Jump to content
It’s a Cob

4501 egr deviation

Recommended Posts

Hi all removed swirl flaps over weekend fitted x8r kit put all back together fires up worked a treat next day drove 100 miles got back home went to go out 5 min later to find no power read code found 4501 fault pulled vacuum hose off worked fine went and did what I had to put hose back on power loss was intermittent 

have I disturbed something or is it coincidence that something had gone straight after swirl flap removal vehicles a 2008 530d just hit 150000 miles drove like a dream before I removed flaps 

many thanks 

Share this post


Link to post
Share on other sites

You've probably got a small vacuum leak or partial blockage in the vacuum system. If you've got diagnostics and a vacuum gauge you can check the vacuum applied to the EGR. The diagnostics will cycle the vacuum every 4s. You should see the vacuum gauge flick from almost nothing to a hefty vacuum in a fraction of a second. If it's slow that's your problem.

 

It can be a blockage in the splitter where the rubber hoses come off the main rigid vacuum pipe. These have 0.5mm holes in the feeds to the EGR and need a tiny wire to poke it through.

Share this post


Link to post
Share on other sites

You can do that just about with just the acoustic cover off. You can easily get to the EGR pipe at the EGR for the check.

 

With a mirror, torch and feel you can get the pipe off the splitter (usually needs a screwdriver to push it off).

Share this post


Link to post
Share on other sites

Ok I’ll have a look when I get home is it worth me picking some pipe up and change it anyway or is it likely to just be a blocked splitter I’ve just ran it for 20 mile with pipe off egr ran lovely but eml is on does that clarify the problem 

Edited by It’s a Cob

Share this post


Link to post
Share on other sites

It could be a lot of things - the diagnosis with the diagnostics and vacuum gauge is key. Without a gauge you can't really tell a good vacuum and a clean switch from good to off.

 

But a blockage would be my guess and the pipe has a 3.5mm ID whilst that port on the splitter is 0.5mm. So any crud is likely to block that hole first.

Share this post


Link to post
Share on other sites

I think so, but what you are looking for is a sharp swing, almost instant from one to the other. A slow change over a second or more means a blockage.

 

You have to use diagnostics to do this. Just looked at my gauge (to covert the units) and I think I see more like about 0 to 25.

 

Normal use and you don't know how slowly the car is trying to activate the EGR.

 

The fact that you are seeing 25 means you are getting full vacuum which means a leak is unlikely.

Share this post


Link to post
Share on other sites

You might have an air leak then. Perhaps a manifold gasket has dropped off - they do! But although that will generate a fault I don't think it would be EGR deviation.

 

The EGR is controlled by the DDE by a vacuum and pressure converter. The car believes it has some control of the EGR (when it's connected) but it's not responding fast enough.... is the EGR gummed up...that's quite possible.

Share this post


Link to post
Share on other sites

It was stripped down and cleaned about 2 months ago would removing the swirl flaps create a mass off gunk is that possible like I said it was fine for about 100 mile up motorway and back then this happened after 5 min off switching off and back on again run perfect with vacuum hose pulled off apart from eml on but it’s not on with pipe connected 

Share this post


Link to post
Share on other sites

Tricky, everything is clearly pointing to an EGR that isn't responding properly. That has to be a vacuum issue or a physical fault with the EGR.

 

With the pipe off (and blocked) the car will run a whole lot better but you will have the emissions warning.

Share this post


Link to post
Share on other sites
43 minutes ago, JasonH said:

Tricky, everything is clearly pointing to an EGR that isn't responding properly. That has to be a vacuum issue or a physical fault with the EGR.

 

With the pipe off (and blocked) the car will run a whole lot better but you will have the emissions warning.

 

Code out the EGR, and fit a bypass :)

Share this post


Link to post
Share on other sites
3 minutes ago, It’s a Cob said:

Wish I never removed the swirl flaps now 

 

If they had failed, you would have written off the engine!

Share this post


Link to post
Share on other sites
4 minutes ago, Clavurion said:

To me this sounds like failed EGR vacuum solenoid letting too much vacuum thru and keeping EGR valve open.

 

Good point.

Share this post


Link to post
Share on other sites

The Pressure Converters are kind of tricky to test. Search for Pierburg Pressure Converter, Pierburg have some test guides.

 

Realistically best bet is to use ISTA/D or DIS V57 diagnostics and run the EGR test. That tells you the pressure values to expect. I can't exactly remember the minimum but I thought it was around 0.

Share this post


Link to post
Share on other sites

FWIW, I did some work in that area on my 520D last summer. I broke the plastic inlet on the pressure converter and bought a secondhand one from eBay.

The car broke down on me the next day and was recovered to my local INDI garage. They put a new EGR on it, saying that was the problem and all was well until May this year when I discovered purely by chance that the vacuum pipe was off the converter, it had put the engine light on and I assumed this was the cause. Refitted the pipe and the next day it conked out on me. Pulled the pipe back off and it started and ran fine but the engine light would come on again after a while.

Had enough, and sold the car with the pipe off!!!   But, reading this in wonder it the secondhand converter was to blame. If you pulled the pipe off, the EGR would clunk as if closing suddenly.

I'll never know for sure now. I have DIS, but never got around to specifically checking those items.

Edited by Phil adams

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×