Diesel Exhaust Fluid - FYI

[Roger C H]

Something I never saw before. When we stopped at a truck stop near Lodi, CA is a station for trucks labeled 'Diesel Exhaust Fluid". Upon asking a trucker, he stated that it is a new EPA Reg that newer diesels use. I found this on the internet:

BlueDef Exhaust Fluid for Diesel Emission Reduction Requirements

What not all. Although I do admit to having seen trucks spewing out clouds of black exhaust gas...

[Eddie Longest]

Another measure to move the big rigs to Natural Gas as the primary fuel I guess.
Eddie

[Thomas G.]

I think it is urea.

[mary and bob]

A couple years before I retired from working on big trucks , the new ones came equipped with a catalytic converter type muffler. Like any new technology they could be a nightmare. If they started to plug up, the driver had to stop and put it into a regenerate mode, during which the engine would go to full RPM and inject fuel or air into the exhaust to clean out the muffler. Now can you imagine a driver who is on a tight schedule or getting paid by the mile, stopping and sitting for 30 minutes or so for his truck to go through this regen cycle, NO WAY. We had problems where it was put off so long that the truck wouldn't go into regen, and we had to send them to the dealer to get it done. There are machines you put the muffler in, to clean it out. Diesel fuel was refined to be low sulphur too. Now the new trucks have a separate small tank to hold this new fluid that somehow further reduces emmissions. I retired just before that system came out, so I never worked on it. Diesel engines are now all computer controlled, with electronic fuel injectors, and even the horsepower is controlled by the computer. OK when all works right, but when something goes wrong it's an electronic nightmare. You shouldn't see black exhaust from any of the new trucks. I don't miss that work at all!!! Bob Tom is correct, it is urea

[Greg H]

As an ex truck driver, hopefully the blue stuff is a long way off for light duty Diesels. The catalytic type filter is already here, it's called a particulate filter and the two of them on my '07 Dodge ram were $1,300.00 to replace.

[mary and bob]

Originally Posted by Greg H

the two of them on my '07 Dodge ram were $1,300.00 to replace.

This is why my pickup is a '76

[Gina D.]

I just transported an 06 40ft motorhome from an auction that only had 3000 miles on it.

It would not go over 20 miles an hour because the DPF was so plugged it's fail safe kicked in and basically shut the system down to prevent it from kicking in the turbo and moving faster. (EPA~California thing)

I had a "Mechanic" come out and do a regeneration on the filter. The mechanics only tool was a laptop computer. It told everything about the engines lifetime use as well as performing the regeneration.

It showed that 87% of the engines life run time had been at idle. It never got hot enough for the system to burn itself off and the particulate just laid there..collecting and clogging. The regeneration process, fortunately, worked. It was basically a software program that ran the engine through some paces to burn it off. It took 40 mins and cost.. 600 bucks!

ouch.

Normally, this process happens when underway. Eventually, the filters will need to be replaced though.

[Andrew Gibbens]

Originally Posted by Gina D.

Normally, this process happens when underway.

Only if you drive on highways. A lot of folk in Europe are getting caught out by these filters - for example, if a passenger car is driven entirely in cities, it may never work hard enough and long enough for the regeneration process to take place and then problems and big bills can arise.

It is almost like the old "Italian tune-up" - you take the car to a highway and drive at over 3000rpm for 20-30 minutes and that does it.

[SilverGhost]

Originally Posted by Greg H

As an ex truck driver, hopefully the blue stuff is a long way off for light duty Diesels. The catalytic type filter is already here, it's called a particulate filter and the two of them on my '07 Dodge ram were $1,300.00 to replace.

Sorry, already in the trucks. The DPF were causing the flame out the exhaust on some models (Ford) before they changed the ECM software. We already have DEF bottles. And the DOC and DPF are NOT the same. Sometimes combined in the same housing for simplicity of packaging.

Originally Posted by Andrew Gibbens

Only if you drive on highways. A lot of folk in Europe are getting caught out by these filters - for example, if a passenger car is driven entirely in cities, it may never work hard enough and long enough for the regeneration process to take place and then problems and big bills can arise.

It is almost like the old "Italian tune-up" - you take the car to a highway and drive at over 3000rpm for 20-30 minutes and that does it.

First a quick primmer - DPF is Diesel Particulate Filter and it's job is to collect particulate matter (soot, the black clouds). After the ECM senses back pressure has reached a preset level it starts the regeneration cycle. Or during a long enough highway drive the DPF will get hot enough to light off with no extra input. Depending on the vehicle this is usually diesel fuel injected during the exhaust stroke or an extra injector in the exhaust. A small amount of diesel is vaporized and when it hit the DPF it ignites the particulate matter and it burns off. The VWs and GMs both will turn on a warning lamp when you haven't driven highway enough - go drive it above 45 MPH for 20 minutes and the light should turn itself off. If you ignore you'll have to bring it in for a tech to try a regen. And if wait too long for that, then you have to replace the DPF.

The DEF (sometimes sold under brand name AdBlu) is urea and is injected into exhaust before SCR catalyst. It's job is to fix NOx emissions. I believe NOx is generally responsible for ozone formation at ground level and acid rain. Some small cars use a different style NOx trap catalyst that does the job without the pee. BUT they use more fuel and get less MPG.

Jason

[mary and bob]

Most trucks have a "regen" warning light and a switch to start the regen process. The truck had to be parked, parking brake on, and it would run at full rpm for about half an hour. A laptop computer became a tool we couldn't live without, and it could give us all kinds of info, some of it the drivers didn't want us to know, like if the engine had been over-revved, panic stops, over the set speed. Amazing technology!!

[Darwin Maring]

It lubricates the muffler bearings.

[Mike Magee]

Originally Posted by Darwin Maring

It lubricates the muffler bearings.

And, I might add, it does so without getting wrapped around the exhaust camshaft, which is quite a feat!

[Andrew Gibbens]

Jason, thanks for a useful write-up.

Originally Posted by Darwin Maring

It lubricates the muffler bearings.

And Darwin would clearly like this stuff, as recommended by Joseph Lucas, Prince of Darkness (for those who have ever had a Brit car with Lucas electrics):

[Darwin Maring]

Andrew, I think you are attempting to play a joke on us because that clearly is a jar of prop wash.

[john warren]

thats not propwas,,,its a jar of blinker fluid

[Andrew Gibbens]

Now, if you're gonna start with the blinker fluid (and I personally only use synthetic blinker fluid these days), you can do no better than visit this fine supplier: KaleCoAuto, Hard to find automotive items!

Not only do they sell gen-you-whine Kuhneutson valves, they now do Seasonal Tire Air which may be exactly what all those trailer tires need - proper summer tire air for use in the summer, not tired old winter tire air.

I believe this may be important as I have a profitable small business exporting drive-on-the-left tyre air (not tire air) for use in Minis exported to North America - owners can have bad control problems when they put American tire air into these cars and then try to drive them on the right side of the road - this makes the air rotate the wrong way and 'unintended acceleration' is a nice thing compared to trying to steer a car on counter-clockwise tire air.