You have received lots of great suggestions. I would add:

1. Unplug viscous heater relay. This will gain at least 2-3 overall mpg. (Plug back in when you fix thermostat problem and get a GDE tune.)
2. It is actually the front caliper pin sleeves (not boots) that grow and jam the pins. (Just remove and pack with plenty of slider grease.) If caliper pistons do not retract EASILY, replace calipers. Check caliper drag with brakes HOT. If it is not either of the previous two things, replace rubber hoses. They collapse internally and jam the pistons, but this goes away when they start to cool.
3. Bigger than stock tires tend to kill mileage.
4. K&N lets in too much dirt. AFE is the best compromise between flow and protection.
5. We now know that the ORM is not very effective. GDE tune (any is fine) is essential for longevity. SEGR disables EGR, but also disables turbo overspeed protection which is essential for turbo life.

DO THE MAF TEST to see if you need rockers BEFORE your pistons hit the valves.

Welcome to the club!

DOC

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2005 KJ CRD Ltd Detroit TrueTrac Bilsteins G2 GDE "HOT" ECU GDE TCM "Tow Tune" "euro" TC SEGR Weeks Elbow New HG at 130K ARPs Clean CAT aFe Filter Magnaflow Exhaust EHM Cumminos In-Tank Lift Pump Hayden Fan Clutch Nylon Fan VH Enabled with GDE lower shutoff point Recalibrated Temp Gauge Tekonsha Prodigy Sears P-1 ZDDP

OK, I've seen a few folks say this, but I'm struggling to understand why. The SEGR is an electronic component fooling the engine into thinking the EGR is actually operating when it's not. Isn't the turbo speed driven by exhaust directly from the exhaust manifold as moderated by the wastegate which is controlled by intake manifold pressure? I've been drilling through the service manual to figure how the SEGR would interfere with the turbo.

Can anyone help explain? I'm a novice with a service manual, and I know that's a really dangerous combination, but trying to understand.

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2005 Jeep Liberty CRD Sport, 85K miles, Provent 200 on CCV, GDE Eco Tune

There is no wastegate. KJ CRD has a VVT. In the OEM configuration, the EGR valve is used to bleed off boost when it becomes excessive to protect the turbo from overspeeding. SEGR defeats this. Also, GDE tunes allow more complete combustion which reduces soot in the oil, besides yielding more power and better fuel economy.

In addition, GDE is plug and play. Even if you are an electronics wizard, SEGR is a LOT of work to connect, even if you do not have to build it. Check my sig, I HAVE SEGR, but I disabled it after GDE came on the scene. SEGR was a HUGE improvement when we only had tuners like InMotion that couldn't/wouldn't modify OEM EGR settings. However, things have moved along a bit since 2007!

A GDE ECU tune should be considered essential if you intend to run a NA spec KJ CRD for more than just a few thousand miles.

DOC

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2005 KJ CRD Ltd Detroit TrueTrac Bilsteins G2 GDE "HOT" ECU GDE TCM "Tow Tune" "euro" TC SEGR Weeks Elbow New HG at 130K ARPs Clean CAT aFe Filter Magnaflow Exhaust EHM Cumminos In-Tank Lift Pump Hayden Fan Clutch Nylon Fan VH Enabled with GDE lower shutoff point Recalibrated Temp Gauge Tekonsha Prodigy Sears P-1 ZDDP

So if the GDE tune still protects the turbo from overspeeding, it must operate the EGR to do that. Not very happy about that, but maybe the benefits outweigh the fact that the EGR still must be operated.

What driving conditions would make the turbo overspeed? I'm wondering if it is something that I can simply avoid in my driving habits.

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2005 Jeep Liberty CRD Sport, 85K miles, Provent 200 on CCV, GDE Eco Tune

Keith (GDE) has previously explained that the turbo overspeed protection does NOT result in any exhaust gas being ingested. Also, occasional "excercising" of the EGR valve is a good thing. Many people have run over 100K miles with GDE tunes with no EGR issues.

BTW, the suggestion with SEGR was to run the bypass plug a day a month.

The EGR valve only plugs up when it is run excessively, as is the case with the NA emission settings.

Try to stop worrying. GDE has so many bases covered for our KJ CRDs, it would make your head spin if you knew them all.

Run EHM (keeps crankcase from pressurizing at higher RPM) and any GDE tune and you will be in good shape.

DOC

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2005 KJ CRD Ltd Detroit TrueTrac Bilsteins G2 GDE "HOT" ECU GDE TCM "Tow Tune" "euro" TC SEGR Weeks Elbow New HG at 130K ARPs Clean CAT aFe Filter Magnaflow Exhaust EHM Cumminos In-Tank Lift Pump Hayden Fan Clutch Nylon Fan VH Enabled with GDE lower shutoff point Recalibrated Temp Gauge Tekonsha Prodigy Sears P-1 ZDDP

Hey canonoch1 - Any recent updates regarding MPG? I am curious if you ever found anything else to help improve your mpg issue.

My '06 is still only getting between 18-20 mpg even though I have cleaned the MAP sensor, replaced a bad thermostat, run a FIA front cover, run Diesel Klean on a regular basis and in the last 6 months I have installed the GDE FT ECO Tune & GDE TCM Tune. The GDE tunes maybe got me back to 20 mpg on a more consistent basis, but nothing major regarding overall fuel usage. I have also played around with both the V-6 airbox mod as well as trying to use under the hood air for the stock box with no discernible difference between either.

I the same as your wife do not drive with jack rabbit starts or quick braking. I try to keep my RPM's below 2K and still crappy fuel mileage. I've checked my brakes for dragging but there does not appear to be any issue, but I will be replacing pads & rotors soon and will be servicing the e-brake so we will see if I am overlooking something here.

Also I just did my u-joints this weekend so we will see if this helps.

Any other suggestions are appreciated.

I average 30mpg and drive moderately but get into it at times.

I don't know what the *bleep* the rest of you are doing but whatever it is, look into it!

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Silver 2006 KJ 2.8L CRD Limited:
GDE ECO Tune / Fumoto Valve / E-Tecno GX3123 7v Glow Plugs / 2nd Gen Fuel Head / Mishimoto RED Hoses / Rockers/Lifters @ 114k / Hayden FC + 11 Blade Nylon / Sears P1 Battery / Transgo 45RFE-HD2 Reprogramming Kit / Timken Front Bearings

If you can measure the MAF sensor after idling for longer than a minute, it can be a good indicator for rocker arm wear. How many miles on yours?

target air flow is about 714 mg/hub or 144 lb/hr or 18.2 g/s. Flow rates 30% lower seem to be failed. This assumes the following are ruled out:

very dirty air filter, failed/leaking air hoses, turbo vanes functioning correctly, CAC plugging, stuck open egr and no other active fault codes.

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Providers of wholly developed aftermarket solutions for the KJ CRD.
(248) 977 - 9531

Ok looks like I need to get the Torque Pro App, an Android phone w/ BT and a BT OBD reader, that is unless there is another way of measuring the MAF sensor air flow. Any other suggestions or possibly with the Scan Gauge II XGAUGE feature - does anyone know what the PID is for reading the MAF? For that matter does anyone of the full PID list for our CRD's?

As for mileage my '06 CRD has 116k miles, ran the ORM from 2K miles to 111K when I installed the FT ECO Tune followed by the TCM tune ~1K miles ago. Since new the engine has only had Amsoil 5W-40 Euro spec. oil changed ~ every 6500 miles until the last oil change when I ran out of Amsoil so I used Rotella T6 Synthetic 5W-40. Air filter is relatively clean (replaced ~5k miles ago) Fuel filter is replaced ~ every 10K miles. Jeep has had new SAMCO silicone CAC hoses since 75K (old hoses still looked great upon removal). The MAP has been cleaned several times and this last time just the other day it was really clean so it is not crudding up (is it weak and in need of being replaced?). Timing Belt was replaced at 106K miles, turbo vanes checked at the same time and no signs of wear or excessive play. There are know failed or leaking hoses that I am aware of and no fault codes.

As for the EGR how would I tell if it is stuck open other than taking it off to inspect it?

I am doing courier work with a CRD in greater Chicagoland. 2 days and 300 - 400 miles of almost all city driving generally gets me about 20 to 22 mpg - less if I am in 4WD0. If I can run down the highway at 65-70 steady, I get from 22 to 26.

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05 CRD Sport in blue. Suncoast TC and ARP studs.

I have the Sealey timing kit I'll loan out.

X2. We mainly drive our jeep in town. Barely gets warmed up by the time we get to destination and average 18-22mpg. If we take on 50+ mile drive on highway, we get 27-34mpg. These jeeps aren't very efficient unless you a cruising on the highway.

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2006 Jeep Liberty CRD Limited
Gen2 Fuel Head - Magnaflow Exhaust - Ram transmission swap - In-Tank Lift Pump
Moab Wheels - 245/75/R16 LR E Cooper Discoverer AT3 Tires - OME Lift 790/90009 948/60069 - Etecno Glow Plugs - V6 Airbox
RUNNING B100
Pic of my Jeep!

Lately I have been getting 15-16 MPG (reported by EVIC). My reasons:

• Cold weather (high temp was -18F/-44F WC on Monday)
• Short drives (my commute is about 10 miles)
• Winter diesel
• Mostly city driving
• Full-time 4WD on all the time
• Factory tune
• Boost leak at flow control valve

But I get 32 MPG (reported by EVIC) on the freeway cruising at 56 MPH in 5th gear lockup with the A/C on!

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