: Sporadic Acceleration; Stalls if Pushed too Hard



stevenriz
09-06-11, 03:26 PM
Hi, been having this weird issue where if I step on the gas about half way or more off the line, it will sputter and either catch and accelerate or just stall but not completely. If it stalls, the engine seems to keep running at less then idle but with no power. I have to shut it down and restart. Then it will show the check engine light. As long as I start off slowly it will run fine. At 30 or faster I can floor it without problems. The dealer looked at it. When they pulled it in, the check engine light was not on any longer but they saw a code reading "misfire". They said just let us know if it keeps happening. I will bring it in as it is starting to happen with more frequency. If I feel it sputtering I just let off the gas a little and it's fine. thoughts?? I have warranty until 100k miles. I have about 89000 now.

hammer489
09-06-11, 11:01 PM
sounds like a dying fuel pump or a clogged fuel filter.

stevenriz
09-07-11, 10:07 AM
Hi, thanks! That sounds promising, one other think I neglected to mention is that about 50% of the time I accelerate now I hear pinging. would that still be the same characteristic of the fuel pump/filter issue? I use medium or high octane fuel.

dkozloski
09-07-11, 11:52 AM
Pinging means lean mixture. I'd be looking for an intake leak. A lot of owners, including me, are reporting loose intake manifold bolts. Pull off the engine beauty cover, have a look, and put a wrench on a couple of them. There are a couple of threads on the subject.

http://www.cadillacforums.com/forums/cadillac-sts-forum-2005-through-2012/239145-intake-manifold-bolts.html

EChas3
09-07-11, 08:47 PM
^^^ Gotta agree. I get the impression that improvement might be found through mere finger-tightening.

stevenriz
09-08-11, 09:18 AM
Thank you all!! Once I get my garage cleared out a little, I'll pull it in and check the intake bolts. After reading that thread it looks like it may solve a few problems I have. Shifting issues, hard start and the subject of this post. Hard accelleration stalls. I'll post back once I check it out.

stevenriz
09-12-11, 10:46 AM
Hello. Over the weekend, I tightened the intake manifold bolts to spec. Some were loose but not too bad I thought. Anyway did seem to address the problem a little bit but not completely. Now during medium to hard off the line acceleration, the car will jerk forward, stop forward, stop, forward stop until it gets going. So with text, I can only describe it this way, it sounds like RUM RUM RUM RUM RUM RUM :histeric: until it gets going or I let off the accelerator a little. Could that be a fuel filter/pump problem? Again, once going on the highway it feels normal! I do think I am getting a little better gas mileage now.

AnderbrA
09-12-11, 11:00 AM
May or may not be close, but I had an issue like this with an Olds Alero years back. Basically would want to die if you gave it more than a little bit of gas. If you let up on the accelerator it would work fine, but it took 10 minutes to get to 60 lol. Nobody could figure it out, including a couple shops and the dealership. We checked Vacuum, fuel, air, spark, etc. Everything was fine. Dealership was stumped. As a last ditch effort, I chopped the catalytic converter out, and low and behold, it ran like a champ. Somehow the Cat became so clogged that it was causing the whole problem. Might be way off, but something to check if everything else is good.

stevenriz
09-13-11, 09:14 AM
well that sounds like it could the problem or part of. I do not see that exhaust is part of my warranty. But maybe it is. Figures though... We'll see what the dealer tells me. Thanks for the ideas!

stevenriz
09-20-11, 07:42 AM
Dealer checked out the car yesterday. Phase I outcome. I went in to have the stuttering problem checked. I walked out with an oil change with 25% left on my oil life!! :|

Anyway, a couple things they told me. I was so low on oil that it didn't register on the dipstick. Ok, go ahead and change the oil instead of just adding a couple quarts. They also found a broken motor mount but nothing else stood out at them. Then mentioned the timing chain may be stretched. I can see how the timing chain could make this happen so I am going to drop it off in a few days when they have a loaner available for me and let them have at it.

So we'll see what happens after they check that out.

MacMuse
09-20-11, 10:16 AM
Dealer checked out the car yesterday. Phase I outcome. I went in to have the stuttering problem checked. I walked out with an oil change with 25% left on my oil life!! :|

Anyway, a couple things they told me. I was so low on oil that it didn't register on the dipstick. ...

The oil life reading is purely math based, and does not include detecting the amount of oil in the system. So rely on the oil life number as the timer to change your oil, but still check the dipstick monthly to make sure you're not burning/leaking oil. The Northstars have certainly improved their oil usage characteristics over the years (mine doesn't use any between changes). However, you should plan on checking yours over the next few months as you may have a N* that's eating a little oil as it ages.

valjan1
09-20-11, 09:05 PM
i experienced the same with mine .the converter was starting to clug now i run it pedal to the metal and it is very good to clean the cat .use 94 octane and add a little acetone in the mix it will clean it good. One quart per tank for 5 tanks. this baby needs to be whipped. lol

valjan1
09-20-11, 09:13 PM
my baby has 180,000 miles it takes 1 quart every 1500 miles . i have beaten the hell out of that car and it never fell.the lifters are a little noisybut ok . the driver door wont open but i can live with it

valjan1
09-20-11, 09:21 PM
butnever let me down

valjan1
09-20-11, 09:23 PM
ohh i forgot .i broke the left engine mount

valjan1
09-20-11, 09:25 PM
and retorque the intake bolts.lol

EChas3
09-20-11, 09:34 PM
If there's no oil on the dipstick, what's left merits replacement.

I think the Northstar should ask for a quart when it needs it. The OLM may not prompt once a year. That's about what we get. In the long run, adding oil can save oil later.

6-er's?

stevenriz
10-20-11, 01:36 PM
Hi everyone. I just got the car returned and here's what solved the problem. They reprogrammed the computer that controls engine and transmission. that was it! they also replaced a motor mount. hard to beleive software can all of a sudden begin to do something different after 90000 miles but whatever. only cost about $80 not covered by my after market warranty.

scott9001
10-20-11, 07:12 PM
the oil change is fine usualy when a vehicle uses oil it is broke down and wore out. GM has there oil monitors set way to high when doing oil changes at work its about 10,000km for a OLM on a gm and oil should be changed every 5,000 k so thats double what the manufactures usualy say there oil is good for. in my old deville i use to change the oil with liek 56% oil life left usualy, also if i dident change it then i had to add aobut 4 litres to fill it back up so screw it and change it. glad you got her running good again for a little pocket change!

EChas3
10-20-11, 09:00 PM
the oil change is fine usually when a vehicle uses oil it is broke down and wore out. GM has there oil monitors set way to high when doing oil changes at work its about 10,000km for a OLM on a gm and oil should be changed every 5,000 k so thats double what the manufactures usualy say there oil is good for. in my old deville i use to change the oil with liek 56% oil life left usualy, also if i dident change it then i had to add aobut 4 litres to fill it back up so screw it and change it. glad you got her running good again for a little pocket change!

I have to disagree. Unless a car sees severe service, changing high quality synthetic oil as often as you suggest is just wasteful. (5,000km oil changes went out with carburetors!) Even at 10,000km, my Mobil1 is still clean and full. The reason GM's OLM won awards from the Society of American Engineers is because it accounts for the number of start/stop cycles, trip length, engine temperature & revolutions, driving style and other factors.

Manufacturers that don't have OLM technology usually recommend oil changes at 7,500km or more for dino-oil and 15,000km or more for synthetic. If a car uses a lot of oil, that does add other factors and synthetic oil isn't practical. The engine will contaminate oil faster and if the owner lets it get more than a liter low, the oil wears out faster and engine damage is multiplied.

GM has specific oil specs to ensure the OLM is accurate (GM6094M for the V6 & GM4718M for the V8). If you want to play it safe, change the oil when the OLM reaches 10% and top it off when low. Check the oil before long trips and every few tanks of gas; more frequently for the V6 because there have been reports of catastrophic changes in oil use.

On the other hand, it's your car. If you want to waste oil, have fun!

KRSTS
10-20-11, 09:31 PM
:annoyed:
I have to disagree. Unless a car sees severe service, changing high quality synthetic oil as often as you suggest is just wasteful. (5,000km oil changes went out with carburetors!) Even at 10,000km, my Mobil1 is still clean and full. The reason GM's OLM won awards from the Society of American Engineers is because it accounts for the number of start/stop cycles, trip length, engine temperature & revolutions, driving style and other factors.

Manufacturers that don't have OLM technology usually recommend oil changes at 7,500km or more for dino-oil and 15,000km or more for synthetic. If a car uses a lot of oil, that does add other factors and synthetic oil isn't practical. The engine will contaminate oil faster and if the owner lets it get more than a liter low, the oil wears out faster and engine damage is multiplied.

GM has specific oil specs to ensure the OLM is accurate (GM6094M for the V6 & GM4718M for the V8). If you want to play it safe, change the oil when the OLM reaches 10% and top it off when low. Check the oil before long trips and every few tanks of gas; more frequently for the V6 because there have been reports of catastrophic changes in oil use.

On the other hand, it's your car. If you want to waste oil, have fun!

I have a V6 and my owners manual requires GM4718M:thumbsup:

EChas3
10-20-11, 09:42 PM
Oops! I was looking at a 2006 manual. The 2006 V6 is not Direct Injected and uses a different spec oil. Thanks for pointing out that all engines 2008 & up use GM4718M oil.

Spyke
10-21-11, 11:23 AM
The v6 3.6l ly7 non-direct injected engines requires GM4718M Spec only for 2004-2005 years. 2006 and 2007 is GM6094M spec.

in 2004-2005, there were no engine oil cooler. Thats why they requires GM4718M spec in those years.