Golf mk5 tdi egr valve

5 Feb 2005
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United Kingdom
Curious really:

Got an "emissions workshop" error and check engine light turn on. Car is 150k, 17ry old golf mk5 tdi 2l.

Took to mechanic who plugged it in and said the warning was egr valve related. Said it wasn't a critical issue / engine wont die and I was OK to drive it till its a annual mot and service next week.

Spoke with a land-rover friend, who said they often remove the egr valve on their vehicles as they cause trouble.

Quick Google indicates they cut emissions by recycling exhaust gas back for combustion.

So what does the error on the car mean? It's stuck open, or shut, or, the sensor/mechanism dodgy?

I guess shut means more pollution but more power? Car does not seem any different, turbo sounds fine, no loss of power.

Just curious. Can anyone shed light on whats going on?
Last edited:
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As you have found out, the egr valve allows burnt exhaust gases to be reintroduced into the engine for burning again......rather peculiar for sure, but this reduces the combustion temperature so nox emissions are reduced. I think this is in the region of 1400 deg c.
At low engine temperatures, i.e tickover, cold start, the egr is only opens as the engine temperature and speed rises. The egr is either vacuum ( yours, probably) or electronically operated.
As you don’t notice any drop on performance, starting or tickover I’d assume the valve is stuck’d be amazed at how much carbon crap can accumulate in the egr.
You are, unknowingly, probably causing more pollution than before and your fuel consumption will be worse, and the engine management lamp makes you aware of this.
You’ll need to get it sorted before the next MOT, unfortunately which requires either a full clean or a new one....egr cleaning chemicals introduced into the fuel or air intake won’t make any difference to this one.
John :)
cleaning these on a TDI is piece of cake, can be done on the drive. you need some keys, breake cleaner, new bolts and gaskets (bolts only if you have OCD and like shiny stuff) and a bit of time. get it done and forget about it, not worth messing with removing it and stuff. there's not much life left that in car in today's political landscape, so keep it trouble free for as long as you can.
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