What's wrong now? Engine surging...

LSAddict

LVC Member
Joined
May 24, 2005
Messages
32
Reaction score
0
Location
Seattle
I sure wish I was here posting about something positive, but every time when I feel I can finally start enjoying the LS, something else pops up…seriously, I think this is one of the LS’s best trait.
Since I’m quite clueless as to what’s wrong, I will tell you what I had repaired recently.

I have an 03 V8 LS. I had problems with the car shifting before. It would exhibit harsh shuddering shifts. I just recently had the shift solenoid repaired/replaced along with the valve body at a local tranny shop. It definitely helped the problem go away, although I still get a harsh shift sometimes from 1-2nd, no biggie.

After that, I went to the dealer to do that recall on the leaky valve cover gaskets. The engine would idle slightly rough, at stop lights and at start-up, but no CEL. Every time I gunned it on the highway, I would smell sulfur. The dealer repaired the VCG, but they didn’t replace the coils since they tested them and they were fine. The car idles fine now, and seems less confused when I make a sudden lane change.

I was feeling great thinking I got most of the problems fixed, that is until I took it on the highway yesterday.

What I’m experiencing is a surge in the engine when I’m driving about 65-70+. The rpms will go back and forth around 2-3k or is it 3-4k? Anyways, if I have my foot lightly on the pedal, it will start to lightly surge. If I mash it, it pulls, but still feels quirky. And I still smell sulfur when I gun it. At lower speeds, I can’t tell if it’s surging or not. In city driving, I can’t tell either.

I don’t know where to begin, nor do I know if anything that was repaired has to do with this problem. Please help! I was so ready to put tints on and finally start hooking up the car, but now, I’ve just been kicked down a notch…
 
LSaddict,
The sulfur smell is a definate sign of a catylic converter. Either somewhat plugged, or gone bad.
I have very little experience with cats, but it seams to me, a bad cat could cause some of the problems you are experiencing.
 
One or more of the coils are bad. The coils tend to be just fine until they get warm which is why at the dealer they may have tested OK, when in fact they are going bad. You have 2 options, you can drive the car until the CEL comes on and sets a code in the ECM telling which cylinder(s) is misfiring, which would indicate which coil is causing the trouble. Then replace the blown coil yourself. Or take it back to the dealer and have them run a diagnostic while the engine is warm and they should hopefully be able to find the bad one (s) and replace them.
 
Thanks guys for giving me some possibilities. As I was driving home, I felt a pretty bad misfire when at a light. Happend only once though. And I think I'm starting to feel really light surges even when accelerating, but that could just be my mind playing tricks :shifty:

I'm going to probably wait it out and find a deal on new coils. I been to the dealer so many times for other reasons these past months, I swear they're going to catapult me and my car to the next state. I wish the CEL will pop up soon.
What a crappy wish...

I will also check out the catalytic converter. Is there an easier way in determining if its clogged or dead? I guess I'll have to take it to an exhaust shop and find out?
 

Members online

No members online now.
Back
Top