Cupra TDI Coughing/Spluttering/Shuddering

[karizma_fas]

Hi all,

Just bought myself a Cupra TDI. Few issues with it.

When idling it 'sometimes' starts coughing/spluttering. When driving at around 1500 - 2000 revs it coughs and splutters again. It jirks and shudders and this is at constant speeds and when accelerating. Also when I 'put the foot down' a lot of black smoke comes out the back (pretty much constantly when the foot is on the floor).

I was told when I bought it that the EGR Valve was needing cleaned out as they had done a Diagnostic check on it a few months before with 'EGR - Restrictive flow' coming up.

I cleaned the EGR valve etc and it was choked with black soot. I thought this would rectify the problem, but it hasn't.

The Engine Management Light keeps going on and off every few days. I've tried to boot it for the last few days because I thought it might just take a little while to clear all the crap out, but it hasn't.

I am thinking now it might be a chocked Injector? Or someone told me it could have had petrol put into it and it's causing it to run poorly.

Anyone got any idea's? Starting to worry

Don't think it's the filters as these were all replaced around 6-7 months ago.

Cheers
Mark

 

[CJRamze]

I'm not 100% if this will make a difference but its possibly an injector problem.
Buy yourself some millers diesel additive, Double dose it (Maybe even triple) and take it for a blast round the hills. Give it some serious beans, Clean that exhaust out and clean the injectors out!

If that doesnt work the car might explode... Don't blame me for that.

Best bet however is to find someone/somewhere with VAGCOM and get the fault codes, Someone here should be able to sort you out.

 

[NickyJam]

diesels can run with petrol although not recommended due to the qualities of diesel fuel and it's lubrification functions, but if mixed there's no bother at all

regarding the juddering between 1750-2100 revs, this is a known problem with SEAT UK as I complained about this on my FR TDi. apparently if it is pretty bad you can have the EGR valve replaced under warranty.

I found that basically the TDi's at those revs prefer a little more gas as it only ever happened when i would tap the accelerator whilst cruising. but yes it is an egr fault

since my remap it is hardly evident i would recommend p-torque

 

[CJRamze]

diesels can run with petrol although not recommended due to the qualities of diesel fuel and it's lubrification functions, but if mixed there's no bother at all

!?!?

 

[NickyJam]

was just pointing out that mixing a bit of petrol won't harm the diesel engine...in comparison to sticking diesel in a petrol as the spark plugs don't ignite diesel

diesels will run (but poorly) on petrol but petrols won't run on diesel

i done it once (stuck £2 worth of petrol in mine lol)

 

[karizma_fas]

Got a diagnostic check. Turns out it was the EGR Valve. The vaccum valve on it was still sticking, so I blanked it and hey prestow - sorted . Run's way way way way better. Now I can enjoy the Diesel power!

Many thanks for all the comments guys. Bought some engine cleaner so gonna give that a try aswell.

Just need to spend some cash on mods as i've got a few hundred burning a hole in my pocket!

 

[CJRamze]

By the way, I used millers on Every other refill or if I was using Tesco's fuel I'd use it on every single fill.
Kept the car running well and smokeless!

 

[karizma_fas]

Is Redex pretty much the same as Millers?

 

[CJRamze]

I think so, Aslong as its Diesel Additive and not petrol additive (My Redex is PetroL)

 

[karizma_fas]

Yeah it's the Diesel one. Put it in so we'll see how it goes.

BTW do you know the Wheel Bore etc for a Mk4 Cupra TDI?

Looking at 20mm spacers and seen these

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=390167677588&ssPageName=STRK:MEWAX:IT

 

[karizma_fas]

Ah seen you answered my other post doh!

Thanks

 

[NickyJam]

i use Redex diesel now and then...mine don't smoke even when pushing it on motorways (obviously it does a tad initially it's a diesel)