: 97 northstar engine miss



fullserviceman
12-04-05, 12:59 PM
Now that it is getting cold in NY my 97 deville has started an engine skip when I cold start it until it warms up an/or I restart it. I reset the codes and haven't got any current codes. I also can't run anything less that 91-93 octane fuel without it spark knocking. I had the b/s valvoline fuel system service and fuel filter done a week or 2 ago and thats about the time the rough idle started.

The car has now 120,000 mi. on it
I bought it with 100,000 and it had a engine miss before I picked up.
The dealer put 4 frontplugs in (cheapo autolite) and new wires. Should I just take it to cadillac and have a real tuneup with the plat plus plugs? Could this be my trouble? How hard are the rear plugs to get to. In my experience the cadillac dealers do sh$t work with cheap parts for high prices.

mcowden
12-04-05, 01:59 PM
Now that it is getting cold in NY my 97 deville has started an engine skip when I cold start it until it warms up an/or I restart it. I reset the codes and haven't got any current codes. I also can't run anything less that 91-93 octane fuel without it spark knocking. I had the b/s valvoline fuel system service and fuel filter done a week or 2 ago and thats about the time the rough idle started.

The car has now 120,000 mi. on it
I bought it with 100,000 and it had a engine miss before I picked up.
The dealer put 4 frontplugs in (cheapo autolite) and new wires. Should I just take it to cadillac and have a real tuneup with the plat plus plugs? Could this be my trouble? How hard are the rear plugs to get to. In my experience the cadillac dealers do sh$t work with cheap parts for high prices.

Replace the plugs and wires with AC-Delco wireset 748J and AC-Delco 41-950 plugs. If you do it yourself, you can get the parts for decent prices at www.gmpartsdirect.com or www.rockauto.com. The rear plugs are not that difficult to access. You don't even need any tools different from what you use for the front plugs. You can dismount the coils with four bolts and that will give you a little better access, but they are still accessible with the coils in place.

If you take it to a dealership, you may have to specify that they use those specific parts, and they will charge you a bundle for it, but if you use those parts, you will be using what GM currently recommends as OEM replacement equipment for the car. Anything else is untested and unknown.

Eldyfig
12-04-05, 11:51 PM
A dealer that puts unrecommended plugs in and then only puts the front four in...that shows their workmanship. Never go there again.

Get the delcos in there like Mike said. It isn't hard to do, won't take much time.

denscor
12-05-05, 12:13 AM
Does the north * do well with NGK? I use them in all my car they burn hotter!

Eldyfig
12-05-05, 10:16 AM
I have heard of a couple others that use them, but haven't heard results. Are the ground electrode and the center electrode both platinum on the NGK?

denscor
12-05-05, 11:24 AM
You can get the NGK in platinum but the standard plug the v grove works the best they are about 2 dollars per plug.My supercharged vette runs great on them. I will try them and post the results.

fullserviceman
12-05-05, 12:59 PM
mind you the dealer i bought this car from was selling if off via Ebay and I think I stole it for $3000 with 90,000 miles on it. He was just a half ass that that wanted to meet bare minimum to get the car running. I will get the Gm platinums in it this week. The wires seem fine. Twice now the security system will not let me start the car on the first try, why I dont know??

mikedean
12-05-05, 04:48 PM
I had a problem with the theft system on my car. Dealer wanted to replace the whole ignition in the steering wheel. After looking everywhere for an answer someone suggested spraying the key with WD40 and pushing it in and out of the lock, then cycling the ignition. It worked perfectly I have not had a problem with it since. Also, I think that feature can be disabled by a car stereo shop, just have a remote start put in.

BTW i will be replacing my plugs and wires this weekend, the dealer wanted 450 for the wires and 120 for the plugs.

My 98 Deville is having missing problems, gave a P0300 code and after i cleared it has not came back, car still missing though. Will do the spark in the dark test tonight, but from what i have been hearing on here, the spark plug cables are prone to failure.

The symptoms are when in drive and stopped engine will idle at 650 and every few seconds feels like a miss and drops to 575.
Sometimes has a jerk during light acceleration at all speeds, goes away when you give it more gas or let off.

keep it fresh
12-05-05, 05:11 PM
sounds like a fuel problem.....

mikedean
12-05-05, 08:21 PM
Well when i got home today i popped the hood and sure enough, LIGHT SHOW. There is at least 3 places the plug cables are arcing in the area of the coils (but not on them). I am ordering a new set of cables and plugs from rockauto tonight...

Eldyfig
12-05-05, 11:35 PM
That was an easy enough test.

fullserviceman
12-10-05, 12:05 AM
$450 for wires? wtf?

mikedean
12-10-05, 02:28 PM
Ya, I live in Everett and the closet caCaddy dealer is 20 miles away, so i thought I would call the Chev dealer and see what they would charge just to change the wires. They said $185 for the wires and $265 for labor. I ordered the acdelco set off of the internet and they are out for delivery so i should be able to install them today.

powerglide
12-10-05, 05:10 PM
Replace the plugs and wires with AC-Delco wireset 748J and AC-Delco 41-950 plugs. If you do it yourself, you can get the parts for decent prices at www.gmpartsdirect.com or www.rockauto.com. The rear plugs are not that difficult to access. You don't even need any tools different from what you use for the front plugs. You can dismount the coils with four bolts and that will give you a little better access, but they are still accessible with the coils in place.
If you take it to a dealership, you may have to specify that they use those specific parts, and they will charge you a bundle for it, but if you use those parts, you will be using what GM currently recommends as OEM replacement equipment for the car. Anything else is untested and unknown.
Bingo! That the thing to do first.
Even if doesnt cure it, thats step one. (forget paying $500) to the dealer its 150$ easy DIY that I performed curbside in NYC in the middle of the winter. (that was my first DIY job btw.....theres a full write-up on here, if you do a search)
A sporatic miss wont trigger the P0300 DTC code, unless its sustained.
And even then, all that means is that its missing.
After the plug and wire change I would next suspsect the ignition coils. They are very easy to diagnose and replace. (again I did this in the autozone parking lot in 15 minutes)
But becuase of what you said, that its happened after the fuel rail service I am willing to bet its the wires. When they moved it around to access the rails they broke them. Its very common. The wires are very brittle inside (especially as they age)
Good luck and tell us what happens.

mikedean
12-10-05, 09:14 PM
Changed plug wires and plugs in under 2 hours, this was a lot easier than i expected. One of the easiest I have ever done. Fired her up and made a 20 mile trip with no problems. Seems to have fixed the problem.

I am not sure what the plugs are supposed to look like after 87000 miles but they on any other car i would say they needed to be changed

powerglide
12-10-05, 10:47 PM
Congrats!

Eldyfig
12-11-05, 12:40 AM
I would have to say your cam covers are still sealed good. Not much oil on your plugs with that much mileage. That's good.

fullserviceman
12-12-05, 08:14 PM
ok I had the plugs changed today and there is no more engine miss. The original rear plugs were toast but the autolites in the front with 20,000 miles on them were even worse. Now we have the correct plugs and no skip but they say a rear o2 sensor is bad but they need a gm wrench to get it out will have it by the end of this week.

eldorado1
12-12-05, 08:39 PM
but the autolites in the front with 20,000 miles on them were even worse.

How so? Did they put in "regulars" that eroded?

powerglide
12-12-05, 09:56 PM
ok I had the plugs changed today and there is no more engine miss. The original rear plugs were toast but the autolites in the front with 20,000 miles on them were even worse. Now we have the correct plugs and no skip but they say a rear o2 sensor is bad but they need a gm wrench to get it out will have it by the end of this week.


Congrats too!

fullserviceman
12-13-05, 10:13 AM
The front plugs were autolites that the guy I bought the car from put in and couldnt reach the back. Well anyways its cold here in Albany this am and dont ya know when i start the car it skips intermitently.not as bad as before but still there. I know they have to replace the rear bank o2 sensor could the be doing it? Wires are near new and plugs are new. It goes away once it is warmed up sounds kinda like an old diesel engine when they started cold hit an miss til it warms up. No codes also loosing about a quart of fluid per week someplace. ANY IDEAS

Ranger
12-13-05, 10:55 AM
No codes also loosing about a quart of fluid per week someplace. ANY IDEAS
What kind of fluid? Coolant, oil, p/s, trans, gas?

fullserviceman
12-13-05, 08:21 PM
coolant , sorry also today it was 15 degrees out and the thing runs at 212 when it was in 100 degree weather the hottest it got on the road was 208 unless I was stopped

Ranger
12-13-05, 08:48 PM
The Diesel noise sounds like cold carbon rap. She needs to be taken out and whooped aka WOT.

I'd pressure test the cooling system and hopefully find an external cooling system leak. Your temps are exactly what my '97 Deville was.

Eldyfig
12-13-05, 10:21 PM
Make sure you aren't overfilling the sytem. You should only fill with coolant/water mix to a couple of inches below the filler neck. If you fill to the top, the extra will go out the overflow tube when the coolant gets warm and expands.

fullserviceman
12-16-05, 11:27 PM
Well I filled the damn coolant tank again and will see what happens. As for the skip the friggin thing only does it when you cold start then goes away in a couple mins. Does idle a little rough but not bad. Its going in tuesday for 02 sensor and will see what else they can find. I know when I WOT this thing it seems to load up on gas and smoke black. In fact today i did wot standing still (I know its bad) Wow the blue smoke cloud came up and I thought I would get lost in the smoke. I will update once this thing goes back to the shop.

Eldyfig
12-17-05, 10:08 PM
Earlier in the post I mentioned your old plugs weren't wet with oil, which is good. However, blue smoke is usually oil getting burned. Normally, I would pull the plugs and check them for oil fouling. Oil fouling the plugs will be worse during a cold start and will cause stumble. Even though you have new plugs now, I would pull them and check. The plugs may be fine, but can't do their job as efficiently when there is too much oil getting in the cylinder. Some oil is normal.

fullserviceman
01-02-06, 06:37 PM
UPDATE!! Well my theftlock system failed completely today forcing me to the dealer. I told them of the engine miss and what has been done so far.. Plugs, wires, rear bank o2 sensor. However the car has been running hotter and hotter the past 20 weeks and using coolant(no sign of leaks anywhere). When the engine warms up the skip goes away. Well they tell me it $300 for the ignition and I need headgaskets. Ok makes sense but $3800 for headgaskets?? I will be getting rid of the car and ending my cadillac experience I think at this point. It runs fine when it warm until I shut it off but If you all have different opions please let me know. I dont wanna drive the car as long as its not too bad in hopes of auctioning it off before it gets really bad.

Eldyfig
01-02-06, 07:58 PM
Earlier in the post I mentioned your old plugs weren't wet with oil, which is good.

My apologies, those were mikedean's plugs in that picture. Just realized that.


However, blue smoke is usually oil getting burned. Oil fouling the plugs will be worse during a cold start and will cause stumble.

Have you checked the plugs to see if they are fouling with oil?

If I were you, I would do the various troubleshooting tests you can find by searching this forum to check for leaking headgaskets. I personally feel too many North*s are diagnosed with leaking HGs by dealers than there really should be.

fullserviceman
01-02-06, 09:44 PM
Well the car has been getting hotter and hotter while driving. And the same day the new plugs were put in nothing changed. Still misses when cold or restarted. Not to mention loosing coolant but not leaking it. I will continue to check into this before I sell. and go back to a caprice LT1

Eldyfig
01-02-06, 10:27 PM
Yeah, that coolant loss doesn't sound good. Good luck with it.

eldorado1
01-02-06, 11:19 PM
the cold miss that goes away when hot is characteristic of a head gasket leak. The water vapor interferes with the operation of the spark plug until it gets up to temp.

fullserviceman
01-03-06, 11:22 AM
then thats the problem I guess. I will have the old eldorado tranny rebuilt to get me through the winter and dump this car before the problem gets worse. Trouble is I dont know what to get next as far as a vehicle:(

FlashRed
01-22-06, 09:02 PM
Bingo! That the thing to do first.
Even if doesnt cure it, thats step one. (forget paying $500) to the dealer its 150$ easy DIY that I performed curbside in NYC in the middle of the winter. (that was my first DIY job btw.....theres a full write-up on here, if you do a search)
A sporatic miss wont trigger the P0300 DTC code, unless its sustained.
And even then, all that means is that its missing.
After the plug and wire change I would next suspsect the ignition coils. They are very easy to diagnose and replace. (again I did this in the autozone parking lot in 15 minutes)
But becuase of what you said, that its happened after the fuel rail service I am willing to bet its the wires. When they moved it around to access the rails they broke them. Its very common. The wires are very brittle inside (especially as they age)
Good luck and tell us what happens.

Is there a specific ignition coil that would perform best on a 97 sts ???

Eldyfig
01-23-06, 12:12 AM
The ACDelco coil. No other.