|
| Search | Car Forums | Gallery | Articles | Helper | Air Dried Fresh Beef Dog Food | IgorSushko.com | Corporate |
|
#1
05-29-2008, 10:05 PM
|
|||
|
|||
|
99 gp gt Repeated problem
99 gp gt. 3.8
Cylinder 6 spark plug keeps getting hairline cracks in the insulator part. Causing a bad misfire. Compression good. Coil good. Plug wire good. Should i assume injecter? 
|
|
#2
05-30-2008, 09:26 AM
|
||||
|
||||
|
Re: 99 gp gt Repeated problem
What brand and heat range plugs are you using? Sure you are not over torquing the plugs and are you using the metal heat shields?
__________________
'08 Pontiac Grand Prix GXP (Dark Slate Metallic) - LS4 5.3L V8 '02 Oldsmobile Alero GL2 - LA1 3400 V6 '99 Buick Regal LS - L36 Series II 3800 V6 '03 Honda CR250R MX - 2 Stroke 250cc '97 Pontiac Grand Prix GTP - L67 Series II 3800 V6 Supercharged (Sold) Timeslip 08/12/06 AF Community Guidelines
|
|
#3
05-30-2008, 12:48 PM
|
||||
|
||||
|
Re: 99 gp gt Repeated problem
In addition to Bob's questions, are you losing coolant, and if so, do you notice any discoloration (orangish if you're still running Dex-Cool, or yellow/greenish if you switched it over to non-Dex-Cool) on the plugs?
__________________
 Still waiting for the "good old days" I'll get to bore my future grandchildren with!
|
|
#4
05-30-2008, 01:46 PM
|
|||
|
|||
|
Re: 99 gp gt Repeated problem
No signs of coolant loss. Im using ac delco rapidfires 14. Yep using heat sheild. Id say no to the overtightening question
. I switched injector today so we'll see what happens.
|
|
#5
05-30-2008, 03:47 PM
|
||||
|
||||
|
Re: 99 gp gt Repeated problem
Your problem is most likely the Delco Rapidfire 14 plugs which can be used but not really a good replacement plug for the OE double platinums. I recall there was a major manufacturing defect concerning them. Here is a pic of one and you can clearly see a crack with carbon tracking. They were exchanged for other brand spark plugs and no further issues.
__________________
'08 Pontiac Grand Prix GXP (Dark Slate Metallic) - LS4 5.3L V8 '02 Oldsmobile Alero GL2 - LA1 3400 V6 '99 Buick Regal LS - L36 Series II 3800 V6 '03 Honda CR250R MX - 2 Stroke 250cc '97 Pontiac Grand Prix GTP - L67 Series II 3800 V6 Supercharged (Sold) Timeslip 08/12/06 AF Community Guidelines
|
|
#6
05-30-2008, 04:15 PM
|
||||
|
||||
|
Re: 99 gp gt Repeated problem
I agree again Bob. The ceramic insulator failure is the reason Delco is starting to phase out Rapid-fire plugs. It's also the reason I would never use them.
__________________
Still waiting for the "good old days" I'll get to bore my future grandchildren with!
|
|
 |
POST REPLY TO THIS THREAD |
 |
|
|
