Hello

 

Wife's Fabia vrs MK1 07 (all standard) has been losing power and getting worse. I'm considering a tow home from work as I write. I drove it last night and it was ok but lacking in its usual power. There seemed a delay in turbo boost , then a puff of black smoke at mid revs. This morning she had a queue behind her up a hill as the car struggled to get her to work. 

 

Reading up on internet it seems it could be

MAP sensor

Temperature sensor (fuel?)

 

The rolling resistance is fine. No unusual noises (not loud). EGR was cleaned back in November so probably not this. Engine is not shaking etc. The boost pipes seem fine (they were replaced a few years ago). If they detach then the car is undrivable I have found btw.

 

ICarSoft scan revealed nothing last night, no engine check light etc.

Edited 10 May, 20233 yr by bmbmdmb

MAF giving live data that mirrors predicted MAF values I got from live scan last night

MAF sensor was replaced when car had 50 to 60 k miles. Live / actual data was zero when it should have given higher values (this is when it failed previously) , so I have ruled out MAF sensor on this occasion.

 

Fuel temperature sensor looks likely - smoke, hotter than normal engine, injectors blocking. Car is over fueling. Car near 100k miles which is their lifespan. 

 

Will vcds pick up this fault? I'm scanning tonight. 

 

Ps anyone with Green Flag - make sure you insist on quoting the older car. I told them at time of renewing, but today because the car is over 16 years mid policy they said it is not covered. Manager authorized tow in the end. I only been with them for 25 yrs

Edited 10 May, 20233 yr by bmbmdmb

Could be the lower boost hose blown off.

It is all new pipes and jubilees 5 years old. They been off for timing belt last November though but were secure. Only one or two horseshoe VAG clip,ie to turbo and maybe intercooler. I had one pop off 1cm and it was obvious. The car stuttered and it was undriveable. 

 

I'll check though when it gets home. 

 

 

Edited 10 May, 20233 yr by bmbmdmb

I suspect the turbo itself since you have no boost leaks, clearly there isn't enough air to go with all that fuel, hence the black smoke.

 

There's no way it's the MAP or FTS causing such a dramatic loss of power.

VCDS - no fault codes. 

I'd be surprised if turbo at fault. Engine oil changed to specification and annually or less. Every 5k miles. Mileage is almost 100k though.

 

I have no siren noises or other noises from turbo. It makes the same tick over growl noise at idle it has always has since ownership began. There is some very subtle intermittent noise though that is coming from engine bay at idle that was not there previously, nothing obvious though .

 

Would a turbo failure be obvious?

 

Fuel filter changed a few thousand miles ago. Air filter looks ok. I'm changing it, but unlikely the culprit. 

 

I'm going to look underneath at the boost pipes and EGR through ASV on top.

 

The fuel temperature sensor area , nearby there is what looks like a fuel pipe (metal aluminium tube) connected to rubber hose - looks damp, but could be oil from a previous change - between engine block and air box, or diesel? The sponge under engine cover has powdered (probably age and heat) so it got removed last night. Some of this stuck to said oil or diesel. 

 

Is the aluminium block the fuel pump? My finger pointing to it.

 

 

 

This is the leak, nothing to write home about though.

 

 

Is this the FTS? Centre right of photo?

 

 

 

Combined fuel pump and vacuum pump 'tandem pump' I think.

Yes, that's the fuel temp sensor, I reckon.

Edited 10 May, 20233 yr by Breezy_Pete
Typo, as usual

Lower and upper boost pipes are in place, check.

 

EGR looks ok, but coated in very dry soot, never seen it like that before. Usually, it is oily. Matches what is coming out my exhaust, a puff of black soot on acceleration. Dry soot left on tailpipe. 

 

 

 

 

Turbo you think? I'm going to take to garage but wanted as much info as possible to save them time and reduce bills. 

 

Engine idles and starts smoothly. 

 

 

If turbo what's my options. Standard turbo had plenty of power. I heard that you reuse the cassette or something similar. Reconditioned calipers were a waste of £. 

 

Same true of turbos?

 

Is there any test I can do to diagnose this?

 

Thanks

You can log boost in VCDS, compare requested with actual, that dry soot is unburned fuel.

Check for a vacuum leak in case the actuator is not working correctly.

Thanks Sep

 

'Log boost in VCDS'   -  Is this a basic or an advanced measuring value?

 

I went through the tickboxes and I could only find the MAF actual and requested values.

 

How are the boost values named? Do I need the car under load (at speed) to measure accurately or can I increase revs with car stationary?

 

I had a look at the vacuum pipes and felt around them for splits. Nothing obvious. Anywhere in particular to look in the engine bay?

 

Thanks

You need to have the engine under load, you're looking for the MAP output in bar, MAF is different and will only give you an actual value.

 

You really need a vacuum gauge to measure leak down realistically.

I have checked the vacuum pipes more thoroughly, feeling underside for splits. There were none.

 

Had a look at intercooler through gaps in bumper, again no damage evident. Boost pipes double checked and felt for holes. Unions secure and tight.

 

Could oil,soot gunk obstruct the turbo fan blades/vanes and it is not spinning as it should? 

A lot of folks on here who have had a turbo failure have had a loud noise or sudden failure. Or can a turbo fail gradually?

 

Would boost values from computer be worthwhile reading? 

 

Cheers

 

Turbo failures are usually detectable a while before they go. Like you say the siren noise is the big giveaway. 

 

100K is nothing on a well maintained standard engine, many last a lot longer than that if driven sensibly, from the Turbo's perspective.

 

Failing fuel sensor will be picked up on vcds as well

What about the tandem fuel and vacuum regulator? It seems I'm getting lack of air though not insufficient fuel?

Garage said the EGR is sticking between open and closed.

 

I disconnected vacuum from EGR and checked with more vacuum tube that it held a vacuum and it did, before taking to garage.

 

Garage said at low speeds it is more pronounced. They blocked the vacuum tube with a bolt and took it for a drive. It was as it should be, performance returned.

 

This EGR has been on car 40k miles and cleaned every 8k miles. It was cleaned last November and just before taking to garage. 

 

I have my original one that blocked up and I cleaned,  or I buy a new one. I'm sick of cleaning it to be honest and it seems that cleaning is not effective. Those rubber o rings between asr and egr are nearly £10 each which expand if cleaning solvent comes in contact.

 

Is blanking and map out EML effective? I read up and it seems opinion is divided. 

 

Where is best place to get a new EGR if I go that route again? I bought from Skoda dealer the last one that failed. 

 

I read on here that the hole in newer

EGR valves is larger - don't know if this is true, ie a superceded part?

 

Thanks

 

Ps at least it is not the turbo 

Edited 16 May, 20233 yr by bmbmdmb

Nonsense, EGR problems would not cause your symptoms, VNT or actuator might.

Ok. Personally, I've not had these symptoms when EGR last played up.

 

Last time the EGR blocked up the car coolant took longer to warm up and the engine shook on idle. When at temperature after a commute and idling the cooling fans came on ( never had these on). Different symptoms this time. But the EGR previously stuck one way. Should it open and close only depending on coolant temperature?

 

Both mechanics are experienced on VAG cars and one owns Skoda's. I trust them. If the turbo needed changing they wouldn't turn that work down.

 

Vnt - the turbo blades

I have heard the turbo noise (as usual on tick over), nothing unusual,  so the turbo blades seem free to spin, whether the blades are adjusting pitch, I don't know.

Actuator - Again I'm not knowledgeable enough. I've read that can fail (it has a vacuum line). Does this spin up the turbo on accelerating?

 

If turbo, is it a new turbo or individual parts. I read it might be a KKK turbo, this one?

https://www.darksidedevelopments.co.uk/products/kkk-bv39-turbocharger-for-1-9-tdi-blt-pd130-ibiza-polo-fabia.html

 

Actuator appears to be available as a separate item

https://www.darksidedevelopments.co.uk/products/kkk-vacuum-actuator-1-9-8v-tdi-engines-for-pd100-pd105-pd130.html

 

What do you recommend is my next step?  I'm about to collect car so any questions I should ask feel free to pose so I can ask. Thanks

Edited 16 May, 20233 yr by bmbmdmb

VNT is not part of the turbo, it's part of the manifold.

Ok

 

The EGR is disconnected currently. I have driven it home and the car boosts as it did do. Mechanic said it smoked badly. When EGR disconnected and bolt in vacuum hose no smoke, driver is thrown back in seat when accelerating (been 10miles). I didn't want to whip car as it was on cold start coming home, but I could tell it felt much better.

 

Looks like the EGR.

 

Garage said if the symptoms return then turbo , vnt, actuator is next on the list.

 

EGR has been tested using vacuum and gauge and although diaphragm holds vacuum the plunger/valve is sticking and opens/closes at different time to the vacuum being applied.  

 

The turbo could be heard healthily boosting, no siren noises etc. On way home.

 

Brakes seem to bite slightly better with vacuum hose blocked to EGR, but hard to say.

 

 

 

Leave the bolt (golf tee also known to work nicely, if available) blocking the EGR vac hose for a few days and see what happens.

You'll get a fault light after a while I assume, but not sure if anything else will happen like limp mode. Easily discovered by experiment.

 

 

Edited 16 May, 20233 yr by Breezy_Pete

Yes, I'm going to keep bolt in place, mechanic said same thing as an experiment.

 

Pete, will the disconnected EGR simulate an EGR delete. I'm interested in how the car differs to EGR connected eg warm up time, mpg, etc.

 

Is it worth replacing the 16yr old vacuum hoses with silicone ones? Any benefit? Eg less pliable material when vacuum applied?

 

Vacuum hoses

The inner diameter is 6mm 

Outer diameter is 9mm

The ones behind expansion tank and above EGR running under windscreen.

 

If yes, any suggested total length to purchase?

 

 

Edited 16 May, 20233 yr by bmbmdmb

Warm up time will be slightly longer, mpg may actually improve slightly without EGR flow.

Only on petrol engines can it save fuel as well as decrease engine-out NOx.

One thing to be mindful of, the OE Skoda vacuum hoses will all be pre-shaped to a degree and will all follow their intended path reasonably well. Replace these with floppy generic silicone vacuum hose and you lose that accuracy in the hose.

 

Also the vacuum hoses last pretty well on these cars, i've has vRS with 200k on still on the original vacuum hoses and they were not brittle or crumbling so unless you really have to, i'd leave alone.

 

The golf tee mod Pete suggested will do the same thing as an EGR delete so run it for a few days and see how you get on.

 

As yours is a 2007, it will have had the BLT engine from new meaning you'll have a shortish EGR, with the Anti Shudder Valve next to it. I'd use blanking plates (readily available) to block off the EGR pipe from exhaust manifold to EGR and on the EGR itself (two blanking plates needed) and leave the vacuum hose plugged. Don't bother with an EGR delete pipe as they look crap and makes it obvious someone's been messing there.

 

You will need to have the EML mapped out as it will (or should) illuminate soon. Not a major job.

It's definitely the EGR at fault. First time out with EGR disconnected. All the symptoms disappeared. 

 

Mpg improved with EGR disconnected, no smoke, not even a puff on starting. Got 65mpg on computer when I'd normally get 58 to 60mpg like for like driving. No smoke on flooring vehicle. I usually get some smoke near full throttle.

 

Car warms up in the same with EGR disconnected as connected and seems to drive better.

The EML took 2miles to illuminate and I cleared p3130 but same occurred on way home. 

 

I was only considering changing vacuum hoses as the mechanic has oversized the hole with a caliper banjo bolt! I guess he doesn't play golf! Ie no golf tees about...which was a good idea Breezy Pete.

 

Good point Lofty about the tailored shape of the original vacuum hoses. I read the silicone hoses can stick to hot surfaces too, like in the engine bay! I'll give the silicone a miss. 

 

The brakes are definitely better with the vacuum hose to EGR blocked off. Less spongy. Any suggestions on why?

 

A new EGR is £42 without gaskets, o rings or  £60 with all bits which I'm going to buy.

 

Is the EML able to be mapped out completely for an EGR blank? The EGR delete kit I've seen would be an obvious modification.

 

What blanking plate would you suggest out of interest?

What about the EGR cooler? Leave in place?

 

 

 

 

 

Functionally, as long as the valve is seating well enough to seal the flow off when 'unpulled open', blanking won't reduce flow at all compared with just golf-teeing (not my idea btw). It seems that your vac blocking is causing a sufficient 'full time closure' as I'd expect. 

A covert blockage inside a connected hose may be necessary tor MOT. As will some method of preventing  EML if you want easy passage through.

Interestingly for you and most other mk1 diesel owners, maybe, the relevant section of the inspection manual 8.2.2.2 opacity suggests in my reading that if the car was first used before 01/07/2008, the tester needn't care about EML function/activation.

 

Anyone who's tried opening one of these valves digitally (with fingers) will know how strong the closure spring is, and therefore why the vac diaphragm is so large, Exhaust gas pressures just aren't enough to push that valve open at all if the diaphragm is inactive, in my opinion. If they could, the valve position wouldn't be controllable in normal service. Blanking kits are more for people who want to 'buy (or maybe sell?) a solution' rather than think one through.

 

Your ECU and vacuum system will not be aware of any difference relating to the vacuum actuation, just the lack of results in terms of absence of MAF-measured fresh air flow reduction when EGR flow has been demanded, so fault light. 

 

All of the above intended to be factual rather than an encouragement to break the UK law by tampering with emissions related systems, MOT is not the only thing relevant here (although it is the front line).

Construction and Use regs are the legal basis for 'don't tamper'.

 

Edited 19 May, 20233 yr by Breezy_Pete