Misfire? maybe a spark plug?

Reply Subscribe

Thread Tools

Search this Thread

Sep 26, 2007 | 07:27 AM

Ryanmgaspard

Thread Starter

TECH Enthusiast

iTrader: (6)

Joined: Nov 2006

Posts: 605

Likes: 0

From: Pineville, LA

Misfire? maybe a spark plug?

The car has no engine light and the engine isn't modded, not even a lid. I ran seafoam through the brake booster and then the engine light came on regarding the driver side cat. Chevy replaced it free and ever since then it's been misfireing? maybe. From idle to around 3k rpm it sounds like a plug has fouled. It makes the engine sound like a cylinder isn't firing. It probably does it above 3k rpm but I can't hear it. The car drives normal and at WOT it still drives normal. I do get a kind of clunking sound coming from the engine area when I'm driving slow. Maybe the tech took the manifold off and reused the bolts? Any help would be appreciated.

Sep 26, 2007 | 08:22 AM

SparkyJJO

TECH Senior Member

iTrader: (11)

Joined: Aug 2007

Posts: 7,364

Likes: 85

From: Ohio

Sometimes after seafoaming it has fouled up plugs before. Have you tried pulling them and checking them out?

Sep 26, 2007 | 08:23 AM

Ryanmgaspard

Thread Starter

TECH Enthusiast

iTrader: (6)

Joined: Nov 2006

Posts: 605

Likes: 0

From: Pineville, LA

Will do that now. If they are black then they are no good?

Sep 26, 2007 | 08:29 AM

SparkyJJO

TECH Senior Member

iTrader: (11)

Joined: Aug 2007

Posts: 7,364

Likes: 85

From: Ohio

Right. You'll be able to see if they are gunked up. If they are, just put new ones in. If they aren't then it'll take a little more time to track down what it is.

Sep 26, 2007 | 09:41 PM

ghardester

TECH Fanatic

Joined: Aug 2006

Posts: 1,407

Likes: 63

From: Knappa, Oregon

Because Seafoam is cleaning a lot of crap out of the engine and the plugs are burning it out, I would always plan to change the plugs after a foam.

Sep 26, 2007 | 09:52 PM

T-56SLPSS

12 Second Club

Joined: Jun 2007

Posts: 275

Likes: 0

always change the plugs after a seafoam. LS1 plugs should be white when you change them b/c each cylinder has its own coil so it always gets plenty of spark causing the ends of the plugs to be white. If that doesn't work go to step 2 and check your blaster packs. If it backfires like a gun is going off its probly you O2 sensors. Your problem sounds plug related. Im 100% against seafoam b/c changing the pugs in a F-body is not an easy task.

Sep 26, 2007 | 10:49 PM

Starion

Launching!

iTrader: (5)

Joined: Apr 2007

Posts: 281

Likes: 2

From: NOVA

Reading this validates my concerns about seafoaming my car. I'll run it through the gas tank, but removing tons of gunk at once is asking for spark plug/o2 sensor trouble IMO. When seafoam says it's safe, I believe the product is........just not the carbon that comes loose all at once.