BMW E46 EGR Valve Bypass [Visual Guide]

This blog post is dedicated to all things related to the BMW E46 EGR valve.

It covers;

• the symptoms you might experience from a blocked EGR valve,
• the benefits of bypassing the E46 EGR valve,
• and how to actually bypass it.

The method of bypassing in this guide can be used on the 318d, 320cd, 320d, 330d and 330xd, as they all use exactly the same EGR valve.

(BMW OEM EGR valve part numbers: 11714701242, or 11717785452 from 2006 on wards).

This post contains affiliate links. Please read my disclosure for more info.

Purpose of an EGR Valve

Exhaust Gas Re-circulation (EGR) valves are used in petrol and diesel engines as a method for reducing Nitrogen Oxide (NO) emissions.

EGR valves work by taking some of the exhaust gases and routing them back into the intake manifold. These gases reduce the peak combustion temperature in the cylinder, which in turn reduces the amount of NO produced by the combustion cycle.

Symptoms of a Blocked EGR Valve

Symptoms of a blocked of faulty EGR Valve can be: poor or decreased MPG, increased smoke or soot from the exhaust, increased harmful emissions, poor throttle response, engine running rough or lumpy, car feels down on power or torque and in extreme cases the vehicle is stalling at low speed.

There could be a number of causes for the above, but it's relatively simple to rule out the EGR value first. To see how your car compares to mine for fuel consumption, check out my post on real world 330d fuel economy. You might also want to clean you mass air flow (MAF) sensor.

Whilst I was carrying out the faulty thermostat replacement, I noticed that the EGR valve had started to coke up pretty heavily, again... Considering the time and mileage since I had last cleaned it, I was quite surprised, and concerned.

Just to show how quickly the carbon build up forms in the EGR valve, here is a photo from my DIY EGR valve carbon clean post, showing the valve freshly cleaned.


Now here's two more photos just 2 months later, after around 2000 miles.




As you can see, it's already looking worse for wear.

Location of the E46 EGR Valve

The E46 EGR valve is located at the front of the engine, underneath the plastic engine covers. The re-circulation pipe runs from the right hand side of the engine to the left where it joins to the EGR valve.

How to Bypass the E46 EGR Valve

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Unlike the earlier M47 and M57, those with the later M47N and M57N engines may get a warning light on the dash by disconnecting the EGR valve.

If you choose to do this bypass on your car, you do so at your own risk, I will accept no responsibility for any damage caused.

That's the disclaimer dealt with, on with the show.
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Fortunately, it's dead easy to bypass the EGR valve, as I will now explain.

Remove the engine plastics until the EGR valve is revealed, then locate the small vacuum pipe (black with a blue stripe) on the left hand side of the EGR and pull it off.


I then rummaged through a tin of assorted bolts and set screws until I found one about the right size to plug up the vacuum pipe I'd just removed. I used a bolt so that I could cut the thread off and just use the smooth shank (to avoid splitting the pipe).






Next I found something to cover up the tube on the EGR valve. For this I used a bit of silicone hose that was a real tight fit. Then plugged it with another bolt cut down.


With everything now plugged, I took the EGR valve off and gave it another clean in a bath of petrol. It's a messy job but the results were good.








Finally, I refitted the EGR valve, ensured both plugs were in tight, then cable tied the two together so that neither flapped around, and so they could easily be located if I wanted to re-enable the EGR valve.




So far I've noticed no adverse affects, only positive ones. The car seems to rev more freely and pulls slightly better. I will update in a few months if there are any developments.

E46 EGR Valve Blanking Kits

A kind of half way house between bypassing and deleting, is an EGR blanking kit*. Everything else remains connected, you just install a blanking plate at the exhaust end of the EGR pipe to prevent any gasses flowing through it. It's still a relatively inexpensive solution too, click the previous link or the image below to buy one on Amazon.

E46 EGR Valve Delete Kits

And finally, if you want to go one stage further than bypassing or blanking the EGR valve, you can purchase an EGR valve delete kit. Searching the phrase "E46 EGR valve delete" on eBay will return umpteen listings to choose from.

A seller on eBay called egr-delete appears to have a bit of a monopoly on the EGR delete kit market, offering kits for a variety of vehicles. The kits, like the one below, consist of a blanking kit and replacement pipe section.

Once fitted, the kit will completely remove the EGR system, providing an unrestricted airflow into the intake manifold.

The only downsides being it takes a bit of time to fit and costs a fair bit more than my method of just bypassing.


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Update: After several thousand miles and over two years of being bypassed, I've seen absolutely no adverse affects. All MOTs have been passed without issue, and with no increase in emissions.
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Let me know in the comments below if you've noticed the benefits of bypassing the EGR, or did you go all in and delete it? Has anyone had a problem come MOT time?

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