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Reman egr or aftermarket


bigredhdt

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On the D12 if the signal to the ECM remains constant or is absent it goes into what one may call a limp home mode. When the ECM sends a signal for the EGR valve to open (or close) it expects a return signal verifying that the EGR valve is working. Unfortunately you can't just bypass them or disconnect the wiring.

 

Thankfully, my EGR valves are working. But, if for some reason they stopped working and I was getting fault codes I would remove the valve and make an attempt to clean the sucker up before doing anything else. The valve is controlled by a solenoid. Inside there can be a horrendous build-up of carbon combined with oil, diesel and water. This mixture can cause the valve to freeze.

 

I have a small benchtop blast cabinet - I paid less than $100 when I bought it. It is a handy item to have in your workshop. Glass beads and/or walnut shells can be used to clean up the valve portion of the EGR - which may be all it needs to get it freed up so it will start working again. As long as the solenoid is not "open" you should be good to go if you can get the valve moving up and down again.

 

I believe the hesitancy of trying to salvage a stuck valve is related to labor (time) and the cost of replacement seals, which are thin pieces of metal. It is a fair amount of work to get those suckers off. Volvo also wants you to replace the V- band clamps and tubing associated with the EGR valves. These parts alone can add a couple of bills to the job.

 

I had to remove my EGR valves when I dropped the turbo to replace a broken mounting stud. This gave me a chance to study them on the inside. You can bench test the opening and closing of a EGR valve after cleaning by simply powering the solenoid. If it doesn't work, you really haven't lost anything. If it does work you can consider the next 400 gallons of fuel paid for.

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All this talk of EGR. Tsk, tsk, tsk. The smart has big ears. Just spent the afternoon, and a good bit of the evening pulling , cleaning and re-installing the valve. After today, I'd much rather deal with a 20 lb turbo and 70 lb manifold than the amount of parts crammed under the "hood" of a smart diesel. The valve cleaned up well, with the sticking being taken care of with Brake-Kleen and rags while manually moving the shuttle. The valve position feedback comes via electronics built into the smart solenoid, but it doesn't know how the valve is oriented in relation to the gas ports in the EGR housing. I may have put everything back together 180* out of phase, but I'm not sure. ;)

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I'm getting intermittent faults. What happens in limp mo? I know light duty trucks are severely speed limited. I'm thinking I can wait till the fall to pull apart and clean or replace if necessary. If anyone has details on their cleaning that would be great to see. If I have to replace I will go with the aftermarket replacement part.

 

Theven egr is an integral part of the engine operation. They actual i.prove the efficiency of combustion. There is research out there that shows significant improvement in efficiency with more advanced egr. You can fool the ecm for a while with a programmer, but I would be worried about the long term damage it is causing to the engine when operating without it.

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EGR shortens engine life. Period.

 

 

Theven egr is an integral part of the engine operation. They actual i.prove the efficiency of combustion. There is research out there that shows significant improvement in efficiency with more advanced egr. You can fool the ecm for a while with a programmer, but I would be worried about the long term damage it is causing to the engine when operating without it.

 

Sadly, you're both right. Past experience proves Glenn's point. The crud that came out of the smart intake tract couldn't be good for much, except for getting me dirty. It was slightly abrasive, sticky, and dissolved in Brake-Kleen. We don't have any emissions inspection requirements here, but I still don't want to remove the equipment. It's functionally removed from service, but still present.

 

The numbers also prove bigred's statement, as today's diesels are making huge power, at reasonable mileage levels, compared to even 2 generations back. As the engineers get better with materials, at price points the accountants can handle, expect the EGR issues to calm down.

 

Does anyone here remember the early '70's, with their smog control equipped vehicles? That's where we are today, in the diesel world. Back then, the rip-'er-out crowd was trying to remove all evidence of anything vaguely "pollution" related. Today, nobody gives their EGR system a second thought.

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What happens in limp mode?

The ECM reduces turbo boost. The thinking is if you loose EGR you are going to pollute more when you put the pedal to the metal. They say without EGR return gasses turbo temps can significantly rise - so boost is reduced to keep temps down so you don't melt your turbo. Again, this is not an answer - only what "limp home" mode results in. Maybe "limp home" is the wrong word(s) - but no matter, you lose power and end up limping home or to the Volvo repair facility.

 

Yes, I would clean one of the valves like Darryl did first. Like everything pollution related or specifically Volvo, the price is way over what it should be. They know you must have it working so they gotcha'. Pay the man.... Been there, done that..... Hate it....I always look for another source or fix.

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