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[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.