Signs of a failing EGR valve

DnA Diesel · **Posted:** Sun Dec 31, 2006 1:38 pm

Ranger, I too noticed an immediate improvement in starting and general manners. I'll see how this tank goes, but I think I found part of my crappy mileage problem. Like you said, so easy to do, that it might be a monthly thing for me. I may also get a spare sensor depending on their cost. Funny how some little things can screw up an entire system. I get the feeling that missing valid data on these two parameters could very well have put the fuel mapping into some kind of degraded/limp mode.

I'm not overly impressed with the dealer though, I had specifically mentioned poor fuel mileage and asked that all systems associated with fueling be checked. I would have thought this would include a verification of all sensors that provide input to the ECM (as in MAF, IAT, boost, etc...) Yeah! Apparently not... :shock:

Next project will be to look at the EGR and mixing valves...but for now, I'll see how cleaning the boost/temp sensor does.

Cheers,
Duey

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

You read my mind. I'm ordering another sensor tomorrow. It's easier to swap in a clean one, then clean and store the old one. I did think of one other reason for the excessive soot in the intake area - my first egr failed open at 12K miles and the 2nd failed close at first at 20K. When failed open, excessive soot is passed into the intake. Then 2 glow plugs failed and I drove it that way with lots and lots of smoke and soot for 10 days until STAR cleared the new gp's. All of this adds up. The only way to eliminate this mess is to find a way to shut the egr off.

Goglio704 · **Posted:** Sun Dec 31, 2006 2:35 pm

There is an older thread on this subject, and I think the poster disconnected the battery and started the learning process over. I'd search for it, but I'm up to my arse in other alligators at the moment. DnA, thanks for the pics. Ranger, thanks for the supporting info. I love to see stuff reach a logical conclusion and add to the knowledge base. I don't guess this is any real surprise to those of us who have had diesels with EGR before - you know, the whiners. :roll:

Ripster · **Posted:** Sun Dec 31, 2006 3:30 pm

Kudos to everyone pushing this item, just checked mine at 11,000 and pretty well shut with soot and
this is with the EHM since 300 miles. Cleaned with electrical cleaner, looks like a dual prong type of sensor
and it takes quit a bit of cleaner to begin to get color on one of the wires. Whomever gets the first spare sensor
post the part number and cost. Will post if any symptoms improve with this cleaner.

DnA Diesel · **Posted:** Sun Dec 31, 2006 3:40 pm

Goglio704 wrote:

....I don't guess this is any real surprise to those of us who have had diesels with EGR before - you know, the whiners. :roll:

No, Matt, it certainly doesn't. I thought that 6 years and newer base technology would make diesels less problematic...I see DCX really did a job on VM Motori's work of art...the R428 is, engineering wise, a very nice engine...still amazed by its power/displacement ratio, stock it's like a 145hp/215ft-lb ALH TDI engine (which is only 90hp/155ft-lbs).

Luckily, the TDI EGR prepared me well for dealing with this vehicle-engine setup.

Cheers,
Duey

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Ripster wrote:

Kudos to everyone pushing this item, just checked mine at 11,000 and pretty well shut with soot and
this is with the EHM since 300 miles. Cleaned with electrical cleaner, looks like a dual prong type of sensor
and it takes quit a bit of cleaner to begin to get color on one of the wires. Whomever gets the first spare sensor
post the part number and cost. Will post if any symptoms improve with this cleaner.

I cleaned the sensor on mine with an old toothbrush, very gently, after soaking it in some of the same spray cleaner. The sensor didn't come clean until I used the bristles on it. Now it's bright yellow, with 2 white wires leading into the base of the yellow sensor.

This issue will also plague the new Grand Cherokee CDI, the MB ML3X0 diesel series as long as they use egr and sensors in the intake plenums.

Now that BlueTec separates NOx into Nitrogen and water, why couldn't they pipe some of the cleaned, nitrogen gas back into the cylinders, after it cleared the particulate filter, to avoid putting this gritty soot back into the intake on the engine?

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

At www.trademotion.com, I found what is labeled as an Intake Temperture Sensor, for $38.80. List is $48.50. This is the description:

Mechanical Catalog - 2005 - Jeep - Liberty
Electrical, Powertrain control, Air intake temp sensor, AIR INTAKE TEMP SENSOR, Liberty, 2.8L

No part number listed on the website, but the Bosch number on my sensor is:

Bosch - 0 281 002 437

part on website here:

http://www.trademotion.com/partlocator/ ... atalogid=1

Goglio704 · **Posted:** Sun Dec 31, 2006 8:37 pm

I was going to change the CRD's oil today anyway, so I had a look at the sensor in mine. Looks about like DnA's. Cleaned it with carb cleaner. Hopefully my mileage will improve. I've always been 1 or 2 MPG short of where I should be. I noticed that one of the prongs for lack of a better term is actually movable on mine. I hope that is normal. It didn't look to be broke.

Ranger1 · **Joined:** Mon Oct 17, 2005 7:40 pm **Posts:** 1137

Quote:

I noticed that one of the prongs for lack of a better term is actually movable on mine.

Same on mine. It looks like that's what that black plastic tab is for - to support the sensor from moving too much.

Does it occur to anyone that what we are looking at is Federal Emissions defective engineering on DC's part? If this sensor clogs up in as little as 11K miles, it is probably failing EPA emissions requirements, due to improper calibration and subsequent mis-fueling. Perhaps we should contact the EPA to investigate whether DC is liable for EPA fines for this. Add in the excessive engine oil from the intake/ccv/turbo seals and we may have a way to use the EPA politicians who caused this emissions mess to force DC to fix it.

Goglio704 · **Posted:** Sun Dec 31, 2006 11:14 pm

I went for a test drive. Cleaning the sensor sure didn't hurt anything. No Evic on mine, so it is way too soon to know about mileage. It does seem to run better. The throttle doesn't seem as twitchy, and the coordination between the trans and engine seems better. Too soon to tell for sure on mine, but I think it helped. It sure didn't hurt.

Mykol · **Posted:** Mon Jan 01, 2007 1:27 am

I would like to check my sensor also. Exactly where is it located, and what tools are needed for removal?

Goglio704 · **Posted:** Mon Jan 01, 2007 1:40 am

Sorry, I'm borrowing DnA Diesel's pic.

In the foreground is the fuel pressure sensor on the common rail. Behind that is the hole for the boost pressure sensor. The black hole is for the sensor. The threaded hole is for the mounting bolt. This is all on top of the engine on the driver's side almost at the firewall. A 4mm allen wrench is needed for removal of the boost sensor. The worst part is getting the wiring harness out of the way enough to work.

Ripster · **Posted:** Mon Jan 01, 2007 11:33 am

4mm allen wrench or socket, you remove the cover and then unclip the two connectors at the
back of the right hand side of the engine when standing in front of it, lift the wiring harness and
don't drop the bolt you remove from the sensor, wiggle it back and forth as you apply pressure
upwards, it has a rubber o-ring.

litton · **Posted:** Mon Jan 01, 2007 12:13 pm

Great info, I think I'll do mine today. How much time should I allow for the project? I have 8300 miles so it will be interesting to see the condition.

Ripster · **Posted:** Mon Jan 01, 2007 1:25 pm

Skill level low, about 5 minutes in and out, the time is how good you clean it, that will take more time
than getting it out or putting it back in.

Got Diesel · **Joined:** Thu Oct 19, 2006 8:13 am **Posts:** 108

I cleaned mine as well and I think we should check it every 3,000 miles and if it looks good, then do it every oil change. I took my intake apart and it was and EGR was ok not full of goop..

GregScuba · **Posted:** Tue Jan 02, 2007 9:23 am

This info is golden. Can we make a post about it in the FAQ?

mrwrangler · **Joined:** Fri Dec 22, 2006 3:43 am **Posts:** 18

Park mode and volla got that buzzing going so dont shut down engine in D lol.

DnA Diesel · **Posted:** Wed Jan 03, 2007 4:04 pm

Goglio704 wrote:

Sorry, I'm borrowing DnA Diesel's pic.

In the foreground is the fuel pressure sensor on the common rail. Behind that is the hole for the boost pressure sensor. The black hole is for the sensor. The threaded hole is for the mounting bolt. This is all on top of the engine on the driver's side almost at the firewall. A 4mm allen wrench is needed for removal of the boost sensor. The worst part is getting the wiring harness out of the way enough to work.

Matt, no problem...I'm going to take a cover-off pic of the engine bay for future reference.

Photos here: DnA Diesel's photo page - Jeep

As a suggestion, I sprayed some silicone lube on the four post attachment grommets on the engine cover...makes it a lot easier to get the cover off.

I have such a marked photo for my Jetta in my photobucket VW folder.

Cheers
Duey

Got Diesel · **Joined:** Thu Oct 19, 2006 8:13 am **Posts:** 108

Well here is my take on this and what I have seen, If you have not done any thing with the CCV ,t he boost pressure sensor will GUNK UP with the system stock every 1,000 with a lot of build up and needing of a good cleaning, now with the ccv mod, every 3,000 is only a slight black powder build up and not sludge up if it were stock. Now with a Chip Tune,ccv mod only a very light powder build up and not blocked or sludged up. I think the best thing to do is very oil change, have a look and make sure its clean.

Signs of a failing EGR valve

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