Tacoma Grinding, No Power, Horrible MPG, Help!

[RememberTheFallen]

Also to the folks griping about the timing belt. I had just changed the timing belt on my tacoma last summer, my OTHER 03 that I sold. It looked in great condition then. So considering that and the fact that I had just done it on another truck I have been holding off for a while. It is on the radar but wasn't first up.

I will go ahead and order the parts and replace it but I am still leaning towards a driveline issue.

The other thing that I didn't mention is that MPG numbers are inverted over traditionally found. I get 14-17 MPG driving around the city and stop and go. It's when I am on the highway that I get 11 MPG which leads me to think it is a drag issue.

 

[RememberTheFallen]

Definitely check timing belt. Had a similar case here at my shop (I manage a Toyota specialty shop) where the vehicle had a lack of power with no check engine light. When hooked up to our scan tool, we could see the ECU was throwing timing all over the place to try and get it to run correct, therefore the power would come and go.

Belt jumped one tooth. 2004 Tacoma with 75,000 miles.

I've seen countless timing belts that the rubber still looks great, but has snapped. More commonly, they stretch further then the tensioner can account for and jump position.

The 5VZ 3.4L is not a interference engine, so even if the belt lets go, it won't cause internal damage.

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Front wheels will always be hard to turn since it's always spinning the front drive axles. A bearing that has that much resistance that's it causing a massive lack of power would most likely be associated with excessive noise and/or bad driving characteristics.

I will definitely look at the timing belt then. Enough of you seem to think it is possible and I was gonna change it in the next 10k miles anyway.

As far as the front tires being hard to turn, this is my 4th Tacoma and none of them have been this hard to turn. I can still turn the tire for sure but it stops as soon as you quit trying to turn it. It is not bad enough that I think that is the issue for sure but that combined with the whump whump whump sound combined with a rougher ride with acting up lead me to the front side of the driveline.

 

[toyotech]

Maybe a sticking caliber?
Timing belt is due so I would do that anyways.


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[RememberTheFallen]

Maybe a sticking caliber?
Timing belt is due so I would do that anyways.


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Ordered a timing belt kit earlier. Hopefully will have it to put on this weekend.

I was worried about the brakes initially as I had just put the bigger Tundra calipers and rotors on the front. It feels a lot like a stuck parking brake or caliper sticking but there is no evidence of that happening. The pads look barely used, the rotors are still nice and not glazed over, and I never felt any heat when checking around the rotors when I was trying to diagnose the issue.

Hopefully it's the timing belt but afraid it is not going to be.

I recently sold the supercharger to buy front and rear regeared diffs from East Coast Gear Supply. I have held off because I want to use that money to straighten the truck out first. I am tempted to go ahead and buy the regeared front clamshell as it will come with all new bearings and I have new CV's to go in with it. If that didn't fix it then I could use the money I had set aside for the rear diff to continue searching for the problem. I would have mismatched gearing for awhile which would mean no 4WD but at least I would know it is not anything in the front end.

 

[Scoutn79]

It might be worth getting a decent scantool. You may just have a sensor that is out of calibration. A temp, tps cam/crank position sensor could have you chasing your tail for years using standard/ oldschool troubleshooting techniques.

Darrell

 

[RememberTheFallen]

It might be worth getting a decent scantool. You may just have a sensor that is out of calibration. A temp, tps cam/crank position sensor could have you chasing your tail for years using standard/ oldschool troubleshooting techniques.

Darrell

I know it's not the same but I do have a OBII plug in and APP for my phone that reads trouble codes and several other things. It has a live time MPG tool . That's where I discovered I was drinking so much fuel just to stay at a constant speed on the highway.

Do the better ones really read that much more?

 

[toyotech]

If it was a sensor. You would have a code already. a/f and O2 sensor can be weak and affect mpg. It can affect drivability but you would get a code.

Easy thing to do in the meantime is clean your Maf sensor.


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[Scoutn79]

If it was a sensor. You would have a code already. a/f and O2 sensor can be weak and affect mpg. It can affect drivability but you would get a code.

Easy thing to do in the meantime is clean your Maf sensor.


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You don't always get a code if a sensor is out of calibration a small bit. If it is out a bunch and other parameters don't sync with one sensors output then yes.

Darrell

 

[RememberTheFallen]

Update for any folks that care.

It was a combination of a sticking drivers rear parking brake and randomly sticking front brake calipers.

Fixed the issues and installed 4.88 gears. Drives great now! Thanks for all of the help.

 

[deadbeat son]

Update for any folks that care.

It was a combination of a sticking drivers rear parking brake and randomly sticking front brake calipers.

Fixed the issues and installed 4.88 gears. Drives great now! Thanks for all of the help.

Glad to hear you got it resolved.

 

[toyotech]

Guess no one was right lol.


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[loudboy]

Guess no one was right lol.


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Dude isn't that the way it is though? All these ideas about why your truck is going slower except to suspect the one device that is SUPPOSED to make it go slower! I don't know how often I've forgotten to KISS: Keep is stupid, simple! ....that might be backwards...

Anyways, glad you got it figured out!

 

[RememberTheFallen]

Dude isn't that the way it is though? All these ideas about why your truck is going slower except to suspect the one device that is SUPPOSED to make it go slower! I don't know how often I've forgotten to KISS: Keep is stupid, simple! ....that might be backwards...

Anyways, glad you got it figured out!

Ya, it figures. The bad things is that I suspected the brakes initially and kept checking them for excessive heat. Never felt any. I then jacked up my truck several times and spun the wheels. They seem to turn ok, not great, just ok. I assumed they would be extremely hard to turn if binding but it seems they were rubbing just enough to slow me down.

I appreciate all of the help you guys gave me!