UKparafire
Member
For the last few months my van seemingly randomly goes into limp mode, without and apparent pattern. OBDeleven throws up many and varied fault codes, mostly relating to turbo underboost (p0299, p0236) and intake air system leaks (p2279). I have never had time to fully investigate when the fault presents, and when I have the time to investigate I can't find anything wrong.
So far I have only smoke tested the intake, and have sprayed brake cleaner around the intake and vacuum hoses whilst the engine is running (when the fault code is inactive) and have not found any obvious air leaks.
The 2 most recent times the problem has presented, it's given an EGR fault too (p0402), I have also noted it occurs only when the engine is hot, usually at low revs, under load, often after stop start driving. It has never happened on my 45 minute journey to or from work which is mostly dual carriageways at times where there is no traffic.
My latest theory is a potential sticky EGR valve - does this sound plausible? Thinking it's most likely to stick open when hot, and could cause boost pressure to leak through the EGR back to the exhaust.
Note, I was a car mechanic for several years, and worked for a Bosch diagnostic centre as a diesel technician, so am not completely green, however I stopped working in the motor trade almost 15 years ago when I trained as a paramedic, so I am very rusty!
I hold very little faith in spray cans of EGR cleaner, am short on both time and money (so can't afford to pay a mechanic, or to buy parts that don't need changing, nor to spend ages stripping down parts). I am wondering, if I remove the flexible pipes either side of the EGR valve and cooler, fill it with DPF cleaner for 24 hours, then drain it, would this be likely to free a sticky EGR valve if that's the problem? Or if I remove the thing that looks a bit like a glow plug in the pictures attached (what even is it) from the EGR valve near the port, could I spray something in there and wiggle a pipe cleaner or something inside to clear and soot?
Otherwise, does anyone else have any other suggestions? Either for further investigations I should do, or ways to clean the EGR?
So far I have only smoke tested the intake, and have sprayed brake cleaner around the intake and vacuum hoses whilst the engine is running (when the fault code is inactive) and have not found any obvious air leaks.
The 2 most recent times the problem has presented, it's given an EGR fault too (p0402), I have also noted it occurs only when the engine is hot, usually at low revs, under load, often after stop start driving. It has never happened on my 45 minute journey to or from work which is mostly dual carriageways at times where there is no traffic.
My latest theory is a potential sticky EGR valve - does this sound plausible? Thinking it's most likely to stick open when hot, and could cause boost pressure to leak through the EGR back to the exhaust.
Note, I was a car mechanic for several years, and worked for a Bosch diagnostic centre as a diesel technician, so am not completely green, however I stopped working in the motor trade almost 15 years ago when I trained as a paramedic, so I am very rusty!
I hold very little faith in spray cans of EGR cleaner, am short on both time and money (so can't afford to pay a mechanic, or to buy parts that don't need changing, nor to spend ages stripping down parts). I am wondering, if I remove the flexible pipes either side of the EGR valve and cooler, fill it with DPF cleaner for 24 hours, then drain it, would this be likely to free a sticky EGR valve if that's the problem? Or if I remove the thing that looks a bit like a glow plug in the pictures attached (what even is it) from the EGR valve near the port, could I spray something in there and wiggle a pipe cleaner or something inside to clear and soot?
Otherwise, does anyone else have any other suggestions? Either for further investigations I should do, or ways to clean the EGR?
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