EGR Valves

[lexusis220]

Hello,

I have an is220d 08 model.  Im having an issue with carbon build up.  I had the car fully serviced and the EGR valve taken off and cleaned.  The mechanic sent me some pics and it was properly clogged.  Even the manifold inlet pipe was clogged.  He cleaned the whole lot out and the car changed in how it responded etc.  FYI for the better!  The service took place in November so it hasnt been that long at all.  The issue is, is that im having similar issues to what i was experiencing before I had the service done which is slow take off.  Then when i hit 2500rpm it kicks in! But on hills if im in 2nd gear its not going anywhere.   So im thinking that the EGR valve is blocked up again and needs a clean.

I will do that this weekend, but wanted to know why it would get clogged up so quickly?  The lexus garage (when i took it to them to reset the engine code) suggested it could be the EGR valve cooler??

Any ideas? 

[madasahatter]

Are you only doing short journeys? Diesels require long runs to benefit.  

[lexusis220]

Nope, i do a semi dual carriage way route.  Its a 44mile round trip commute.  So the engine, exhaust system is getting nice a hot.

[johnatg]

What is the mileage? and is the car using any oil? I suspect that EGR valves work OK when diesel cars are new, but as the mileage builds and piston rings wear there gets to be a bit more oil in the exhaust, and EGR valves are very sensitive to even small amounts of oil in the exhaust. Just my theory!

The objective of EGR valves is to reduce combustion (and exhaust) temperatures!

[lexusis220]

what if any, would be the fix for that?

 

[johnatg]

New rings, I suppose - but that would be a major operation and the economics would be questionable.

[Shaunomercy]

Is the egr valve still working ?  I had a zaffira b turbo diesel.  When the egr failed, I had no boost till around 2500 and then it was off on full boost.

Are you driving like a pensioner ?  That's not meant to read as a may comment.  The problem with these modern diesels is they have to be thrashed all the time or live on motorways.  Drive them gently and they start getting blocked filters.  Drive them harsh, fuel economy drops, so you may as well have a petrol, the torque shreds your tyres, and there are the dreaded dual mass flywheels to contend with.

[lexusis220]

How do i check/know if the EGR valve is working?

[Shahpor]

Hello,

As far as I am aware, you need the TechStream software in order to test the EGR valve.  (Unless anyone knows otherwise?)

There is an active test you can run on there wherein you can set the target opening percentage and see how it responds.

Before any of that though I would confirm it is blocked.  How many miles have you done since it was last cleaned?

[lexusis220]

maybe 4000 miles.  I have ordered a new EGR valve so going to replace that headache! I hope it sorts the issue out.

[Texas]

Yes it will, for a while, until it clogs again and it will! Only save and grace will be that you can clean one at your leisure while using the other on the car.

From my college days I remember a lecturer stating that Diesel engines were idea for heavy loads ie heavy plant/machinery( not a car), long run durations (hours/days/weeks) ie Ships/generators ( not exactly cars) and were most efficient when under a constant load, again not in a 'small' car. So when not used under these ideal conditions problems are going to occur and any ancillary equipment to reduce the levels of solids in the emissions is going to need maintainance at some level no matter what Gucci type of 'Re-Gen' system you employ.

Paul m.

[johnnyroper]

Sounds just like mine did when I first got it, egr was fairly clean but overtime it had worn so was not closing fully even with no carbon crap in there.

egr replaced car performed so much better.

[lexusis220]

Thought id update.  Bought an aftermarket EGR valve.  People DO NOT WASTE your money.  I had the EML light....and some others.  I then returned that and bought an original toyota/Lexus part.  And behold!! its changed in character for the better.  And MPG has gone up from a measly 28mpg to creeping past 37...All in all looks good.

[normski2]

Do you keep the old original EGR valve?

If you did have a play with it and get to understand how it works and how easy it is to clean. There are quite a few good videos on Youtube. It will benefit you to do that. That piston inside needs to seat well when in closed position.

When I had a 220d, way back when, I used to remove and clean the EGR every 8000 mls or so. Whilst the EGR is out of the car clean the main port into the manifold with a screwdriver and suck out all the old crud with an old hoover, if you have one.

Opinion is divided on additives. But I will say from my own experiences, I used Archoil (AR6200) diesel additive at about 5-6 ml to a tank of fuel and found the amount of soot in the EGR was much reduced. Seemed reasonable to assume that the amount of soot going into the DPF will be reduced too.