BMW 2002 E46 320D EGR Valve

IK09

Hi Guys,

My car has developed a rough idle and i have been told in passing by a mechanic that USUALLY cleaning out the egr valve sorts this out. Ive done my research and tbh think i can do this myself.

Does anyone see anything wrong with these instructions?

http://www.bimmerforums.co.uk/forum/f91/cleaning-your-egr-valve-320td-320d-t15943/

Also is there anything else that i should look out for? I was told that carburetor fluid was the the best thing to clean it with?

challengemaster

Those instructions are fine, they're what I was working off when I cleaned mine. I used brake cleaner and it still took quite a while, it will really, really be caked with crap.

Nothing really to look out for, it's pretty straight forward. Just remember to put everything back exactly the way it was. Make sure the EGR is completely dry before you put it back too, any moisture left is going straight into your engine which isn't good.

Aside from that, I hope for your sake it is the EGR valve... it could be in need of a new MAF

drunkmonkey

Check the fat pipe coming off EGR valve for leaks, look down at the very bottom of the pipe there's a clip there that gets loose and the pipe starts to take in air. I'd nearly bet it's that, it's pretty common....solved the rough idle in mine..

IK09

I did it last night, and ran into a problem. I must have lined up the egr value incorrectly when i was putting it back on, and i snapped one of the bolts that connect it back to the manifold.

Started at 5.30pm finished at 11.20pm. It took me an absolute age to get the bolt out as i didnt have the tool to get it out. Then rang my mate who is a mechanic, called up to his and he had the right tool for the job. It came out first turn then. Anyway I was running out of time as i needed the car for work today, and it was getting dark. So i guess i was kinda rushing. Got the egr back onto the car minus the bolt, and it was fine at first, nice steady idle.

Then this morning the idle wasnt as bad as before but there was still a bit of roughness in the idle still.

Please dont tell me its the MAF?

IK09

drunkmonkey wrote: »

Check the fat pipe coming off EGR valve for leaks, look down at the very bottom of the pipe there's a clip there that gets loose and the pipe starts to take in air. I'd nearly bet it's that, it's pretty common....solved the rough idle in mine..

Only got yer messages late last night so didnt check this. I will the second i get home though. Could you post a pic of where you are talking about? Is it the end of the black pipe leading out of the manifold or is the plasticlike tube the pipe connects to?

drunkmonkey

There's only one fat pipe coming off the erg, trace it the whole way to the bottom, it's probably half disconnected at the bottom and that's your problem. They get loose. It's about 2ft long. Connects directly to the erg, you can't miss it.

IK09

drunkmonkey wrote: »

There's only one fat pipe coming off the erg, trace it the whole way to the bottom, it's probably half disconnected at the bottom and that's your problem. They get loose. It's about 2ft long. Connects directly to the erg, you can't miss it.

Is the end of the black pipe? That leads into a silver plastic tube just an inch out of shot of the pic

drunkmonkey

It's the big fat one in the picture, trace that the hole way to the bottom, it has the same kind of ratchet connector at the bottom but I'd bet it's slipped off, either that or there's a whole in the pipe, if that pipe gets in any air you'll get a rough idle and the car can hunt for revs now and again. Check the jubilee clip at the bottom if you can't see it from the top you may have to stick you head underneath just make sure it's fully on, it may be half on.

IK09

Are you taking about the pipe itself? (red arrow) or the tubing that its leading into (green arrow). Just out of shot in the pic, there is a large tube that goes to the other side of the engine

Nissan doctor

TBH I would have had the problem diagnosed properly before stripping things down.

There are any number of issue that could cause a poor idle. If the EGR was clogged enough to cause the problem then there would likely be other issues like power issues at higher RPM, excess smoke and possible EML light with EGR flow and NOX sensor reading faults.

The breather pipes under the inlet manifold are very prone to splitting which can cause an imperfect idle, as can something as simple as the oil filler cap not being correctly fitted.

whelaneng

I have same problem. Poor idle and Just checked that pipe your talking about and mine is loose. Is there supposed to be a clip on it? And what's the easiest way to get access to it?

IK09

Ok just an update,

I bit the bullet an forked out for BMW to diagnose the problem and this is the report i got back.

**Checked the vehicle over for faults
Fault found with fuel pressure,
Tested volumn control valve,
failed test,
volumn control valve will need to be replaced,
vechile will need to e rechecked after.**

They quoted me 790e to sort it. This seems pretty excessive to me. Any thoughts or tutorials would be appreciated

dieselbug

IK09 wrote: »

Ok just an update,

I bit the bullet an forked out for BMW to diagnose the problem and this is the report i got back.

**Checked the vehicle over for faults
Fault found with fuel pressure,
Tested volumn control valve,
failed test,
volumn control valve will need to be replaced,
vechile will need to e rechecked after.**

They quoted me 790e to sort it. This seems pretty excessive to me. Any thoughts or tutorials would be appreciated

Hi IK09

What are your symptoms? Does the car perform well under load and high rev's and start ok? 150bhp version?

I don't know how the dealer came to this diagnosis so have to take the info at face value. The first thing to confirm would be fuel supply, filter, low pressure side etc.

I'm not sure what system your car is running, so cant really give you definite info. If it;s a Bosch CP3 system, the fuel metering valve is mounted on the high pressure pump and is not available separately afaik. So the complete pump has to be replaced and expensive.

Older systems will have the pressure regulator mounted on the fuel rail, but again it often means replacing the complete rail as this is the way it is supplied.

Anyway, the best advice I can think of is to get a second opinion and if there is a fuel pressure problem a good independent garage or diesel specialist will surely cost less than the main dealer.

I;m no authority on BMW so someone else may come along with better info.

IK09

Hey man,

Firstly thanks for the reply. The symptoms are that when idling, the revs will drop and the car will nearly konk. The car performs well other wise. To be honest i have no idea what system the car is running. I had the car looked by indy, and he diagnosed it as the fuel rail. So he changed the rail but the issue persisted. They said (BMW Dealer) that the parts will cost €175. Thats why i dont want to go to them. €615 labour is extortionate unless its going to take them 3-4days imo

dieselbug

Bear in mind BMW dealer labor rates may exceed €100 ph + vat

After a bit of research it seems the metering valve is available separately. There is also it seems two low pressure supply pumps on one control relay which has a reputation for giving problems. So lots of possibilities for pressure problems.

My advice would be to take it to either a diesel specialist or an independent garage with BMW experience. If you give your location someone may be able to make a recommendation in your area.