NOTE: I know there's a thread active right now on high fuel consumption but I didn't want to hijack his thread seeing that he has this white smoke issue I don't have. viewtopic.php?f=5&t=78596

Hey guys,

I'm the happy new owner of a CRD 2006 limited, 75K, well maintained, super clean etc.

Thing though is that I've been experimenting higher than expected fuel consumption. On fuelly the average for the 2006 CRD is 22MPG. Mine averages around 16-17mpg (doing 50% city/highway). When I do more highway it goes down to about 18-19MPG. City only will get me around 14.5-15mpg.
At one point I was stuck in traffic and I reset the the data on the consumption display on the Jeep and I was getting 14-15MPG.

Is this considered normal consumption?
What would you suggest I should have inspected? Some research led to people talking about faulty thermostat, turbo VGT control issues, EGR valve issues, injectors, etc.

Would an electronic check up help determine the problem and test the above potential issues? ( thermostat, turbo, EGR, etc.) Would that show up on there? I don't really know how to check for all of those myself...

Some information that might help
- I'm in a winter climate right now. Temperature might contribute to issue (But I got data from the previous owner and she had an average of 15.5MPG doing maybe 60% city. And that was in autumn and not as cold.)
- What also drives me to conclude I might have an issue with the consumption is that when I was completely stopped in traffic the consumption data kept getting worse even though I wasn't moving. Now it's my understanding that diesel engines need very little fuel when idle so the fact that the MPG was decreasing tells me I might have an issue. Idle issue?

Hope I can get some of your help so I can look into this more efficiently.

Thoughts to consider before addressing your issue - a) read Sir Sam's NOOB guide, b) consider doing the timing belt soon based on age not mileage.

MPG
1. the mpg figures on the EVIC are not to be relied on and both the speedometer and the odometer can be off by up to 5% in different directions. So do a GPS run to figure out the corrections for the 2 dash gauges (relatively brief 60mph run will do for the speedo correction - best to do 2-3 relatively flat/straight 25 mile runs for odometer corrections). Adjust your mpg calculations accordingly and that will give you a rough idea of how far off the EVIC mpg is for future comparision.
2. if your dash temp gauge is not reaching ca. 1/2 a needle width left of dead vertical you thermostat has failed open and is costing you ca. 10% mpg.
3. clean your MAP sensor
4. install new air filter (paper element ones are best - I like WIX or NAPA)
5. pull and check boost (CAC) hoses and check for leaks or if soggy, like a sponge, with oil - replace as needed.
6. while CAC hoses are off inspect bottom of air box to turbo hose for crack just in front of the turbo - replace as needed - be sure upper end of hose touches or nearly touches MAF sensor before snugging, no godzilla, the clamp.
7. will air box to turbo hose if off check turbo fan for play - slight fore/aft ok, barely perceptible side to side ok
8. check turbo variable vanes for movement (per GDE You can check the vane functionality at idle in park. Underneath the vacuum actuator on the turbo is rod extending downward connected to the vane mechanism. If you pull off the vacuum line at the turbo, the arm should drop about 1/2 inch and then raise back up after reconnecting the vacuum line. It is a bit difficult to see the rod, but this is the easiest method to check for proper VGT vane moevment.)
9. be sure tire pressure is proper and jack up the front end so you can hand spin front tires to see if brakes are binding.
10. if you using "winter" diesel mix that's another 10% mpg penalty. In any case a good dose of diesel cetane booster/injector cleaner would likely help.

Best single investment for engine health and mpg improvement is a GDE tune (http://www.greendieselengineering.com/g ... ethod=home). Normal consumption on an untuned 05/06 CRD with OEM tires is 17-18ish in town (10 mile drive, average speed 25, max speed 45, few hills, ambient temp 75F) and 26-28maybe on highway (interstate, 1800 rpm=62mph, wi/wo AC)

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

Measure the MAF (mass air flow) sensor after idling for a minute. This data can help determine early valve train issues like worn rocker arms.

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

What tool is needed to measure MAF sensor?

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2006 Liberty CRD 275K, JBA 2.5 with Fox Shocks, GDE Turbo Kit, GDE TCM Tune, Suncoast TC, OEM fuel filter housing converted to fit Caterpillar Fuel Filter 1R-0749, OEM themostat housing modified to accept Hemi 203 F thermostat.

Torque pro for Android or an obd2 friendly reader (which I can't tell the brand and model because I use torque pro, not any obd works with this jeep)

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2005 kj CRD, samco, suncoast tc, provent, Kennedy lift pump, GDE ECO full torque, 2nd gen filter head, 245/70/16 a/t tires, mopar light bar, fumoto oil valve, OEM Skid Plates, ARB Front bumper and HD OME, tru cool LPD47391 40k GVW tranny cooler (stock cooler delete), FF Dynamics e-fan and shroud, rocker arms replaced, HDS2 190F thermostat.

I use Dash Command on iPhone with a wifi dongle. Works well. There's a whole huge thread on this topic here: viewtopic.php?f=5&t=74420

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SOLD - 2005 Blue Ltd CRD
Purchased 68k 09/13 | Build 01/05
GDE FT Eco Tune | Blue Samcos | Bosch 5v GPs | 2nd Gen Fuel Head | New Bosch MAP | Hayden Fanclutch | New TB kit ~74.2k (Geordi)
Tow Package | Engine/Tranny/TC Skids | Fumoto F102S | Roof Rack | USA Spec PA-11CHR | EVIC | auto dimming mirror | Yoko Geolander A/T-S LT225/75R16

Thanks a lot guys for your answers, really appreciated.

papaindigo, thanks a lot for that procedure and making me aware of the great Sam's Noob guide. I will do and check everything I can myself but since I guess I'm a novice with cars I wouldn't know how to do things like checking those CAC hoses, stuff related to the turbo, etc. I will try my hand though at cleaning the MAP sensor and replacing air filter for instance, thanks to the Sam's guide.

I have yet to find a good diesel guy in my region or a mechanic I would trust with all the fine tuning stuff. I will be traveling to California though in the coming months and I'd love to learn more about all of that stuff so if you have some recommendations for a mechanic or a fellow forum user who'd be willing to show me so I can learn, I'd be really up for it.

A couple of questions
1. How long should it take for the car to reach optimal temperature? I've been doing short trips lately and the temperature gauge only gets to about 1/4 but that might be because I'm not doing long enough trips.
2. How can I be sure that I'm using a winter diesel mix? Since I'm in a winter climate then I can assume I'm on a winter mix? How about locations that get cooler during winters but not cold like it is in some parts of the US or in Canada?

I will do the GDE Tune. I actually called him yesterday before I posted here and we had a little chat.

Aside from everything that has been mentioned in papaindigo's procedure and in Sam's guide, is there something else I should look into?
Like having the injectors checked?
What about the idle? Since it seems to consume a lot of fuel when parked with engine running or waiting at red light, wouldn't that mean potential issues with Idle? Always thought diesel engines didn't consume much fuel when idle, but maybe I'm wrong?

Thanks a lot guys!

Hey Keith! Nice to see you here. We actually spoke yesterday about the tune and a little bit about that fuel consumption issue.
If I come and see you locally so we can do the Eco Tune, do you think we could check all the points of papaindigo's procedure, measure the MAF sensor like you mention in that checkup we talked about doing?

I'll also send you an email so you have mine as well.

Cheers!

1. If you temperature only gets to the 1/4 mark you need a thermostat.
2. Don't worry about the winter blend as there is nothing you can do about the fuel you purchase. My recommendation is to use a good diesel additive with cetane additive.

To get up to temperature I see as much as:
10 mins highway driving
12 mins on country roads.

In town it may never reach operating temperature.

At traffic lights it can drop from normal operating temp (1/2) to 1/4 in less than a minute.

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Share your ideas freely at https://www.facebook.com/groups/libertydiesels/

Brody - post your location in your signature if you want more or less local assistance, also check out the trusted mechanic by state post.

How long to reach operating depends on ambient temps. Best I can say is in town maybe 3-4 miles at say 50F+ vs maybe twice that at 25F or so; thats more or less flat roads; average speed 25; top speed 45. If I run the block heater in winter then 3-4 miles. Cannot speak for "normal" behavior with a fully operating thermostat in northern colder areas.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

Thanks guys for the precisions.

I was asking about winter diesel since I'll be driving to California soon and expect no winter diesel there and was wondering in what state the diesel blend should start to switch to non-winter. From Montreal to SF. I'll be putting an additive ASAP.

BTW, additives are only effective for winter-diesel or any diesel fuel? Is it recommended to use additives at all times? My father used a little bit with each fuel up.

I also updated my location. I spend about half my time in California and Montreal. I'll leave soon with the CRD for the long trip so I'd love to have it optimized before or on the way. Any recommendations for mechanics or fellow members willing to share their knowledge could be in either Montreal or San Francisco / Los Angeles or any place on the way to those cities.

In most areas: winter to summer in mid April and summer to winter in mid October

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

Thanks for the info.

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2006 Liberty CRD 275K, JBA 2.5 with Fox Shocks, GDE Turbo Kit, GDE TCM Tune, Suncoast TC, OEM fuel filter housing converted to fit Caterpillar Fuel Filter 1R-0749, OEM themostat housing modified to accept Hemi 203 F thermostat.

Hey guys,

A little update, I cleaned the MAP sensor, checked air filter, tire pressure, if brakes were dragging, etc. (stuff I could do with my limited knowledge)
Removed to MAF sensor too (temporarily before ECO tune). Already I'm seeing improved MPG.

My tstat is clearly problematic. Read a bunch of threads and posts here on Lost Jeep.

I've been looking at the inline Stant 13519 solution. What is your opinion on housing or no housing and then drilling a hole or not?
There are so many opinions here on the different threads and my head is spinning a bit.

Would a housing be really better? And would drilling a hole create potential problems as some have suggested?


Thanks!

I personally am sticking with OEM pending receipt of mod from Kap but:

Housing is not required but it does fix the inline tstat in place although you have to be a bit careful to cut the hose properly to avoid a kink. If you don't use a housing you do need to add a worm clamp to fix the in line tstat in place otherwise as has been reported it can migrate down the hose the radiator inlet.

Drilling a hole is an old school method of a) preventing excessive overheating if a tstat fails closed (engine temp will go high but not badly high) by allowing some coolant past the closed tstat and b) letting the system do a bit better job of bleeding air as early as possible in the warm up cycle after a coolant system refill (best to have the hole on the "top" edged of the tstat) and c) allowing a bit of coolant to go past the temp sensitive part of the inline tstat so it opens properly as coolant warms. In point of fact a number of tstats come with a small hole, often with a little "toggle" in it, already installed. Having a small hole (say 1/32"-1/16" no bigger than 1/8") won't cause a problem although some have reported that in really cold operating conditions an inline tstat with a skirt hole can cause the apparent, per the gauge, coolant temp to drop when engine load is reduced which can occur when driving down hill or when at a stop.

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Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

The stant 1351x comes with about a 1/32" hole. I enlarged it to 1/16 in one jeep, and it takes a mile or two more to warm up than the other jeep, and will drop quite a bit at idle in cold weather. I think the peace of mind is worth it.

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05CRD: GDE Hot ECU & TCM tunes, Provent, Cat filter, Facet lift pump, TransGo kit, Florida TC, Samcos, stainless brake lines, HDS thermostat, Renegade light bar,
Bilstein adjustables, Al's Gen 4.5 Arms, 235/85-16 Duratracs, DTT rear, Elocker front, EVIC+TPMS, Turbo timer, McNally pillar gauges, Weeks Stage II kit.

Thanks guys!

So if I understand this correctly, drilling a hole is safer to prevent overheating but it will take longer to warm up and at idle temp will drop quickly.
If I go with the housing route, none of those issues will be a problem is that right? It will create the required flow of coolant and will warm quickly and idle will be optimal?

The Meizere stat housing is crap when installed on this engine. Don't make extra cuts in your hose. The drop in Stant is great. Even with a1/16 hole the time to warm up is short (5 mi) and it doesn't drop fast at idle unless it's very cold out.

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05CRD: GDE Hot ECU & TCM tunes, Provent, Cat filter, Facet lift pump, TransGo kit, Florida TC, Samcos, stainless brake lines, HDS thermostat, Renegade light bar,
Bilstein adjustables, Al's Gen 4.5 Arms, 235/85-16 Duratracs, DTT rear, Elocker front, EVIC+TPMS, Turbo timer, McNally pillar gauges, Weeks Stage II kit.

I dissagree.
I've been using that same thermostat housing for two years now.
It works great and no leaks.
Plus you can use any thermostat from a small block chevy inside it
which can be found anywhere.
Any yes, I drilled one small hole in the thermostat.

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U.S. Army Retired