Question regarding EGR valve on 1999 Q45

[acr-c]

Hey guys, I have an Service Engine Soon light on in my '99 Q45. It has been on for about 60 to 90 days now. I need to get a California SMOG check asap so I need to deal with it.

Anyway, my buddy ran a scan on it and the code indicated that there was a fault in the EGR Valve. I have heard that the EGR Valve can sometimes get clogged or dirty and that cleaning it can often remedy the problem and stop the code from getting thrown.

I pulled my strut tower brace and the decorative cover off the engine. I can see the EGR Valve but how does it come off? I have searched for about an hour and don't see a DIY tutorial on that issue. Also, what is necessary to do the cleaning? What should I be looking for in terms of the clog or dirt?

After disconnecting the battery for a while (which I hope will clear the code after my repair) I should know fairly soon whether a new EGR Valve is needed or not I guess.

Thanks in advance for any help.Christian

[Q451990]

I'm not sure how it is set up on the Y33, but on the older Q it is common for the plenum port that is fed by the EGR to clog. Check first to make sure the EGR valve flutters when you rev the engine... if there's no movement it's a control problem instead of (or in addition to) clogging.

You might want to download your FSM (factory service manual) at http://www.phatg20.net

Heath
Modified by Q451990 at 2:14 AM 10/22/2008

[Q45tech]

Remember EGR is almost 40 year old technology not something new.........the only newness is the 13 year old monitoring of its functioning via a temperature sensor that show if egr gases are actually flowing into or near plenum.

[maxnix]

I pulled my strut tower brace and the decorative cover off the engine. I can see the EGR Valve but how does it come off?=

With great difficulty. The tube into the plenum is probably clogged with coked carbon. The only way to access the is tube is to remove the upper plenum, which probably could use a cleaning also, as could the EGR and IAC valves and the TB.

Be sure you have all the necessary gaskets including the upper manifold gasket. You can clean the lower runners with some good carburetor cleaner and rags. A dremel with a cable and wire brush workd great on the EGR tube in the plenum.
Modified by maxnix at 9:34 PM 10/20/2008

[fixer]

on y33 models ther is a diaphram at the back of the engine for exh feedback TO EGR . the bottom of this diaphram has a short rubber hose that always deteriorates. this hose is a high temp hose to pass exh gas pressure to diaphram. in a pinch you could use regular vacuum hose temporarily. that is the most common egr related problem. the diapram is located next to the egr valve toward the passenger side. I havent seen too many clogged egr passages on y33 but i would not rule it out. a quick test would be to lift on the bottom of the egr valve while idling and see if idle changes os stalls. if idle changes then the passages are probably not plugged up.

[Q45tech]

Since EGR is only flowing at a steady highway speed, the amount of EGR goo is directly related to the amount of time hours, years that the vehicle spent cruising.

City driven cars rarely have the build up problem.............Japanese could not envision our Interstate system nor how we drive thousands of miles in a few days.

[Unnatural1]

That is absolutely true. I've be told that by some Japanese auto engineers personally.

The Japanese are sure starting to now. In Mazda's case, they have started sending their engineers to live and work here for years at a time. They're here solely to improve on their vehicles sent to the US. This was the reason Mazda delayed the release of the new Mazda 6 till 2009. It was originally slated to be released for 2008. I'm sure the other Japanese manufacturers are doing the same especially since many manufacture here too. It's nice that we are getting such personal attention now!

[acr-c]

Since EGR is only flowing at a steady highway speed, the amount of EGR goo is directly related to the amount of time hours, years that the vehicle spent cruising.

City driven cars rarely have the build up problem.............Japanese could not envision our Interstate system nor how we drive thousands of miles in a few days.

That makes total sense as to my Q then. I really only drive it on the highway. Not a lot of city driving AT ALL. So, as an update, we checked the code again at my buddy's shop and his computer came up with the EGR solenoid valve. The Part # is 14956-35UOA. Anyway, do you guys know where this part is located in the car? I see a part that looks really, really close to it, located near the back side of the motor, above the intake manifold, toward the passenger side. Anyone know if this is the part?

Thanks guys.Christian

[Q451990]

Might be worth posting a picture. I would check the electrical connections to make sure there's no corrosion.

Heath

[maxnix]

The general location is correct.

Clean the EGR valve and tube first.

[acr-c]

The general location is correct.

Clean the EGR valve and tube first.

Good info...I'll try cleaning it first.

Christian

[Dabizzo1]

When I first started r&ring my 94Q 2 years ago, the egr passage in my plenum was carboned solid (it was a Dallas commuter car for a doctor before me). I have since replaced my entire egr system, including the egr valve, the egrc solenoid at the front of the engine, and the temp sensor. The temp sensor which should mount on the plenum itself gets carbon gooked up as well. The carbon acts as an insulator preventing it from giving a proper reading of the exhaust gasses coming from the egr, so a CEL is thrown. Check the electrical connector on the egr temp sensor for corrosion and after cleaning, apply dielectric grease to guarantee signal integrity....that goes for EVERY electrical connector under the hood. Even after a year of driving from my first cleaning with 8 brand new oem injectors, the carbon that accumulated in the 90 degree bend was amazing. I've heard of an annual decarbonizing of the intake recommended on this forum and I believe it. Depending on the mileage of your car, check the O2 sensors as well. The error code thrown for obd2 will point you right at the culprit. My criteria for a clean intake is very strict now as a result of this forum...listen to the hardcore veterans on this forum...they know what they are talking about. If the egr system and the O2 system are aok and you still get a CEL after reset, THEN suspect ignition or fuel. Keep us posted and good luck. Boris