Compression Test Results...Big Relief..but ?s (*PICS)

[95strokerPSU]

Ok so I did a compression test today because I have oil in the intake manifold and I wanted to rule out piston rings, head gaskets, and valves. Here's a pic of the average amount of oil in the intake...

Does this look like a normal amount for a 331?

But the compression test showed about 150psi in each cyclinder. The first stroke they would all jump to 100-120psi and then the second stroke 140-150psi.

But take a look at my number three spark plug...(left to right: #1,#2,#3,#4)

And #3 by itself...

#3 was the only one with oil deposits. What could cause only this plug to get that way.

One small thing I should mention even though I doubt it's related, the #3 plug wire must have been resting on the header and a small portion of the outer casing melted. It's not bad at all, it didn't even melt the nylon fibers inside. Here's a pic...

I think my major lack of performance is clogged cats, which will be getting hollowed on Tuesday, and a need for a tune, which I'll be getting an SCT on the 27th.

But your feedback about the amount of oil in the intake and the #3 plug would be appreciated.

Thanks
Dave

 

[BlackVert]

good news about the compression test.

i think our cars can tend to suck oil thru the pvc valve into the intake. how much is normal?

isn't the #3 exhaust header where the egr tube comes from? coincidence?

 

[WhiteDevil]

Thats about how much my stock blocked 95 puts into the intake. Its just from the PVC.

 

[95strokerPSU]

Okay good to hear about the oil in the intake, I guess I need to start to piece together an oil seperator or maybe get the turbo coupe pcv, or both.

isn't the #3 exhaust header where the egr tube comes from? coincidence?

Not sure about stock headers, but with my BBk LTs the EGR bung is on the #1 cyclinder tube.

Anybody else about my #3 spark plug?

 

[RIO5.0]

Did you OHM that wire??? That plug and your compression test dont seem to go together....Plug looks fouled or something....I'd replace it and take a run and see if it comes back?? Its not fuel on the plug??

I pulled my Cobra upper and had that same oil....least your intake has nice places for it puddle... I got a Steeda oil separator coming...Im curious to see just how much mines getting...

 

[BlackVert]

Okay good to hear about the oil in the intake, I guess I need to start to piece together an oil seperator or maybe get the turbo coupe pcv, or both.

Not sure about stock headers, but with my BBk LTs the EGR bung is on the #1 cyclinder tube.

Anybody else about my #3 spark plug?

Thinking about it more, I'm pretty sure now that the EGR bung is on the #2 tube on stock headers, not the #3 one.

It is curious that the wire being marred and the plug being fouled are both #3. How about changing the plug and wire? Maybe the wire is arcing to the header and you aren't getting any spark.

Maybe you have some blowby on just that one cylinder? But one would think the compression test would show something ...

Are the heads ported?

 

[gmkillr]

Oil seperators are your friend!!

 

[FastFord]

Yea... definitely on my goodies list

 

[91LX_5L]

whats this oil seprator do?

 

[FastFord]

For oil that is sucked or pulled into the upper intake throught the PCV, the seperator allows air flow while capturing the oil thereby preventing the oil from entering your upper intake.

 

[SlowGT]

Oil seperators are your friend!!

We've got those all over the place at work. It never occurred to me to have one under the hood. Thanks for the tip

 

[95strokerPSU]

Oil seperators are your friend!!

Can you give a little write up about what you used? Thanks.

 

[SlowGT]

Can you give a little write up about what you used? Thanks.

I can't say for certain, but it looks like 2-->1/4"npt x 1/4"tube fittings and a generic oil separator that you should be able to find at most hardware stores or the local Tractor Supply Co. And a few extra feet of hose.

 

[SorsCode]

I had 150compression on all 8 cylinders on my car with blow by. My issue was like yours oil on some plug, I had oil puddling up on the intake valve, oil in the intake. So I pulled the shortblock apart and come to find out had some worn out rings. Couldn't believe it. Great compression still bad rings.. Answer me that one...

 

[95strokerPSU]

I had 150compression on all 8 cylinders on my car with blow by. My issue was like yours oil on some plug, I had oil puddling up on the intake valve, oil in the intake. So I pulled the shortblock apart and come to find out had some worn out rings. Couldn't believe it. Great compression still bad rings.. Answer me that one...

Didn't want to hear that!

I should find out more next Monday as I'm taking the car to JDs High Performance to get an SCT tune. I talked to the guy today and mentioned the oil on the #3 plug, so he said he'd look into it for me. Hope the rings are okay, but if not, my engine builder included a 12,000mile one year warranty on my engine. So I won't have to pay anything, it will just be a PITA getting the engine pulled and put back in, and getting rides to work. We'll see.

 

[gmkillr]

I bought 3' of 3/8 heater hose, 2 3/8 npt fittings and the oil seperator. You can get everything at walmart. I also used the 2.3 turbo pcv valve. You'll want to mount it over like I did to keep it away from the high temps. Any more questions just let me know. I got everything for under $20 and it only took me about 20 mins. or so to hook it all up. Very easy!

 

[SlowGT]

I bought 3' of 3/8 heater hose, 2 3/8 npt fittings and the oil seperator. You can get everything at walmart. I also used the 2.3 turbo pcv valve. You'll want to mount it over like I did to keep it away from the high temps. Any more questions just let me know. I got everything for under $20 and it only took me about 20 mins. or so to hook it all up. Very easy!

Great info Thanks. That'll make the shopping easier than I thought.

 

[AznStanger3v]

i think you may still want to look into your car more. Oil deposits are bad on plugs. You may be getting 150 still because you are doing a wet compression test and dont even know it. the rings may be messed up and the oil is sealing the rest.