Suddenly poor acceleration, hard starting, and a decline in gas mileage.

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

PaPa_Brewskey

Member
Joined
Jun 22, 2017
Posts
57
Reaction score
56
Location
Gilbert, Arizona
Ram Year
2015
Engine
Hemi 5.7
Here is a little story about checking things out, after having work done on your truck.
Last month, I had my '15 1500 into the dealer for some warranty work. When I picked up the truck, I got the spiel about how my throttle body was dirty, and I need the injectors cleaned. I declined the service (dealer wanted $395) and the service adviser went on to tell me that if I noticed lag in acceleration, worsening gas mileage, and harder starts, it was all indications of needing the fuel system serviced, and I should bring it back and they'd do it anytime. OK, and I went on my way.

Guess what, I started noticing all of these things happening, and I started to second guess my decision not to have the fuel service done. Maybe it was psychological, you know, just imagining those symptoms the service advisor put in my head. not...

Well the next week, I took the truck on a road trip from AZ to San Diego and back, a trip I do two or three times a year, and I got the worse mileage I've ever had on that trip. I typically get about 19 MPG average on that trip, this time I got about 15. I am also sure, that my acceleration was definitely not what it was before.

So last weekend, I went out to take the throttle body off, and have a look at just how dirty it was, and give it good cleaning I took the air intake tube off, and inspected the MAF sensor, I intended to clean that as well, but then...wait a second, somethin don't quite look right here. I noticed that the MAF was askew about 45 degrees. I grabbed the MAF sensor plug on the outside of the air intake tube, and gave it a little jiggle and a little clockwise twist, and low and behold it locked right into place. I thought to my self, I'll be damned, could this be the culprit? Well I went ahead and pushed the TB butterfly open an took a look down throat with my inspection camera, to my surprise that thing was shiny and showed just a little but of carbon build up, nothing at all like I was expecting. To hell with it, I put everything back together, fired the truck up, and headed out for a test drive. Sure enough, acceleration was back, and all this week, the truck started right up with no hesitation. I'm assuming that my mileage will be back to normal now as well. I filled up today, so I'll know for sure next week.

Now boys and girls, I'm not saying the tech at this dealership gave the MAF a little twist on purpose, but I am a little miffed that it was left askew. If he did in fact take the air tunnel off to inspect the throttle body, like the service advisor said he did, I suppose it could have incidentally turned, IDK. I'm just saying its all a little bit on the coincidental side, and by coincidental, I mean shady. I mean, the exact symptoms described by the service advisor?

So, sorry if I've rambled on, I'm passing on this little tip, if you are suddenly having acceleration, starting, or mileage issues after having your truck serviced, it might be worth giving this simple little item a check.

Lesson learned!
 

Pull Ya

U.S. MARINE VETERAN
Supporting Member
Military
Joined
Jan 16, 2012
Posts
15,787
Reaction score
23,056
Location
Cedar Creek, Tx
Ram Year
2015
Engine
5.7 Hemi
I would really hate to think you may be right but I'm also not naive enough to think it would never happen. I'm glad you found the problem and it should be something we should all be aware of. I guess sometimes our faith in mankind just sorta sucks!!!!
Jay
 

RysRam

Senior Member
Joined
Aug 11, 2016
Posts
198
Reaction score
177
Location
Ontario, Canada
Ram Year
2013
Engine
Hemi 5.7L
That's not a MAF sensor, it's an intake temp sensor. The 4thgen Hemi 1500s don't use a MAF system, they use a speed/density system.
 

Ramnewbie

Senior Member
Military
Joined
May 8, 2017
Posts
3,029
Reaction score
3,880
Ram Year
2017
Engine
Hemi 5.7
Here is a little story about checking things out, after having work done on your truck.
Last month, I had my '15 1500 into the dealer for some warranty work. When I picked up the truck, I got the spiel about how my throttle body was dirty, and I need the injectors cleaned. I declined the service (dealer wanted $395) and the service adviser went on to tell me that if I noticed lag in acceleration, worsening gas mileage, and harder starts, it was all indications of needing the fuel system serviced, and I should bring it back and they'd do it anytime. OK, and I went on my way.

Guess what, I started noticing all of these things happening, and I started to second guess my decision not to have the fuel service done. Maybe it was psychological, you know, just imagining those symptoms the service advisor put in my head. not...

Well the next week, I took the truck on a road trip from AZ to San Diego and back, a trip I do two or three times a year, and I got the worse mileage I've ever had on that trip. I typically get about 19 MPG average on that trip, this time I got about 15. I am also sure, that my acceleration was definitely not what it was before.

So last weekend, I went out to take the throttle body off, and have a look at just how dirty it was, and give it good cleaning I took the air intake tube off, and inspected the MAF sensor, I intended to clean that as well, but then...wait a second, somethin don't quite look right here. I noticed that the MAF was askew about 45 degrees. I grabbed the MAF sensor plug on the outside of the air intake tube, and gave it a little jiggle and a little clockwise twist, and low and behold it locked right into place. I thought to my self, I'll be damned, could this be the culprit? Well I went ahead and pushed the TB butterfly open an took a look down throat with my inspection camera, to my surprise that thing was shiny and showed just a little but of carbon build up, nothing at all like I was expecting. To hell with it, I put everything back together, fired the truck up, and headed out for a test drive. Sure enough, acceleration was back, and all this week, the truck started right up with no hesitation. I'm assuming that my mileage will be back to normal now as well. I filled up today, so I'll know for sure next week.

Now boys and girls, I'm not saying the tech at this dealership gave the MAF a little twist on purpose, but I am a little miffed that it was left askew. If he did in fact take the air tunnel off to inspect the throttle body, like the service advisor said he did, I suppose it could have incidentally turned, IDK. I'm just saying its all a little bit on the coincidental side, and by coincidental, I mean shady. I mean, the exact symptoms described by the service advisor?

So, sorry if I've rambled on, I'm passing on this little tip, if you are suddenly having acceleration, starting, or mileage issues after having your truck serviced, it might be worth giving this simple little item a check.

Lesson learned!
It's a damn shame that we can't trust the dealer to do things right. I myself have had issues over the years that make me think who the hell are these people that are supposedly certified Mopar technitions. I've had hoses left off or clamps not tighted, engine covers not put back on properly, wrong oil put in, and drain plugs just finger tight. Also suspected one time that they changed oil but not the filter. The only reason I go back to the dealer at all anymore is for a warranty issue that's more than pocket change or for a recall. Sometimes I think I'm paranoid because if anyone does anything to my vehicles I give it a look see, just to satisfy myself.

Sent from my XT1650 using Tapatalk
 

BiGMERF

Senior Member
Joined
May 9, 2017
Posts
1,738
Reaction score
791
Location
Florida
Ram Year
2017 SLT 4x4
Engine
v6
Wow I would not be surprised.


Sent from my iPhone using Tapatalk
 

SYKRAMMAN

Banned
Joined
Jul 10, 2017
Posts
2,401
Reaction score
1,640
Location
Jersey shore
Ram Year
06 Mega
Engine
5.7
That’s an easy 400$ for the dealer to just skew the sensor so it runs like ****, that dealer probably does it often and gets away with it cause who would know. When my wife’s car goes in for warranty work only, I turn the dash cam on and put it on the bottom of dash up close to windshield where you can see the engine compartment, haven’t caught anything yet (probably cause they can see it on) but I’m not trusting the so called tech’s with ****!
 

adrianp89

Senior Member
Joined
Sep 3, 2015
Posts
3,175
Reaction score
1,273
Location
Tampa Bay, FL
Ram Year
2019
Engine
Hemi 5.7
I would go back in and have a conversation with the manager about it.
 

huntergreen

Senior Member
Military
Joined
Jan 5, 2011
Posts
12,186
Reaction score
25,923
Ram Year
2016
Engine
hemi 5.7
It's fixed so I wouldn't say anything. If it happened again, I would have a "heated " conversation about it.
 

RedSRT4Me

Senior Member
Joined
Oct 28, 2015
Posts
2,734
Reaction score
2,086
Location
Scottsdale, Az
Ram Year
2015 CC Sport
Engine
5.7
That's not a MAF sensor, it's an intake temp sensor. The 4thgen Hemi 1500s don't use a MAF system, they use a speed/density system.

I think all dodge or ram vehicles from at least 1998 on use map sensors. My 98 neon, 03 SRT4,
05 ram and 15 ram all use them.

Makes it super easy if you need a 2 or 3 bar map sensor to boost your vehicle
 

SYKRAMMAN

Banned
Joined
Jul 10, 2017
Posts
2,401
Reaction score
1,640
Location
Jersey shore
Ram Year
06 Mega
Engine
5.7
was reading map and maf as the same, Been doing that a lot lately, can’t concentrate for some reason for the past week!
 
Last edited:

Pull Ya

U.S. MARINE VETERAN
Supporting Member
Military
Joined
Jan 16, 2012
Posts
15,787
Reaction score
23,056
Location
Cedar Creek, Tx
Ram Year
2015
Engine
5.7 Hemi
I've gotta say that in my experience and dealing with lots of the tech's at different dealerships there are some really good techs out there. They are conscientious, knowledgeable and want to do a good job and they are proud of their work. They are also the minority. The others act like they are doing you a favor to work on your car, could care less about their workmanship and all they want to do is get the job done as fast as possible and move on to the next job. And some are probably dishonest. They have no pride in their work, or themselves for that matter. I am just kinda cautious about painting all techs with a broad brush as all being bad, when in fact there are a few who do a really good job. We have a couple on this forum who are extremely helpful and are willing to answer everyone's questions. I can't help but believe they are some of the few good and professional techs. Just my view of the other side of the coin.
Jay
 
OP
OP
PaPa_Brewskey

PaPa_Brewskey

Member
Joined
Jun 22, 2017
Posts
57
Reaction score
56
Location
Gilbert, Arizona
Ram Year
2015
Engine
Hemi 5.7
That's not a MAF sensor, it's an intake temp sensor. The 4thgen Hemi 1500s don't use a MAF system, they use a speed/density system.
Hmm, well that explains why it, didn't quite look like any MAF sensor I'd seen before. What it doesn't explain, is if indeed locking it into place, really is what made the difference. I don't understand how positioning of the temperature sensor would have that much of a difference in what it is reading and sending, but then again, I'm not an engineer. I did fill up again today, and calculated my MPG was back to 17 combined. I would say maybe I did just have bad gas, well not me, but the truck, but too many different gas stations in the mix. Perhaps the truck was adjusting to the "Summer Blend" of gas, IDK...

OMG I'm second guessing my whole life now...\_0_/
 

RysRam

Senior Member
Joined
Aug 11, 2016
Posts
198
Reaction score
177
Location
Ontario, Canada
Ram Year
2013
Engine
Hemi 5.7L
Hmm, well that explains why it, didn't quite look like any MAF sensor I'd seen before. What it doesn't explain, is if indeed locking it into place, really is what made the difference. I don't understand how positioning of the temperature sensor would have that much of a difference in what it is reading and sending, but then again, I'm not an engineer. I did fill up again today, and calculated my MPG was back to 17 combined. I would say maybe I did just have bad gas, well not me, but the truck, but too many different gas stations in the mix. Perhaps the truck was adjusting to the "Summer Blend" of gas, IDK...

OMG I'm second guessing my whole life now...\_0_/

The IAT sensor 100% has an up and a down. It's supposed to be positioned with the clip's fastener at the top, facing towards the hood. Having it sideways in the intake tube would move the blue pellet at the end of it out of the airflow as it would be shrouded by the sensor's body. I.e. having it installed wrong is likely to send bad info to the ECM. :)

Looks like you nailed it, good find!
 
OP
OP
PaPa_Brewskey

PaPa_Brewskey

Member
Joined
Jun 22, 2017
Posts
57
Reaction score
56
Location
Gilbert, Arizona
Ram Year
2015
Engine
Hemi 5.7
The IAT sensor 100% has an up and a down. It's supposed to be positioned with the clip's fastener at the top, facing towards the hood. Having it sideways in the intake tube would move the blue pellet at the end of it out of the airflow as it would be shrouded by the sensor's body. I.e. having it installed wrong is likely to send bad info to the ECM. :)

Looks like you nailed it, good find!


Thanks for clarifying both the part and the description, you've taught me something new today. In all seriousness, I honestly hope it wasn't done intentionally, IMO it does reflect bad on the dealership, but I also know there are a lot of good tech's who would absolutely condone doing this. If we've helped anyone else out here, it was worth the post.
 

Alan Summers

Junior Member
Joined
Feb 17, 2018
Posts
18
Reaction score
10
Location
Metro Atlanta, GA
Ram Year
2010
Engine
5.7L Hemi
I have a question on the throttle body. Can you really just push it open with your fingers with the vehicle off? I thought that was a no-no. I want to clean mine as well but sure that I read on here somewhere not to manually open it...was that my imagination?

Thanks in advance!
 
Top