Cadillac Owners Forum banner

1 - 4 of 4 Posts

·
Registered
2005 sts
Joined
·
3 Posts
Discussion Starter #1
Just posting information regarding my 2005 STS. Found useful information here recently whenI recently started having problems with my vehicle. Approx one year ago i purchased a used engine with approx 5,000 miles, after my original engine blew when my daughter was using it for several months while attending school. Dont really know what happened to it, but it was low on oil when it was brought to my mechanic. When the used engine was installed it didn't run, and only ran when the ignition coil harness and coils from the original engine was used . The engine ran fine for about a year. Several months ago it began running rough and cutting off at stop lights. A diagnostic check showed it was one of the coils. After changing the one coil from the left bank,that the diagnostic machine said it was, the car ran a little better, but still had a miss. Several more coils were changed,but car continued to run rough. The coils that were used were from the original engine. A diagnostic machine then stated that it was one of the injectors. I then went out and bought brand new injectors. Problem was still there. I then checked fuel filter and it was found to be clean. The fuel pump was then checked by my mechanic and found to be working properly.I believe the pressure was 59 PSI. I then bought a brand new maf senor and map sensor and the problem was still there. The last thing i did was to buy all ignition 8 coils with the harness, cost me 159.00 for each side, but the car drives perfect now. I wish i did it from the beginning. The electrical expert that my mechanic used cost me 400.00 dollars and he couldn't find the problem.
 

·
Registered
2006 STS-V and 2007 STS-V The Murdalac
Joined
·
1,905 Posts
Thanks for posting the process you went through to fix the problem. That is a great help to people in the future who have the same issues.
 

·
Registered
2005 sts4
Joined
·
13 Posts
Hey there!

I'm having a similar problem with my sts4. I posted a thread about it. I went digging around a little bit and cleaned the air intake manifold and tightened the bolts. I also cleaned the injectors.

This is the sound my car is making when it idles. It is missing every now and then. At the end of the video i put the camera to the exhaust pipe and the sound it makes shows you when it misses. When i was recording the video, I saw the engine shutter every time it missed but you can't really see it in the video.

https://www.youtube.com/watch?v=i9IR56CYR0U

let me know what you think and hopefully we can exchange notes on this one.

-Teale
 

·
Registered
2007 1SG STS v8 awd
Joined
·
502 Posts
My car is doing the same thing. I was getting ready to drop it at my mechanic because it's almost undrivable at this point. It pisses me off also. It hesitates just as op describes in low rpm so almost every time it changes gears and the rpm drops It hesitates.

----------

Mines also was throwing an oxygen sensor code so I changed it now it's throwing p0300 random misfire. The engine light comes on then goes off about every two weeks. Then stays off for two weeks then on again. I changed all plugs last year that I purchased from Cadillac and one coil. I was gonna change all eight but the price woulda been really stiff. Let me know what you find. I'll take mines to the mechanic in the next few days and see what they come up with.
 
1 - 4 of 4 Posts
Top