Terrible CRD Fuel Mileage - What is wrong with my CRD ?

benzer · **Posted:** Wed Mar 02, 2011 8:47 pm

I think the winter fuel is a big factor.
I checked my air filter, clean.
The driver's side wheel seemed to have resistance so I took the
caliper off and checked the sliders. The rubber boots were in place
and the sliders were lubed nicely. I put it back together.

I did push the piston back to make it easier to get the
caliper back on, it went in with minimal resistance.

After pumping the brakes, I jacked the driver's side up
again, it seems to spin more freely, not sure why.....

The passenger side and both rear wheels seem to spin
freely too.....

The fan spins freely with the normal amount of resistance for
a clutch fan. The MAP was cleaned not long ago.

My EVIC reads 17.7 so far for this tank, all city driving....

Last tank was 19 hand calculated, combination city/highway.

Tires at 40 PSI

John

CATCRD · **Posted:** Wed Mar 02, 2011 10:56 pm

If you have a small boost leak in your intercooler, that will kill mileage. You can rig up a test kit with some pvc endcaps and a tire valve stem to pressurize your boost hoses and intercooler to about 20psi and check for leakdown.

benzer · **Posted:** Thu Mar 03, 2011 12:02 am

CATCRD wrote:

If you have a small boost leak in your intercooler, that will kill mileage. You can rig up a test kit with some pvc endcaps and a tire valve stem to pressurize your boost hoses and intercooler to about 20psi and check for leakdown.

Good idea,
I did smell oil slightly under the hood. I need to check the intercooler
and hoses to make sure they are not leaking.

Thanks,
John

benzer · **Posted:** Fri Mar 04, 2011 12:13 am

I still have to get the fittings to pressure test the intercooler.

It looks like the oil was coming from a loose clamp on the hose
going from the turbo to the intercooler. The clamp felt snug with
a screwdriver, but I tightened it with an 8mm wrench, and it snugged
down much tighter. The two clamps from the intercooler to the throttle
body were good and tight.

The other clamp on the intercooler inlet was not tight either, there
was oil residue where the hose attaches to the intercooler.

There was a dent rubbed in the hose from the turbo to the intercooler.
One of the ribs on the hose from the filter box to the turbo was rubbing.

I don't think it was leaking, but I cleaned it with rubbing alcohol and wrapped
it with high-temp silicone tape.

Anxious to see if this helps. It surely can't hurt.

Thanks for the input.............

John

gsbrockman · **Posted:** Fri Mar 04, 2011 1:32 am

rayamash wrote:

Any other suggestions?

Are you idling excessively????

crdjoe · **Posted:** Fri Mar 04, 2011 7:03 pm

About the fuel quality I usually change gas and diesel filters every fall regardless of mileage I downloaded the service manual and it said 20k I had about 12k so I waited till 16k and the filter element was black! Consider that filters are 20-30$ and the fuel pump is about 850$ I'll go back to every fall or around 12k Mine was running pretty bad I flushed it with seafoam directly in the filter and than in the tank and it started to run better.

When you buy diesel I guess its like flipping a coin!

boilermaker2 · **Posted:** Sun Mar 06, 2011 11:43 pm

Things that have hurt my mileage:
Air filter
Bad T-stat
Winter fuel
Low air in tires
Heavier tires (than stock) with more aggressive tread (than stock)
Continuous full-time 4WD.
e-Brake
Lastly, stop-n-go kills the mileage of this heavy vehicle. Acceleration below 2200 RPM also make a difference.

Good luck,
Boilermaker2

SargeIndustries · **Posted:** Mon Mar 07, 2011 2:40 am

rayamash wrote:

I Cant get more than 19-20mpg. I drive 60 highway miles a day round trip to work. Cruise control set to 70mph. Have installed elephant hose mod and unplugged MAF sensor (ORD) and cleaned the MAP boost sensor, installed new air filter last month. Tires air pressure is correct.

I have owned this crd for 6 months now. Has 90,000 miles. Fuel mileage has been this way since i purchased this. I thought this was normal until i read that other crd owners were having higher mpg in the low to mid 20's and some have high 20's mpg.

I purchase my fuel from local Marathon and Shell stations. Each of these has winterized fuel for use here in colder Michigan climate. I was also wondering if winterized fuel can contribute to decreased mpg.

Any other suggestions?

It wouldn't hurt to test the MAP sensor. I tested mine by taking it out of the vehicle and hooking a 6volt battery to the appropriate terminals on the sensor. I believe 2 - 4.7 volts is a high boost reading for the sensor. Mine tested at 2 volts sitting at the dining room table. For the longest time my sensor was saying there was more boost there than there actually was and causing more fuel to be injected than necessary. I gained 2 mpg when I replaced my sensor. I must have damaged mine when cleaning a while ago...

woodtick · **Posted:** Wed Mar 23, 2011 10:00 pm

SargeIndustries wrote:

rayamash wrote:

I Cant get more than 19-20mpg. I drive 60 highway miles a day round trip to work. Cruise control set to 70mph. Have installed elephant hose mod and unplugged MAF sensor (ORD) and cleaned the MAP boost sensor, installed new air filter last month. Tires air pressure is correct.

I have owned this crd for 6 months now. Has 90,000 miles. Fuel mileage has been this way since i purchased this. I thought this was normal until i read that other crd owners were having higher mpg in the low to mid 20's and some have high 20's mpg.

I purchase my fuel from local Marathon and Shell stations. Each of these has winterized fuel for use here in colder Michigan climate. I was also wondering if winterized fuel can contribute to decreased mpg.

Any other suggestions?

It wouldn't hurt to test the MAP sensor. I tested mine by taking it out of the vehicle and hooking a 6volt battery to the appropriate terminals on the sensor. I believe 2 - 4.7 volts is a high boost reading for the sensor. Mine tested at 2 volts sitting at the dining room table. For the longest time my sensor was saying there was more boost there than there actually was and causing more fuel to be injected than necessary. I gained 2 mpg when I replaced my sensor. I must have damaged mine when cleaning a while ago...

Can you give test procedure and possibly pics? this may be a problem for lots of us getting poor mileage. Did you have any fault codes (CEL) that led you in this direction? :?:

Radman · **Posted:** Thu Mar 24, 2011 11:55 am

I only get between 18 and 20 MPG. And this is with the ECO tune (full torque) and the TCM tune. Needless to say I am not impressed with the lack of economy the CRD has presented. Note however this has been during winter months with winter tires (245/70/16), winter fuel and some 4wd mode. Also city drving for the most part. No idling as I park in my garage. MAP, MAF, Fuel and air filters etc all new and clean. Tires all well inflated, no brake drag. No apparent boost or oil leaks. Temp gauge stays one line below center so I assume thermostat is ok?? maybe viscous heater problem? I also find the power not so great even with the tune, seems sluggish when in lock-up. Torque Converter has shown signs of shudder on two occasions.
Summer tires will go on in the next 2 weeks so will see if that and the warmer weather / summer fuel helps.

boilermaker2 · **Posted:** Thu Mar 24, 2011 12:07 pm

If you're doing strictly stop-n-go, in town driving, 18-20 is actually good. In the 3.7 it would be much worse. It would be much worse in ANY 4WD vehicles except for those that have Front wheel drive that have RWD assist when needed (and they are not heavy off-road vehicles). Apples to apples, all vehicles do worse in city driving except hybrids with regenerative breaking.

The more HD, the heavier the components, the lower the mileage. Slow starts help but it is simple physic. When she is at rest, she does want to get moving again...

Check my fuelly and you can easily see, regardless the time of year, the changing city/hwy ratios. Tires, filters, oils, wheels and weight reduction all help in a cumulative fashion.
Good luck,
B2

LibertyCRD · **Posted:** Thu Mar 24, 2011 12:59 pm

boilermaker2 hit the nail right on the head. It's easy for us to get discouraged and upset when our diesels are only giving us 18-20 MPGs. But what you have to remember is that under those exact same conditions, a gasoline version would be doing 13-15 MPGs.

It doesn't matter how you cut it, the CRD is always going to be more fuel efficient than a 3.7L V6.

tulsa · **Posted:** Tue Mar 29, 2011 6:26 am

DOC4444 wrote:

We also got the same mileage at the beginning. Keys are rebuild/modify front calipers to eliminate drag, disable VH, stock size tires inflated to at least 36 psi, GDE ECU and trans tunes, 190 degree thermostat, blanked off headlight intake for winter, religious block heater use and grill blanket for winter, Magnaflow exhaust. Should get 28-30 on winter fuel in 50/50 mix of highway/local driving (with a LIGHT foot). Should get 32-33 in summer on summer fuel.

Also, add 5% to your mileage in calculating to correct for low reading odometer (with stock tires, of course).

DOC

DOC is right about everything here. If your temperature gauge is more than one tic to the left of center pull the viscous heater relay. In cold weather it can run full time if engine temp is less than 167F according to GDE.
Lewis

SargeIndustries · **Posted:** Wed Mar 30, 2011 2:27 am

woodtick wrote:

SargeIndustries wrote:

rayamash wrote:

I Cant get more than 19-20mpg. I drive 60 highway miles a day round trip to work. Cruise control set to 70mph. Have installed elephant hose mod and unplugged MAF sensor (ORD) and cleaned the MAP boost sensor, installed new air filter last month. Tires air pressure is correct.

I have owned this crd for 6 months now. Has 90,000 miles. Fuel mileage has been this way since i purchased this. I thought this was normal until i read that other crd owners were having higher mpg in the low to mid 20's and some have high 20's mpg.

I purchase my fuel from local Marathon and Shell stations. Each of these has winterized fuel for use here in colder Michigan climate. I was also wondering if winterized fuel can contribute to decreased mpg.

Any other suggestions?

It wouldn't hurt to test the MAP sensor. I tested mine by taking it out of the vehicle and hooking a 6volt battery to the appropriate terminals on the sensor. I believe 2 - 4.7 volts is a high boost reading for the sensor. Mine tested at 2 volts sitting at the dining room table. For the longest time my sensor was saying there was more boost there than there actually was and causing more fuel to be injected than necessary. I gained 2 mpg when I replaced my sensor. I must have damaged mine when cleaning a while ago...

Can you give test procedure and possibly pics? this may be a problem for lots of us getting poor mileage. Did you have any fault codes (CEL) that led you in this direction? :?:

When the intake manifold pressure is low sensor voltage output is 0.25-1.8 volts at the ECM. When the intake manifold pressure is high due to turbo boost, sensor voltage output is 2.0-4.7 volts . The sensor receives a 5-volts reference from the ECM. Sensor ground is also provides by the ECM. The ECM uses boost pressure combined with intake air temperature to determine the volume of air entering the engine.

Let me know if this helps at all...

dirtmover · **Posted:** Wed Mar 30, 2011 8:31 am

Here is my data for the last five years (since new). 20-21mpg is typical for this time of year but don't forget to correct for odometer error (5.26% in my case) which, if you haven't done this, would bring your 19-20mpg in line with mine. My circumstances are also almost the same, 50 mile round trip highway @ 75mph but a bit colder up here.

Now, as for this year something unusual is going on. I've dropped about 1.5mpg since January. My average temperature may be a bit in the low side but more noticeable is the variation as it tends to drop more than I recall during previous winters when idling.

boilermaker2 · **Posted:** Wed Mar 30, 2011 11:05 am

dirtmover wrote:

Here is my data for the last five years (since new). 20-21mpg is typical for this time of year but don't forget to correct for odometer error (5.26% in my case) which, if you haven't done this, would bring your 19-20mpg in line with mine. My circumstances are also almost the same, 50 mile round trip highway @ 75mph but a bit colder up here.

Now, as for this year something unusual is going on. I've dropped about 1.5mpg since January. My average temperature may be a bit in the low side but more noticeable is the variation as it tends to drop more than I recall during previous winters when idling.

Fantastic Post Dirtmover. The only time I had a consistent loss like you posted was when my t-stat died :dead:

B2

bhc04 · **Posted:** Wed Mar 30, 2011 1:37 pm

My 06 CRD Limited, only mods EHM and K&N air filter. Clean my MAP sensor 2 times a year, spring and fall. Mixed driving consistantly since new: 21-22 MPG, checked with actual milages per gps and fillups. Average driving speeds, AT tires run about 38 lbs. cold. Highway milage 27-28 MPG running about 68-70 mph.

bhc04 · **Posted:** Wed Mar 30, 2011 1:37 pm

My 06 CRD Limited, only mods EHM and K&N air filter. Clean my MAP sensor 2 times a year, spring and fall. Mixed driving consistantly since new: 21-22 MPG, checked with actual milages per gps and fillups. Average driving speeds, AT tires run about 38 lbs. cold. Highway milage 27-28 MPG running about 68-70 mph.

bhc04 · **Posted:** Wed Mar 30, 2011 1:37 pm

My 06 CRD Limited, only mods EHM and K&N air filter. Clean my MAP sensor 2 times a year, spring and fall. Mixed driving consistantly since new: 21-22 MPG, checked with actual milages per gps and fillups. Average driving speeds, AT tires run about 38 lbs. cold. Highway milage 27-28 MPG running about 68-70 mph.

Tree Catcher · **Posted:** Thu Mar 31, 2011 12:51 am

Thanks to what I have learned from this site, my mileage has went from 22 hwy to 26 hwy and 21 around town. I have replaced fluids, didn't notice an increase but when I cleaned the MAP sensor the mileage improved. Question is that everyone talks about winter diesel and it killing MPG. How do I find out when the dealers switch from winter blend to summer blend and is there really a winter blend in southern California?

Sean

Terrible CRD Fuel Mileage - What is wrong with my CRD ?

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