Thread: Ingnition coils

I have 162000 on my 1999 3.8 grand prix. I was thinking of putting in new coils or high power coils like msd. I have new plugs and wires and no misfires. Do you think there will be a slight performance increase or smoother idle with new coils?

When i first bought my car i put msds on they lasted three months before the first one went out lol..

MSD makes good products just not these coils. Stick with stock. Djudge1970

3800's are a waste spark ignition system... MSD coils will not last for crap and they misfire slightly at high speeds. Not that you need to speed but just wanted to give you an example that they don't hold up and don't put out the power the ignition system was designed for. just like plugs, only iridiums will last the longest due to the systems configuration. Stay Stock.

GOt MSDs on mine about 5 years now 150,000 miles they seem ok but not sure any better than stock

A lot of good information here. Remarks coincide with what I read on other forums about aftermarket coils which is save your money. I ordered 3 OEM Delco coils from Rock Auto which I should get in about a week. Noticed a slight vibration at wide open throttle. Have new wires and Delco Iridium plugs. Of course there could be a lot of other reasons which don't mean the coils are a little week. Went to a guy with an $8000.00 Snap On scanner and he told me a few misses at WOT wont show up as a code. I am just guessing have, all new mounts, engine and transmission, and cv joints.
If you guys are interested I will post the results if any of adding new coils at 162,000 miles. Nothing is too good for my baby.

Do it!

Originally Posted by highoctaneracing

Do it!

Since you were interested here the full report. Anyone driving my car before the change, unless a OCD GEARHEAD, would have said the car drives fine. Its one of those things that only you know because you drive the car every day.

I got 3 new GM coils from rock Auto for $138.00 including shipping to Florida. The first thing I noticed after installation was a big change in the torque curve. Where I had to push my foot down maybe an inch now I barely had to touch the accelerator pedal to get the same acceleration. The other thing I did not notice the transmission changing gears when driving. The 4 sped auto was shifted totally seamlessly unless you punched the accelerator. Note I did not disconnect the battery before installing the coils. I did not want the PCM to ago into a default setting. Therefore I would not be comparing apples to Oranges. Now for the part you wont believe. Since I am retired, I drive the same roads every day. Go to the same stores. I always keep track of my gas mileage which was averaging 18.5 to 19 mpg because here in FL the air conditioning is never off. After the coil change I am averaging 22.5 to 23 mpg. I checked this twice to make sure using 1/2 of tank of gas with 2 fill ups at the same station same pump. 1/4 a tank each time. I am in shock. When I first got the coils I thought here you go again always trying to make something perfect when it isn't broken. Spending $138 what a dummy. Now I feel like a genius. Even though it will take some time to get my $138 dollars back for the coils in gas savings I really don't care. The real question is should I have done this earlier before 162,000? My mechanic with his $8000 Snap On Tool analyzer did not think so. All I know is I am happy and my car is happy. That's what matters to me. Sometimes it pays to be a little nuts. YMMV.