: check engine light (ON) 06 STS



Mullah88
07-12-12, 11:09 PM
on my way back from work on the highway, the car misfired whenever i accelerated! after the second time, the check engine light came on, i drove straight to firestone and they ran a diagnostic check and this is what they found out:

i need to replace these parts


ignition coil - parts: 139 labor: 323
plentum gasket - parts: 59 labor: 142
spark plug - 15 labor: 294
fuel filter - parts:44 labor: 76


and a fuel system cleaning and an oil change.

for those that use warranty direct, should i get it fix ASAP (pay out of pocket)? will they cover all of these or will they only cover one of the repairs? the warranty will kick in on the 2nd of next month...that'll make it the 30th day after i changed my filter and oil (i have 200miles to go to hit 1k after the oil change)...i can foot the bill but if they'll cover it, then ill just pay the 100 deductible and call it a day!

EDIT:

CRANKCASE FLUSH : 180.00 (problem solved)

curtc
07-12-12, 11:12 PM
Warranty won't cover the spark plugs or the fuel filter, but should cover the ignition coil and plenum gasket I would think.

Mullah88
07-12-12, 11:21 PM
am i risking driving the vehicle as is now, or should just park it until i can get it fixed? seeing as i need to put a couple more miles on it

curtc
07-13-12, 12:18 AM
If is is misfiring you could potentially do some damage if you keep driving it...You're dumping raw fuel into the exhaust during the misses, not so good on the catalyst system.

ddalder
07-13-12, 12:49 AM
Which engine do you have? Which cylinder did they say is misfiring? Was your check engine light on solid, or was it flashing at any time?

Mullah88
07-13-12, 12:51 AM
Alright, ill update when I take it to my mech. Back to the Seville

ddalder
07-13-12, 01:08 AM
So as an example, the GM labour times to replace a plug in cylinder 1, 2 or 3 (if you have engine code 7 - V6) is 1.4 hours or if it's cylinder 4, 5 or 6 it's only 0.2 hours. With engine options A or D (V8 engines), the labour time is a straight 0.4 hours. None of these times include diagnosis and the times are to replace a single plug only. Of course you have to remove the coil to get the plug out so times include coil R & R. Book time for the fuel filter is 0.6 hours.

Their labour charges are ridiculous. It seems they are charging full labour time as though they were completing each task from start to finish individually. Which Firestone location is it so I can tell my friends never to go there?

Mullah88
07-13-12, 01:20 AM
Lol Its in charlotte...off independence blvd. First it was goodyear that didnt catch the check engine light (when I did the oil change) even tho I asked specifically to run an engine diagnostics...now firestone is trying to rape my wallets ( $1,354 parts n labor).

ddalder
07-13-12, 01:26 AM
I can fly down from Canada to do that work and probably make a few bucks after all is said and done for that price LOL :)

EChas3
07-14-12, 07:38 PM
^^^ It certainly does sound high. If the light isn't flashing you have time to take it to a Cadillac service department. Don't believe all shops are the same. These cars ARE different.

Mullah88
07-14-12, 08:00 PM
Which engine do you have? Which cylinder did they say is misfiring? Was your check engine light on solid, or was it flashing at any time?

I have the 3.6L V6 engine and the second cylinder misfires, the light blinked on and off before when I accelerated hard but this time around its a solid light

ddalder
07-14-12, 10:27 PM
A flashing check engine light is a definite warning that damage is possible. If it's solid, drive gently and you should be able to get it to a shop without a problem. Since it's cylinder 2 there is more labour, but not anywhere close to what they've quoted. Good luck with everything and be sure to post the outcome.

Mullah88
07-14-12, 11:21 PM
sure will, ill have to drive the car on monday though since my seville's AC is out and the windows dont role down either. ill have to drive the STS to work then drop it off at my mech. to work on it....but yeah its a steady light not a flashing one phew

Mullah88
07-20-12, 04:27 PM
ok update: i left the car for my Mech. and all he did was flush the crankcase 3 times. after the first flush the check engine light went off but he held the car for 2 more days to be certain (he did it again for each day)...he said it should fix the problem but if the light comes back up again then he'll have to take the engine apart

RippyPartsDept
07-20-12, 04:33 PM
'flush the crankcase' ??

i'm not really familiar with that

anytime anyone says the word 'flush' i get hyper skeptical

the misfire is due to a coil issue and will not go away until that is dealt with

Lifer
07-20-12, 04:41 PM
'flush the crankcase' ??

i'm not really familiar with that

anytime anyone says the word 'flush' i get hyper skeptical

the misfire is due to a coil issue and will not go away until that is dealt with

Hey Chis, cool avatar (picture). :thumbsup:

RippyPartsDept
07-20-12, 04:44 PM
.... that is unless the coil and plug were never bad to begin with

but that terminology doesn't sound right

RippyPartsDept
07-20-12, 04:45 PM
Hey Chis, cool avatar (picture). :thumbsup:

thanks, i had been using the other one for a couple years now and just changed that one a month or two ago

Mullah88
07-20-12, 04:45 PM
'flush the crankcase' ??

i'm not really familiar with that

anytime anyone says the word 'flush' i get hyper skeptical

the misfire is due to a coil issue and will not go away until that is dealt with

as a precaution i might as well change the ignition coil and see what happens

edit: sorry about the "term" but it had something to do with the crankcase. and you are right, it had nothing to do with the ignition coil in the first place. i learnt that firestone is not a reliable place to go to

Mullah88
07-22-12, 04:12 PM
the lights came on again today...blinked about 5 times and went off. ill change the coils and spark plugs like recommended

matts05sts
07-29-12, 12:18 PM
My light came on yesterday and blinked for a few seconds then went to steady. It didnt throw any codes though. I do have P0430 right now with a bad catalytic converter so the light has been on for a week now. It seems like the engine is louder though and missing power at hard acceleration. normal driving is fine and MPG is unaffected. I just joined this forum today to find a fix.

Mullah88
07-29-12, 02:09 PM
exactly what I am experiencing, car is back in the shop right now. the lights came back on again and stayed on

truckinman
08-19-12, 07:51 PM
My 05 3.6 STS just started same thing only my light flashes bout 5 times during hard acceleration but good rest of time. Gonna try and tackle this job myself once I find out what spark plug(s) are needed. But since my light doesn't stay on, I'm afraid they won't be able to figure out exactly what's wrong using their diagnostic equipment. Least not until it's staying on steady. But I'm sure coil pack will prob need replaced. Idk how hard these engines are to work on but I'll find out. Lol

Just outa curiosity, what did your mechanic charge to do the work with parts for ur coil pack and plugs?

Mullah88
08-19-12, 08:58 PM
was under warranty

Ludacrisvp
08-20-12, 11:40 AM
Flashing typically means misfire. If you are seeing it under hard acceleration I would bet that one or both of your cats are partially blocked / clogged up.

Mullah88
08-20-12, 11:51 AM
mine got cleaned/flushed, the lights went off but came back on 5 days after

fredolan
09-03-13, 05:33 PM
POWERWASHED THE MOTOR WHILE IT WAS RUNNING ON SATURDAY. Started chugging. Engine light came on immediately. I have v-8 2005 sts. 205,000 miles on it.
Took to dealer today. code came up for misfiring number 8 cylinder only. Recommending new coil for low price of 600.00 parts & labor.

Also recommending cleaning throttle body (thought I probably accomplished that with the powerwasher: )) 135.00 parts & labor.
Is this close to a decent deal?

What did I do with the power washer to make the coil go bad? MANY THANKS TO THIS FORUM FOR GETTING MY VEHICLE TO 200,000 MILES!!!
BOB

ddalder
09-03-13, 05:44 PM
I've never washed my engine while it was running but I don't know that really relates to the problem. When I wash mine, I always use the low pressure tire/engine cleaner, let it sit a while and then rinse it with the spot free rinse option (also low pressure). All the electrical connectors are sealed so there shouldn't be a concern with water intrusion, however with a high pressure wash, this is still a possibility of moisture getting past the seals. You may have a cracked coil either because (relatively) cold water hit it while it was hot or it was already cracked and the introduction of water caused the problem to become apparent.

When they refer to cleaning the throttle body, they are referring to internal cleaning. A pressure washer won't accomplish this for you.

fredolan
09-03-13, 07:21 PM
Thanks ddalder!
So it doesn't sound like your completely offended by the cost of these two repairs.
I am going to have the work done.
I will follow your direction on future engine cleaning.
Best Regards

ddalder
09-03-13, 11:54 PM
I can't really speak to the quote because I know the US part and labour prices are much lower than here in Canada. The dealerships here charge in/around $140/hour and part costs seem to be near double the US in many cases.

btlegacy
09-04-13, 12:22 AM
That is pretty big rip off if they were charging separate labor on all of those items as some of them can be done in one sweep.

In order to change the spark plugs the plenum has to come off anyway so there should not be double labor cost there. It was most likely just a single bad coil and in my shop I would replace the coil and replace all the spark plugs since I am in there if they are close to age.

Looking at the retail prices I charge this is what the breakdown would be:

Plenum Gasket - Parts $53 Labor $120
Ignition Coil - Parts $59 Labor $15
Spark Plugs x 6 - Parts $8.50 x 6 = $51 Labor $30

The fuel filter is about $16 but I am betting it was just an extra unnecessary addon.

The crankcase flush is a gimmick some shops use to get money out of people. They basically dump a $5 can of solvent in the crankcase and then dump it out with oil and refill with new oil. They usually state that it cleans dirt and contaminants but it is nothing more than snake oil as the oil filter on the engine is designed to trap these contaminants so the flush does not give you anymore benefit than a regular oil change.

fredolan
09-04-13, 05:25 AM
Gotcha. No one else is screaming that I am being completely ripped off so I will bite the bullet.
I still love this car and am not ready to part with it.

By the by. I have spent a lot of time in CA. My parents owned a cottage in Grand Bend. Hung
in London quite a bit. I just watched a home remodel show on cable. I was blown away
by the prices for real estate in Tronto! OMG. Incredible.

Have a great day. Thanks again!

Ludacrisvp
09-04-13, 08:53 AM
FWIW ... the fredolan has the 4.6L northstar V8, not the 3.6L V6 (like the OP did and the thread was about)...

Short story:
---------------
$600 is obscene for the coil.
:jawdrop:

$100 coil, and 30 minutes of labor. :yup:

The throttle body on the other hand I've never messed with so that might be an OK amount.
---------------

Long story:

The N* is really easy to change plugs in comparison to the V6.

The coils are easy to replace on the V8 as well since you are removing and re-inserting them when doing the plugs.
They are about $107 GM list price for each coil, which would be about $800 for all 8 of them (not that you would need or want to do all of them).
GMpartsdirect has them for $55 + shipping GM P/N 12597745.

The plugs are GM P/N 12571535 and list for about $10 each, GMPD has them for about $5 + shipping.
( for my location in MN it would run $120 shipped for 8 plugs and 1 coil - Chris at Rippy Cadillac would be a better choice to get the parts from in my mind )

Labor on the plugs is about 2 hours, labor on the coil is 30 mins for 1 coil, and about 8 minutes per each additional coil.

Here are the directions on how to change the plugs on the V8.

Gap is 0.050 in
Torque 11 lb ft. or 15 lb ft depending on which documentation you are looking at.

Spark Plug Replacement

Removal Procedure

1. Remove the ignition coils.


- Bank 1 and 2 are the same.

1. Remove the fuel injector sight shield. (the N* engine 'beauty cover')
2. Remove the ignition coil cover from the cam cover by lifting straight up.
3. Disconnect the ignition coil wiring harness electrical connector from the coil that needs to be replaced.
4. Remove the ignition coil retaining bolt.
5. Carefully remove the ignition coil.


Caution: Wear safety glasses when using compressed air, as flying dirt particles may cause eye injury.

Notice: Clean the spark plug recess area before removing the spark plug.
Failure to do so could result in engine damage because of dirt or foreign material entering the cylinder head, or by the contamination of the cylinder head threads.
The contaminated threads may prevent the proper seating of the new plug. Use a thread chaser to clean the threads of any contamination.
Notice: Allow the engine to cool before removing the spark plugs.
Attempting to remove the spark plugs from a hot engine may cause the plug threads to seize, causing damage to cylinder head threads.


1. Clean the spark plug recess area with low pressure air.
2. Remove the spark plugs from the cylinder heads.
3. Inspect the spark plugs.


Spark Plug Inspection

Worn or dirty spark plugs may operate well at idle speeds, but frequently fail at higher load. Bad spark plugs are often responsible for the following conditions:

Power loss
Poor fuel economy
Loss of speed
Hard starting
Poor engine performance

Normal spark plug operation results in brown to grayish tan deposits on the area of the spark plug that enters the cylinder.
A small amount of reddish brown, yellow, and white powdery residue may also be present on the insulator tip around the center electrode.
These deposits are normal combustion by-products of fuels and lubricating oils which contain additives.

Misfiring is a general term that applies to a poor running engine.
With misfiring, the ignition spark is not igniting the air/fuel mixture at the proper time.
While other possible causes must be investigated, the spark plugs should be inspected first.
Spark voltage should not reach ground before jumping across the gap at the tip of the spark plug.
This leaves the air/fuel mixture unburned, causing misfiring.
Pre-ignition misfiring occurs when the spark plug tip overheats, igniting the mixture before the spark jumps.

Carbon fouling of the spark plug is indicated by dry carbon deposits on the portion of the spark plug inside of the cylinder.
Excess idling and driving at slower speeds under light engine loads can keep the spark plug temperatures so low that these deposits are not burned off.
Rich fuels or poor ignition system output may also cause carbon fouling.

Oil fouling of the spark plug appears as wet oily deposits on the portion of the spark plug inside of the cylinder.

This may be caused by the following conditions:

Oil getting past worn piston rings
Breaking in a new or recently overhauled engine

Deposit fouling of the spark plug occurs when the normal reddish brown, yellow, or white deposits of combustion by-products become sufficient enough to cause misfiring.
In some cases, these deposits melt and form a shiny glaze on the insulator around the center electrode.
If the fouling is found only in one or two of the cylinders, valve stem clearances or the intake valve seals may be allowing excess lubricating oil to enter the cylinder, particularly if the deposits are heavier on the intake valve side of the spark plug.

Excess gap means that the air space between the center and side electrodes at the bottom of the spark plug is too wide for consistent firing.
This may be due to improper gap adjustment or to excess wear of the electrodes during use.
A gap that is too small may cause idling instability.
Excess gap wear might indicate vehicle operation at continual high speeds or with high engine loads.
This causes the spark plugs to run too hot.
Excessively lean fuel may also cause the wear.

Improper torque or seating can cause a spark plug to run hot, eventually leading to excess gap wear.
In extreme cases, an overtightened or under-tightened spark plug can cause exhaust blow-by.
The cylinder head seats must make good contact for sufficient heat transfer and spark plug cooling.
Dirty or damaged threads in the head or on the spark plug can keep the spark plug from seating even though the proper torque is applied.
Once the spark plugs are properly seated, tighten the spark plugs properly.

Cracked or broken insulators and insulator tips may be the result of improper installation or heat shock.
Heat shock is a rapid increase in the insulator tip temperature which causes the insulator material to crack.
The upper insulators can be broken when a poorly-fitting tool is used during servicing, or when the spark plug is hit from the outside.
Cracks in the upper insulator may be inside the shell or invisible.
The breakage may not cause problems until oil or water penetrates the crack later.
Heat shock breakage in the lower insulator tip generally occurs during severe engine operating conditions such as higher RPM or heavy loading.
Over advanced timing or low grade fuels may also cause heat shock breakage.
Always replace spark plugs with broken or cracked insulators.

Damage during gapping can occur when the tool is pushed against the center electrode or the surrounding insulator, causing the insulator to crack.
When gapping a spark plug, bend only the outside electrode.
Keep tools free of any other parts.

Spark plugs with less than the recommended amount of service can sometimes be cleaned and regapped, then returned to service.
If there is any doubt about the serviceability of a spark plug, replace the spark plug.

Installation Procedure

Notice: Use only the spark plugs specified for use in the vehicle.
Do not install spark plugs that are either hotter or colder than those specified for the vehicle.
Installing spark plugs of another type can severely damage the engine.

Notice: Check the gap of all new and reconditioned spark plugs before installation.
The pre-set gaps may have changed during handling.
Use a round feeler gage to ensure an accurate check.
Installing the spark plugs with the wrong gap can cause poor engine performance and may even damage the engine.

Measure the spark plug gap on the spark plugs to be installed.
Compare the measurement to the gap specifications.

Notice: Be sure that the spark plug threads smoothly into the cylinder head and the spark plug is fully seated.
Use a thread chaser, if necessary, to clean threads in the cylinder head.
Cross-threading or failing to fully seat the spark plug can cause overheating of the plug, exhaust blow-by, or thread damage.


1. Install the spark plugs to the cylinder heads.
- Tighten the spark plugs to 20 N.m (15 lb ft).

Install the ignition coils.
Important: Ensure that the spark plug seals are in place when installing the ignition coil.

1. Install the ignition coil.
2. Install the ignition coil retaining bolt.
3. Tighten the ignition coil retaining bolt to 10 N.m (89 lb in).
4. Reconnect the ignition coil electrical connector.
5. Install the ignition coil cover to the cam cover.
6. Install the fuel injector sight shield.

btlegacy
09-04-13, 09:03 AM
I see. I didn't catch that it was a N*. In that case, the coil is even cheaper. You can snap up an ACDELCO unit for less than $40 on Amazon

http://www.amazon.com/ACDelco-D596A-Ignition-Coil-Assembly/dp/B000NWA92E/ref=sr_1_1?ie=UTF8&qid=1378299762&sr=8-1&keywords=D596A

Mullah88
09-05-13, 06:50 PM
Um that's too much, I'll find the receipt of when I changed all 6 coils and did the 150k maintenance work (which I think included throttle body cleaning). I don't think it was that high

EChas3
09-05-13, 08:15 PM
I'm a fan of throttle body cleaning & Top Tier fuels. With electronic throttle control it doesn't take much to affect throttle response. Even unseen deposits can increase wear.

KRSTS
10-26-13, 03:09 PM
I just replaced my #4 coil pack and plug. Car started misfiring and check engine light came on and threw a code P0304. Car is running fine now. How many start cycles will it take to clear the code and turn off the light or should I just disconnect the battery?

carter's_sts
10-26-13, 03:49 PM
Best way is to clear it with a scan tool. If not, I would disconnect the battery.

Mullah88
10-26-13, 04:13 PM
Looks like my starter is giving out. Car will not start on first crank, but after sitting idle for about a minute, it starts normally.

Also my mpg is abysmal! I don't know if it's the Rims (20s) I put on but the car is now getting only 15.5mpg combined! Rpm on normal drive Coasts above 2000 and above 3000 when maintaining just 45mph?? Something is definitely not right

It used to be 65mph and the Rpm usually say above the 2000 Mark

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DarkMingBlueSTS
11-01-13, 08:31 PM
Looks like my starter is giving out. Car will not start on first crank, but after sitting idle for about a minute, it starts normally.

Also my mpg is abysmal! I don't know if it's the Rims (20s) I put on but the car is now getting only 15.5mpg combined! Rpm on normal drive Coasts above 2000 and above 3000 when maintaining just 45mph?? Something is definitely not right

It used to be 65mph and the Rpm usually say above the 2000 Mark

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The aftermarket wheels maybe heavier causing you to have to accelerate harder to get them to move. Your overall tire/rim diameter is different from the oem setup which is throwing off the way the car was designed with oem rims/tires which is changing your rpm to mph and that too is affecting your mpg. Lol now you know why mine is still oem.

----------


Looks like my starter is giving out. Car will not start on first crank, but after sitting idle for about a minute, it starts normally.

Also my mpg is abysmal! I don't know if it's the Rims (20s) I put on but the car is now getting only 15.5mpg combined! Rpm on normal drive Coasts above 2000 and above 3000 when maintaining just 45mph?? Something is definitely not right

It used to be 65mph and the Rpm usually say above the 2000 Mark

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Oh yeah and the starter....does it click multiple times or just one click? Or does it start real slow?

Mullah88
11-01-13, 08:50 PM
The aftermarket wheels maybe heavier causing you to have to accelerate harder to get them to move. Your overall tire/rim diameter is different from the oem setup which is throwing off the way the car was designed with oem rims/tires which is changing your rpm to mph and that too is affecting your mpg. Lol now you know why mine is still oem.

----------



Oh yeah and the starter....does it click multiple times or just one click? Or does it start real slow?

The Rims I kinda figured would mess with things but not that much lol. For the starter, it starts really slow! like the car is struggling

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DarkMingBlueSTS
11-01-13, 10:54 PM
The Rims I kinda figured would mess with things but not that much lol. For the starter, it starts really slow! like the car is struggling

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Sounds like it could be the starter but have you had the battery checked?

Mullah88
11-01-13, 10:59 PM
Changed the battery last year when the ignition coils were changed.

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STSJr
11-02-13, 08:58 AM
I had 20 inch rims on my Honda CRV before my Caddy. I got 20 mpg with a 4 cyl. Now I have a V8 and I get 24 mpg with original 18 inch wheels. I'm keeping the classy chrome Caddy look. FYI. I lost a huge amount of money selling aftermarket wheels. They lose their value real quick.

Mullah88
11-04-13, 07:50 PM
I had 20 inch rims on my Honda CRV before my Caddy. I got 20 mpg with a 4 cyl. Now I have a V8 and I get 24 mpg with original 18 inch wheels. I'm keeping the classy chrome Caddy look. FYI. I lost a huge amount of money selling aftermarket wheels. They lose their value real quick.

Lol don't Plan on selling my rohanas, my next car purchase will be the 08 - current cts and I believe the bolt patten is the same as the sts

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Mullah88
02-20-14, 11:46 PM
@Mighty_Tore your inbox is full but I guess you're referring to this thread on the pm you sent. I had the ignition coils and spark plugs changed. That solved the problem. No more misfiring or jerking while accelerating...but the car holds the 4th (or 3rd?) gear for far too long when in WOT. I need to get that looked at