Truck Hesitates after driving for a while

Hello everyone, I’m new here. I have an issue with my 2004 V8 Toyota Tundra Access cab. When I first drive my truck it runs great and feels strong but after driving it for about 15-20 minutes it hesitates, I also noticed that when pressing the break at a red light or stop sign my rpms go up a little before coming to a complete stop. it idles normal when completely stopped, no vibrations or anything. I replaced the air filter, spark plugs, cleaned throttle body and MAF sensor but didn’t fix the issue, no check engine light either. Any ideas or solutions? I would really appreciate it.

 

Vacuum hoses. Check for disconnected ones or dry / old / cracking ones. Replace as necessary. A vacuum leak will cause symptoms like yours. Especially after the truck has warmed up. PCV valve (driver's side valve cover near the throttle body) is another good one to check. The valve can become non-functional and the seal around it can dry out and leak. Good luck.

 

Thankyou very much. I replaced the PCV valve and also did my valve cover gaskets because they were leaking, it seemed to have helped a little bit I can still feel the hesitation, another thing I noticed was that my truck seems to be running hot but it’s not overheating, the needle it’s always on the middle. I used to be able to put my hand on the hood and now I can’t because it immediately burns my hand. I replaced my radiator about 6 months ago. My fan seems to be working properly any other ideas?

 

Perhaps the vehicle is overheating. I would do a recheck on the recently replaced radiator. If everything seems in order, hoses, thermostat, properly flushed and purged of air etc., then I would rethink why the radiator was replaced in the first place? Perhaps the issue was present prior to the radiator replacement. Overheated engines will run poorly. Gas can pre-ignite in hot cylinders and cause poor performance. I would trust your instincts on the heat issue as gauges can fail as well.

 

Hello again, back with my running hot issue. Just the other day I was able to get back and work on my Tundra, I replaced the radiator cap with an OEM one and it seems to have fixed it, my truck doesn’t seem to run hot anymore and it runs better now. Hopefully this helps anyone that’s having similar issues.

 

Radiator cap or thermostat. Cooler engines run a lot more efficiently

 

maybe now that you are paying more attention to every little details you have noticed this but I think that's normal and the torque converter is unlocking so the rpm goes up a little.