Hiya folks, just perusing the forum for a couple of months so far while waiting for my car and I`ve noticed that the lads with the vRS tdi`s seem to be experiencing more problems with their cars than the petrol owners are. I`m rather pleased I ordered the petrol as with most forums I`d be worrying when my tdi was going to fail for some reason!

I think that may partly be down to the split between petrol and diesel being in the region of 70/30 ( tdi/tsi)

However, the tdi does appear to be suffering from af sensor issues

There does seem to be far more oilers than petrol. It does seem to be in general that the diesel cars suffer from more problems with dmf`s dpf`s and other little niggly things. Diels used to be the go to vehicle power if you wanted reliability and longevity but not now it seems. 

I think generally speaking the 'Oilers' would appear more reliable but only as the miles really pile on.

A diesel unit is designed for the long haul and should ( i say should) prove more reliable over a longer period.

As most cars aren't held by the same owner for more than say five years, it shouldn't be a problem either way.

The sensor issue is indeed unfortunate but is just a sensor problem and not a fundamental failure of the power unit.

DPF issues may in many cases be down to individual users and their driving style / journeys, for what it's worth, I haven't encountered either issue yet or with my previous VAG Diesel.

Looked on here before ordering and was put off a diesel for that reason and that i only do 7-8k a year was advised against it by the dealer due to dpf issues.

It is not so much a diesel engine that is unreliable, more so the technology used to control the emissions. EGR/DPF technology for diesel engines will become redundant in the future, it will be replaced by SCR. This means manufacturers will not invest a huge amount in developing these systems as they can already see end-of-life in the product life cycle.

Explanation of the difference in this thread:

 

http://www.briskoda.net/forums/topic/329318-ea288-detailed-information/?hl=%2Bscr#entry3963206

The newer technology has been used by VW Group for some time in the USA, and is already on some European vehicles including those in the UK. Just look how much is piled up outside motorway service stations here in the UK next time you fill up.

 

http://www.volkswagen.co.uk/technology/diesel/adblue

 

https://www.youtube.com/watch?v=1h9hWlvg6sM

Any idea how many real world miles you'll get before the adblue will need refilling ? Car won't start without it !!!

 

Kinda makes me consider just how years left diesel engines have left in production cars as no OEM is spending on diesel engine R and D currently and Toyota are going all petrol/hybrid by the end of 2015

 

Guess it'll all come down to popular opinion and legislation in the end

Diesels have more bits to go wrong. DPFs, EGRs, DMFs, High Pressure Fuel Pumps, etc. I'm back with petrol as I don't fancy playing the emissions lottery anymore.

The diesels are more popular because they are far cheaper to run (low 30's v high 40's MPG under normal conditions) also the diesel is cheaper to buy on finance as its residual value is a fair bit stronger.

 

The TSI is the better car of course but many people either cant or wont justify buying one because of the higher ownership and running costs.  I cant run one because the emissions are too high for my company car allowance scheme.

 

Does appear the 184 TDI motor has been suffering some boost pressure sensor issues but probably just a bad batch of components..it does happen.

 

My 150 TDI really hasnt skipped a beat in 20k miles/13 months so I dont think the TDIs are inherrently any less reliable.

 

Id be surprised also if the TSI didnt have a DMF and definitely has a form of HPFP but granted no risk at all of any DPF woes, not that they are really problematic on the newer CR TDI motors anyway.

Edited 14 March, 201511 yr by pipsyp

Are the TSI engines still using the coil packs that allow water to drop down onto the top of cylinder 3?

I only ask as this was an issue on the MK2 Leon.

Any component/manufacturing faults tend to show up within the first year or two so will be covered by warranty. Both engines should do 150K miles easily with routine maintenance, but the diesel will likely go much further.

 

I went TSI because my mileage is low and I prefer the added performance and sound. If I drove high miles the diesel would have been my choice. They should both be as reliable as eachother unless used as a 50K mile per year Taxi, in which case the diese is the obvious winner.

Any idea how many real world miles you'll get before the adblue will need refilling ? Car won't start without it !!!

 

There's a couple of threads at http://forums.tdiclub.com/showthread.php?t=436096  and  http://forums.tdiclub.com/showthread.php?t=350310 which suggest 10,000-15,000 miles for a Passat, and also suggest that at least some places top it up as part of the service (albeit they charge as well). Granted those are US-spec Passats, and US dealer service packages, but I would assume that generally it's likely to be designed to last between services - can't see them having a different size tank for US models.

I'm guessing the newer tdi engines are more reliable than the older 2.0tdi vag engines as my Passat had just had a new engine fitted before i bought it at 80k due to oil pump failure. Also two guys at work have also had their 2.0 TDI engines fail due to oil pumps before 100k. One was an 2009 a4, and one was a Passat

Edited 14 March, 201511 yr by V6Jules

I'm guessing the newer tdi engines are more reliable than the older 2.0tdi vag engines as my Passat had just had a new engine fitted before i bought it at 80k due to oil pump failure. Also two guys at work have also had their 2.0 TDI engines fail due to oil pumps before 100k. One was an 2009 a4, and one was a Passat

 

Oil pump failure on the PD diesel never affected the Octavia - only the Superb and Passat family. The Octavia had the transverse variant of the engine of slightly different design.

 

The pump failures could just as easily happened to a petrol - caused by bad VAG design again.

Ok that makes sense although the Passat engine was transverse in the Passat from 06 on and the guy with the A4 was a CR engine I think.