Y33: How to clean EGR valve?

[miata007]

Continue from another (regarding to failing smog check), how do you actually clean the EGR value?

I was able to take out the part last nite. Took some effort to remove the big nut connecting the bigger pipe...had to use some WD40 before able to get it loose. While disconnecting other hoses/pipes of EGR value, discovered 2 things:1. One pipe has been broken in half (already). That hose connects to a part that looks almost like EGR valve (circular frisbee looking). Believe damage were caused by high heat for all these years (since 1997).

2. One metal pipe is loosely connected. The nut/bolt is not firmly tighten.

Q45tech/allCould these pipe connections failures have impact to failing smog check?

Back to the main topic, how do you actually clean the EGR valve? I've read few posts talking about using sprays (ex. carb clearner). Do you actually spray everywhere you see opening of the valve? I don't see anywhere I can use brush/tools to scrape/clean.

Thanks007

[elwesso]

its typically not the EGR valve that needs cleaning but the EGR passage from the EGR valve into the intake manifold that needs cleaning. Look inside, i bet its caked full..

[paranoidjack]

Scrub it with carb cleaner, whatever you got! I used bottle cleaners and soaked them overnight, got it damn near perfect, shiny and everything. No after pics, sorry.

[3Q Jay]

the 'pipe' you claim is broken: are you sure that you are not looking at the skinny tube that connects to the BPT (the frisbee looking thing) from the EGR valve with a short length of rubber tube?

good pics from pJack. note that to do what he shows you must remove the upper plenum (that shaft does not have enough room to slide out otherwise.

cleaning the EGR and passages is a good idea, will mostly improve NOx, not HC.

do you have that TPS part number that you replaced?

[miata007]

3Q Jay,Yes, I am referring to the skinny tube with with short rubber tube. Do you know what is the purpose of BPT?

Regarding to part #, this is what it says in the original box which I still have. 22620-6P010

You can also check with IOS to make sure the part # matches.

007

[maxnix]

Wire brush on a Dremel with cable extension helps, along with Berryman Chem Tool.

But Wes is correct in that once the valve is cleaned, it won't do any good if the EGR tubes are blocked, and it is usually the intake manifold that blocks first.

On the VH41DE, there is a tube that slides into the plenum that distributes the EGR gas, and not very well, I might add. This tube gets clogged at about 60K to 80K depending on driving style (highwya miles). You'll need two gaskets and will probably have to remove the plenum to get to it. Here, the cable extension on the Dremel with a worn down wire cup brush will earn it's price in seconds instead of hours with other devices. It's the inside, not the outside that matters.

200% endorsement of what Jack and Jay say. You don't have to remove the lower runners to clean them with a rag, ChemTool and an flexible wire extension grabber. But if your KS are bad, go all the way like Jack did. You must have all gaskets and some OEM fuel hose. Be very careful with the injector tips, and I like sending them to Deatschwerks for cleaning and calibration (latter is free for NICO members).

Modified by maxnix at 7:49 AM 7/11/2009
Modified by maxnix at 9:18 PM 7/12/2009

[paranoidjack]

The EGR tube slides out towards the firewall from here:

That's why the upper plenum has to come off to get it out.


Modified by paranoidjack at 1:59 AM 7/14/2009

[3Q Jay]

3Q Jay,Yes, I am referring to the skinny tube with with short rubber tube. Do you know what is the purpose of BPT?

Regarding to part #, this is what it says in the original box which I still have. 22620-6P010

You can also check with IOS to make sure the part # matches.

007

007 thanks for the p/n. BPT is backpressure transducer. here is the epitomal thread on the BPT:

zerothread?id=234059

i'm not sure your skinny pipe is broken? you will need to replace the short rubber tube if cracked or missing.