Skoda superb 2.5 tdi giving me a lot of trouble!

[vk10]

Hello to everyone on this forum.! Im a proud owner of a 2005 skoda superb 2.5tdi auto 163

Though the car is giving me nothing but trouble! I would be really grateful if one of you experienced people here could advice me.

The car starts with a lot of diesel smoke and misfiring shuddering vibrations in the morning. It clears out after 10 minutes and the idle becomes smooth, though it is utterly impossible to drive the car on low revs, uptil about 2000 rev the whole car shudders misfires and shakes really badly. I put the car through a diagnostics but go no fault codes. My local garage thought it could be the timing out and everything was stripped down, (bumper headlights etc to get to the timing) only to find out that the timing is spot on. On the motorway that is at high rev's the car is absolutely fine. I just cannot figure out what else could be wrong on this car. Have already changed the diesel filter.

Please help

thanks

[trundlenut]

What sort of diagnostics equipment was used? Some will not pick up all possible faults.

Sent from my Nexus 4 using Tapatalk 2

[CRC]

Possibles -

Failure of the water temperature sender potentially telling the system that the engine is warm when in fact it is still cold. After ten minutes, engine warms up and it really is warm now, so idle smooths out? £10 for a new sensor and 10 minutes to change ( it lives under the engine cover between the front Vee)

Injection timing way out - can be monitored using VCDS as detailed on a recent thread (glow plugs). No need to strip the front to monitor this.

All the glow plugs gone - unlikely as it wouldn't take ten minutes to smooth out.

[vk10]

Thank you for your replies. The diagnostic equipment that was used was vcds vagcom

Even when the engine warms up it still shudders and vibrates upto 2000revs.

I thought of the injection timing too. But is that different to the timing of the engine? As the garage checked the timing and apparently it was spot on.

Now the new thing they are thinking of doing is a compression test to see if a valve or piston shot or worn. But what I can't understand is that if it is a valve or piston the car would not drive fine at motorway speeds? I'm really confused.

[CRC]

Hmmm .... 2,000 rpm is just about the point at which the turbo cuts in ... what would cause an engine to run fine when it gets a boost of air pressure, but shudder when it's normally aspirated?

I'm confused now ....

[trundlenut]

Leaky injector perhaps? having excess fuel dribbling into the cylinder could cause a smokey start.

Does it start easily (apart from the smoke)?

[vk10]

its hard to explain, in the morning it starts up on the first crank, but turns over a bit before firing up. The rest of the day it literally starts on the key. The injectors seem fine on the diagnostic vagcom. Does the leaking injector come up on the diagnostic?

[dieselV6]

My local garage thought it could be the timing out and everything was stripped down, (bumper headlights etc to get to the timing) only to find out that the timing is spot on.

The description you posted is best proof that the garage involved has no clue. Putting the front in "service mode" position without dismantling it takes about 20mins if you read service manual step by step, half that time if you did it at least once before. Plus you do not need to do it, injection pump timing is perfectly measurable with VCDS, and there is no reason (yet) to suspect camshaft timing has changed (unless a bodged timing job happend prior to symptoms you described).

I would not take the answer from garage that the injection timing is "fine". How many degrees exactly? Besides, injection pump timing is set separately.

The low rev symptoms and problematic cold startup are similar to timing belt that jumped a tooth (I saw 1.9 doing that) or a grossly incorrect pump setting. Get someone with VCDS, and on a warm engine go to Basic Settings group ?4? (possibly 3), this shows injection timing, for good starts should be 0.6-1.2ATDC in the "actual timing". Adjustment is 3 screws on the injection pump wheel, under timing belt cover, recently covered, search for the thread mentioned earlier. Coolant temp sensor is also worth a go.

Most importantly though, how did the problem start? Was the engine working fine and then one day you found a problem? Or has it gradually deteriorated? Any service work done just prior to the problem occuring?

Edited 21 March, 2013 by dieselV6

[CRC]

It wouldn't be something as simple as contaminated fuel?

Would imagine that diesel with water in it would run badly at low revs, but with the extra oomph of the turbo and the heat generated in the combustion chamber would maybe overcome this? Air getting into the fuel lines would also give problems, and I believe there are clear plastic lines leading to / from the VP44 that would show any air ingress as bubbles.

Don't really want to mention the dreaded "mis fuel" option.

[Octygone]

I had a faulty injector on a pd engine that made it vibrate quite badly...might be a place to start looking

[vk10]

Thanks for all your suggestions. Diesel v6 I took ur advice and took the car to another garage who specialize only in rebuilding engines. I told them to check the pump timing. Got a call later in the day that the pump timing was out and now has been adjusted. Also was told that the egr valve was sticking but probably I need to blast it down the motorway to clear that.

Now the update is I got the car back and the shuddering and smoke has gone but after driving 20 miles the engine management light and the circle triangle light has come on. I scanned it and the error code that comes up is p0252. I guess the car is going back in tomorrow

[vk10]

Though what I'm more interested in is the cold start in the mornings

[vk10]

octygone funny enough I just sold my 1.9pd a6 and had a faulty injector on it last year but frankly the car gave me no trouble in the 3 years I owned it and this superb is nothing but a lot of trouble.

[vk10]

Hopefully it all gets resolved before my bank account goes into limp mode!

[dieselV6]

Thanks for all your suggestions. Diesel v6 I took ur advice and took the car to another garage who specialize only in rebuilding engines. I told them to check the pump timing. Got a call later in the day that the pump timing was out and now has been adjusted. Also was told that the egr valve was sticking but probably I need to blast it down the motorway to clear that.

Now the update is I got the car back and the shuddering and smoke has gone but after driving 20 miles the engine management light and the circle triangle light has come on. I scanned it and the error code that comes up is p0252. I guess the car is going back in tomorrow

p0252 is indeed injection pump code (problem with metering fuel), before you panic, definitely change the fuel filter as stuffed filter can produce this code (and has in the past on quite a few 1.9 engines). Make sure no air bubbles in the clear fuel lines next to injection pump. Recheck pump timing afterwards as it was adjusted with pump under stress/cavitating.

Even when the fuel filter is new and the code returns, it still could be that one of the 2 timing belts jumped a tooth. Have the timing belt been replaced recently? Only after this possibility is eliminated, blame would fall on the injection pump itself.

[MalcForrest]

Since no one else has mentioned it (forgive me if I haven't noticed it) but has the EGR valve been removed and cleaned at any point?

[vk10]

I had changed the fuel filter as theme first cheapest option so that's done. What i also replaced was the plastic return valve on the fuel filter which is a common fault ive heard. Taking it back to the garage to ask them to sort it out. Lets see what they come back with.

Malcforest no I haven't taken out the egr and cleaned it yet.

Just out of curiosity how about if I blank it off completely?

[MalcForrest]

Hypothetically, if the valve isn't there it can't cause a problem providing the wiring is done correctly.

[dieselV6]

Can you see any air/vacuum bubbles in the fuel line to the pump?

[vk10]

Il check on the air in the fuel lines now. Quick update the car is now back from the garage and the engine management light and circle triangle light is still on. Really don't knw what to do

[vk10]

Have checked the fuel lines and there are no air bubbles. I have a strong feeling this is to do with pump timing. The car seems better than it was before but still shakes shudders and needs quite a bit of cranking to get it started in the morning not to mention it still fills the street with smoke.

The reason I feel its the pump timing is because before the car went into the garage vcds read the tdi timing at about 26 29 dgrs and now is reading 111. From what I've heard it needs to be around the 55 mark??

Can anyone suggest someone or a garage who can really adjust this pump timing for me please. Um willing to travel to get there but can't keep driving like this as my fuel economy is down to 17 mpg in town and not to mention the noise the engine makes.

Please give me your suggestions

Thanks

[dieselV6]

Basic timing as shown by VCDS in Basic Settings tab should actually be 0.6-1.2 (one point two) degrees ATDC for the 2.5V6, though normally was set at factory to 0.8 - 3.2 degrees (resulting in hard cold starts for many users and a service notice afterwards).

111 may be some raw number as clearly 111 degrees out would not work, Even 11.1 degress would likely mean timing belt jumped a tooth.

Once again, has the car been serviced recently (timing belts)|? it really might help diagnosis. injection pump rarely changes timing on its own, and the known failure modes on earlier pumps mostly affect injection duration (either no injection at all or too much/too little fuel injected). At idle / basic settings even faulty pump would have correct timing.

Read this post of mine, it tells you exactly how to check basic timing with VCDS (you do not use TDI timing checker for this). The rest of that thread may be useful to whoever you find to fix the issue.

[CRC]

Also, there's a link below to a "walk through" that one of the forum members did with a PDF that shows a screenshot of the the VCDS check, and it's definitely showing degrees of advance / retard (+10 to -10)

Other searches show a Ross Tech screen shot with numbers in the range of 50 odd, but it seems that these are not related to the V6.

http://www.briskoda.net/forums/topic/142684-superb-v6-tdi-injection-pump-timing-a-walkthrough/

[vk10]

From the service records the timing belt was done in November about 3000 miles ago. The last owner said that the car drove fine till December when it completely gave up on him and he was moving abroad (so he said) and wanted to sell it. So I bought it and sent it off to my usual garage who checked the pump in the tank replaced the fuel filter and when they did not succeed they took the injection pump off to get it tested. After getting it back they put it all together again and the car started with a lot of effort, (mind you this was the first time I had seen it running). All this time I had no errors on the vagcom and no lights flashing. The car just ran like a bag of nails shuddered and shook and couldn't hold speed below 2000 revs, though once it crossed that it pulled really well. The garage thought the timing was out so they checked that and couldn't find anything else wrong with it and gave up.

I sent It off to another garage who said it is a clear case of engine timing being out and they are going to do it again, to which I said well and good go ahead. Once again they said the timing was spot on and nothing was wrong with it. ( all this time I have not heard anything of pump timing being out). They said its probably the compression or the valve and to get a compression check done.

3rd garage I sent it to diagnosed it straight away saying that its nothing to do with compression and that its a pump timing issue and they can do it. I said well and good go ahead. They had it all day and when I got it back it was warm yet but started great no smoke no shaking and started pulling from start through all the revs well. After about 3 miles engine management light comes on with the triangle and circle light. Car still drives fine but at high revs sounds like a tractor. TO add to this the cold start up in the morning is still the same, Takes a while to start and the whole car shakes and misfires (I know diesels normally don't misfire) and fills the place up with smoke. It calms down after about 5 minutes.

the 3rd garage has given up as well as they cant rid of the lights on the dash board. I know that they don't have vagcom and that they use snap on solace.

So now iam really stuck with this, ive always wanted a skoda superb 2.5 since the last 4 years and now when I did manage to get my hands on a fully loaded one I cant really drive it. I don't know who to send the car to who can time the pump correct once and for all.

[vk10]

I Just used the vcds that I have again and ran basic setting 004 and what I got is this ( mind you this is engine not fully warm but yet not a cold start since I drove it about 2 hrs ago. The results I have is 0.2 ATDC TO 4.2 btdc which fluctuated to 8.6 btdc.

Can you explain what this means ?

thanks