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Mod | | | Forums66 Topics128,184 Posts1,057,267 Members48,467 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Oct 2006 Posts: 9,671 'Bolter | | 'Bolter Joined: Oct 2006 Posts: 9,671 | Well I know this isn’t the most tasteful subject but I’ve been getting more of it showing up the last few months than was in the previous period. I’m getting a frothy discharge from the breather as can be seen in this picture. http://rides.webshots.com/photo/2263826480098611668dgjBCs I know it’s the product of oil and water but I’m pretty sure its just from the humidity in the air that passes through the engine. There is now froth or any residue on the dip stick so I’m sure that it is not forming in the crank case and when I drained the pan a few weeks ago there was nothing like this in the drain oil. Ya’ll got stuff like this spewing from your sixes? Denny Graham Sandwich, IL
Denny G Sandwich, IL
| | | | | Joined: Aug 2005 Posts: 157 Wrench Fetcher | | Wrench Fetcher Joined: Aug 2005 Posts: 157 | No, mine doesn't but my F**d tractor did that until I put a 180 degree thermostat in it. If your engine is running cold, that might be causing it. | | | | | Joined: Feb 2000 Posts: 5,241 'Bolter | | 'Bolter Joined: Feb 2000 Posts: 5,241 | I am with Fred on this, heat that engine up a little more and I bet it goes away. Joe | | | | | Joined: Jul 2007 Posts: 461 Shop Shark | | Shop Shark Joined: Jul 2007 Posts: 461 | That looks to me like a lot more froth than would be expected with normal operation and with normal temperature variations. I think the 180° thermostat is a good idea if you don't have that now. Also, I would run the truck fast enough to get the engine fully to normal operating temperature, at least a half hour at normal temperature. After that, I would do a cylinder leakage test to see if there is any leakage between the cylinders and the cooling system. Next, or before doing the leakage test if you want to, I would take the cover off to see if there is any evidence of head gasket leakage. If you don't find any evidence of cooling system leakage, then I would watch everything for a while- the condition may only be the result of weather and operating conditions.
Harvester | | | | | Joined: Oct 2006 Posts: 9,671 'Bolter | | 'Bolter Joined: Oct 2006 Posts: 9,671 | Always ran 180° stat, never drive the truck without it coming up to operating temperature, most trips more than 10miles. Rockers at last valve adjustment looked like this: http://rides.webshots.com/photo/2775711870098611668bZCvUm No foam showing up on the dipstick or under cover. Haven’t done a leak down test, might try that this weekend although I know the rings are weak. Hoping it’s just the weather. Denny G
Denny G Sandwich, IL
| | | | | Joined: Jul 2007 Posts: 461 Shop Shark | | Shop Shark Joined: Jul 2007 Posts: 461 | Denny,
It sounds like your operating conditions should keep moisture out of the crankcase. And your top end looks like new- nice condition. Have you done dry and wet compression checks? Since water is a product of gasoline combustion, it might be reasonable to associate a higher level of crankcase moisture with compression ring leakage and blow-by. If that is the case, engine temperature and operating conditions would have a lessor effect on the crankcase humidity level. I think the blow-by idea is somewhat of a stretch, but worth investigating. In engines I've seen with worn rings and a large amount of blow-by, there typically has been a visibly larger amount of exhaust from the road draft tube. If dry and wet compression tests and/or a cylinder leakage test don't indicate ring wear, the foam might be more weather related than an engine condition, especially if cool temperatures and high humidity are prevalent.
Harvester | | | | | Joined: Aug 2008 Posts: 230 Shop Shark | | Shop Shark Joined: Aug 2008 Posts: 230 | i would check to make sure the valve cover breather . might want to check the cooling system to see if it is leaking coolant into the oil passages ,put a pressure gauge on it !see if it holds pressure . | | | | | Joined: Jan 2008 Posts: 4,963 'Bolter | | 'Bolter Joined: Jan 2008 Posts: 4,963 | If you're getting that much water in the oil, I would suspect coolant. I never ran a Chev, all GMCs, and if it were a GMC I would suspect a cracked head. A compression leak down test would tell for sure. Or take all the plugs out and roll the cylinders to TDC one at a time and put about 110 lbs of air pressure to each cylinder for for a minute or two. If you get bubbles in the radiator, you have a problem. | | | | | Joined: Sep 2007 Posts: 154 Wrench Fetcher | | Wrench Fetcher Joined: Sep 2007 Posts: 154 | Thought ???? Thinking that you may have permanent anti-freeze in the engin, then why not park the machine for a couple of days and then carfully turn out the oil plug and see if you get any green stuff dripping from the oil plug before it is completly removed. This would tell you if you have a water leake into the cranke case or just condensation ( clear water ) If it's a head gasket concern you still should not see coolant in in the crake case unless it's bad enought to run down the cylinder walls. If it's leaking bad enough the coolant level would be of concern and the engine would be missing on the cylinder affected. | | |
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