1997 Pontiac Bonneville - Three blinks

Hello. I have a pontiac Bonneville 1997. Engine suddenty started to shiver on acceleration. Check engine light blinks for 3 times then gone.

That means you have a severe misfire

Could be due to overdue plugs and wires, could be ignition coil(s), injector(s), could me many things

Do you plan on fixing it yourself or bringing it to a shop?

If you don’t know when the plugs and wires were done last, replace them now. Buy only the plugs listed in the owner’s manual.

When you remove the wires, pay particular attention to the coils. If any of the coil towers seem corroded, replace them. If any coils are visibly cracked, replace them.

What engine?

How many miles?

1 Like

Hi. Thx for replying. Engine 3800 serie II
I have bought the spark plugs and wires but hadnt got the time to change them yet. When changing plugs shld the engine be hot or cold?
I opened a topic about this. I suspect the missfire is due to something wrong with the alternator! Battery almost new and it is draining fast now.!
Yeah also the car has a good mileage on it! I past 150 000 miles

Change when cold. This is to prevent you from getting injured on hot engine parts.

I have changed spark plugs and wires and got rid of the missfire!
Now as for the power drain an electrician tested it and said no power drain found. Im going to have another opinion for that. I disconnect battery cables after parking the car got back after few days and i start battery still running! But if i leave battery cables on overnight it drains. I heard also googled that a bad alternator can drain battery power even when car is off… so next task will be testing/fixing the alternator

Congratulations on tackling that misfire! ::rocket:

As for the “electrician” saying you’ve got no drain . . . sounds like he’s incompetent

If you have to remove the battery cables to prevent a dead battery the next morning, it would seem you do have a rather substantial parasitic drain, and if he can’t figure that out . . .

Do you have a halfway decent digital multimeter?

If so, you could google parasitic drain, I’m sure there are youtube videos showing you how to perform the test properly.

By the way, 50 milliamps draw is the maximum allowable. Don’t let anybody tell you that 150 milliamps or more is acceptable, for example.

You do have an owner’s manual, yes?

If so, it’ll be relatively easy for you to determine exactly which circuit has the offender

If not, let me know and I’ll point you in the right direction, a website where you can view your owner manual for free

Thank you so much for the help.
Sadly only few ppl are still trustworthy either electricians or mechanics…!
Anyway im stubborn enough to do my own brain storm for that matter… was trying many things until i decided to lock the car manually without triggering the alarm… and guess what? No drained battery in the morning… i really donno how it occured to me but i am happy that i may have shared something that might be useful! Problem solved for that issue!

Good for you for sticking with it. Car alarms, especially aftermarket versions, are notorious as far as reports here go for draining the battery overnight. It can be hard for a mechanic to catch, b/c it might not do the draining until 3 am in the morning for some reason, like maybe the wind blows.

Yes indeed!
It was that crazy moment when u think of something that is considered lame and neglected and it works!