headscratcher: hestitation at 40-45-50 mph driving me crazy, HELP

[triskelion]

99/100 series
driving back to NJ from florida felt a shuddering and has progressively gotten worse
some idle hesitation as well at times
NO CEL no codes stored
drive car, get on highway easy on gas 45 mph starts bucking goes away around 60mph and doest come back until it slows down again and have to add power
needed to add coolant 2x in 4 weeks since coming back early august
coolant changed and flushed before trip
feels like a engine bogging not a trans bog or slip

any one have the same thing happen to them and what you did to resolve, troubleshoot

thanks guys for input

help

 

[Spike555]

How many miles are on the truck?
When was it’s last tune up?
Have you checked the transmission fluid level? What color is the fluid? How does it smell?
Do you have any pending trouble codes? You can check those with a OBDII scanner, you can buy a cheap one for $15, a good one that reads live data, ABS and SRS codes for $100.

Sounds like you just had to top off the coolant after it was flushed and the air pockets were getting pushed out.

 

[triskelion]

How many miles are on the truck? 180k
When was it’s last tune up? plugs coils 6 years when i first got truck
Have you checked the transmission fluid level? yes
What color is the fluid? clean
How does it smell?normal not burnt
Do you have any pending trouble codes? no codes stored as mentioned
You can check those with a OBDII scanner, you can buy a cheap one for $15,i have a basic one i use
a good one that reads live data, ABS and SRS codes for $100. i dont have this

Sounds like you just had to top off the coolant after it was flushed and the air pockets were getting pushed out.

any more ideas suggestions, great questions, added input, thanks

anyone else experience what im experiencing right now, im thnking there has to be someone who has.

 

[Spike555]

6yrs since your last tune up but how about miles since then? 200 or 200,000?
Do you know which plugs the used? Cheap copper plugs do not last very long. 60k if you’re lucky.
Iridium last more than 100k, my wifes Kia Sedona original Denso Iridium plugs lasted 185k before the van started idling rough, still no check engine light came on. I put E3 plugs in it and it’s smooth as silk.
I also have E3 plugs in my truck.

There are reports of the plugs coming loose on these engines, so far the reports are only of trucks that have had a shop do the plugs and torqued to spec. I do not torque, I tighten until good and tight. Some say the Toyota torque spec is to low, others say it’s fine, again, I do not torque spark plugs and I’ve never had one come loose.

Check your spark plugs to see if any are loose, loss of compression blowing past the plugs could cause your issue, eventually a plug could be so loose that it strips the threads out of the head.

 

[92LXAZ]

Throttle body

 

[triskelion]

t

6yrs since your last tune up but how about miles since then? 200 or 200,000?
Do you know which plugs the used? Cheap copper plugs do not last very long. 60k if you’re lucky.
Iridium last more than 100k, my wifes Kia Sedona original Denso Iridium plugs lasted 185k before the van started idling rough, still no check engine light came on. I put E3 plugs in it and it’s smooth as silk.
I also have E3 plugs in my truck.

There are reports of the plugs coming loose on these engines, so far the reports are only of trucks that have had a shop do the plugs and torqued to spec. I do not torque, I tighten until good and tight. Some say the Toyota torque spec is to low, others say it’s fine, again, I do not torque spark plugs and I’ve never had one come loose.

Check your spark plugs to see if any are loose, loss of compression blowing past the plugs could cause your issue, eventually a plug could be so loose that it strips the threads out of the head.

ill check this but with symptoms described, does it sound like plugs and coils? just wondering wouldnt that be observable at all rpm ranges, this is the part that bugs me and that its not throwing a code

 

[triskelion]

Throttle body

ill check this but with symptoms described, does it sound like plugs and coils? just wondering wouldnt that be observable at all rpm ranges, this is the part that bugs me and that its not throwing a code

any suggestions?

 

[92LXAZ]

ill check this but with symptoms described, does it sound like plugs and coils? just wondering wouldnt that be observable at all rpm ranges, this is the part that bugs me and that its not throwing a code

any suggestions?

Nope. Our old 06 was doing pretty much the same thing. Random as heck, often when just taking off from our house pulling onto the road would lose power, even cruising at 65 down the freeway would lose power for no reason. No codes, no hint of any kind. Camelback Toyota here couldn't troubleshoot because it couldn't be replicated. They suggested throttle body. Fixed.

 

[aljollano]

Throttle body position sensor.

A.J

 

[Spike555]

t


ill check this but with symptoms described, does it sound like plugs and coils? just wondering wouldnt that be observable at all rpm ranges, this is the part that bugs me and that its not throwing a code

I don’t know. I’m just throwing info out there, others are suggesting to replace the throttle body, not cheap but easy to do.
Shop around for one and go from there. It very well could be the throttle position sensor, if everything else is good then I’d replace it.

 

[2001LC]

Coolant, did you just not get burped properly after flushing, or do you have a leak. This need address first thing.
If you explain in detail how you checked coolant level? I can give you very good idea of which this is.

Throttle body in the 98-99 seem to have issues report more than other years. So very worth exploring.

Have you monitor engine temperature and fuel trims during this issue?

If this a well care for and well tuned engine (oil, filters, breathing, vacuum, A/F & spark). I find one area that does not throw a DTC and only acts up usually when under load "Coil(s)". I test for this by watching for misfires via tech stream, while under load or condition present.
To simulate load. I simple run engine, with foot on brake put in "D", raise RPM while watching for misfires.
To test while actual condition present. Either record (in tech stream) as you drive or watch as a passenger.

Spark plugs are know for walking out as early as 30k miles, in engine with very frequent cool down cycles. As spark plugs walk out, they can cause spark & coil issues.

Compression AND Clogged exhaust system should also be explored.

 

[gatormark91]

Classic torque converter lockup shudder. Had the same issue. Full trans drain/fill and a week of driving, the fresh cleaners in the ATF will clean the lockup clutch and the issue will go away.

 

[triskelion]

very great suggestions
gatormark91 i like your reply because of same issue you experienced firsthand, im leaning towards that
can you tell me more of your expriences that led to this?

anyone else experience this classic shudder?

you guys are the best, pease continue to brainstorm and reply

 

[gatormark91]

very great suggestions
gatormark91 i like your reply because of same issue you experienced firsthand, im leaning towards that
can you tell me more of your expriences that led to this?

anyone else experience this classic shudder?

you guys are the best, pease continue to brainstorm and reply

Normally, at about 40-45 mph, the TC lockup clutch locks up the TC. It gets dirty over the years because the degraded detergents in the ATF no longer keeps it clean, so it slips. You get a hesitating shuddering shake as it engages. Once it finally engages, everything works normally.

 

[triskelion]

Normally, at about 40-45 mph, the TC lockup clutch locks up the TC. It gets dirty over the years because the degraded detergents in the ATF no longer keeps it clean, so it slips. You get a hesitating shuddering shake as it engages. Once it finally engages, everything works normally.

would that issue also give you a n intermittent shudder at idle stop in gear? or should be unfelt when in park and motor
running?

 

[JT4runner]

I am having the same exact issues with my LX470. I am going to start with the easiest solution and change all 8 coils and spark plugs then go to the TB position sensor and then the TC converter. Coils should arrive tomorrow so I will give an update.

 

[JT4runner]

would that issue also give you a n intermittent shudder at idle stop in gear? or should be unfelt when in park and motor
running?

Did you ever figure out your problem?

 

[gatormark91]

I am having the same exact issues with my LX470. I am going to start with the easiest solution and change all 8 coils and spark plugs then go to the TB position sensor and then the TC converter. Coils should arrive tomorrow so I will give an update.

Change the ATF.

 

[JT4runner]

Change the ATF.

Hey I am going to just change it all. The coils look bad and I am overdue for plugs. So I’m just going fresh with the coils, plugs and also the ATF. Thanks for the help! I appreciate it.

 

[JT4runner]

So I received my ignition coils today and changed them and mine is running new again. I also plan to change the ATF soon.