check that EGR!

[Mister Bishi]

So about two weeks ago, during that cold snap we had, my Pajero suddenly started losing power and began to produce heavy black smoke and even knocked on heavy throttle. First thing I thought was frozen fuel filter (it was pushing -40) so I limped the truck home with a new filter, but no joy. The problem got worse, could barely start it, even when plugged in. Several friends theorized a bad injector, but I wasn't convinced, since they'd been rebuilt 60k kms ago. I checked them anyway, but they all seemed fine (got the truck running smooth, then cracked them one at a time and watched for the one that didn't affect the idle).

At the suggestion of some UK friends, I decided to check my EGR valve. The valve was non functioning when I got the truck so I had blanked it off and thought no more about it...when I took it apart again, now three years later, the problem was immediately apparent: I had blown a hole through my blanking plate!! Exhaust gases are more corrosive than I realized! Wow.

So... I got heavier gauge sheet metal, then DOUBLED it up and made a new, stronger plate to sandwich in between the valve and the engine, and BAM. Problem solved. Smooth starting, power, no smoke.

So the moral is, yet again, check the simple stuff first! How many times do I have to relearn this lesson?

Oh, and CHECK THOSE EGRs!

Cheers,
Phil

[jdmvip]

This is a good post but I'm guessing mainly applies to people with your engine who have blocked off their EGR?

I know a bad EGR can cause lots of problems but I'm also surprised to hear that it corroded the plate you put in.

[JDB]

Whats a EGR and why are you able to block it off?

[Mister Bishi]

Originally Posted by jdmvip

This is a good post but I'm guessing mainly applies to people with your engine who have blocked off their EGR?

I know a bad EGR can cause lots of problems but I'm also surprised to hear that it corroded the plate you put in.

No, I would say anyone with an EGR valve should include an inspection of the system in their annual maintenance, and should have at least a cursory understanding of how it works...

EGR stands for exhaust gas recirculation, and does exactly that, to reduce emissions, principally NOx. It usually uses a valve, which can get sticky over the years. This is exacerbated by diesel exhaust which has a higher particulate count, but all systems are prone to sticking/clogging if not maintained.

Here's a short article that explains the basics if anyone's interested...

http://www.cambustion.com/products/egr

If you have a functioning system, this is obviously the ideal, but if it is not working then you really should consider cleaning your existing valve, buying a new one, or at the very least a blank off plate. If you have a diesel, one could argue that the disadvantages of an EGR system outweigh the positives...

Do your research and decide for yourself, but don't ignore the EGR valve, whether you have a gas or diesel engine...

[Mister Bishi]

Here's a shot of my defunct blanking plate, along with my new double plate above. If you look close, you can see the hole in one! LOL!

[jdmvip]

I know most cars have EGRs but thought it was special case for your engine that the EGR could be blocked. Wouldn't this increase emissions (I have to always consider that because of Aircare every 2 years).

I suspect my Aristo may have a slightly plugged EGR or bad cats but I'd guess EGR first because my NOX was a bit high (I think it technically failed but Aircare passed me anyway because my HC and CO levels were so low).

[Mister Bishi]

yep, EGR removal will definitely raise emissions, if it was functioning properly. If it isn't functioning, and still in place, your emissions could actually go up, depending on the application.

But if you've gotta do aircare, then you will definitely want it in tip top working order.

I'm pretty sure my Paj's cat (OE and 19 years old) is getting plugged as well. I may soon pull it off and "inspect it" with a long metal bar.