[Closed] Sound like the EGR valve?

That's exactly what happened when the egr valve went in my astra. Don't have the car nor receipt any more but I'm sure it was £200+

I'm going to say it's a split turbo hose. Cheap fix, easy to DIY too.

Garage can test it or you can examine it yourself. The turbo pressurises the air, then it goes into the engine via rubber pipes. The thing that measures how much air is going in is before the turbo. So, if some of that pressurised air is leaking out of the pipes then the car thinks there's more air going in than there is. So it adds how much fuel it thinks it needs but there's not enough air so it doesn't all burn, hence the smoke and lack of power. The whistling sound is the air escaping.

Whistling noise = air leak = split hose.

Bad EGR will cause it to run like a sack of poo, but unlikely to whistle.

Thanks Molgrips, at the beginning of the week, i noticed slight flat spots in acceleration especially in between 1000-2000rpm, once over 2000rpm (which is 70mph plus in fifth, difficult living in a county with no motorways!), and thought maybe split turbo hose.

But then once it started to lose power overall this morning, coupled with the smoke, was a bit worried it was more.

Will have a look myself tonight at turbo hose and if nothing apparent, get local garage to have a look

my 2001 gt tdi golf did this very recently --- £135 to fix .... turbo boost pipe split.

The EGR valve diverts some of the exhaust to the air intake to reduce the NOx emissions (the bad stuff you hear about on the news). It'll run fine (in fact better) without this, but it'll produce more pollution. The engine can tell if it's working by comparing pressures and calculating stuff, and if it isn't it'll probably go into 'limp mode' where it restricts the power, allowing you to do about 40mph probably. It's possible that flat spots could be caused by the EGR - the engine turns off EGR when you accelerate, and if the valve isn't working properly then this could cause flat spots.

It's possible that you have multiple problems of course. It's also possible that you have a small leak or split that you cannot see and is only revealed by a pressure test. But if you have whistling, then this really should be the culprit.

Great thank all, Molgrips you've just doubled my mechanical car knowledge..

On those engines it is vital to keep the oil topped up and to use only the correct type of oil.

https://www.ukdieselparts.com/blog/psa-1-6-hdi-turbocharger-failure-fitting-warning/

I agree it sounds more like a leaking hose than anything else. An EGR problem will usually light up an amber engine warning light on a Ford. Worth putting an OBD reader on and seeing what it says, if anything.

Interesting reading that Paton, thankfully i have just done basic service a few weeks back, so hoping oil level is OK, but will check tonight again.

As has been said before an EGR is about emissions reduction, not increased power so shouldn't notice a performance drop. When mine went on my 2ltr TDi VW engine it ran fine, just clouds of white smoke billowing out of the exhaust as the EGR is water cooled and the water was leaking into the induction manifold.

One test you can try for a leaky hose is as the engine is ticking over take some WD40, or something similar, and selectively spray it around the hoses. If you see an increase in engine RPM then potentially a leak on the induction side of the engine (sucking in air and therefore WD40). If not then could be a leak in the exhaust/pressure side of the system. Not a definitive test but might help locate a potential hose leak. Worked for me once...knew I had a hose issue, did the test above, didn't get an RPM rise, so focussed inspections on pressure side of the engine and then very quickly found a loose clip on the intercooler intake (sealed OK off boost, but boost pressure was enough to open up a gap and leak air). A nip up with a screwdriver and all sorted.

Whatever the problem, with a car that age I'd get a egr blanking plate of ebay. Yes you can argue it will cause more pollution, but not much and a better running car will pollute less in other areas. Your choice.

As has been said before an EGR is about emissions reduction, not increased power so shouldn’t notice a performance drop.

Hmm... I'd disagree. The EGR went on my old Volvo V50 and the car went straight into "limp mode". Scary when it was on the motorway.

On EGR valves, stuck closed you probably won't notice, might even run better. Stuck open is when it all starts to go wrong.

It’ll run fine (in fact better) without this,

Not quite. The higher compression ratios of modern engines mean higher temps,. The egr serves to lower the combustion temperatures in the cylinder. Blanking off your egr is likely to cause knock, which will cause the knock sensor to act, which will reduce power. You will also lose heat that could be working for you to the cylinder walls, valves, piston and plugs. This may not bode well for longevity. It also reduces pumping losses from the engine trying to suck the inlet air in.
It is possible the whistle you are hearing is due to the vacuum hose which activates the egr leaking or the rubber boots on the egr itself.
Cost to replace and egr depends largely on whether the circuitry is built into it or not. If so, it is an expensive part.

Blanking off your egr is likely to cause knock

Can a diesel knock?

I took the egr valve out of my Volvo V40 & cleaned it with brake cleaner. Worth trying if you think you can manage it.

Can a diesel knock?

Sort of. I use the term as shorthand. It is a timing issue mostly with diesels. The injection takes place before peak compression and the Piston and expanding gases end up going in opposite directions. Or the injected fuel burns too close to the injector (partly plugged nozzle e.g. causes too much atomization) which forms a shield around the later fuel, which then goes off too late/not at all. Which will produce black smoke.
It is unlikely to have a knock sensor though, didn't really think that part through.
If you have randomly overheated cylinder parts you can get uneven ignition which causes wavefronts going in all different directions crashing into each other.

Now you've made me think about it, a stuck open injector/partially plugged could cause some of the problems the OP is experiencing. The egr would set a code, asticky injector wouldn't, necessarily - although it would almost certainly cause a bit of 'knock'

If you have randomly overheated cylinder parts you can get uneven ignition which causes wavefronts going in all different directions crashing into each other.

I used to have an all mechanical pump and I could advance the injection timing with an adjustment screw. It became more clattery if it was too advanced. I don't think you can get too uneven ignition though since the fuel is injected from a point or points outwards into the already hot air. Reading up a little, you can get pre-ignition if the injector is faulty and fuel gets in there too early.

However, most cars turn EGR off under mid to high throttle input (mine does) and this being Europe, where the same cars are sold in Germany, they are designed to run at high speed for long periods likely with the EGR valve closed I'd imagine it'd work just fine.

The higher compression ratios of modern engines mean higher temps

I think modern diesels run lower compression than older ones (16:1 rather than 19:1 on my older one) because they run more boost which has the effect of increasing cylinder pressure - and at lower boost i.e. normal driving, the lower ratio reduces temps and hence NOx along with EGR.

I don’t think you can get too uneven ignition though since the fuel is injected from a point or points outwards into the already hot air

In a diesel, unlike a gas engine where the mixture forms before the spark happens, each droplet of fuel has a local combustion, is the best way I can describe it. That's why you can get the effect of the outer droplets combusting but the inner ones not, for instance.

'Timing' is usually the problem with diesels but it is timing of peak compression temperature etc, not 'just' when you squirt the fuel in. Also the time it takes to inject the fuel matters. My inpression is diesels are more sensitive to fuel injection problems.

Egrs typically open at less then 25% load, above 15mph, above 1500rpm etc. They are most likely to be in operation at a constant speed, relatively low load situation like a motorway. They don't usually open and stay open though, they are variable.

I think modern diesels run lower compression

Yes, good point. I should have distinguished between static compression ratio and effective compression ratio, which varies with boost. Petrol engines are typically higher than they were, static.

Sounds like a split hose to me too. Had these symptoms on my old MK3/2004 Mondeo TDCi. Gentle whooosh noise under acceleration and soot, lots of soot...

No warning lights but it worsened rapidly during the 75 miles after first noticing it and by the end it was struggling up the bigger hills at 55-60.

It was a fairly cheap fix.

Our 2.0 tdi VW just had the egr replaced and it would light the warning on the dash. It still ran but used more fuel and was sluggish.

Replaced the egr which VW kindly buried on the back of the engine behind the subframe and driveshafts. Why stick it there, it was on the top front and simple to get at. A total bill of Euro 1100, thank the baby Jesus for mechanical warranties....

It's now switched off in the software and closed forever.