LS - 1st and 2nd Gen (1990-2000) Discussion topics related to the 1990 - 2000 Lexus LS400

Car jerking at a stop

Old 07-17-06, 07:32 PM
  #1  
Phucanese
Rookie
Thread Starter
 
Phucanese's Avatar
 
Join Date: Jan 2006
Location: Washington
Posts: 80
Likes: 0
Received 0 Likes on 0 Posts
Default Car jerking at a stop

i did some searches but could not find what im looking for.

i just noticed this the other day.
at a stop light or when ever i have to brake for a long period of time
the car starts jerking. the RPMs drop about 100rpm and then the car
goes back to normal. but now this happens continuously at stop light.

even when i let go of the brake to let the car roll forward, the car still jerks
only until i press the gas the car is normal. and then when i am braking to
a stop it also jerks.

the jerking is not noticable outside, but inside the car you can definitly feel it.
the car drives fine with no jerking, this only happens at a stop...

this has happened in the past but not continuously like it does now.
before i would only notice it once in a while at a stop.
and this happens only when the car is warmed up.

could this just be a tune up thing? my 93 has about 129K on it,
but i think the last time it was tuned up was around 75K...
Old 07-17-06, 08:16 PM
  #2  
RA40
Super Moderator

iTrader: (6)
 
RA40's Avatar
 
Join Date: May 2003
Location: California
Posts: 20,850
Received 463 Likes on 361 Posts
Default

When was the last time the tranny fluid was changed?
Old 07-17-06, 08:26 PM
  #3  
Phucanese
Rookie
Thread Starter
 
Phucanese's Avatar
 
Join Date: Jan 2006
Location: Washington
Posts: 80
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by RA40
When was the last time the tranny fluid was changed?
i have no idea. i bought the car at 123k... and have put on 6k since.

do you think that the tranny fluid could be the problem?
Old 07-17-06, 10:26 PM
  #4  
GRAND_LS 4
3UZ-FEEEE
iTrader: (2)
 
GRAND_LS 4's Avatar
 
Join Date: May 2004
Location: Northern VA
Posts: 6,251
Received 17 Likes on 12 Posts
Default

Does this happen with the AC on too?
Old 07-17-06, 10:39 PM
  #5  
Phucanese
Rookie
Thread Starter
 
Phucanese's Avatar
 
Join Date: Jan 2006
Location: Washington
Posts: 80
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by GRAND_LS 4
Does this happen with the AC on too?
i dont know. ill see if it does tomorrow.

what are you guys thinking it could be?
quit giving me more questions, i want answers!
i want to figure this out quick because it is seriously bothering me.
i dont feel like driving the car anymore until i solve this problem...
Old 07-18-06, 08:53 AM
  #6  
Phucanese
Rookie
Thread Starter
 
Phucanese's Avatar
 
Join Date: Jan 2006
Location: Washington
Posts: 80
Likes: 0
Received 0 Likes on 0 Posts
Default

ok, i just drove to work and it does jerk with the ac on.
and i think the tranny fluid might be too low...

a couple things i noticed is that it does it in every gear.
and that it seems that the engine is stuttering.
it doesnt run smooth, like it wants to die and shut off, but it catches it self...

i dont know whats going on.
help me out guys!
Old 07-18-06, 10:09 AM
  #7  
RA40
Super Moderator

iTrader: (6)
 
RA40's Avatar
 
Join Date: May 2003
Location: California
Posts: 20,850
Received 463 Likes on 361 Posts
Default

Pull the dipstick for the tranny and describe the fluid condition...

It should be a translucent red when fresh. It wil get darker as more miles accumulate. Smell it...if it is burnt...that is not good. Many people ignore tranny service until it starts acting up but it requires regular drain intervals every 30K. You can go longer, but it's just not a very conscious way of car care.

Good thing is that the 1UZ trannies are near bullet proof so if it is the fluid, a drain will make it happy again.
Old 07-18-06, 11:49 AM
  #8  
Phucanese
Rookie
Thread Starter
 
Phucanese's Avatar
 
Join Date: Jan 2006
Location: Washington
Posts: 80
Likes: 0
Received 0 Likes on 0 Posts
Default

the fluid is actually clear and clean. so it looks good.
i dont know about the smell yet tho.
Old 07-19-06, 08:11 AM
  #9  
Phucanese
Rookie
Thread Starter
 
Phucanese's Avatar
 
Join Date: Jan 2006
Location: Washington
Posts: 80
Likes: 0
Received 0 Likes on 0 Posts
Default

ok, the tranny fluid looks good, and smells fine.
if its anything, it might have too much fluid?
looks like its above the "hot" section, even when cold.

ill try draining some out this weekend.

but how could this be the problem?
i havnt touchd the tranny fluid, why did it start doing this now?
Old 07-19-06, 09:38 AM
  #10  
RA40
Super Moderator

iTrader: (6)
 
RA40's Avatar
 
Join Date: May 2003
Location: California
Posts: 20,850
Received 463 Likes on 361 Posts
Default

If the tranny fluid is good then there is probably something else causing the problem. An overfilled tranny exhibits problems but this is immediate onset, not delayed. Ted from Dynamic told me that you will also get a check engine light in this case.

Possibly an ignition wire or spark plug issue? Might have to pull the plugs to inspect.
Old 07-19-06, 01:29 PM
  #11  
GRAND_LS 4
3UZ-FEEEE
iTrader: (2)
 
GRAND_LS 4's Avatar
 
Join Date: May 2004
Location: Northern VA
Posts: 6,251
Received 17 Likes on 12 Posts
Default

Since it does it with the AC on... that rules out a lot of other parts. Sounds like a spark plug. Might want to pull one out to check it out.
Old 07-19-06, 02:24 PM
  #12  
Lexmex
Super Moderator
 
Lexmex's Avatar
 
Join Date: Apr 2004
Location: Miami, Florida
Posts: 17,238
Received 159 Likes on 136 Posts
Default

Besides checking the fluid itself, also should check the tranny filter and the tranny pan. True, many people do drain and fills and even flushes of their ATF, but particles can build up regardless with that many miles on the vehicle. If those particles get back into the system since the magnets in the pan or the filter itself is saturated, there can be issues.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
kur1j
IS - 2nd Gen (2006-2013)
17
01-10-22 08:37 PM
mafitch
LS - 4th Gen (2007-2017)
19
05-20-12 07:41 AM
betsy
IS - 2nd Gen (2006-2013)
30
02-02-11 03:11 AM
Max Power
LS - 1st and 2nd Gen (1990-2000)
5
11-11-10 10:21 AM


Thread Tools
Search this Thread
Quick Reply: Car jerking at a stop



All times are GMT -7. The time now is 02:59 PM.