: 05 Cadillac STS V6...bucking jerking and rattling



CadillacRon
06-19-12, 10:56 AM
Hello, I have a 05 STS V6 w/107K miles on it Just had the timing chains and water pump changed at 102K miles. Everything was fine until recently, the car started jerking. and it rattles on start up as if my timing chains were going out. it's only a second and then everything is quiet again...before the repair I could hear my chain rattle even when I was driving, but this time I don't hear it at all after the rattling stops. While Im driving, the car jerks real bad as if it wants to cut off. The revs don't dip or anything while this is happening, it just jerks...I'm calling my mechanic today, but I wanted to get everyone's opinion on what to expect...

curtc
06-19-12, 12:20 PM
If it's rattling at startup the chain is going again...that is the first sign of failure.

CadillacRon
06-19-12, 03:13 PM
Man that sucks, a chain going after 5k miles??? I talked to my mechanic (who changed my timing chains), and he said I need an oil change...these engines are really finnicky about oil, and not to use the OLM. I'm about 1K past my last oil change, so I'll give it a shot, he siad if it continues he'll diagnose further. My friend has an 09 CTS V6 DI and his was doing the same thing, the dealer said he was a quart low on oil.

curtc
06-19-12, 04:16 PM
Yes...That is the problem with the 3.6, they use oil...check your intake, full of oil? That's where it is going...all 3.6 owners should check their oil religiously and never go a hair over 5k between oil changes. Low oil leads to chain wear, which leads to rattling...a quart of oil won't stop the rattle...the damage is done...GM has tried extending the coverage for 07s but the issue is still there...bad PCV design is the culprit.

Hope your mechanic replaced the tensioners as well...it shouldn't be rattling...

malatu
06-19-12, 06:57 PM
Yes...That is the problem with the 3.6, they use oil...check your intake, full of oil? That's where it is going...all 3.6 owners should check their oil religiously and never go a hair over 5k between oil changes. Low oil leads to chain wear, which leads to rattling...a quart of oil won't stop the rattle...the damage is done...GM has tried extending the coverage for 07s but the issue is still there...bad PCV design is the culprit.

Hope your mechanic replaced the tensioners as well...it shouldn't be rattling...

Why do you state, "Never go a hair over 5k between oil changes"?

CadillacRon
06-19-12, 09:05 PM
I saw the parts he replaced....he replaced the tensioners and the chains, as well as the water pump, new coolant new oil....its frustrating...I just spend a grand on the repair

CadillacRon
06-24-12, 05:35 PM
So I changed the oil...and when I drained it, only a quart and a half came out (according to the pan). So I'm assuming it was really low on oil...so I refilled it, changed the filter, and everything is working fine. no rattle and no jerking while driving. I'm going to have to keep an eye on the oil consumption a lot better. I'm going to do some research on it.

Pjazz
06-24-12, 05:55 PM
Holy sh** that could of been a very expensive mistake.

DarkMingBlueSTS
06-24-12, 08:48 PM
I had the same exact thing going on with mine but like 2 months after getting a few oil leaks and water pump repaired...my fault for not regular checks on the oil...but c'mon any decent mechanic would fill the oil after repairing oil leaks(so I thought)...checked the level, stick showed none, added what it needed and problem was gone

curtc
06-24-12, 11:53 PM
The issue with low oil and rough running symptoms is the VVT system, it runs on solenoids that respond to oil pressure.

nosrac
07-09-12, 02:29 PM
I have had this experience twice. After the first time, I took the car to the dealer and the service manager was unaware of
any problems. He changed the oil, and reprogrammed (or calibrated) the computer and the car ran like a top. I experienced the same problem again this past weekend. I checked the oil, and it did not even register on the dipstick. I put 5 quarts of oil in the car and she is running like a top once again. What boggles my mind, is the fact that there is no sign of oil leaking and no warning light or check engine light came on. Is there a fix to this??

dkozloski
07-09-12, 02:47 PM
The fix is to check the oil level when you gas it up like your grampa did.

curtc
07-09-12, 05:58 PM
Check your intake, bet it's caked with oil.

ktr-sb
07-09-12, 06:45 PM
Several people claim to have cured oil consumption on the 3.6 by drilling larger holes in the PCV fitting orifices. Here is how to do that mod:

http://www.cadillacforums.com/forums/cadillac-srx-first-generation-forum-2004/264073-free-fast-oil-consumption-mod-fix.html

curtc
07-09-12, 09:28 PM
:yeah: Been done by a few members and so far they have seen good results, looks like a few gear heads figured something out that the GM engineers either couldn't or chose to blatantly ignore...

EChas3
07-09-12, 10:27 PM
In a car this sophisticated, GM should have provided a low oil indicator that comes on when it's over half a quart low.

My N* uses far less than a quart every 10,000 miles. My wife's uses about a quart every 10k. I keep them both full of Mobile1.

Ludacrisvp
07-09-12, 11:07 PM
In a car this sophisticated, GM should have provided a low oil indicator that comes on when it's over half a quart low.

My N* uses far less than a quart every 10,000 miles. My wife's uses about a quart every 10k. I keep them both full of Mobile1.

It would go off too often, like every time you park on a hill.

curtc
07-09-12, 11:09 PM
I believe my earlier STS, 2001, had a low oil indicator at 2 qts. low.

EChas3
07-09-12, 11:27 PM
These cars do have an alert. It's just set far TOO low.

sharley24
07-11-12, 11:38 PM
I had the same problem too. changed the oil now running fine. i thought my transmission was bad. i have never seen a car run this bad on low oil.

DarkMingBlueSTS
07-11-12, 11:47 PM
I thought the same thing with my tranny too...we are lucky we didn't destroy the motors sharley :)

curtc
07-12-12, 01:01 AM
The problem with low oil is VVT, it runs on solenoids that are triggered by oil pressure...I non VVT car will knock when low on oil, a VVT equipped car with misfire and eventually start to rattle its chain to pieces.

EChas3
07-14-12, 08:30 PM
I was fortunate to have the initial owner of my car have the oil changed every 3,000 miles, 4 times before evolving to a more normal frequency. I know this because it's on the dealer service record. I now have almost 80,000 miles on it and experience outstanding oil consumption.