Brown gunk on Spark plug cylinder 7. 82 C3
10-08-2018, 09:39 AM
#1
Brown gunk on Spark plug cylinder 7. 82 C3
found this when I removed the spark plug from cylinder # 7. This car was purchased brand new, maintenanced regularly, and has 43k miles on it. Could this just be the dielectric grease on the plug? The car has never had a single issue whatsoever. Also it's been sitting since 98, and this is the first time the plugs have been removed since before it began sitting. not sure if that bit of info helps
Last edited by Shyine2; 10-08-2018 at 10:57 AM. Reason: Forgot attachment
10-08-2018, 09:59 AM
#2
Team Owner
Member Since: Jun 2000
Location: Southbound
Posts: 38,928
Likes: 0
Received 1,469 Likes
on
1,248 Posts
Cruise-In II Veteran
No pic.
10-08-2018, 11:13 AM
#6
Well there was oil leaking from the valve covers. So I pretty much assumed it needs gaskets. everything else seemed fine though. It never overheated, and there isnt anything mixed in with the oil. so i'm assuming, and also hoping there isn't an issue with the head gaskets
Last edited by Shyine2; 10-08-2018 at 11:13 AM.
10-08-2018, 12:32 PM
#7
Team Owner
It appears that plug #7 hasn't been firing, or, at least, not well. It could be a bad head gasket which is allowing some coolant to get into the combustion chamber; or it could be that the plug or plug wire is defective and not allowing full spark to generate. If it were me, I would install a new plug AND a new wire for #7, then run it for a while and pull/check it again. If you see similar condition to your photo (or early stages of the same thing), you should do a 'compression test' to see if pressure is low in #7. If so, you should pull the head to determine what is going on with that cylinder. And, if you have to go there and you have lots of miles on the engine (or heads), it would be best to have the heads refreshed (not much money) while you are at it.
The following users liked this post:
Shyine2 (10-08-2018)
10-08-2018, 12:35 PM
#8
It appears that plug #7 hasn't been firing, or, at least, not well. It could be a bad head gasket which is allowing some coolant to get into the combustion chamber; or it could be that the plug or plug wire is defective and not allowing full spark to generate. If it were me, I would install a new plug AND a new wire for #7, then run it for a while and pull/check it again. If you see similar condition to your photo (or early stages of the same thing), you should do a 'compression test' to see if pressure is low in #7. If so, you should pull the head to determine what is going on with that cylinder. And, if you have to go there and you have lots of miles on the engine (or heads), it would be best to have the heads refreshed (not much money) while you are at it.
10-08-2018, 09:04 PM
#9
Burning Brakes
If it is a blown head gasket, which it certainly looks like from the condition of that plug, when the car is running remove the radiator cap and if you see bubbles, then that will confirm the diagnosis. Of cause the worst scenario is a cracked head!
Good luck.
Good luck.
The following users liked this post:
Shyine2 (10-09-2018)
10-09-2018, 01:05 PM
#12
10-09-2018, 01:07 PM
#13
10-09-2018, 03:28 PM
#14
Burning Brakes
I'd lean towards the intake manifold gasket leak. If it ran OK before it was put away, the head gasket didn't just go bad on its own. Also, the valves for #7 could have been open for the 20 years it sat and the constant humidity changes could lend to the problem as moisture got in. Change the plug and wire and run it for a few weeks. Then check it and see what's up.
Duane
Duane
The following users liked this post:
Shyine2 (10-09-2018)
10-09-2018, 03:52 PM
#15
I'd lean towards the intake manifold gasket leak. If it ran OK before it was put away, the head gasket didn't just go bad on its own. Also, the valves for #7 could have been open for the 20 years it sat and the constant humidity changes could lend to the problem as moisture got in. Change the plug and wire and run it for a few weeks. Then check it and see what's up.
Duane
Duane
10-09-2018, 04:01 PM
#16
Drifting
Wait! Don't try to start the engine with the plugs in it. If the cylinders have water in them, you could destroy the engine in 3 seconds. Hydrolock is not fun! That plug shows that the cylinder is filled with water. Remove all plugs, turn the engine over and watch for the gyser. Lube the cylinders before installing new plugs and firing it up.
If it were me, I'd remove the heads and inspect the cylinders before turning it over. The engine has sat for 20 years....things happen.
Just my advice.
If it were me, I'd remove the heads and inspect the cylinders before turning it over. The engine has sat for 20 years....things happen.
Just my advice.
10-16-2018, 06:29 AM
#17
Advanced
You might also consider applying air pressure to the cylinder via a hose adaptor. Bring #7 up on TDC, apply air pressure and check radiator for bubbles.
There's also a concern about aged gasoline and associated gum deposits in the tank and carb. As previously stated, setting for 20 yrs can cause a lot of stuff to happen.
Vic
There's also a concern about aged gasoline and associated gum deposits in the tank and carb. As previously stated, setting for 20 yrs can cause a lot of stuff to happen.
Vic
10-16-2018, 12:25 PM
#19
Safety Car
i agree to all, spin the engine a couple times with the plugs out.
You have absolute evidence of water in the cylinder. maybe even water in the oil so even change the oil and all the other remedys for firing up a engine that has been sitting.
You have absolute evidence of water in the cylinder. maybe even water in the oil so even change the oil and all the other remedys for firing up a engine that has been sitting.
