Transmission shudders randomly, limp mode kicks in

Driving up and down and level roads a random shudder shows up like driving on the rumble strips . Was bad enough pulling a hill one time the exceleration got jerky at hesitant . Pulled over turned off vehicle went away . Then does it randomly . Trac off light is on as is check engine and maint required . Codes says 2 and 3 cylinder misfire and repeats ... Is this limp mode even though all runs great and shifts great after battery disconnect ? Ready to junk my truck 166000 miles

 

Diagnose the problem, may be super simple like fowled spark plugs or could be something like worn out fuel pump.

 

The simplest and easiest thing to do would be to change the spark plugs. When is the last time the plugs were changed?

 

Yeah that's where I started . Bought new Bosch platinum s . Old plugs barely hade center electrode three ngk and three nippondensos . One coil pack was oil on the side , clean light oil and a tiny bit of dark oil . Does those coils above the plugs have oil in side ?

 

If you have oil in the spark plug tubes your valve cover gaskets are leaking, also some people have had issues with running platinum plugs in the 4.0l.
Having 3 NGK and 3 denso plugs means they were original, the stock plug for the 4.0 is copper Denso K20HR-U11.

If the coil boots were soaked in oil they should be replaced but don't do that until you get your valve cover gaskets fixed.

 

Doesn't sound like you are in limp mode. That is a self preservation condition that disables certain features, like AC, and greatly reduces the speed you can drive. What are the codes for the two cylinders? I’ll speculate you need to replace those two ignition coils. 166K miles on a set of plugs is a-lot and explains why the center electrodes were worn down so much; that puts a strain on the coils. Hopefully, that’s the only damage you’ve done. If you hate replacing coils, get iridium plugs - that’s what I have. They’ll last 80-100K compared to 50K for copper plugs - Toyota recommends 30K but that is for the emissions warranty, the plugs should easily last 50K, but not 166K!

 

You may want to replace these.

https://www.rockauto.com/en/moreinfo.php?pk=5414352&cc=3310144&pt=10150&jsn=417

 

I thought that was exactly what limp mode is?



As for OP, Toyota's DO NOT like Bosch parts, and the 4.0 does not like platinum electrodes.

Get some NGK Iridium and call it a day there but don't unload the parts shotgun yet get your codes pulled and some diag done. Check your fluid levels colors and age.

If your plugs had tripple the milage interval on them I suspect your trans fluid is equally neglected.

 

Soo no I don't neglect tranny did flush last year . Switched all plugs truck runs great at 85 mph to the Toyota dealership . The ran the codes and nothing shows up at all and truck ran great up hills at 85 and flats at 85 to 90 . No mis fires , no shudders . Gave me a great deal on a factory air filter and an alignment and tire rotation . Plugs are more work than draining and sucking and blowing tranny fluid . Plug swap took half hour from start to finish on cold engine . I'll post again If shudder reappears . Really appreciate the feed back . I did find a giant dent in the oil pan for the transmission so I might take apart replace filter etc

 

I may have read his initial symptoms differently. He said the hesitating was random.