5.7L Lurches when cold while going up hill: tach jumps between 2200-2800 rpm

So I just bought a 2007 5.7L 4x4 with Tow Package with 98,400 miles.
Service records show regular maintenance and all recall maintenance was done. Also the problematic water pump had been replaced. Engine and interior is immaculate, as is the body.

So everyday I start my Tundra, back up my driveway, and must head up an 8-10 degree hill for about a 1/4 mile. After backing up my driveway onto the street/hill, I put the tranny in D. As I move forward up the hill the Tach jumps to about 2000-2200, and I'm going up the hill at about 25-30 mph....after a few seconds the engine starts lurching between 2200 and 2800 and back to 2200, and over and over again, until I get to the top of the hill. The lurch is enough to move my body back and forth if I don't slow down or stop.

I have tried this in D, in S3, S4, S5. It makes no difference. There are no engine codes being activated. The service tech at Modesto Toyota in Calif told me he has a 2020 T and his lurches when cold too. I cannot believe this is "normal" or "acceptable". Anyone know what might rectify the problem?

 

Welcome from WA.
That's definitely not normal, he's just trying to get you out the door.
The only thing I can think of would be to clean the throttle body and MAF sensor.

If it doesn't have issues any other time going down the road I don't think it would be fuel pump/filter, spark plugs or injectors.

 

Were you able to show your exact condition to the tech to have them confirm that their "lurch" is the same as what you're experiencing...? My truck when cold "lurches" between shifts but that is only when it's cold and for the first few shifts, wonder if that is what the tech thinks you're describing.

How rapidly is the engine cycling between 2200 RPM and 2800 RPM? Is it a smooth up/down/up/down or is it jerky? Better yet, do you have a video of this happening? This actually sounds like flex lockup is slipping, but S-mode is supposed to disable that...

There's also http://media.fixed-ops.com/Toy_ServiceBulletins/tc018t07.pdf

 

Hey Chris I used to live in Hayward... Up in Sonora now☺️

I did video record it... I'll try to upload.
the tach surge is happening 2-3 times per second. I also order the MAF and Throttle valve cleaner as recommended above too.

My VIN starts 5TFVB58107... I can't tell from that report if my truck is effected or not. It's a double cab 4x4 with standard 6'+ bed.

 

Ah, congratulations for going up that way, it's beautiful up there.

A video would be great to help diagnose this, but generally surging is going to be either a T/C or transmission, neither of which is necessarily good news. I suppose you could also be dealing with converter drainage, where it's draining when sitting. Does it do it on subsequent climbs of that hill?

 

Site doesn't want to accept my iPhone video. The only time the surging happens is first thing when the engine is cold. Later in day it doesn't do this.

I do have a dealer warranty for 3000 miles on drive train...I wonder if this would be covered?

 

Potentially; I would say that the fact that it only does it when cold is a little bit better than it doing it all the time, but still definitely a problem that needs to be corrected.

I would recommend uploading the video to YouTube and posting the link here -- you can also use this video when conversing with your service advisor/tech/whoever would be correcting the issue. Ideally, they could find an area that would reproduce it and use TIS to datalog things like torque converter lockup to see what the transmission thinks it should be doing.

 

Do you start the truck and then drop it into gear in 20 seconds and go?

 

Yes....I start, let idle while I buckle up, and back up my drive. Then within the minute I am in D going up a 8-10% hill for about 1/4 mile.
I go between 25-30 mph. I'm uploading a couple videos to Youtube...will complete shortly.

 

Chris.... here's a couple of video links from two different mornings.
Tomorrow I'll try to remember to turn off the Traction Control and see if that makes a difference.

https://youtu.be/qveHO8ztLrA

https://youtu.be/1iMML0isp1I

 

with that age/mileage, time for spark plugs and I would suggest trans drain and fill. Both items could in fact help unless there is some kind of trans issue. Hopefully it is something simple or maybe a combined effect of a few things needing maintenance.

Fluid changes, new plugs, new filters can make a big difference in performance/driveabillty if those items are beyond service limits. I would check the typical maintenance items first.

 

It kinda seems like your torque converter is slipping. What happens when you give it more gas up the hill?

What happens when you let off the throttle up the hill?

Can you go down the hill then drive back up?

 

if I stay on the gas it's pretty violent. I haven't tried flooring it.
the lurching seems to subside if I let off the gas.
if I go back down the hill and come up again, by then the engine/ drive train is warm and it doesn't happen.
it doesn't happen later in the same day even after several hours.
I have an appointment to have the transmission fluid flushed later this month. They drop the pan, change
any filters....look for shavings... I suspect they would be able to analyze the torque converter at the same time?

 

Asked my good friend Google and they suggested checking your fuel ratio.

You might be running too rich (warm up mode) or too lean (failing to reach warm up mode).

Since it only happens when cold, I'm not sure where to start looking.

 

Same thing happened to me. Three things I did. Clean MAF. (Didn’t help me). Change your spark plugs. Then try changing trans fluid. One of the last two fixed it for me. See I changed my spark plugs and all of my fluids at the same time. So yeah. Give those a try.

 

My guess: trans fluid low, or something with the throttle position sensor (which I believe is just part of the throttle body which also should be cleaned. Good luck.

 

Problem Solved!
I accidentally drained the trans fluid when I was going to do an oil change. So then I had to figure out how to fill the tranny pan and bring it to the right level.
With that done, the lurching problem disappeared: either too low of fluid as suggested above, or too dirty, as I was just under 100k miles. So to fill the trans, I used a
funnel and 2 hoses that I put into the fill hole. I had the funnel tied to my garage door to hold it in place, and then went through the wheel well to reach the
tranny. After I put back approximately what I drained out, I started the engine and got the tranny warm.... then I put it in park and pulled the "fill level" bolt...
with the engine running nothing was coming out, so I added about 1/2 quart at a time, and checked for the overflow...after about another quart I started to get
runoff, and that's when I stopped adding fluid and tightened the bolt up. Then I put about 680 miles on it over the long weekend, and everything seems fine.
I am having it flushed tomorrow.... slow method with no pressure, so as not to loosed debris, and will replace with Amsoil. Thank you all for your suggestions
By the way I did get the oil changed with Amsoil as well.

 

Here are the instructions to check the level. I would put Toyota fluid in. If you drained it one more time, then reset the level according to these instructions, I wouldn't bother paying a shop to do anything.