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[aaronjb]

Evening all..

I just took ownership of a 1996 2.5TD with the autobox as a runaround/lugger/hack (since the other car has no boot at all  ) and after a long drive I realise it's quite.. gutless.

On a long stretch of uphill motorway, for example, it needs dropping out of top (overdrive?) or your foot planted on the floor just to maintain 75mph.. the question is, is that normal?  The closest thing I've driven is a friends 2002 2.2TD manual which has a good chunk more poke, it feels.

It seems to run fine apart from that, although motorway miles it looks like I'll get about 500 to a tank, which seems low to me?

I'm wondering if there are any common faults that would cause a lack of power but no other poor running.. obviously the first one that came to mind was that the turbo is siezed (which would explain why the previous owner got shot!) - though I should add the car has 93k on the clock, and a full Vauxhall service history..

Hints, tips, common faults to look for appreciated - I had a scour back a couple of dozen pages of threads and nothing jumped out at me particularly..

Thanks!
Aaron

[markspark]

i to have a 2.5 td mine tends to lack power around 70mph if i do get it to kick down it will drop 2 gears so maybe this is normal my fuel is pretty much the same aswell i get 500 mile to the tank then its really empty but i do drive with lead boots normaly over 70mph when you consider the weight of the omega the mpg aint that bad really

[MickAP]

Evening all..

I just took ownership of a 1996 2.5TD with the autobox as a runaround/lugger/hack (since the other car has no boot at all  ) and after a long drive I realise it's quite.. gutless.

On a long stretch of uphill motorway, for example, it needs dropping out of top (overdrive?) or your foot planted on the floor just to maintain 75mph.. the question is, is that normal?  The closest thing I've driven is a friends 2002 2.2TD manual which has a good chunk more poke, it feels.

It seems to run fine apart from that, although motorway miles it looks like I'll get about 500 to a tank, which seems low to me?

I'm wondering if there are any common faults that would cause a lack of power but no other poor running.. obviously the first one that came to mind was that the turbo is siezed (which would explain why the previous owner got shot!) - though I should add the car has 93k on the clock, and a full Vauxhall service history..

Hints, tips, common faults to look for appreciated - I had a scour back a couple of dozen pages of threads and nothing jumped out at me particularly..

Thanks!
Aaron

Give it a service including new fuel filter with some Diesel magic in there. Check all air connection hoses/pipes for splits and take off that air charge  pipe to see how much black cruddy oil is in there.
Some have even removed the inlet manifold to clean that, gets build up with black crud, doesn't help.
Ther's also an how to on cleaning the injectors, but see how it goes with a dose of the magic stuff, certainly improved the perfomance of mine

Mick

[Evo]

I had a similar problem caused by oil in the hose to the inlet maniford pressure sensor. It will take you 5 minutes to check. You take off the top engine cover. The small bore hose goes from the underneath of middle of the inlet manifold to the pressure sensor (a 1" cube) on the passenger side of the engine compartment. Its just above the dipstick.

[aaronjb]

Thanks guys! I'll give all that a check one evening this week

[hoofing it]

you need to remember diesels have a higher torque low rpm where petrol is the other way.
As mick says service it new air/oil/fuel filters just mind and put diesel or diesel treatment(forte) in the fuel filter before replacing

[aaronjb]

you need to remember diesels have a higher torque low rpm where petrol is the other way.

Very true.. but I still wouldn't expect to have my foot nailed to the floor just to struggle up to 70mph on a gentle motorway incline Granted I know I'm a little spoiled (the other car has some ~250bhp in a 1000kg car), but still.. it was a bit more gutless than I expected 

I just ordered some Forte diesel treatment and new oil/air/fuel filters & fluids.. something for the weekend, so to speak 

[Sixstring]

You will probably see a good difference in running/performance after all that, have you had a diesel before?  quite a difference in driving characteristics to a petrol if you havent. Diesels need oil changing/ cleaning out of things a lot more than their petrol equivalents, so not trying to tell you how to suck eggs if you are familiar with them. The Omega is a heavy car, but you will need to wind it up a bit compared to say, a V6. But you will notice the difference when it is running right. 550 to a tank is considered usual range before fuel light comes on, then another 50 before it flashes, then perhaps 10 before you have to walk.................(and change the fuel filter  cos of tank gunk!!)

[zirk]

Do above as suggested, my 2.5TD did the same when I first got it, would struggle to do over 80, did the service with not much difference, mine turned out to be the MAF sensor in the end, so might be worth checking this as well.

Chris 

[hoofing it]

Forgot to say earlier paperclip it and see if any codes are lurking around.
another thing to do is clean out the swirl pot in the fuel tank i found feathers in mine

[aaronjb]

Ahh yes - codes.. I'll search about and find the thread with instructions on paperclipping it

You will probably see a good difference in running/performance after all that, have you had a diesel before?

Yeah I've had a few - mostly older naturally aspirated lumps, though (one Metro Diesel a long time ago with a 1.4 Pug lump, and two cars with the 1.8 XUD engine.. honestly, the Omega feels like it has less power up hills than the XUD Pug that just ate it's headgasket!  )

It looks like I'll get about 350 to a tank around town, too, which seems quite thirsty - having said that, it is a very big & heavy car.

another thing to do is clean out the swirl pot in the fuel tank i found feathers in mine

How on earth... 

[MickAP]

Getting around 33 mpg from my manual, around town.
You will get less being an auto, maybe 28-30 ish.

Mick

[Radiomarko]

If its any guide, my 1997 manual 2.5 lump returned 46 mpg on a recent long motorway run, 32-36 around and about. So 500 on a tank seems a bit low for motorway.

Does not lack power - stays in 5th all the way to London traffic permitting, in fact she needs to be reined in a bit as 100mph + no problem.

Does the turbo kick in OK?

[Seth]

Forgot to say earlier paperclip it and see if any codes are lurking around.
another thing to do is clean out the swirl pot in the fuel tank i found feathers in mine

Take a look here .........

Click:   http://www.omegaowners.com/forum/YaBB.pl?num=1251298222

[Seth]

If its any guide, my 1997 manual 2.5 lump returned 46 mpg on a recent long motorway run, 32-36 around and about. So 500 on a tank seems a bit low for motorway.

Does not lack power - stays in 5th all the way to London traffic permitting, in fact she needs to be reined in a bit as 100mph + no problem.

Does the turbo kick in OK?

Roughly the same as mine!

[aaronjb]

Does the turbo kick in OK?

That's a good question.. I'm not sure I'd be able to tell with it being an auto; but I suspect maybe not, given just how gutless it is - I certainly don't think it could reach 100, let alone need reigning in 

[hoofing it]

Does the turbo kick in OK?

That's a good question.. I'm not sure I'd be able to tell with it being an auto; but I suspect maybe not, given just how gutless it is - I certainly don't think it could reach 100, let alone need reigning in 

lift the bonnet and rev up the engine and watch the bit that says turbo diesel and the connected pipes they should move when under preasure or listen for a soft whistle

[Sixstring]

Good Point!!

My mates 1.9tdi had the turbo gone, it struggled to reach 75mph.............
However.....s/h turbo and 2hrs later, did 120 easily!

Big possibility?

[aaronjb]

lift the bonnet and rev up the engine and watch the bit that says turbo diesel and the connected pipes they should move when under preasure or listen for a soft whistle

Ah - first turbo diesel car.. I didn't know if it would build boost without load (i.e. moving the car) I know my other car doesn't, but that's petrol.

s/h turbo and 2hrs later

I get this feeling it wouldn't be a 2hr job on the Omega 

[aaronjb]

So I had a bit of a poke around last night (not much, since I didn't really want to get completely oily  ) and two thing strike me..

First there is an absolute TON of oily crap right below the horizontal plastic intake pipe (the 'TURBO DIESEL' one or whatever it says) that I've read can crack.. so I'm wondering if there's a giant split under there pumping out the oily intake air.

Secondly.. I read about MAFs failing, and see that ECP do list a replacement MAF (at either £260 or £70 depending on manufacturer) .. but I'll be damned if I can see one in the engine bay.  Does the 2.5TD have a MAF or a MAP (I found the MAP sensor someone mentioned - thanks!)?

[unlucky alf]

looking at the age of yours i doubt its got a MAF, mine is a 95 & aint got one, as others have said it could be a turbo issue as i chipped one for a member a while back & it was still gutless, turbo was very whistley so he got another fitted & that sorted it.

[aaronjb]

Excellent, that means I'm not going blind.. well, not that blind, anyway 

I'll pick up a secondhand snail if the charge pipe is intact, and clean all the rest of the stuff out this weekend.

Speaking of chipping.. would I be right in assuming that the autoboxes tend to grenade themselves if you chip the engine?

[unlucky alf]

ermm yes, the ar25 dont like power & tries to escape from your car in pieces, , you dont say where you are as i do happen to have a turbo i bought the other day as a spare, anyhow see how it goes & good luck.

[aaronjb]

Ah shame, but I suspected as much

Just added my location - and I'm keeping an eye on a spare turbo on fleabay at the moment, which will hopefully go quite cheap.

[Shackeng]

ermm yes, the ar25 dont like power & tries to escape from your car in pieces, , you dont say where you are as i do happen to have a turbo i bought the other day as a spare, anyhow see how it goes & good luck.

I've now done 30,000 on a chipped 2.5td with an AR25 box. The car goes VERY well, and occasionally gets a heavy boot, and the box is still good (touches wood).
NB. I have an AR35 in the garage just in case!

[aaronjb]

Interesting - good to know

OK, I think I've found one reason why the car is so gutless.. now, let me tell you a little story

Firstly - I should say while I don't consider myself a genius with cars, I have re-built a few more or less from the ground up (most recently a ~420hp Nissan 300ZX and a ~250hp Toyota MR2 Roadster) so I think I know what I'm looking at when it comes to petrol engines, but diesels are more of an unknown.. anyway, extrapolating my knowledge and what folks here have posted, I went looking for the MAP sensor.

I think this car has had a new engine at some point (tell-tale yellow marker 'X25' on the engine cover) and .. I suspect someone didn't write down what hose went where

This, if I'm right, is the EGR valve:


Which, I would assume, would be hooked up to an EGR solenoid (i.e. a small black box with two hose connections).. only it's hooked up to this - which I'm putting good money on being the MAP sensor, am I right?



Now, I wondered where the EGR solenoid had gone, if that's the MAP sensor.. so I peered into the gloom and found this dangling free:


Which is attached to two hoses that disappear off to the inlet manifold - I presume these are supposed to be the manifold reference for both the EGR valve and MAP sensor?




So if I'm right, what I need to do is unhook one of the manifold reference lines from the EGR solenoid and attach it to the MAP sensor (probably the one that double-backs around the dipstick tube!) and then attach the EGR valve line to the output of the EGR solenoid. Right?

If so - does it matter which manifold reference goes to the solenoid vs. the MAP? I see one has what looks like a one-way valve or filter in-line?

[aaronjb]

Anybody know? The diagrams in the service manual are.. less than clear when it comes to following itty bitty pipes

[aaronjb]

I know, I'm just replying to myself, now, but

Took it all apart tonight and yes - the previous owner had the vacuum pump connected to the EGR solenoid, and the EGR solenoid connected to the intake manifold (errr..) and then the EGR valve connected to the MAP sensor.

Fixed all that and now it has much more power up hills - in fact, it's a totally different car.. you can feel the turbo spool up and the car takes off.


The only thing now is.. it's very sluggish to pull away in 1st gear from a standstill.  In fact, far far worse now than before I fixed everything  I'm wondering if the ECU needs a reset to unlearn fuel trims, if the ECU is advanced enough to have stored trims?  That would also explain the giant plume of grey smoke every time I give it some beans, too..

[hoofing it]

well done in finding that mix up also put a new fuel filter on and fill it with forte diesel treatment.
To delete old codes turn ignition on-off about 30 times wait till the management light goes out before turning off then back on this resets the codes as ecu thinks its had 30 fualtless starts.
I would recomend you take out injectors strip and clean them 
as for the bit that says turbo diesel there are photos floating aroud of how to replace it with hose and bends

[aaronjb]

Aye it looks easy enough to replace that part - odd, though, is that the hose going into the inlet manifold was covered in black oil on the underside after a run.. not quite sure where it's coming from, unless that hose just isn't sealing properly on the inlet manifold.

Would you completely fill the fuel filter with forte, or mix forte & diesel? I have a fuel filter waiting to go on at the weekend (and air/oil/etc), and a bottle of Forte here too.

The main thing will be to make it be less.. utterly hopeless at pulling away (honestly, it's worse than before!).  If it were a petrol I'd suspect an air leak in the intake, but it's diesel so.. that wouldn't really matter. Hm.

[hoofing it]

Aye it looks easy enough to replace that part - odd, though, is that the hose going into the inlet manifold was covered in black oil on the underside after a run.. not quite sure where it's coming from, unless that hose just isn't sealing properly on the inlet manifold.

Would you completely fill the fuel filter with forte, or mix forte & diesel? I have a fuel filter waiting to go on at the weekend (and air/oil/etc), and a bottle of Forte here too.

The main thing will be to make it be less.. utterly hopeless at pulling away (honestly, it's worse than before!).  If it were a petrol I'd suspect an air leak in the intake, but it's diesel so.. that wouldn't really matter. Hm.

this bit tends to split hence oil underneath.
Yes fill the filter with forte dont mix with diesel don't worry engine will start and run ok just give it a little throttle
Yes the manifold gaskets tend to wear out and draw in air they only cost £38.00ish to replace this will effect performance.
also clean out the small pipe thats under the manifold that leads to egr sensor this gets bunged up with oily crud

[aaronjb]

Cheers Interestingly the plastic 'TURBO DIESEL' bit doesn't seem to be split (I had it off and cleaned it out and all the oil off it), but I wonder if the short pipe between that and the manifold is sealing properly - it seems a bit shorter than it ought to be.  Shame the bits of silicone hose I have laying about from the other car aren't the right diameter!

Speaking of EGR.. I found my sluggish pulling away problem, I think: http://www.omegaowners.com/forum/YaBB.pl?num=1276852056/5#5

(EGR solenoid stuck open holding the EGR valve open permanently.. might also explain all the oil - the turbo must have been spinning like an idiot trying to pressurise the universe via the EGR pipe!)

[hoofing it]

Blank off the egr at both ends
I also increased the boost to come in at 1200rpm not 1400rpm

[aaronjb]

Aye I was considering that I did an EGR-delete on the Nissan 300ZX too a long time back.. not that I'd ever condone deleting emissions equipment, of course   

[hoofing it]

mine just passed mot yesterday no egr and emissions were very low according to tester
 now I advance pump again