[SDCaddyLacky]

Hey guys, well I just changed my oil tonight, it's only been about 3,500 miles since the previous oil change, and already the oil smells bad and looks like chocolate.

I use only Royal Purple, before I put in 0W40 to see if it would quiet down the lifter noise, it didn't do anything. I have actually done multiple oil changes within a year since I have owned the car, and this keeps happening, oil blacking too soon.

I can't afford Royal Purple at the moment, so I went ahead and got Pennzoil Ultra 5W30. Pennzoil Synthetics get good reviews on Bobistheoilguy,com so thats why.

My question is, do the LT1's old pushrods wear out oil faster than a modern OHC engine? I have a lot miles on my car, about 160,000 miles, this I am sure is part of the reason, plus years of old oil build up, previous owners not changing the oil on time, but I can't believe how dirty and smelly the oil becomes just after 3,000 miles. I notice the car had less power, was more fumy, and was starting to idle funny, sure enough after I checked my oil, it was really black. It's like all the additives wore out, and the oil thickened up.

Since I changed the oil, the car gets up much better, faster, and runs really smooth now. It's like something let it free! lol

Do any of you LT1 owners or anyone that owns a 5.7 Bro, notices there oil becoming darker faster than usual?

 

[albymangled]

mebbe ya rings are tired and all the blowby is contaminating your oil....

 

[outsider]

i change my oil every 3 months whether it needs it or not...and mine is always a little dark but nothing out of the ordinary.

You could try running sea foam in the oil (for only a couple hundred miles) before your next oil change. that will help clean any deposits up and stuff.

 

[deVille33]

I agree with albymangled. Do a compression and leak down test on your cylinders. You can also test cylinder sealing by applying air to the cylinder with the valves closed. Observe where the air escapes.

 

[creeker]

How many miles on your car?.

 

[outsider]

original poster said 160,000. mine has about 127,000

 

[sven914]

I've never though of it as too much of a concern. Any engine (even a factory new one) is going to have blow-by. And if your engine if running slightly rich, even on one cylinder (for Port fuel injection), you will get a noticeable gas smell in the oil. As for the blackening of the oil; I've worked as a lube tech at several different places, servicing everything form your run of the mill, beater of the month, to new Mercedes and Porsche, and I have never seen clean oil drain from an engine.

But, that being said, the oil shouldn't smell like pure gasoline. There should, at most, be a hint fuel smell. And if you get the oil on your hands, it shouldn't be impossible to get off. Wetting your finger in it, the oil should still be slick and not feel gritty.

If there is an overly strong fuel odor, then it might be the rings, or it could be the valve guides or a malfunctioning PCV valve. If the oil is really dirty and burn, then there might be something wrong with your cooling system, causing the engine to run a little too hot.

 

[SDCaddyLacky]

The engine runs fine, what I noticed though yesterday, is I saw some vapor fumes leaking from the PCV valve. It wasn't even fitted properly because the hose is too short, and the little rubber grommet came loose.

Could this be part of the problem? I replaced the hose this morning with a slightly longer one, and fitted the grommet right. I am going to check to see if vapors are still escaping tonight.

 

[pompste]

i change my oil every 3 months whether it needs it or not...and mine is always a little dark but nothing out of the ordinary.

You could try running sea foam in the oil (for only a couple hundred miles) before your next oil change. that will help clean any deposits up and stuff.

Be careful if you use seafoam in the oil.I made the mistake of running a little seafoam in my '78 Deville`s oil right after i bought it about a year ago."Before" running the seafoam there were absolutely no leaks at all from underneath---bone dry."After" running the seafoam,within 2 weeks i had oil leaks from both valve covers which to this day leak down to the oil pan---not major leaks but a nuisance.
After finding the leaks,i had the oil drained and changed.The only good thing that happened was when the seafoamed oil was draining into the collection pan---gobs and gobs of pure black sludge also drained out.It seems the seafoam dissolved the sludge around the valve cover gaskets which caused the leaks.
So again,be careful----if you`ve got good gaskets,there should be no problem with the seafoam.

 

[SDCaddyLacky]

I don't notice a gas odor in the oil, it just smells burnt. I fixed the
PCV valve and the grommet, no leaky vapors now. The temperature of the engine is around 180-190 degrees, I do eat a lot of fast food, idling in line for minutes at times. But the engine fans never come on, I think only a few times in really hot weather the engine temp went above 195, and the fans came on.

Plus the temps in CA have been mild, like always, nothing extreme.

The old oil did feel smooth when I touched it.

I am going to do a compression test eventually to see what is going on, which is a good idea.

 

[sven914]

^Was the engine hot when you changed the oil? If it was at or close to operating temperature, then to oil is going to have a distinct burnt smell to it.

 

[cadillacmike68]

I ran my old 1995 Fleetwood brougham up to 198,000 miles. the oil ws never clean coming out, but the engine always ran fine, and didn't burn oil. I never experienced any power loss, and I always waited for the change oil light to come on. That, and i used whatever 20W50 was on sale at auto zone or discount auto parts. These oils all have to meet API specs.

What is this sea foam stuff?? I use a 1 qt can of gunk engine flush or something similar on my cars.

Lastly, these pushrod LT1s are VERY durable, unless the valves or rings got burnt somehow...

 

[SDCaddyLacky]

I changed the oil when it was hot, ran it for like 10 mins at idle. Yeah I have never had any engine issues so far with the Caddy either. It does leak oil from the front main seal, but barely. It doesn't burn oil, it's always full.


I haven't had any kind of engine sensor problems which is pretty amazing considering how many miles the car has.