Are my spark plugs telling me something? Pics...

[1-8-4-3-6-5-7-2]

Here are some pics of the spark plugs from my recently purchased 1994 K1500 with a 350 TBI motor.

Things I know about the truck...

1. The timing is about 10* off from where it should be (It should be at 0*)

2. The truck runs hotter than it should

3. A very noticeable erratic miss at idle

4. A small amount of continuous white smoke from the tailpipe at idle, engine warm or cold

5. The plug wires were trash and the distributor cap had a lot of corrosion inside on the terminals.



Do these plugs indicate any problems, or do they look bad from neglect?

The first pic is cylinders 2,4,6, and 8. The second pic is numbers 1,3,5, and 7. The third pic is a close up shot of numbers 2 and 6.

 

[resurrected_jimmy]

ewww.......

 

[70jimmy]

Nasty!!

 

[Jason4x4]

cylinder 4 looks like it is burning coolant, and the rest look like they are burning oil.

 

[sled_dog]

cylinder 4 looks like it is burning coolant, and the rest look like they are burning oil.

pretty much agree. You could try a tuneup, but I'd check compression on all cylinders first.

 

[1-8-4-3-6-5-7-2]

Thanks for the replies. I'll get a compression tester and test the cylinders to see whats going on. The spark plugs are out right now and both exhaust manifolds are off, is it still ok to do a compression test with these parts off?

 

[xpndbl3]

that's fine to do it with it all off, make sure to put a brick on the gas pedal to keep the throttle open so you'll get more accurate results, disconnect fuel pump fuse and ignition obviously

 

[roadnotca]

You didn't say how many miles are on it, or what it was used for.
Also, compression testing is supposed to be done on a hot motor. Thats why nobody likes to do it.

 

[1-8-4-3-6-5-7-2]

Well, it's 98* here today... is that warm enough for testing?

The odometer shows about 167,000 miles and the truck is a daily driver/work truck for me, although I know nothing about it's life with the previous owner.

So, with a cold engine would it be a waste of time to do a compression test? Or would I still be able to tell if I have a weak cylinder?

 

[roadnotca]

98* outside is not enough.
If a cylinder is really bad, temp won't matter.
Check all of them (cold).
If any show about 70-80 psi., then I'd recheck when hot, normal should be over 100 psi.
If any are 0-50, try squirting a little engine oil through the plug hole and check again. If it comes up, it might be rings. If it doesn't, its valves; likely exhaust valves 3 or 5.

 

[JNygard]

From the description of the white smoke and the pictures of the plugs I would say Head Gasket, specially if that white smoke smells a little sweet like antifreeze.

 

[1-8-4-3-6-5-7-2]

Ok, I went to AZ earlier today and bought a compression tester.

I just got done testing, and here's what I got...

Engine cold, all plugs removed, exhaust manifolds removed, throttle wide open, fuel pump fuse removed, coil disconnected:

Cylinder number then compression number

1 180
3 180
5 185
7 190

2 185
4 185
6 180
8 185



.

 

[roadnotca]

Good results. Looking at your first post, I'd say give it a proper tune with plugs, wires, cap & rotor. Drive for a week while watching the coolant.

 

[1-8-4-3-6-5-7-2]

I've got an Accel cap and rotor, Accel plug wires, Autolite 25 plugs, and a Wix fuel filter for it. I need to set the timing also since it's off 10 degrees. By the looks of the old cap, wires, and plugs the truck should run a lot better with the new parts. Hopefully I'll get everything put back together in the next day or two.

 

[1-8-4-3-6-5-7-2]

I installed the new cap, rotor, plugs, and plug wires and adjusted the timing to 0* and the engine runs real good now and idles smooth. I also put on some headers.

But now my check engine light is on. Code 43. Neverending fun...



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