owen on 10 July 2007, 13:18:52
Quote
tighten everything ensure everything is sealed ( in other words retrace your steps)

Is it lumpy when blipping throttle and under bonnet is it at all gasping ( air leak)

It wont be serious, but its also not right.



Im not sure if theres a hissing or not, my hearing aint what it used to be! :-[
But it isnt lumpy when blipping the throttle, or on hot start.
If it has any bearing first thing in the morning when its cold it has stopped starting on the first turn. Never touch the throttle when I start her cold, but ita ushally the 3rd turn when it starts!!
Title: Re: Comsumption!
Post by: Abiton on 10 July 2007, 13:45:29
Seriously grotty spark plugs?
Title: Re: Comsumption!
Post by: JamesV6CDX on 10 July 2007, 19:40:02
Martin spoke of a failing crank sensor affecting his comsumption...
Title: Re: Comsumption!
Post by: Owen on 10 July 2007, 19:56:33
Quote
Martin spoke of a failing crank sensor affecting his comsumption...


Would the crank sensor affect consumption that much?
Title: Re: Comsumption!
Post by: Mike Collins on 10 July 2007, 21:58:25
Don't know about fuel consumption, but crank sensor change certainly fixed my wife's 2.5 not starting first turn. No eml, just 19? stored.
Title: Re: Comsumption!
Post by: TheBoy on 10 July 2007, 22:00:57
Quote
Don't know about fuel consumption, but crank sensor change certainly fixed my wife's 2.5 not starting first turn. No eml, just 19? stored.
A 19 is always a bad sign. If you get a 19, change crank sensor immediately.
Title: Re: Comsumption!
Post by: cem_devecioglu on 10 July 2007, 22:48:10
Tired lambda sensors also will effect..even thermostat effects (specially in winter)

And there are others..
Title: Re: Comsumption!
Post by: cdx25 on 10 July 2007, 22:55:56
Quote
After doing the breathers, icv, rocker gasket, multirams, oil filter and oil, air filter,  and all the gaskets between, consmption is at 18 >:(
And thats driving it grandad stylie!
Shes a 2.5 auto, and I know the auto's are a little juicy to run bit 18mpg? That cant be right. My 3ltr Elite used tol do 26 at average driving round here!

So anyone any ideas? what I could have missed, or what else might be wrong??? :(

Wellll, mine (2.5 auto) runs smoothly.  No rough running or misfire.  New crank sensor this year, new exhausts from Cats back, breathers cleaned out and no evidence of any air leaks...

And I get 17-18 mpg round town!!!  It does creep up to 30-32 on a motorway run.

Jon
Title: Re: Comsumption!
Post by: Martin_1962 on 10 July 2007, 23:08:43
Quote
Quote
Martin spoke of a failing crank sensor affecting his comsumption...


Would the crank sensor affect consumption that much?

Odd but true about 1 or 2 mpg difference
Title: Re: Comsumption!
Post by: cem_devecioglu on 10 July 2007, 23:09:22
from the conversion I get 23.54 mpg around the town ..This is average for last 3 months..(road computer)

mine is 2.5 auto ..

PS: EGR blocked
Title: Re: Comsumption!
Post by: Owen on 11 July 2007, 09:28:50
Quote
Quote
Don't know about fuel consumption, but crank sensor change certainly fixed my wife's 2.5 not starting first turn. No eml, just 19? stored.
A 19 is always a bad sign. If you get a 19, change crank sensor immediately.



19 is all thats coming up, so i recon I should go and get meself a crank sensor. But I seem to remember there being 2 types as Timbuk mentioned a few weeks ago when he was changing his! I recon with my car being a 97 its gonna be the older type.
Title: Re: Comsumption!
Post by: nemesis_v6 on 11 July 2007, 09:35:06
if the crank sens cures the proplam happy driving if not i used card cleaner to test for air leaks spray around intanke pipes when the revs pick up  i tighted up the jubile clip hope this helps
Title: Re: Comsumption!
Post by: Owen on 11 July 2007, 12:07:08
Recon I might have found the air leak! Had the wife use here 2 good ears on listening for a hissing!

There is either a sucking/blowing comiing from the side of the breather box as shown in the picture! And as Im going to the scappy thisafters will see it there an airbox there and try that! ;)

(http://i204.photobucket.com/albums/bb53/trooper30/airescaping.jpg)
Title: Re: Comsumption!
Post by: Owen on 11 July 2007, 15:45:36
New one on, took on 10 mile run, consumption still the same! >:(
Title: Re: Comsumption!
Post by: TheBoy on 11 July 2007, 18:45:55
Quote
Recon I might have found the air leak! Had the wife use here 2 good ears on listening for a hissing!

There is either a sucking/blowing comiing from the side of the breather box as shown in the picture! And as Im going to the scappy thisafters will see it there an airbox there and try that! ;)

(http://i204.photobucket.com/albums/bb53/trooper30/airescaping.jpg)
You need a gasket that goes underneath. Again, if you need one in hurry (Crownhill normally dont stock), I have one in garage.
Title: Re: Comsumption!
Post by: TheBoy on 11 July 2007, 18:46:37
Quote
Quote
Quote
Don't know about fuel consumption, but crank sensor change certainly fixed my wife's 2.5 not starting first turn. No eml, just 19? stored.
A 19 is always a bad sign. If you get a 19, change crank sensor immediately.



19 is all thats coming up, so i recon I should go and get meself a crank sensor. But I seem to remember there being 2 types as Timbuk mentioned a few weeks ago when he was changing his! I recon with my car being a 97 its gonna be the older type.
That crank sensor WILL let you down. Been there, done that  :-[
Title: Re: Comsumption!
Post by: Owen on 11 July 2007, 20:05:29
Crank sensor! Its on the list for thursdays scrapy visit!

Saying as Im gonna take 2 or 3 of them from the scrapy (well ones gotta work) is there a quick and easy method for getting them out bearing in mind I dont have to be carefull with it and can slice a few corners off. Apart from the bit I want of course ;)
Title: Re: Comsumption!
Post by: TheBoy on 11 July 2007, 20:16:46
Quote
Crank sensor! Its on the list for thursdays scrapy visit!

Saying as Im gonna take 2 or 3 of them from the scrapy (well ones gotta work) is there a quick and easy method for getting them out bearing in mind I dont have to be carefull with it and can slice a few corners off. Apart from the bit I want of course ;)
Hmmm, I doubt you will remove one in tact....
Title: Re: Comsumption!
Post by: x25xe on 11 July 2007, 20:23:40
Yep, I second that.  Will be difficult if not impossible to remove as the wiring from the sensor goes round the back of the engine.  I would also expect that if the sensor on the car is original it will probably be duff anyway.
Title: Re: Comsumption!
Post by: Owen on 11 July 2007, 20:40:54
Oh 'dangle berries'! :(
Yup just read the guide in the 'Maintenance Guides' and I see exactly what you mean!
But there is one in the scapy with the whole top end missing so will take a peep anyway!
Title: Re: Comsumption!
Post by: Marks DTM Calib on 12 July 2007, 10:22:10
If the heads are off you can get them out........

I dealy we need to do a vaccum test on your car to understand better whats happening.

Are the multirams fully working?

Has the mpg recently dropped?
Title: Re: Comsumption!
Post by: Marks DTM Calib on 12 July 2007, 11:05:49
Ow yes, check the main brake servo pipe for chaffing, saw one last night with a hole in it and it affected the fuel consumption.
Title: Re: Comsumption!
Post by: VXL V6 on 12 July 2007, 11:31:30
You certainly did.... About a 6mpg - 8mpg drop!
Title: Re: Comsumption!
Post by: Abiton on 12 July 2007, 13:05:15
Quote
Ow yes, check the main brake servo pipe for chaffing, saw one last night with a hole in it and it affected the fuel consumption.

And the braking presumably!
Title: Re: Comsumption!
Post by: VXL V6 on 12 July 2007, 13:32:53
Yes but not as much as you would think. Though TBH if the fault was always there on my car since I had it, then I would never have known any better!

Brakes are sharp now whereas they were slightly spongy (but perfectly good IMO).
Title: Re: Comsumption!
Post by: Owen on 12 July 2007, 18:46:08
Quote
If the heads are off you can get them out........

I dealy we need to do a vaccum test on your car to understand better whats happening.

Are the multirams fully working?   Yep, they wernt, but have been working all week

Has the mpg recently dropped
 Yes it dropped today again [/quote]  


After changing the y-pipes, and the 2 smaller breather pipes, it went up to 26! Today on the journy to the scrapy it droped to 18. Only a 4 mile run to the scrapy as well! ::) Left the house, range-53, 4 mile to the scrapy, on arrivel range-32 ::)

Just said in the general forum, took 3 crank sensors from the scrapy today, all of the were the square fitting, mines the slightly oval fitting ::)

I have tried everything else, so I guess It must be the crank sens! Oh and after reading about the brake servo pipe, I had that off today and checked ot over! Seems air tight, but taped up potential week spots!

One other scrapy to try tomorow for the crank sens, hopefully will find the oval fixture fingers crossed! SWMBO is starting to get the serroius hump about it all, trying to keep her sweet til I conquer the dam car! ;)