flashing glow plug light VW Golf VI Hatchback 1.9 TDI Diesel 2009 - what to do? VW GOLF VI (5K1)
06.04.21
31.10.25
@Coltoldest4709.04.2021 16:29MemberLike you said yourself, you need to run diagnostics because there's a number of things that could be the issue here. Once you have the fault code I'm sure someone here will be able to give you some advice.- @EsmePatelArt30.10.2025 13:11MemberHonestly sounds like it could be vacuum hose related, mate. Had something similar on my Passat few years back - lost power on motorway, flashing coil light, the works. Turned out one of the little rubber vacuum pipes to the turbo actuator had split. Cheap fix once I found it!
- @Phillips_130.10.2025 15:11MemberAgree with diagnostics first, but I'd bet money it's either vacuum system or N75 valve. The fact it cleared after restart is typical - means limp mode was triggered by something that's intermittent. My Golf did exactly this before N75 packed in
- @JAS.MORRIS30.10.2025 17:10@Tram1980Member@Tram1980 Could be boost control issue. When mine did this I checked all vacuum lines around the turbo first - found one that was perished and leaking. Once I replaced that hose everything went back to normal, no more limp mode
- @WLewis730.10.2025 17:34MemberI'd suggest checking the MAF sensor as well, not just turbo stuff. Friend had his Golf TDI going into limp randomly and it turned out to be dodgy MAF giving wrong readings to ECU. Easy enough to test by unplugging it temporarily
- @G.Hill.M30.10.2025 18:03Member@Coltoldest47 Spot on about getting codes read. But just to add - if it's throwing P0299 (underboost) or anything turbo related, first place to look is those vacuum hoses. They get brittle over time especially on Mk6. I replaced all mine preventatively after one failed
- @ethan_tech30.10.2025 18:41MemberThe stop-start not working is interesting detail. That usually means ECU detected something serious enough to disable auxiliary functions. Could be EGR related too - seen that cause similar symptoms on TDIs
- @e.wright1431.10.2025 21:13@Tram1980Member@Tram1980 My bet's on either split intercooler hose or N75 valve failing. Both give exactly those symptoms - sudden power loss, flashing glow plug light, then fine after restart. Check pressure side hoses from turbo first, they're known weak spot
- @James Baker31.10.2025 22:20MemberWorth mentioning DPF issues can cause this too, though usually you'd get DPF light as well. If it was trying to regen and something interrupted it, could trigger limp mode. But given it cleared so quickly I'd look at boost system first
- @daniel.scott_3431.10.2025 22:33MemberHad exact same thing happen on my Mk5 TDI couple months back. Flashing coil light, no power, cleared after restart. Turned out to be perished vacuum line behind the engine near the EGR. Proper pain to spot but once replaced never came back
- @F. Adams31.10.2025 22:44MemberI'd check the turbo actuator arm as well when you get it scanned. Sometimes they stick or the linkage gets stiff, causes underboost codes. Mate's Golf had this and adjusting the actuator sorted it right out
- @WOOD C. J.31.10.2025 23:01MemberDon't ignore it even though it cleared mate. These intermittent faults usually get worse. Start with visual inspection of all vacuum lines - look for cracks, splits, anything perished. Most common cause of these symptoms on 1.9 TDI
- @SportKing 👑31.10.2025 23:20Member@Tram1980 Get it on VCDS or similar proper VAG diagnostic tool when you can. Generic OBD readers sometimes miss stored codes. But yeah, classic symptoms of either N75 valve going or vacuum leak somewhere in boost control system. Seen it loads of times on these engines
Today I was driving my VW Golf Mk6 1.9 TDI Bluemotion on the motorway with cruise control set to 60mph in 5th gear when I suddenly heard a ding, along with the message Engine Fault: Workshop! and a flashing glow plug light.
The cruise control stopped working and the limp mode was activated. I got off the motorway at the next exit, which thankfully was where I have headed anyway, and didn’t have any power/turbo for the last 5 minutes to my destination. The stop-start function wasn’t available either.
When I parked I turned the engine off and on again and the light didn’t come back on. I did a quick turn around the car park and the turbo and cruise control were both working again.
As you can imagine, I’m still worried about why this happened and if it could happen again. Does anyone have any experience of a flashing glow plug light on a VW followed by a sudden loss of power? I know I need to have diagnostics run on it but wanted to ask here first to see if anyone has any ideas about it.