HELP!!! 2001 LS V8 jerks around 4500+

[Brake.My.Window]

I noticed a week after i bought it it starts to jerk really bad around 4500 and i did the plugs n everything im kinda trying all the options before going to the dealer

 

[eastcoastLS]

I noticed a week after i bought it it starts to jerk really bad around 4500 and i did the plugs n everything im kinda trying all the options before going to the dealer

maybe your prob is in the tranny. i have also heard of misfires taking a few driver to clear up, not sure if thats true or not

 

[hotrodllsc]

I've seen pin holes in the spark plug boot cause a miss fire like what you are describing multiple times. It's one of those things that you won't even be able to see it just by looking at it. At the dealer when we would get one of those we would do a driving power balance to see which one it was, then swap that COP with another to see if the miss moves. Usually if it did we sold the entire COP assembly. Without the test equipment though it's near impossible to know which cylinder it is. This is what we did before suspecting the trans depending on if it did in fact feel like a miss.

 

[Fla02LS]

First thing i noticed in your post is YOU changed the plugs. I'm not trying to doubt your mechanical skills but maybe something didnt go back together correctly. Also, when you say it jerks at 4500 rpm, does it go away at say 5500 rpm....or will it jerk at 4500 then go away if you back off to 3500 rpm? Just thinking.

 

[Brake.My.Window]

well i work at a BMW n Mercedes shop so i pretty sure i did it right it was doing it before but it starts doing it at 4500 and keeps doing it

 

[dtangerini]

Your problem could be a fouled injector, try using a good fuel injector additive.
This worked for me.

 

[00_slow_5spd_ls]

what additives are you using?

 

[Brake.My.Window]

im not using any at the moment but i think ill try that im gettin the codes pulled this weekend so hopefully only a coil or something simple and not the tranny

 

[Brake.My.Window]

i got it back from the dealer and they said it was a limiter and didnt sayanything else which is totall bs......iv ran ijector cleaners through it a few times. i dont know what to do...is there a adjustment on the fuel pressure...iv had bmws in the past that had pressur problems that did the same,

 

[Eliot_Ness_Ls]

5-1 its the start of a coil problem.

 

[SoonerLS]

Year and engine would help in the diagnosis, but there's no limiter at 4500 RPM on any year of the LS. There's a rev limiter at ~3K RPM in neutral/park or when the wheels lose traction (like when your drive wheels are on ice...don't ask ), and there's a rev limiter at redline, but not at 4500.

You say you did the plugs, but did you change the COPs as well? This sounds suspiciously like a coil-related misfire, which often won't throw an error--and even when it does, it doesn't always ID the correct cylinder. Also, double-check all the connections on and around the coils to make sure nothing has worked its way loose.

Also, if you found oil in the plug wells, you need to replace your valve cover gaskets and coil boots, or you will lose coils when the oil comes back. The gaskets were redesigned in mid-'03, so the later cars don't generally have this problem, but it's a common failing on the earlier V8s.

 

[Frogman]

Year and engine would help in the diagnosis,

I'm betting it's a 2001 V-8...

 

[SoonerLS]

I'm betting it's a 2001 V-8...

Oops. It's been a long week. C'est la vie...

 

[MDavis0424]

Was there any oil in the plug wells? Do you know if the valve cover gaskets were ever replaced? Lots of posts about the valve cover gaskets leaking and ruining the coils.

 

[Brake.My.Window]

its a 01 v8....i havent done coils...kind of a exspensive guess....there was no oil what so ever andall the connections are good i have no idea what it could be....think it could just need a tranny flush or something stupid like that

 

[Brake.My.Window]

oh and it only does it over 2/3 throttle but itll go right up to redline if its at half it makes no sense......kind of annoying some little rice burner smoked me because of this

 

[ground_zero298]

When my conti got the studder it was right after a tranny flush, took it in and it was a missfire. previously i Ran some super strong fuel system cleaner thru it, and as a result i had iron oxide build up on all my plugs, they looked red, and because of this the spark was traveling down the side of my plugs. And i'll tell ya what I would have bet the farm it was a tranny problem.

P.S. if the bottle says for offroad use only, put it back on the shelf.

 

[Brake.My.Window]

is there a way to test the coils since they are exspensive

 

[Frogman]

Yes there is.

 

[Eliot_Ness_Ls]

Some one says you can do it yourself but I think the only GOOD way is to get a dealer that can stress test them for you.

 

[Brake.My.Window]

i checked them with a ohm meter they all read 6 so i dont know... i know you can test regular coils like that....uhm i dont know what to do the dealer ship near me isnt very smart about ls's so i think i may be stuck with it like this

 

[97stscaddy]

Take the coils to a local Autozone or Advance/checker/western/kragen auto parts store. They can test them for you for free.

 

[Brake.My.Window]

ok thanks!