Mut

Hello folks,

My 99 RX300 has been having this problem for the last couple of months now. It's only happened 8-10 times but it's still a concern.

Regardless of how fast I am going, when I brake, sometimes without even coming to a dead stop, my car's engine will rev and the RPM gauge will go up but the car won't move until a few seconds later it will jerk as if it's been rear ended. This has usually happened when I've come to a complete stop at a stop light or pressing on the break and then the gas while making a turn in a parking lot (i.e. going under 10 mph). It also feels like it happens mostly within the first 5 minutes of my car being started after sitting for a while.

The only real work that's been done to my car is cleaning of the IACV and changing of the transmission fluid by myself and replacing the MAF sensor and charcoal canister.

I hope this issue isn't a sign of something terrible. If you guys have any idea on what's going on and how I should approach this, I would really appreciate it.

Thanks!

code58

Mut- How long ago did you change the trans. fluid? What was it like when you changed it? Dirty, smelly, etc.? Did you remove and clean the pan and replace the filter? What were the magnets like? Does it have the paper (fiber) filter or the metal screen? Did you only change the 4 qts. or so that you can drain out. What kind of fluid did you put back in? It doesn't sound very good, for sure. I would remove the pan and see if you have any metal shavings in the pan or on the magnets. (steel or aluminum) That at least is the 1st. thing I would do and decide what the next step is from there, Though it doesn't sound good, there is always a possibility that if caught soon enough, it might might be a sensor or something else that could be taken care of before it destroys its self. Good Luck!

Mut

Ugh... transmission problem was exactly what I didn't want to hear. The only reason why I changed the transmission fluid was because the mechanic said it wasn’t bad but getting there so I decided to change it myself. The fluid was obviously darker than the cherry color. I can’t quite remember how much I changed, but at least 4 quarts. I didn’t drop the pan or anything, just drained the oil and filled it up.

Once I drop the pan (I’m assuming this part is in one of the DIY guides somewhere?) and take a look inside, where should I go from there?

From what I’ve described regarding how the car is acting, does this sound more like a transmission issue than anything? I’ve been lucky enough to go 10+ years without a single transmission problem on the ’99 (knock on wood) so I hope my streak doesn’t end.

thomas1

Could be a bad or dirty speed sensor, there are two on the tranny....

Lexmex

Another possibility is the ABS system. It can have its issues when coming to a stop and even when you think you are fully stopped, under 5 miles an hour, it can jerk the vehicle forward. When you come to a full stop, does it then jerk forward (or attempt to) shortly thereafter.

Low or dirty tranny fluid will also cause a similar issue...hesitation then a quick jerk. The DIY thread on the transmission fluid changeout is at the top of the RX300 forum as one of the stickies.

I'd also run some fuel injector cleaner through the system.

code58

Didn't even think about that. It has never ceased to amaze me at how reliable the ABS systems are. When they 1st. came out I took a look at that pump system and thought, Oh boy, this looks like an expensive trouble prone nightmare. Hasn't seemed to be true at all. But, if man made it, it can go wrong!

Mut

Thanks for the replies, guys. This happened to me yesterday. I pulled out of the parking garage (my car had been sitting there for 8 hours) and then put the gear in drive and started to go forward. I took my foot off the gas (I was going 5 mph) and made a right turn without touching the brake at all, then in the middle of my right turn I heard my engine go quiet, not turned off but definitely quiet, and I knew immediately what was going on so I kept turning without pressing the gas or the brake to see what was going to happen. A few second later, my car jerks, again as if it's been slightly rear ended, and everything went back to normal.

Basically, the car jerked without me pressing the brake prior, unlike what I previously experienced.

From what I wrote, is your guys' assessment any different from when I initially described it?

Lexmex

hmmm,

I had an issue once at a light by my track where I had a sharp RPM jump and the RX turned off. Was P0171 error, but I turned the vehicle back on and no issue.

The power steering system however does use juice. Have you tried in Drive and with foot on the brake turning the wheel back and forth?

code58

Mut- You got any easy problems for us to try and solve? You've got us all scratching our heads over this one!

aejaz

Check for any misfires, A freind's RX300 (2002) was found to have compression loss in one of the pistons.. (This came out after they did a compression test).

This could be something further to the spark plugs.. if you have already changed the spark plugs, then a compression test could help.

Lexmex

One other thing, try adding some fuel injector cleaner (Amsoil, Lucas or Redline). You might have an issue with a clogged fuel pump and/or injectors. I remember now such an issue after talking to my uncle last night on the phone.