Author Topic: Gunk under valve covers  (Read 3926 times)

Offline oldblue76

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Gunk under valve covers
« on: October 04, 2015, 07:40:17 pm »
I recently obtained a 1976 Chevy K10. Its a 76 so it is not in perfect condition. I took off the valve covers a day or so ago to change the leaking gaskets. When I removed the cover I noticed there was a good amount of what looks like burnt oil on the heads. Is there a good procedure to clean the heads without removing the heads and why is the gunk there. Also is there something I can do to keep it from building up again. The motor runs struck except for what I believe is loose lifters/rockers.

Offline rich weyand

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Re: Gunk under valve covers
« Reply #1 on: October 04, 2015, 07:54:44 pm »
Did it have a PCV valve hooked up on it?  Lots of people took them off.  If not, you will build up gunk in the oil system from blow-by not being evacuated.
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline oldblue76

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Re: Gunk under valve covers
« Reply #2 on: October 04, 2015, 08:04:17 pm »
PCV Valve is still on the truck. Would cleaning the heads then replacing the PCV valve correct the issue?

Offline enaberif

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Re: Gunk under valve covers
« Reply #3 on: October 04, 2015, 09:02:16 pm »
PCV Valve is still on the truck. Would cleaning the heads then replacing the PCV valve correct the issue?

Its normal for gunk to be under the valve covers especially if the motor is original and very little maintenance was ever done. You could run some seafoam through the engine but you have to be careful as that could cause more issues especially on a older engine.

Offline rich weyand

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Re: Gunk under valve covers
« Reply #4 on: October 04, 2015, 11:36:28 pm »
Does the PCV valve rattle?  That's the test.  If it's good, it should rattle.  No rattle, it's stuck with gunk.

You could run some Seafoam through it, then follow it up with an oil change with a bottle of this.
http://www.amazon.com/ATP-AT-205-Re-Seal-Stops-Bottle/dp/B000NVW1LM
Rich

"Working Girl": 1978 K-10 RCSB 350/TH350/NP203 +2/+3 Tuff Country lift

Offline philo_beddoe

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Re: Gunk under valve covers
« Reply #5 on: October 08, 2015, 01:13:24 pm »
I have small drips from rear main seal, will that stuff work?  Can it cause harm?
Behold, the day of the LORD cometh, and thy spoil shall be divided in the midst of thee.  Zechariah 14:1

Offline fitz

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Re: Gunk under valve covers
« Reply #6 on: October 08, 2015, 07:53:52 pm »
I'd adjust the rockers & don't poke the bear.
Its a 39 year motor, that sludge may be holding it together.
I'd run it till it don't run no more.  When the time comes, drop in a $1500 GM crate motor.
Let Rick Weyand pick the cam.

Offline VileZambonie

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Re: Gunk under valve covers
« Reply #7 on: October 08, 2015, 07:58:16 pm »
Get a bag of rags and a shop vac. Carefully break out and suck up what you can. If you drop pieces of sludge/carbon down into the pan it will plug up the pickup tube. As stated, this is caused by poor maintenance, lack of quality oil & filter changes.
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