07-25-09, 06:29 PM
99 Seville STS
My Service Engine light has been on for a few weeks. Codes pulled Cylinder 4 Misfire/TCC Solenoid.
I noticed when going up a hill by my house that is 35mph speed limit when I drive at say 37mph then slow down to 35mph I notice a kind of soft kick, I'm not sure if its just down shifting. I kinda messed with it last night about 3x then got to the top of the hill and went to 7-11. I got in and had to back up and repark myself. When shifting into R and D the car jerked really really hard and was idling at 2k. I turned it off and turn it back on and all was fine.
Today, at the end of my drive to work when I was getting off the freeway and making a left onto the street my car cut out on me with no warning. I was able to stop and turn it back on. As I got to work and pulled into the parking space the car jerked really really hard again but was idling at only 1.5k.
My normal idle is 1k, but a bit rough. I was planning on having a tune-up done in a couple of weeks.
What could be causing this?
07-25-09, 11:12 PM
Either Idle Speed Control or Throttle Position Sensor. There are ISC passages in the throttlebody which need to be clean.
Normal warm idle in gear is 650. At cold start the engine should fast idle at 1200 for about 15 -20 seconds, ramp down to about 900 and then go to 650 after a minute and a half or so..
Do a LOT of studying for plugs, wires, coils, wire connections, and throttlebody cleaning before you take it to someone other than a Cadillac dealership for a "tune up". ACDelco #41-950 Platinum plugs only. DO NOT get creative with aftermarket wires, coils, plugs, whatever. Lots of info on why not in here............
07-25-09, 11:38 PM
^The guy I'm going to take it to is a mechanic out of his house garage. It my girls stepdad. I fully trust him. He knows what he is doing with all cars.
Yeah, I was mistaken. My car actually is about 500-650 at start up. Exactly like you said.
I should mention to that I did not come to a complete stop when exiting the freeway. I slowed down to about 15mph and as I went into the turn I couldn't turn it and that's when I realized my car had died and I was able to stop before hitting the curb infront of me. It started right back up :D
I turned the car on about 4hrs after this happened today and it came out of park and into reverse and drive and back in park easily.
07-26-09, 12:29 AM
Do you lack power. if so I would check to see if you CAT. wasn't clogged.
07-26-09, 02:02 AM
Still has the same power as when I bought it...
I forgot that when I was entering the freeway after work at about 45mph I mashed it to the floor til I reached about 70mph then slowed down to 65 and hit the cruise control. I never do that ever...also I forgot after 7-11 I did go down the same hill to McD's and then backup with no problems.
The shifting into/out of Park, Reverse and Drive when it jerks really hard is whats worrying me. Since this problem happened twice after being on the freeway.
Could this maybe be just a sticky TB?
I really hope its not the TCC Solenoid...from what I read the car will stall out when you go slower than 35mph (I think) which is about what happened today when it died on me but it was fine after that.
I'm getting off work in about 2.5hrs so hopefully all will be well this trip. I'll update tomorrow afternoon
07-26-09, 05:44 AM
Had time to upade.
Threw car into Cruise Control, at 63/64, about 19miles of the 23mile trip and the rest was street driving.
Got home and car was idling at under 1k, ideal rpm, car changed from D to R to D easily with no problems like before.
I guess it only changes gears hard when it's idling to high. Now to find the cause of this.
Also, whats bugging me is why it died on me when getting of the freeway. Maybe the rpm issue has to due with this.
EDIT: My reply about my RPM 2 posts above this, it does exactly what you described it should be doing.
07-26-09, 10:09 AM
Using your car's built in Diagnostic Trouble Code reader look for one or more PCM codes, namely P0300 (stall detected) and P0335/6 or P0385/6 (CKP performance).
Your car uses OBD-II protocol for DTC interpretation.
TCC faults will also set codes.
07-26-09, 10:31 PM
The Service Engine has been on for about a month...
Here is the strange thing:
The light came on about a week after I got it. Went to a mechanic and he got the code for Cylinder 4 Misfire and TCC Solenoid. He reset it and it came on the next day and I went back and he pulled the same codes. I went and looked at some paper work from the owner I bought it from and both those codes had come up in July of 2008.
I just can't figure out how it took the car a week for it to show me the light then it came on the next day after my mechanic erased the codes yet the codes had already shown up a year prior...