I changed my oil yesterday in my '98 SR5 185K, AT, and after checking for leaks, I took it for a test drive. When I put the car into gear (any of them, R included) and step on the gas, it does not respond immediately. I did not have this problem before the oil change. I have to assume that I did something when changing the oil. My car will eventually engage (transmission) and go, but it revs higher than normal, then almost clunks as it snaps into gear. It's strange that it doesn't do this everytime, but most of the time.

1) Does the transmission engage/shift through a vacuum line? I wonder if I pushed it out of placed, crimped it or did something to compromise it?

2) Could the small amount of oil that spills when I take off the filter drip onto something causing this problem?

3) I used to have a problem and it's showing up a little now, where when I decelerate, I felt a clunk (kinda felt like someone hitting you in the back). I read on hear that greasing fixed this and it did... for a little while. I am wondering whether this is related?

Appreciate any advice?

 

None of your symptoms sound related to an oil change, unless you took apart a bunch of stuff that wasn't necessary for the oil change...

You did put it all back together correctly right? Oil cap and everything?

 

Ha, yes, the oil change was smooth and no issues. :-) It's just odd that the problem started on the test drive after the oil change.

I have an old Corvette and recall having a similar issue with it once and the problem was that one of the vacuum hoses was leaking and this was preventing the transmission from engaging. It feels very similar to what mine is doing, but I sure hope that there is better technology in my 4Runner than in my nearly 40 year old Vette. :-)

I did some searching on the forum and most people with similar issues said that a tune-up fixed it, so I may not be describing the problem correctly. When I hit the gas, the engine revs immediately but it will not move, then the transmission/differential kicks in and I can go. FWIW, I had a full tune up about a year ago (new plug wires, plugs, etc.) using all Yota dealer spec'ed parts.

 

this sounds like what was happening to the runner a couple months ago- fixed with new plugs/wires. (the old plugs were CRAZY gapped!)- wouldn't hurt to pop one out to check they're wearing as expected.

sounds like it could be vacuum related in terms of delayed response...

 

I really wouldn't expect it to be ba plugs/wires issues- they were replaced with NGK and dealer spec'ed wires less than 5,000 miles ago.

I really think it has to do something with the vacuum lines. Today I noticed that when on the highway, the RPM's will stay elevated after I take my foot off the gas causing a hard downshift, too. So, it works in both directions (accelerating and decelerating).

Is the transmission vacuum actuated? I suppose I should ask that fundamental question first.

 

This may sound very dumb, but did you drain the transmission fluid instead of the oil?

Yes I have done this before when I was a noob.

Other than that, if it is a vaccum line it should be very apparent as most are hooked up to the intake and intake plenum.

 

Did you top up the atf or anything? Most ppl dont relise you need to check your atf when the vehicle is running, so they fill to full while off, then its really over filled when running. Over filled tranny could maybe cause delayed shifting? Sorry if this doesnt help, just trying to spitball on everyone elses ideas

 

Wow, that would be bad. No, I didn't drain the transmission fluid. I'd better give up, if I did that.

The reason I keep going back to the vacuum line is because I did move them aside to put in the oversized funnel for pouring in the oil- well, that and the fact that my Corvette did something similar once when I unhooked a vacuum line.

 

Well all vacume is created by the plenum so spray around with some carb cleaner around the hoses you moved, if it idols up then you have your problem, just need to pinpoint and fix

 

I'm pretty sure now that the oil change is completely unrelated to my hardshifting/hesitation.

I believe the problem became worse, not due to the oil change but due to the 25 degree temperature drop and that the problem may just be a transmission fluid that needs replacing. (Crossing my fingers.)

 

Not totaly sure about toyota transmission, but ive changed the filter in ford automatics before. There is probably one in your toyotas trans, could help. It helped the fords I worked on. Maybe someone else can chime in? I had an auto in my 88 but it was such a slush box I 5spd swapped

 

Appreciate all the advice. I don't understand the correlation with the oil change but I'm now wondering whether I should change it more frequently than 5,000 miles? I use Mobil-1 filters and Mobil-1 synthetic oil.

This weekend, I drained all the old fluid and it wasn't pretty. I then refilled with the Lucas AT fluid as well as one bottle of Lucas' transmission "fix" fluid. The problem isn't fixed but it certainly is better. I wonder how long this will last.