Question about 2001 Cadillac Sts

1 Answer

My 4.9 cadillac northstar is running rough. starts fine but power loss is evident...jus ??t like the the term "misfire" is what i'm feeling. any history with these engines with this symptom

No smoke ..was stuck on ice when problem startd

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Cadillac Master
  • 954 Answers

Hmm... I would start by checking the power train control module or the transmission control module. Caddies are famous for transmission shift control module going hay wire. Since it is shifting up when it should be shifting down, this gives you the feeling of losing power.

Posted on Jan 06, 2015

Ad

6 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
New users get to try the service completely Free afterwhich it costs $6 per call and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Ad
chiquititas
  • 1010 Answers

SOURCE: 1994 Cadillac DeVille Concourse - Runs rough?

The "check engine" light will "light" when there is a malfunction in the engine management system. The fault code is then stored in the computer. The computer must be scanned to retrieve these stored faults to pinpoint the malfunctioning component. We recommend buying your own scanner and doing it yourself. With a pocket scanner you can check for fault codes to find out why the light came on in the first place. You can clear your cars trouble codes after you replace the malfunctioning sensors.

Posted on Jun 26, 2008

SOURCE: 1999 deville 4.6 northstar engine

say what?

Posted on Aug 18, 2008

  • 1 Answer

SOURCE: codes po174/171 cadillac deville northstar engine

Check for vacuum leaks around the intake. This is the most common cause for these codes.

Posted on Mar 16, 2009

  • 95 Answers

SOURCE: 95 cadillac eldorado engine stalls rough idle check engine light is on

My son has this same car with the same problem. So far after tune up and other process of illimination, the problem points to the catalytic converter. If it is clogged you will get this problem with the rough idle and stalling. Look under the car at night after running it and see if the catalytic glows red. If so you need a new one. Hope this helps.

Posted on Mar 20, 2009

csmock132
  • 4669 Answers

SOURCE: '99 cadillac eldorado, Northstar engine w/AC problem

Have you unhooked the battery since you put the freon in? If not, do it.

Posted on Jul 04, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

2007 Cadillac 3.6L chugging then stalled while driving.


You need to address those misfire codes, have it tested again.

Mar 21, 2017 | Cadillac Cars & Trucks

2 Answers

Check engine light flashing check engine soon smell of gas and not running smouth


Check engine light flashing means there is a bad misfire , it flashes to tell you your damaging your catalytic converter . You need to have it check , you don't won't to have to replace the catalytic converter . Can cost up to $1,000.00 . Flashing Check Engine Light CarMD

Feb 03, 2016 | 2004 Cadillac Deville

1 Answer

I am having ongoing problems with the truck miss firing and rough running. Timing is ok, replaced cap and rotor,coil. It still starts rough,idles rough and misses when at cruising speed,although it seems...


Misfire is a common driveability problem that may or may not be easy to diagnose, depending on the cause. A misfiring cylinder in a four-cylinder engine is, pardon the pun, hard to miss. The loss of 25% of the engine's power output is the equivalent of a horse trying to run on three legs. The engine may shake so badly at idle that it causes vibrations that can be felt in the steering wheel and throughout the vehicle. The engine also may be hard to start and may even stall at idle, depending on the accessory load (air conditioning, headlights and electric rear defroster, for example).

When misfire occurs, performance suffers along with fuel economy, emissions and idle quality. And, when a misfiring vehicle is subjected to an emissions test, it will usually fail because of the unusually high levels of hydrocarbons (HC) in the exhaust.

What causes a cylinder to misfire? Basically, it's one of three things: loss of spark; the air/fuel mixture is too far out of balance to ignite; or loss of compression. Loss of spark includes anything that prevents coil voltage from jumping the electrode gap at the end of the spark plug. Causes include worn, fouled or damaged spark plugs, bad spark plug wires or even a cracked distributor cap. A weak coil or excessive rotor gas inside a distributor would affect all cylinders, not just a single cylinder.

"Lean misfire" can occur when the air/fuel mixture is too lean (not enough gasoline in the mixture) to burn. This can be caused by a dirty, clogged or inoperative fuel injector; air leaks; or low fuel pressure because of a weak pump, restricted filter or leaky pressure regulator. Low fuel pressure would affect all cylinders rather than an individual cylinder, as would most air leaks. A leaky EGR valve can also have the same effect as an air leak.

Loss of compression means the cylinder loses most of its air/fuel mixture before it can be ignited. The most likely causes here are a leaky (burned) exhaust valve or a blown head gasket. If two adjacent cylinders are misfiring, it's likely the head gasket between them has failed. Also, if an engine is overheating or losing coolant, it's likely the head gasket is the culprit.

Intermittent misfires are the worst kind to diagnose because the misfire comes and goes depending on engine load or operating conditions. They seem to occur for no apparent reason. The engine may only misfire and run rough when cold but then smooth out as it warms up. Or, it may start and idle fine but then misfire or hesitate when it comes under load. Also, it may run fine most of the time but suddenly misfire or cut out for no apparent reason. Intermittent misfires can be a real challenge to diagnose, so let's start with a steady misfire in one cylinder before moving on to intermittent misfires.

Hope this help.

Mar 25, 2010 | 1989 GMC Sierra

2 Answers

Please describe your what is the number one cause of a northstar cadillac sts 96 to not start and run but turn over but it acts like it wants to run but just wont fire checked the fuel pump and it is...


There can be a misfire too from the cylinders.

An engine that hesitates, stumbles or misfires when accelerating or when it is under load is an engine that is either sucking too much air, not getting enough fuel or misfiring. If the Check Engine Light comes on, you may find any of the following codes:

• P0171, P0174 Lean fuel condition codes
• P0120 to P0124 Throttle position sensor codes
• P0222 to P0229 Throttle position sensor codes
• P0400 to P0409 EGR related codes

If there are no misfire codes, a common cause of acceleration stumble is a bad throttle position sensor (TPS). The TPS tells the computer how far the throttle is open. The computer uses this information to determine how much fuel is needed to maintain the correct air/fuel mixture and when extra fuel is needed if the throttle suddenly opens wide.

Another common cause is dirty fuel injectors. If varnish deposits have built up in the tips of the injectors, they won’t spray as much fuel as they normally do, or will “dribble” fuel instead of spraying a fine mist. This creates a lean fuel mixture and conditions that are ripe for stumble and hesitation (also misfire). Look at short term fuel trim (STFT) and long term fuel trim (LTFT) with your scantool. If the numbers are high, it tells you the engine is running lean and the injectors need cleaning. Treat mild cases with a high quality fuel-injector cleaner additive. Severe cases require professional cleaning equipment.

Also if this sensors apply to your vehicle, camshaft sensor or crankshaft sensor if sensors bad you don't get any spark.

Good luck and rate this solution, please.

Mar 16, 2010 | Cadillac STS Cars & Trucks

2 Answers

Sc400 has lost acceleration!!!!


A simple loss of power could be contributed to several different things without knowing the exact symptoms. Throttle position sensor, a slipping transmission, faulty coil pack(s) or fuel pump can all cause power loss. Is it intermittent? constant? does the car run smoothly and just experience power loss or does it run rough? The more information provided the better I may be able to help.

Apr 17, 2009 | 1995 Lexus Sc 400

1 Answer

Northstar Engine


First NORTHSTAR ( 1992 ) engines were quite troublesome, from faulty starters ( in the middle of the engine ) to loss of oil pressure.

Apr 08, 2009 | 1992 Cadillac Eldorado

3 Answers

Skipping/no power


It's the alternator man.

Jun 01, 2008 | 1999 Cadillac Seville

Not finding what you are looking for?
Cars & Trucks Logo

64 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cadillac Experts

yadayada
yadayada

Level 3 Expert

76630 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22219 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8514 Answers

Are you a Cadillac Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...