View Full Version : Major lack in power & speed. Help please

04-25-2015, 03:06 AM
I've had my 2004 118 wb T1N at my mercedes mechanic for the last 3 days. I gave him a list of minor tweaks to work on (o2 sensor and glow plug replacement).

The main reason why I took it to him was because there is a major issue (to me) with acceleration! When I floor it going up hill, it doesn't accelerate quickly! Off the block, she moves slower than normal but will get up to speed. She slowly gets it to almost 4,000 RPMs then smoothly shifts gears and keeps roughly the same speed. Max speed uphill is about 55mph. Going down hill seems to be fine, though I don't ever need to accelerate quickly going downhill.

The mechanic is a great person, but he is not a sprinter guy. He ran the codes and nothing came up at all other than a small glow plug issue that he fixed. :thinking:

I would love to hear if this has happened to others. What could this issue be? Any suggestions will help greatly!

04-25-2015, 03:42 AM
We need a bit more information....!
When you try to accelerate "When I floor it going up hill, it doesn't accelerate quickly!" up this hill, WHAT gear do you have your Sprinter in?
What speed are you attempting to accelerate from and what speed are you wanting to attain quickly?
If the RPM slowly builds to almost 4,000 revs, that would indicate that your transmission is NOT upshifting normally.
Floor boarding your Sprinter to get better acceleration is probably not the best way to gain speed.
Downshifting so you are starting out in the lowest gear possible and accelerating about 1/2 throttle should get you
going as quickly as possible.
If this is not fast enough, might be a good idea to find someone with a DAD or DRB-III unit that can pull the
Diagnostic Trouble codes that are stored in your engine management computer.
This would tell you if you are in Limp Home Mode (LHM) and probably what has triggered the engine management
to limit your power.
Could be lack of turbo boost (MAP), dirty or sluggish EGR valve, cracked and leaking turbocharger resonator.
Having a full diagnosis should give you all the clues as to what might be wrong and what to replace to restore
full power.
Hope this helps,

04-25-2015, 11:57 AM
"Wot he rote" ^^^^^^^

From experience the 04/05 models have more than a few boost issues that don't always show up as hard codes and CEL on scenarios.

The air pressure sensor on the air cleaner has been superseded about 5 times and the MAP sensor twice to my knowledge. Only by checking with dealer parts can you get the right one for the specific Vin # of your van.

Additionally subject of a Dodge bulletin the ambient temp sensor will affect the boost if it is missing, corroded, or simply defective. Found behind the front bumper it can throw a lot of mechanics unfamiliar with the vehicle a curved ball. A simple check to verify its veracity is to push the temp button on the dash info panel and observe what you have as a reading. Then check the temperature by doing a 'uman dog sniff out the window! (doing a "nose" comparison.) If its wildly out the $25 dollar part is often the issue.

Then the only none time wasting/non stargazing diagnostic method, is to hook the vehicle up to a suitable scanner giving live data and simply drive it observing the information on the scanner screen. Obviously you need to know what to look for, but a target boost figure should be somewhere around 2000 millibars. Anything below 1750 mb and although it won't throw a code it will be sluggish.
Just as a side bar with the professional scan tool I have the "actual" live data lines will go red if they drop out or are below spec so glitches, lost signals and and such are instantly registered during a test drive.
Hope that helps & all the best

Gordon Smith
04-25-2015, 12:11 PM
Dennis: I have a gasoline engine in my Sprinter (07). My ambient temp sensor behind the front bumper has taken a beating over the years, and is usually 20 degree F, or so off. What's your best intuition about whether the sensor has any meaningful role in gasoline engine. If so, is it an easy job to replace the sensor…for someone who is a bit of a numb-nuts?

04-25-2015, 01:06 PM
No on that model of yours its more for infotainment!:laughing:

04-25-2015, 06:12 PM
Roger and Dennis!
Wow, lots of details, I wish I were a little more familiar with this vehicle- something tells me I will be soon though.
I took to the hills this morning to really analyze what what going on. And, of course, it was back to it's good old spunky self...
This power issue comes and goes, so I'll try again this afternoon and hopefully I'll be able to report back with specifics.

I'll also head under the hood when it stops raining here. Hopefully it's that temp sensor Dennis.

Roger, I was under the impression that the limp home mode drops you to just first gear? I'm able to get up to highways speed on the flats, but up hills it's lacking in power... I don't gun it ever, usually. More than anything I was doing it to try to analyze the issue at hand, hoping it would get it to down shift. That didn't seem to help, won't do it again.

Thanks again for your help with this issue. I've been reading up on DAD and hopefully I'll find someone in the Sacramento Foothills area that has one!


04-25-2015, 09:07 PM
Almost sounds like you are still listening to "old diesel wisdom".
Your Sprinter has a fairly small....hi revving... diesel engine and a completely
shift able (safely) automatic transmission.
Just tap the shift lever to the left, and it will drop down/manually downshift one gear ratio.
Tap it again and it will drop down (manually downshift) another gear.
Your highest gear is 5th gear when you are in D for drive and this is a 0.83 : 1 overdrive gear.
Not the best gear for accelerating unless you are already going 50+ mph.
There is nothing wrong with running your Sprinters OM-647 2.7 liter Inline 5 cylinder engine in
it's most efficient and powerful range which is ~2700-3200 RPM.
So, when you want some power, manually downshift to get he RPM up into this range, then
manually upshift when the RPM reaches 3200.
Probably not a good idea to run it all the way to the 4000 RPM redline.
Also not good to run it @ < 2000 RPM unless you are practically coasting on level ground with no
Hope this helps,

04-26-2015, 02:58 AM
It sounds like loss of boost pressure. There are many ways this happens. Some of them are purely mechanical, such as a split or loose hose, or the common bad turbo resonator (replace with Dorman and it will be fine). Oily spots are the tell-tale of a boost leak in the hoses or resonator. The EGR could be bleeding off boost pressure, or the turbo actuator arms are rusty and stuck. Or, it's electronic. Some sensor is sending info to the ECU that it calculates and determines to put the vehicle into LHM. The sensors could be failing and sending bogus info, or there is a real issue. It could be anything from the MAF, IAT, Rail Pressure sensor, transmission; no way to tell unless you do a scan for stored codes.

04-26-2015, 05:16 PM
Thanks Roger and Surlyoldbil
Roger, I have been very used to letting the automatic transmission do it's thing, but manually shifting is something I've done from time to time, especially down shifting going down hills to save my brakes. More than anything, I just want the engine to have the same power it had before. It hasn't happened again, but i'm ready to take notes when it does.
Bill, Thanks for the time to explain. I will need to find someone local to read the codes. As I mentioned, the mechanic i took it to couldn't find bad codes besides glow plugs... You're in Richmond, which isn't to far from me. Do you have a mechanic that you'd suggest that I take it to get read codes and possibly work on it???

04-26-2015, 05:46 PM
You need a DRB-3 or D.A.D. unit to read the codes properly, so ask shops if they have those scanners. People's Precision in Berkeley works on Sprinters, but I've never used them. MobileCC on this forum has a DRB-3 and could scan it for you (go to him in Santa Rosa if possible, because he charges by the hour and charges for trip time). He helped me with an injector issue years ago. Dodge 5-star dealers have DRB-3 scanners, or are supposed to (ask on the phone if they have one). Generic OBD scanners can give some info, but not anything in depth.

I'd take a close look for signs of boost leak from the turbo to the intake. Being an 04, you might have the failure prone OEM turbo resonator still on there. VERY common for it to separate at a seam when under a lot of turbo boost pressure, and then the seam closes and disappears when idling or stopped, making it hard to find, and often there are no codes stored! The aftermarket Dorman resonator for $30-40 has been shown to be very sturdy, or if you want to go overkill, there is a resonator made from billet aluminum available for about $100. Pretty much everyone who has an 04 or 05 has replaced the OEM resonator.

04-27-2015, 05:22 PM
THANK YOU BILL! I'll start by replacing that Resonator. I saw a 3 part youtube video where I guy replaces it on this exact vehicle. So, i'm going to order the part now and replace it right away. This is a newer vehicle to me and I'm the 3rd owner. So, who knows if it's original... Seems like a good first step.
Many thanks for the shop references. If the resonator doesn't do the trick, i'll try one of them!

04-27-2015, 10:47 PM
You might want to see if you can find out what resonator you have, if it's already a Dorman, there is no need to replace it, I think. Taking it off to see would be good practice for replacing it, anyway. Not sure if you NEED to take it off to see, though...

04-27-2015, 10:56 PM
Oh, I should mention that you can get some useful information via OBDII adapter and a free or cheap app for your iProduct or Android device. I have a generic ELM 327 bluetooth adapter plugged in to my OBD port, and the Torque app on my Samsung android tablet. It allows me to see sensor data such as intake, coolant and trans temp, mass air flow, turbo boost pressure, load, etc. as gauges of my own choice and configuration. There are some other apps that are highly reviewed, as well. The whole cost of this scanning technology is about $10, assuming you already have a phone or tablet with bluetooth. This is the same or higher level of diagnostics as a scangauge or other dedicated OBDII scanners, with a much better screen. I've used mine to clear codes on the spousal equivalent's car as well. http://www.ebay.com/itm/Mini-ELM327-V2-1-OBD2-OBDII-Bluetooth-Adapter-Auto-Scanner-TORQUE-ANDROID-US-BL-/291261648793?hash=item43d08c0f99&item=291261648793&vxp=mtr

You can watch the boost gauge in real time as you try to see what conditions cause it to shut down the boost.

07-20-2015, 10:41 PM
Could the fuel filter be a reason for this lack in boost?

I'm going to replace my filter either way, just curious to know if that could be a reason. I've been having some starting issues lately. It turns over, but won't fire up first time. I need to let the engine cool before it will start...

The lack of boost still happens, but only for a day or so every 2 or 3 weeks. I can't really figure out the pattern... And, its now swiching from LHM to full boost after 10 miles of driving or so... I'm super frustrated with this! Does this sound common to anyone?

07-21-2015, 12:05 AM
Fuel filter has nothing to do with the turbocharger boost pressure, but if you are losing fuel pressure and your
ECM is setting the LHM, shutting off the boost could be one of the consequences.
Since you are in a T1N, there are a number of things that normally trigger LHM.
Leaking turbo plumbing.....leaking or damage turbo resonator.... EGR issues.
Might be good to have a full diagnostic scan to determine what's stored in the ECM in regard to setting
That may lead you to the problem or the wonky sensor that's the root cause of your issues.

07-21-2015, 12:15 AM
. I've been having some starting issues lately. It turns over, but won't fire up first time. I need to let the engine cool before it will start...

Poor hot starting is sometimes a worm/clogged fuel injector or a leaking fuel rail pressure solenoid's seal. A simple injector leak-off test will help determine