: 97 Catera coil problem



SNOWANGEL
03-12-08, 12:34 PM
I have a 97 Catera.

Cylinders #3 & #4 were misfiring, so I brought the car in for diagnostics and was told that my coil pack was burnt.

I had it replaced, and the car ran fine ... for about a week.

After a week, the engine started misfiring again.

I didn't have the money to get it fixed, so I parked it until I could afford another repair.

When I brought it in for another diagnostic, again, my coil pack is burnt.

I'd hate to put another coil pack in, only to have it go out in a week, and the Cadillac dealership said they can't figure out what's wrong, since the coil pack doesn't have a "electronic control module" underneath it.

Has anyone else had this problem?

srinne
03-12-08, 03:23 PM
Did you check the plug wires, spark plugs, or injectors? (Do you have any pictures of the "burnt coild pack"?)



(also, try to pull the plug wires out of #4 and #3....are they covered in oil?)

satse
03-12-08, 04:12 PM
I have a 97 Catera.

Cylinders #3 & #4 were misfiring, so I brought the car in for diagnostics and was told that my coil pack was burnt.

I had it replaced, and the car ran fine ... for about a week.

After a week, the engine started misfiring again.

I didn't have the money to get it fixed, so I parked it until I could afford another repair.

When I brought it in for another diagnostic, again, my coil pack is burnt.

I'd hate to put another coil pack in, only to have it go out in a week, and the Cadillac dealership said they can't figure out what's wrong, since the coil pack doesn't have a "electronic control module" underneath it.

Has anyone else had this problem?

How has your antifreeze level been? If I remember right, a leaking heater bypass valve can drop antifreeze on the coil pack and destroy it. Given the failure rate of the HBV, it may be worth checking.

frank moran
03-12-08, 06:09 PM
I have a 97 Catera.

Cylinders #3 & #4 were misfiring, so I brought the car in for diagnostics and was told that my coil pack was burnt.

I had it replaced, and the car ran fine ... for about a week.

After a week, the engine started misfiring again.

I didn't have the money to get it fixed, so I parked it until I could afford another repair.

When I brought it in for another diagnostic, again, my coil pack is burnt.

I'd hate to put another coil pack in, only to have it go out in a week, and the Cadillac dealership said they can't figure out what's wrong, since the coil pack doesn't have a "electronic control module" underneath it.

Has anyone else had this problem?

I doubt the coil bured out again if this was the case to start with, especially since they note cyl 3 and 4. This is a waste spark system and the coil fires 1-4, 2-5 and 3-6 simultaineously, point is 3 and 4 are not together in the coil make up. I would suspect the wires from the ecm to the primary connector on the coil, but first do the checks the other responders sent to you. Possibly the primary wire connector on the coil was moved a bit and made contact, just a guess, at the coil primary connector gry and blk is plugs 1-4 term 49,blk and red is 6-3 term 51, and 2-5 blk and yellow term 50 at the ecm. Check these for continuity...the ecm controls the coil firing, but again as suggested first check the basics, wire resistance,, plugs ... any codes????

SNOWANGEL
03-13-08, 09:32 AM
Did you check the plug wires, spark plugs, or injectors? (Do you have any pictures of the "burnt coild pack"?)



(also, try to pull the plug wires out of #4 and #3....are they covered in oil?)

The plug wires are fairly new, I had all six replaced about two years ago.

Spark plugs are also new, I had a set put in about one year ago.

The plug wires were pulled, and they came out clean, no oil on them.

I'll have to see about a picture - I'm not mechanically inclined, so I'd have to have someone point out what it is I have to take a picture of.

SNOWANGEL
03-13-08, 09:33 AM
How has your antifreeze level been? If I remember right, a leaking heater bypass valve can drop antifreeze on the coil pack and destroy it. Given the failure rate of the HBV, it may be worth checking.

I checked with the mechanic, and the heater bypass valve had no leaks.

SNOWANGEL
03-13-08, 09:44 AM
I doubt the coil bured out again if this was the case to start with, especially since they note cyl 3 and 4. This is a waste spark system and the coil fires 1-4, 2-5 and 3-6 simultaineously, point is 3 and 4 are not together in the coil make up. I would suspect the wires from the ecm to the primary connector on the coil, but first do the checks the other responders sent to you. Possibly the primary wire connector on the coil was moved a bit and made contact, just a guess, at the coil primary connector gry and blk is plugs 1-4 term 49,blk and red is 6-3 term 51, and 2-5 blk and yellow term 50 at the ecm. Check these for continuity...the ecm controls the coil firing, but again as suggested first check the basics, wire resistance,, plugs ... any codes????

Codes: P0303 -> cylinder 3 misfire; P0301 -> cylinder 1 misfire; P0300 -> multiple cylinder misfire

I'm sorry, my husband had thought it was #3 and #4, but I spoke to the mechanic this morning, and it turns out it was #3 and #1.

Also, I am told that there may be three coil packs on a 6-cylinder engine, one coil pack per two cylinders. Is this true?

Po Pimp
03-13-08, 02:42 PM
To answer your question SnowAngel, yes and no. On the earlier versions of the Catera there are actually three coil packs. They are in a sealed unit together and have to be serviced at the same time. 90's and up on other GM V6s you can service one coil pack at a time (2.8L, 3.1L, 3.4L, 3.8L) but again not on the Catera.

Have you checked the spark plugs? I know that they are newer but a leaking cam cover can quickly cover them in oil, causing them to misfire. They are on the same bank (same side of the engine). I never noticed any oil leaking exteranlly when mine went bad. It was not until I got a misfire code that I pulled the plug on the suspect cylinder to find that it was coated in oil.
I suppose that could be a possability. Seems like everone else has covered all the other bases.

frank moran
03-13-08, 02:55 PM
To answer your question SnowAngel, yes and no. On the earlier versions of the Catera there are actually three coil packs. They are in a sealed unit together and have to be serviced at the same time. 90's and up on other GM V6s you can service one coil pack at a time (2.8L, 3.1L, 3.4L, 3.8L) but again not on the Catera.

Have you checked the spark plugs? I know that they are newer but a leaking cam cover can quickly cover them in oil, causing them to misfire. They are on the same bank (same side of the engine). I never noticed any oil leaking exteranlly when mine went bad. It was not until I got a misfire code that I pulled the plug on the suspect cylinder to find that it was coated in oil.
I suppose that could be a possability. Seems like everone else has covered all the other bases.

good info, 1 and 3 are next to one another, that changes the whole picture when it's not 3&4...

SNOWANGEL
03-14-08, 11:58 AM
Have you checked the spark plugs? I know that they are newer but a leaking cam cover can quickly cover them in oil, causing them to misfire. They are on the same bank (same side of the engine). I never noticed any oil leaking exteranlly when mine went bad. It was not until I got a misfire code that I pulled the plug on the suspect cylinder to find that it was coated in oil.
I suppose that could be a possability. Seems like everone else has covered all the other bases.

The first time I had the coil pack replaced, I had the spark plugs pulled and there was oil on them ... but I had the coil pack replaced and some other work done, including something to do with the fuel injector, and when they fixed all that they also put new plugs put in.

When I brought the car into the shop earlier this week, they pulled the plugs and said they came out completely clean.

mr.ism
04-13-12, 10:53 AM
Hello everyone,

This is my 1st post. would anyone be able to tell me what resistance is on the coil pack for a 1998 catera? I called the dealer and most auto part stores, it seems to be a spec not published. Any help would be greatly be appreciated.

investor74
04-13-12, 09:41 PM
Why don't you measure them all and see if there is an odd man out? Are you getting misfires? What exactly is your coil problem? Resistance is not the whole story with coils, but if the one serving the misfiring cylinder is an odd resistance from the others, it is is probably bad.