The 1,984cc four-cylinder petrol engine used in the Volkswagen Golf GTI Mk5 uses four valves per cylinder and produces 200hp at 5,100rpm, or 230hp at 5,500rpm for the uprated Edition 30 engine that uses a K04 turbo in place of the standard GTI's K03 turbo. In normal guise, it provides 207lb ft of torque spread between 1,800rpm and 5,000rpm, or 221lb ft between 2,200rpm and 5,200rpm in the Edition 30.
The engine is coupled to either a six-speed manual or DSG dual-clutch gearbox with six gears. VW didn't offer the seven-speed DSG 'box in the GTI as it was not considered strong enough to cope with the engine's power and the sort of use a GTI would be subjected to.
200hp and 207lb ft as standard
If you opt for the manual gearbox, you should have no problems at all as it's regarded as trouble-free. It's supposed to be a sealed for life unit, but specialists recommend at least checking the oil routinely at every second service. A clutch should last anywhere between 40,000 and 100,000 miles depending on use.
The DSG gearbox needs more circumspection when looking at a car to buy as the Mechatronic ECU can fail, leading to a lurch as the car takes up drive from a standing start. From Volkswagen, a replacement Mechatronic is £900 plus fitting, but fortunately ecutesting.com can supply a rebuilt ECU with two-year warranty for £250.
Another area to check carefully with this 2.0-litre engine is the cambelt. It should be replaced at 80,000 miles or four years, whichever is sooner. The water pump and tensioners should also be replaced at the same time, so check the service history for evidence it's been carried out on schedule. A big service including the cambelt and water pump could set you back £850.
The high pressure fuel pump is driven off the camshaft and the cam follower can fail. It's easy to rectify but needs to be dealt with immediately to avoid more serious damage to the engine. The pump costs around £30 for a replacement and experts recommend replacing it every 20,000 as a service item to avoid the risk of failure.
Another common problem with the Mk5 GTI's engine is the positive crankcase ventilation (PCV). Check for this by removing the dipstick. If the engine begins to falter, the PCV valve is fine, but if the engine continues to run fine then the valve is faulty. You can also check for signs of oil being forced out of the filler cap and leaking onto the engine.
Easily tuneable for those seeking more
More common problems are the diverter valve and air conditioning compressor failing. For the former, the rubber diaphragm wears and allows air past, so the engine cannot achieve full boost. You will notice a flat spot or lack of power. It's another easy and cheap fix thanks to an upgraded part that uses a plastic piston in place of the rubber diaphragm for around £30 plus fitting.
For the air con's compressor, check the vents are pumping cold air when the climate control is at its lowest setting. If not, a new compressor will cost around £100 but fitting could increase the bill substantially.
The engine's coil packs are yet another regular point to fail on this Mk5 GTI and a new set costs £80 from independent specialists such as Awesome GTI and PSI Tuning.
A cracked airbox is less common but some owners report it. Many get round the problem by fitting an aftermarket airbox, such as the ones from Revo, Forge or Carbonio, with prices up to £450 for the best set-ups.
Other tuning options include a remap, with a stage one remap likely to offer around 240hp. A de-cat exhaust back box is another popular upgrade to give the engine a bit more of a voice. If you intend going down the bigger turbo route for 300bhp or more, a limited-slip differential becomes a necessity and will cost from around £1,100 from the likes of AKS.
A lot of PHers recommend running the Mk5 GTI on 98-octane unleaded to get the best performance and economy from the engine. Many also report the engine can use up to a litre of synthetic oil every 1,000 miles.
"To drive, it's a real hoot. It positively goads you into pressing on. The delivery's not too laggy and it seems to get a second wind at 3,500rpm. The delivery starts to tail off as you approach the redline, but that seems to be the way with these modern light-pressure turbo lumps."