Car bother

I must admit I do like this car more than I probably ought to. I'd be willing to take a punt on a new MAF sensor if I could be confidentthat that's the problem.

Another symptom, intermittent misfire aside, when accelerating on less than full throttle, at about 3000 rpm, there is often a distinct change in engine note and a slight drop in torque, as though I've just lifted off the throttle slightly. Not a total power loss, just a slight reduction. Then at about 3500rpm it comes back to normal. If I maintain 3000rpm, with consistent throttle, it's like she is constantly adjusting something. Below 3000 and above 3500 she is usually perfectly stable.

 

All of a sudden it is sounding like the EGR is failing. Not blocked, more like the actuation solenoid is weak.

 

Mechanic mentioned the EGR as apossibility. He said it could be clogged. I reminded him that they'd cleaned everything when they replaced the turbo. He said only the intake side.

When the turbo failed, two things happened. Oil leaked into everything, and unburned diesel made its way through everything. Iwonder if these unburned things have now baked onto the moving parts of the EGR, rendering it stuck, possibly destroyed. Plausible ? Likely ?

 

I doubt it. Your last set of symptoms are classic EGR failure.
Less likely but don't rule out a knackered or badly fouled up O2 sensor.
As always, prove the theory as far as you can before chucking cash at it.

So it won't need the full £200 Terraclean treatment then.

 

A thought occurred to me.

The turbo failed, which would have seriously messed with the sensors and baffled the ECU. In the lead up to the turbo failure, the turbo, I suspect in hindsight, was not blowing at the pressure that the ECU will have assumed, again messing with its head. Then shortly after the turbo was replaced, a hose clip snapped, a hose blew off, a monumental air leak occurred, and the car barely managed to limp at 20mph back to the garage, smoking and misfiring like crazy, and raising the warning light.

Is it not possible that all the fault codes were logged then, so that now they are red herring?

Ordinarily I'd think if the ECU was going to start ignoring a sensor and running off pre mapped settings, the light would come on and stay on, but I've discovered with this car it takes a lot to raise the light. When the turbo blow a pipe off I knew immediately (its hard to miss a loud bang and immediate loss of power), but I'd limped it a good mile before the light came on.

So now I'm wondering, could it be that it's been running on pre mapped settings, ignoring various sensors ever since the catastrophic failure, and its only the fact that it's breathing very cold air now that's made its mapped settings inadequate? I think they cleared the codes yesterday. Certainly they didn't do any engine work, but today she seems to drive smooth and more powerful, so something seems to have changed.

 

They would have cleared it down when they refitted the hose.

 

I don't think they did. It wasn't mentioned anywhere on the report, or by the mechanic, who always tells me what he's done.

 

@fat controller , @longk , Well this has been a superb masterclass on Diesel engines
! Just bought my first diesel after 48 years of driving . It's a Mitsubishi with the 1.8 DiD engine , it really is a great drive on country roads and motorways, love it.
One point not mentioned in this post , my friend a few years ago suffered from a "sticky" Vw engine. He was advised not to use supermarket diesel all the time as the detergent additives in Shell , BP et al , are superior for a modern diesel.
@clueless1 , may be worth sticking a tankful of Shell V-Power in and give it a blast. Standard Shell diesel is down to 99.9p around here now so its not worth putting Tesco stuff in.

Plenty articles on the web and motor forums on this subject to get you totally confused

 

Hopefully it's a masterclass on why modern diesels are no longer the best choice unless you're doing hard blasts across country or high speed motorway work.

Totally agree.

 

I've had no end of bother over the years with both petrol and diesel from one particular supermarket, while another supermarkets fuel has never given me any bother.

In my current situation, I think all my woes boil down to a combination of previously undiagnosed failed glow plug, and my previous reluctance to use the full rev range.

So far, fingers crossed, no further bother. When starting from cold, she is initially firing on 3 cylinders because of a failed glow plug. I'll get that sorted at some point, but for now when I start her, I give her some throttle. After a couple of seconds, there is a distinct change in note, as the fourth cylinder fires up. I also no longer force the old girl to chug along in too high a gear, so that more heat is being generated in the engine. So far, so good. Like driving a brand new car.