2002 Lesabre randomly shuts off while driving - no codes (to cause this)

[HotZ28]

Mistakes, are often overcome by due diligence and checking the recommended specifications.

 

[Mad_Coachman]

I think that;s what they were when i purchased then. Didnt. check gap with a tool.

-------------------------edit------------------

Your probably right. Looks like Iridum plugs for a 2002 lesabre w/3.8 come gapped at .060 I didnt change the gap. Jutst the plugs some miles ago. (less than 20,000 moles ago.)

Unless you bought Denso plugs it looks like they all come set at .060 😳

2002 BUICK LESABRE 3.8L V6 Spark Plug | Shop Now at RockAuto

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[2007LucerneCXL]

Looks can be deceiving. See enough ISO non-conforming parts and the only way to know for sure is to check it yourself.

 

[dadymurano]

Unless you bought Denso plugs it looks like they all come set at .060 😳

2002 BUICK LESABRE 3.8L V6 Spark Plug | Shop Now at RockAuto

Ignition Parts and More for Your 2002 BUICK LESABRE at Reliably Low Prices. Fast Online Catalog. DIY-Easy. Your Choice of Quality. Full Manufacturer Warranty.

www.rockauto.com

Pretty sure i got them at rockauto. ACDelco. Not at home so can't tell you the # but were purchased for the car.
The only time i get the po306, and it was only twice befor changing the plug and looking at the injector, was when i was under load like going up ramp to enter freeway.

I've put about 300 miles on the car the last week or so. It never shuts off anymore, so maybe progress has been made. Still havent put the ICM on it and I do remember replacing the center coil pack at 1 time. (but it was bad as they come so an easy fix that time.

 

[BuickGirlFromMars]

Looks can be deceiving. See enough ISO non-conforming parts and the only way to know for sure is to check it yourself.

if you are to check an iridum, you should very very veyr very very carefully use a wire gauge, not a stepped gauge, and carefully check the opening and im saying use a table and chair and to carefully. you can be the one regretting shoving it into a step gauge or you can trust ngk to produce to the spec and then trust ac delco to do remotely any QC and then all the hands it passed through till you cheaper than ruining 6 plugs and buying more lol.

Not comforting, correct, but be careful is the key word

 

[BuickGirlFromMars]

Pretty sure i got them at rockauto. ACDelco. Not at home so can't tell you the # but were purchased for the car.
The only time i get the po306, and it was only twice befor changing the plug and looking at the injector, was when i was under load like going up ramp to enter freeway.

I've put about 300 miles on the car the last week or so. It never shuts off anymore, so maybe progress has been made. Still havent put the ICM on it and I do remember replacing the center coil pack at 1 time. (but it was bad as they come so an easy fix that time.

Cylinder 2 and 5 are the center coil pack

Can your monitoring software allow you to view a misfire table or graph, counter, etc.. basically tallies misfires based on cylinder? note, codes only set when its OBD2 critical, and the light flashes when the misfire is catalyst damaging but like, if you keep doing that it will be toast in no time. That usuaully means engine too but you said under load, ive seen that before. Does your MIL flash during those or if you keep accelerating at that pace will it come on?

If it helps understand more, I originally had to replace 1 coil pack back in the stone ages (2019 january)when I got my car, infact, its 3rd birthday(to me) is probably like today or next couple days lol

this is a picture of my engine when it was still so young and not YOLOed like it is now, but I have no regrets and make no apologies.(Lol) but you can see I have three stock coil packs(top one has dirt and they were faded)
2 and 5 are the same coil pack, however, I had an interesting experience since the bottom and top coil pack have always been fine, they are still on my shelf and they ohm fine and worked fine. I boguht green ones in the aftermarket and they worked, at least mostly, when replaced but I replaced Them because my ICM was going bad and the 2 and 5 misfires I figured was probably hard on the coil so I didnt want to put a worn coil on the new ICM since it was auto store special.

My first coil pack issue was 2 and 5, because the tower on the plug wire for 2 i think was rusted.


I replaced the wires and got those new coils, ICM stayed till last year when I put coils and icm on.

The ICM when it dies, often shows as 2 and 5 misfires(see top graph, that was my diagnostic research into it)


The PCM misfire monitor is not a 100% straight forward thing. They count misfires pretty loosely until they encounter a threshold at which they will count them more aggressively, some of this could potentially overlap with rough road or spark knock Stuff that the engine is already going to account for, so realize that not all graphs would look like mine, mine was from sitting in a lot and increasing engine speed but I dropped into gear for dramatic effect at like 1200 and the pic doesnt show that moment but the car was doing the rpm fine and then dropped into gear it wheezed and spit a second and then went into normal sputter or whatever of moving but once I got into fast enough I needed to drive normally because it would be dropping into 3rd and I would be speeding soon lol, the load was lower and it stopped.


I think if you see misfire codes for 2 and 5 or you can view a graph/monitor/counter, you should do that first, but you should Ohm your coil in the center hot and cold, if its fine, swap to the bottom and put that there. If you still have 2 and 5, you definitely have an ICM.

since you have an ICM, get some thermal paste from a computer store or order some, and put it on, and then you should know pretty quick if that was fix.


Since its age, and 2/5 behavior, I am going to say ICM most likely. Coil is still in the running because 1) a bad icm may strain coil 2 )ac delco NOT of oe level coils are just auto store special with AC delco name, and they cost much much less than AC Delco coils of good variety do

Do you remember the botom of the coil look? if you ever buy those expensive coils, a blue tab is better than white. You have a NA but some people report better smoother acceleration with the L67 coil on an L32. Just a fun little toss in 🙂

 

[2007LucerneCXL]

Good note on step gauge, never had one - never will, wouldn't even use one on my lawnmower. But having checked millions of vehicle parts that were supposed to be in spec and still have NC parts, one up to 90% fallout, I have trust issues and all the GM TSB's to back me up lol.

 

[BuickGirlFromMars]

Good note on step gauge, never had one - never will, wouldn't even use one on my lawnmower. But having checked millions of vehicle parts that were supposed to be in spec and still have NC parts, one up to 90% fallout, I have trust issues and all the GM TSB's to back me up lol.

I get it. Im saying to trust 41-101 until or unless one has issues, because of the tip thing. prevents the more likely scenario of damaging. but if its a "Hey I have spark isssues" and then at that point you can instruct someoen to use a wire gauge slowly and only on the size its supposed to be, you dont end up with "wheres the end of the spark plug" lol
I took an old 41-101 to a wire gauge it was still close, then I tried the step, because of it being a tip it would seemingly come out in the .03_ somewhere but its because of not being perpendicular I think because a flat copper surface would kind of force it to be that way vs the tip. i didnt get forceful but I kinda dumbly kept wiggling to try and get it further and got it there but it seemed ok. I found on NGK or possibly champion site that if you would do that even with a wire gauge to a degree, you could push the electrode up into the spark plug because its not retained by much other than the surface area of ceramic for the insulator and just of course breaking it internally or moving the electrode thats bound to cause problems from either just total failure or ground out to be weak spark at the wrong gap etc. Im guessing the wire one is more apt because of the smaller tip more force can be applied esp being dumb with it

 

[HotZ28]

I am getting tired of reading all this about PLUG GAP! It is very simple .060 as specified.

 

[BuickGirlFromMars]

I am getting tired of reading all this about PLUG GAP! It is very simple .060 as specified.

yeah. like I said.

 

[2007LucerneCXL]

Consider it a reminder when you see something like this posted "Looked at the plug and the gap is too big and the electrode is whiter than it should be. Replaced it with a fairly good used plug"

 

[Homer Jay]

 

[2007LucerneCXL]

LOL, I guess we can go back to EVAP now!

 

[BuickGirlFromMars]

 

[John Canon]

yeah. like I said.

It seems that GM has stuck with .060 plug gap ever since the HEI from the 70s

 

[BuickGirlFromMars]

It seems that GM has stuck with .060 plug gap ever since the HEI from the 70s

except when they dont
045 and 035 have been used a lot in many instances

 

[John Canon]

View attachment 35075

The 1970 Lesabre has the same body style as my 1969 Beaumont convertible, except mine has the Pontiac grille. Plus I only have the lowly 307 V8 with the even lowlier 2-speed powerglide transmission.

 

[BuickGirlFromMars]

The 1970 Lesabre has the same body style as my 1969 Beaumont convertible, except mine has the Pontiac grille. Plus I only have the lowly 307 V8 with the even lowlier 2-speed powerglide transmission.

heres the 283 and powerglide from a 67 impala coupe, blue


want to see that , too!? Im sorry for the war crime youre about to witness


it was once a nice car. the thing on top was a 1970 too

 

[2007LucerneCXL]

A little buffing and those Chevys will be good as new

 

[John Canon]

Buff it with a cutting torch.