View Full Version : Power Loss

07-26-2011, 03:01 AM
Started my vacation today. Heading to Washington state from So. Cal. in my '06 sprinter with 73k MILES. Climbing the hills prior to "the "Grapevine"(central valley). It's hot out and motor's running approx. 215 on the gauge. Working the car pretty hard but not that hard. Running great.Getting tired so I ask my wife to drive. Pull over. Switch drivers. She tries to accelerate back onto the freeway and car just isn't pulling hard. Car accelerates moderately, then poorly. . Inconsistent acceleration. Gear lever on its own changes from "D" to "4". I bump lever back to "D" and it again changes on its own back to "4". I move lever again to "D" and this time it stays. Go down the hill into Bakersfield and it runs great downhill and can go 55 on the flat (no real load on it). Give it some throttle and it won't accelerate well at all.
Car's 5 year engine-only warranty expires in 3 days. What to do? Is there an Orange County dealer that has qualified techs? I don't tend to trust dealerships. Bought van at a Dodge dealer in Garden Grove which went out of business a few months later. Do I take it to Mercedes Sprinter dealer? I assume it's still under warranty. I noticed somebody had their Sprinter fixed at San Bernardino Dodge. Are they decent? Any advice would be greatly appreciated. Signed, "Stuck in bakersfield"

07-26-2011, 03:09 AM
It could be a blown turbo resonator or split hose. (common, relatively easy to fix... if it's the resonator a bunch of JB Weld can do it)

If you had a ScanGauge (pick one up at a local auto parts store?) you could monitor the MAP (manifold air pressure) for expected consistency.

*Call in* the problem to your regular service dealer. That may get it registered as an item within the time window.

good luck

07-26-2011, 04:16 AM
I agree with autostaretx...... find a ScangaugeII and install it.
If you need help with the install, send me a PM and I'll walk you through it on the phone.
It sounds like you are on the Bakersfield/Central Valley side of the Grapevine.
There are some quite good Sprinter shops further up the Valley. Might be better
to limp up the low elevation flat valley rather than going back over the Grapevine
(it's a good bit steeper from north to south, just not as long a grade).
That said, your Sprinter's systems were all working to "do the right thing".
When it "auto downshifted" to 4th gear, it was telling you that it needed to be in the
lower gear as the % of engine load was exceeding the limits set in your engine control
module and transmission control module.
If you were only traveling around 55 mph, in 5th gear (D for drive is an overdrive (0.83:1
ratio) and Sprinter engines just do not like to be lugged along at max. fuel flow and max.
turbo boost at low RPMs (<2800RPMs).
The 5th gear (OD) downshift to 4th (1:1 ratio thru the transmission) is approx. 500 RPMs.
If my memory serves here, 55 mph in Overdrive in a T1N is approx. 2300-2400 RPMs.
Your engine/transmission modules were trying very hard to make the downshift and bring the
RPMS up to 2800-3250 where the engine makes much better power and can use the extra fuel and boost efficiently.
I used to run my T1N ('06 3500 158 wb 4.18 rear end) at 3200 rpms for pretty much all day when towing my 4500 14' x 7 wide cargo trailer up grades or into headwinds.
What I discovered was that the temperatures will drop noticeably, the fuel mileage will be at least twice as good, and with 24-26 PSIA boost (vs 34-36 PSIA in overdirve maxed out) there is far less risk of turbo resonator or turbo hose issues.
So, if you can get a ScanGauge II and tell us what the MAP (turbo boost) number is, we can help you to rule out turbo resonator/turbo hose issues.
Once you engine has cooled off and everything is reset in the morning, you may find your power is back to normal.
If so, it might be prudent to visit one of the Sprinter shops further up the central valley (Fresno and in that area).
Or you can see if there's a MB Sprinter service facility in that area as well and ask them to run a diagnostic on your RV to narrow down the possible issues.
Basically, you ran your Sprinter a little too hard going over the Grapevine in very hot weather. Downshifitng to 4th gear @55-62 mph could have made a tremendous
If you face the same situation in the future, learn to manually downshift to 4th gear (maybe even 3rd gear going north to south on the Grapevine) and slow down to keep the engine RPMs in the 2800-3200 range. You can safely downshift in Cruise Control or with your right foot on the accellerator pedal. The ECM will prevent any downshift that will
be damaging.
Your Sprinter and your wallet will thank you!

07-26-2011, 05:30 AM
Thanks guys, I'm holed up in the Rodeway inn for the night. I've got one of those aluminum Riordan resonator eliminators in my spare parts bin in the back of the Sprinter (118" low-roof) but few tools.Takes forever for that engine to cool off. In the morning I was gonna try and see how it drives and maybe change the resonator if it doesn't run right. If that doesn't pan out, I was gonna tow it (I have AAA 200 mile towing I think) as I don't see it climbing the grapevine and take it to a dealer (but what dealer?) in Orange County. Is driving likely to hurt it? I think not...but I'm not positive. Remember, my dealer went belly-up when Dodge eliminated many dealers a couple years back, so I'm not sure really where to take it. It's never acted up before, thank God.
How does the warranty work on our "Dodges" now that Dodge no longer sells Sprinters? Do I go to a Benz dealer? Anybody know? Seems like the typical culprits are 1: resonator/turbo hose problems. 2.EGR issues 3. Intake air sensor. Right? I hate to go through all the hassles of figuring this out on my vacation time,especially if it's still under warranty.Thanks in advance.

07-26-2011, 05:42 AM
Hi RB7,
There are 2 MB Sprinter dealers/service centers right in Bakerfield, CA.
Do a search on MB Sprinter Service in Bakersfield, CA.
Might also be a Dodge dealer in that area.
Call the MB Shops and see if they can give a a diagnostic scan.
Then you can decide to have it repaired or towed back to SoCal.
They probably won't install you Riordan Turbo Resonator Replacement, but
you can certainly ask them.

07-26-2011, 06:03 AM
You only need a screwdriver and a 1/4" 12pt box wrench to change the resonator.
If there's oil on the seam of the resonator, it's a good bet that it has failed. One hose clamp and two Torx bolts and it's done. I don't think the resonator is covered under the 5yr/100K mile diesel engine warranty, because it's not specifically listed.

I've used San Bernardino Dodge once to replace a blown turbocharger under warranty and they got it done by 3PM the same day I brought it in. Only one experience, but it was excellent.

07 Navion

07-26-2011, 06:05 AM
I agree with SailQuik... you could probably continue your trip (at least to the next servicing dealer) by simply downshifting (or not fighting it when *it* downshifts).
The engine load will be less, it'll cool better, your mileage will improve.

Your 5 year warranty probably covers "anything touched by engine oil", plus the ECU.
Your 8 year emission warranty would cover the EGR system
(the above are extrapolations from my own 2005 warranty... which was a bit better than the 2006's)

good luck

07-26-2011, 06:20 AM
Thanks for the quick response guys. And yes, the Resonator has the tiniest bit of oil on its outside that appears to have wicked up the dusty coating on it. But very little. I was under the impression that the later resonators rarely failed, however.

I confess to trying to drive around at peak torque rpms (1600-2400 rpm) where the engine tends to be most efficient. But I imagine that the high pressure in the cylinders combined with the low revs is stressing the heck out of the engine, particularly on hills. I should know better! I tow in 4th.
Thanks and good night!


07-26-2011, 03:38 PM
Not to be argumentative here, but do you have any documentation to demonstrate that
any version of the T1N (OM-612 '02/'03 or OM-647 '04-'06) Inline 5 cylinder engine is
MORE efficient at 1600-2400 RPMs?
Everything I have seen (Operators Manuals, internet performance specs, etc) indicates that the I5 Sprinter engine makes max. torque @ 2750-2800 RPMs, and Max. horsepower @3200-3250 RPMS.
What is "efficient" about running an engine well below it's designed power band?
If you had some sort of performance OBD-II compliant gauge, you would clearly see
that the % of engine LOD and boost are runing at max when @ 1600-2400 RPMs.
What you would not see are the changes that the ECM/ECU makes to the injector duration to pack in as much fuel as possible.
Not so good (or efficient) for an engine running well below an RPM range that can efficiently use that much fuel.
You could see the GPH increase by 2X or the MPG drop like a rock when the LOD/MAP increase, which would seem to indicate a rapid
loss of efficiency.

07-26-2011, 04:14 PM
Everything I have seen (Operators Manuals, internet performance specs, etc) indicates that the I5 Sprinter engine makes max. torque @ 2750-2800 RPMs, and Max. horsepower @3200-3250 RPMS.

You probably have not seen the torque/power curves (OM612) I have in the brochure I got when I was making my decision to buy. That plot has a legend stating 154 hp @ 3800 rpm & 243 lb-ft of torque at 1600-2400 rpm. The torque curve is not truly flat in the stated rpm range, but looks to be at max at ~2000 rpm. Torque falls off slowly above 2400 rpm and precipitously above 3800 rpm.

07-26-2011, 04:23 PM

I guess I was just misinformed. Somewhere I thought I read something somewhere about Sprinter torque between 1600 and 2400rpm. Must have been a statement about how flat the torque curve is during this band or somethinglike that. I knew the H.P. peak wasn't down this low!

Glad to know I'm wrong on the torque. Where did you get your info? I'd love to see a dyno chart on a 2.7. Is it on the net somewhere? Now I won't be as hesitant to buzz the little booger.It'll bring me back to my VW bus days! I don't "lug" it now per se, but I rarely drive over 2500 rpm. I cruise from 55 to 62 mph or so in top gear. I use 4th with my 3000 lb.car trailer.

Anyway, I'm gonna go fire her up... wish me luck!

Thanks for your advice,


07-27-2011, 12:20 AM
I apologise if I came off too strongly on this.
Please let us know how you made out after starting your Sprinter this morning.
I base my "opinions" here on what I have read + 104k miles experience in a T1N/OM-647.
Yes, the charts do to show that your OM-647 does indeed make it's max. torque
@ 1600-2400 RPMs. Max. HP is either at 3250 (some charts) or 3800 (other charts).
I'm still looking for the performance chart that I originally picked up on that said the
optimum was 2800-3200.
I've found some other information that suggests that pure torque is less important in a
turbocharged engine than in a normally aspirated engine due to the boost allowing significantly more fuel to burn efficiently with the turbo pumping in more oxygen
at higher RPMs.

I drove my '06 T1N 3500 dually with the same OM-647 engine for 104k miles.
Probably 30% if that mileage was towing a pretty heavy (4500 lbs.) 7' wide x 14' long
trailer across Texas, up through the midwest to MN and back to the East coast a few times.
Part of what I suggest is experiential, some of it is "it just seems to pull more freely into
headiwnds/up grades, and lastly a good portion of it is watching that darned ScanGauge II.
Being diligent on keeping the % engine LOaD as low as possible without losing speed/RPMs.
I'll keep looking and share with the group any info that changes my opinion on this.

07-27-2011, 01:54 AM
Stolen from the Photos area of the Yahoo Sprintervan group:
(memo: please post graphs as GIF files, not Jpeg)

That's a 2003 (hence OM612) Sprinter
...the red line is before adding an ECU modification, the blue line is after.

From a SailQuik post, the "torque curve" is roughly:
Stock base line run
43.5 2037 59.70 154
49.7 2328 79.80 180
55.9 2619 95.00 191
62.1 2910 108.3 196
72.1 3376 121.2 189
(from http://sprinter-source.com/forum/showthread.php?t=4961 post 8 )


Altered Sprinter
07-27-2011, 02:11 AM
Or Global HP 156 BHP on the OM 612
Transmission ratios are altered to match the 5 speed Automatic W SA-380

07-27-2011, 05:54 AM
Well I fired up the sprinter this morning and it ran fair but didn't accelerate like it should. Went to the Mercedes dealer in Bakersfield and he told me my 5-year warranty ran out today! The car broke down yesterday and like a fool I didn't call it in. Too late now.
They wanted $175 to attach their scanner and I said "No thanks". They also said the turbo isn't covered anyway. I get the distinct feeling they didn't appreciate me buying their product!

I decided to drive back home and try and fix it myself. My neighbor has a scanner and is ASC certified in all areas. Up popped something like "Insufficiient boost", I decided to try to replace the turbo resonator just for the heck of it with the Riordan eliminator. After doing so, we couldn't find a thing wrong with the oem part. Hmmm.

We started looking for a turbo hose leak and discovered one an inch before the boost hose enters the intake casting. A slit about an inch long inline with the hose. We fired up the engine and revved it up a bit, and, sure enough, boost came blasting out. I put a hose clamp around it for now and its working for the moment. I'm gonna order a hose and maybe the Riordan fix kit in the a.m. I fell I got off easy all in all!I'm trying to figure out a way to receive the hose on my trip. Europarts has 'em but that's one expensive hose! Any opinions out there on the Riordan Hose kit that's supposed to increase hose life?

Thank you all for your advice and taking the time to help me.You Sprinter guys are alright!

07-28-2011, 12:49 PM
Thanks for the follow up!
Been wondering how things turned out.
Europarts has pretty good prices, so not sure you are going to find the hose
assembly for less $$.
How did you manage to get back over the Grapevine with the cut hose?
That must have been a "white knuckle ride".
If you are going to set off on your vacation again, I would cut open an
aluminum soda can or 2 and get andother hose clamp.
Use a wrap or two of duct tape over the cut in the hose.
Wrap the aluminun sheet over the duct tape, then another wrap of
tape. Put your 2 hose clamps over the top of the layered duct tape and
aluminum sheet.
I still suggest you think about the Scan Gauge II.
If you set it up and monitor your MAP you would have had the information that
the boost was low (insufficient) and been able to buy a hose in Bakersfield.
Also you would have been able to see how heavily you had your engine loaded
going up the Grapevine from LA and that may have helped you to decide to
take the grade in 4th gear.
The true value of the SGII is not just that you can see the performance data,
you can use that data to "troubleshoot" on the road to some degree, and I
believe that the SGII would have give you some code associated with insufficient

07-31-2011, 05:16 PM
Hi guys,

I'm up in Washington now and the Sprinter is driving well. Was able to get the turbo hose before I left home. I'm downshifting a lot more now. Once the revs drop below about 2400 on a hill, it's time to drop a gear. The spacing from 4th to 3rd gear is a bit more than I like, however, resulting in a significant increase in revs. Sprinters are great travel vehicles. What other car could take the 7 of us and all our crap. And mine's a 118" low-roof! I borrowed a Suburban once to drive to San Francisco and we felt like sardines in it. I marvel at all the cars I see with stuff strapped to the roofs and on trays slid into the trailer hitch. Heck, I still can fully see out all my windows and can change kid's diapers and have 'em take leaks ---without even stopping if need be (5 boys). I wonder why so few people have bought Sprinters for personal use.
Thanks again,