Transmission troubles

[Seanz0rz]

The last two times i have driven the truck long distances i have noticed a "chudder" coming from the drive train and engine at only very specific times. 3.4L, auto trans, very well maintained.

when going about 1700 RPM (55ish miles an hour i believe) on the highway, and needing to pass a car, i put my foot down on the gas and it downshifts out of OD. well when it downshifts, it "chudders" like it takes a few trys to get into gear. the RPMs on the tach dont jump or fall, but stay where they were before i mashed down on the pedal. it kind of feels like im losing traction out back, but i know im not, pavement is dry, and its on straight roads. only happens when the engine is fully warmed up. i have no leaking, etc.

thats the best way to describe my problem, if you want me to clarify anything let me know. it only does this at this particular time, and even then not all the time downshifting out of OD.

i have yet to check the fluid, didnt have time this weekend, and now at school i have my what used to be less reliable car.


what do you guys think? transmission? if it is, would it be better to swap in a manual transmission? thanks, really appreciate it!

[slosurfer]

Fuel Filter possibly?

[MTL_4runner]

Assuming it is not an engine miss (ie no bucking or loss of power) then it may be your clutch packs beginning to go. Best way to get an idea of what's going on with the tranny is to drop the pan and clean the filter screen. You can adjust the kickdown cable to give you more fluid pressure but if the clutches are beginning to go, it may not buy you that much additional time.

When was the last time the tranny pan was dropped?

[Seanz0rz]

i purchased this vehicle august 1st last year, at 136k, the transmission fluid was replaced (im guessing that means a drain and refill, not flush and refill) just prior to me purchasing it. i am now at 142k and i totally baby the thing.

as for no bucking, i wouldnt say that. you definitely feel it, but im not sure if its coming from the tranny or the engine. however, it only does it at specific times. they coil packs look to be original, should i go ahead and replace those and the plugs/wires, since that needs to be done anyway, and see if that solves my problem? fuel filter needs to be replaced too.

obviously this is a problem i dont want to throw money at, but should i go ahead and replace those things that may be causing it that are relatively cheap? and see if that is the solution, or should i have my mechanic concentrate on the transmission? and should i replace with another auto? or should i swap in a 5spd?

[MTL_4runner]

Ok, so it could be engine or transmission related?

I would start by doing the easy stuff (ignore what you've done already) like changing the plugs, air filter, fuel fliter, clean the TB, do a Seafoam treatment and drop the tranny pan. If the tranny is on the way out you'll usually see evidence of it in the pan. There's no need to change coil packs just because they're old. Wires could be replaced with another stock set but it's not likely the problem if it only happens during a hard downshift from OD.

[Seanz0rz]

i have been meaning to do those maintenance items anyway.

thanks for your help guys, really really appreciate it.

now that you mention it, this only occured after putting seafoam through the gastank. any relation? i went and cleaned the throttle body too, it was pretty bad. ill try doing a seafoam through the pcv hose, then changing out plugs, since they might be fouled from the breaking up of carbon.

[MTL_4runner]

Take a look at the plugs because that is a good indicator of how the engine is running. You're looking for any plugs with a color much different than the rest. The plugs should all be a very light brown when it's firing correctly. The Seafoam might have caused that studder if you got a large amount sucked into the fuel pump all at once, but not likely since it will mix with the fuel as soon as it is poured in the tank. If this happened at WOT the fuel filter is definately suspect too. Do the regular maintenance as I mentioned above and see where that gets you.

[Lee]

just try to avoid it being something in the trans if you can. take it from me, it is NOT cheap to get a used trans put in and the whole thing is rather scary because you lack confidence in the trans for the first 3-5K :(

i got a used one out of a 2002 put in, it started making a grinding noise in 13K miles. so i got one out of a 2000 limited put in a few weeks ago under warranty (GET A WARRANTY, PAY FOR IT, ITS WORTH IT) and this one is a lot tighter. its almost like this ones torque converter is a lot better, but that could be in my head.

also check your u joints for play in the dshafts too. :)

[Seanz0rz]

my friend thinks it is the fuel system, same thing happened on his ford truck.

are there any procedures on checking the fuel injectors, etc.?

any other ideas or suggestions, etc?

[MTL_4runner]

my friend thinks it is the fuel system, same thing happened on his ford truck.

are there any procedures on checking the fuel injectors, etc.?

any other ideas or suggestions, etc?


I'm not sure I'd be linking your friend's issue and yours just yet. Sure we can walk you though testing fuel injectors but that's usually a fairly involved process and often comes after the basics have been eliminated. Any reason why you don't want to start tackling the simple stuff as was suggested above?

[Seanz0rz]

im trying to get as much stuff together ahead of the weekend. im at school, without the vehicle and without proper tools to work on it anyway. this weekend i will pull each plug and check, etc. but i would like to be able to check everything while i have the engine partially torn apart. no guarentee i will even get to it this weekend, i have a few other obligations to fulfill.

[MTL_4runner]

You can test the passenger side injectors easily, but the driver's side need to have the plenum removed to probe resistances for those. Each one should be between 13-16 ohms or it may need replacement. Without a CEL showing a P030X code, it's not likely that's the issue or if it is, it is still intermittent enough to possibly test fine even if it isn't.

You can see the injectors in this pic (they are light gray):
http://i9.photobucket.com/albums/a81/jdub765/fuelinjector/IMG_4101.jpg

Passenger side:
http://img109.imageshack.us/img109/8435/43679999lq8.jpg

Resistance check:
http://img169.imageshack.us/img169/2702/injectortest004wk1.jpg

[Seanz0rz]

jamie, you are awesome! thanks! like i said, i will check those last, but i still feel they should be checked, just to eliminate the simple and relatively inexpensive components first.

[Chaplain]

Did you ever figure out what the trouble was?

[Seanz0rz]

as far as i can tell, a good cleaning of the entire upper intake tract, along with new plugs and wires, has solved my problem.

i made sure to deep clean the idle air control valve, and replace the PCV valve (it had gone bad)

[Chaplain]

as far as i can tell, a good cleaning of the entire upper intake tract, along with new plugs and wires, has solved my problem.

i made sure to deep clean the idle air control valve, and replace the PCV valve (it had gone bad)


Thanks, I'm having simular issues with mine now.