Engine, Owners and 'Techs'
The THP despite being initially lauded and winning countless awards even up to 2014 has shown in most of it's variants as being problematic especially so the PSA/BMW designed earlier variants, was it the N13/14's? less so the later modified and enhanced PSA only variants....think much of the consensus revolves around the fact that such a small capacity engine was not really able to handle 'so much' power and torque in it's turbocharged applications. Main issues seem to be
Carbon build up on valves, excessive oil consumption, recurrent timing chain/tensioner failuire or issues (most as a result of poor lubrication and some due to lack of decent/frequent oil changes).
Ancillaries: The High Pressure Fuel Pump fitted/supplied unable to cope with the demands of the direct injection engine, Thermostat....maybe more?
It seems as time went on parts were updated and supplied to 'cope with flagged issues, seems suppliers to Peugeot weren't producing decent gear'; with the 'newer' timing chain kits and HPFPs proving to be more reliable......fair to say many early 156's have the most issues?
Many Owner's from reading posts on here, come onto the Forum solely to get information about issues with their cars, many people with the RCZ are not 'enthusiasts' they bought a good looking cheap used car for everyday use, no problem with that obviously but being more fragile the THP/RCZ demands constant empathy and maintenance, so actually checking the oil every couple of weeks/monthly and not relying on the car to tell you it is low by then damage may have been caused etc, staying on top of maintenance, frequent oil and filter changes i.e every 4K miles, listening for engine bay noises, not fitting cheap or the Barry Boy parts/mods that some seem to think will enhance their cars or unproven remaps causing heat and pre det issues etc.....many of the catastrophic failures seem to be Owner induced.
Posts on here suggest that common issues with the RCZ are not understood or dealt with quickly by some Owner's, some don't wish to spend money, don't service on a regular basis and bodge, some Owner's use their local spannerman, garage or even the Main Dealer with codes being misinterpreted and parts changed out failing to remedy the situation, this seems to happen to a lot with people posting on here. For instance time and time again we see people having new plugs, coils (even a new ECU) to fix HPFP issues..... The RCZ scored well on reliability in surveys, as did Peugeot.....many like Range Rover, Porsche, Mercedes etc do not.
Fact for me is having older 1990's-2000s cars and more modern cars.....the modern cars are shite, overloaded with pollution controls, crash and safety systems, electronics and sensors everywhere and basically built for a time span and multiple visits to Dealers and Specialists due to the need for expensive code reading and diagnostics with parts that are designed not to last....planned obsolescence?
As I have wittled on several times I bought my car private with the Peugeot Warranty, I would not have purchased without it and I still renew it due to possible issues and the expensive bespoke parts on the R.....within months of purchase the HPFP went, had to wait 3 weeks for MD to repair/source a new pump. Broken front spring from previous owner, both springs replaced and then 18 months or so ago a new clutch and DMF this in 4 years of ownership and around 4K miles with a replacement turbo shield after a Main Dealer melted his glove onto it when using it as a hand support dented it and the scraped off the residue with a metal implement! None of this cost me any money to sort save for servicing at the MD; now using a Specialist.
Much depends on individuals, the actual car purchased, the previous owner, maintenance and servicing, the mechanics that have worked on it etc, get them all good and the RCZ is as reliable and as anything else, possibly.
