Hoping for some seasoned vet opinions here.

My new 383 is in and running pretty strong. Pulls strong and smooth all the way from idle to the 6500RPM rev limit on the PCM. I've easily pulled away from a new C5 and LS1 fbodies. So far everything is going according to plan, except..................

My oil. It's getting black way too quick.

1. I changed it after running the engine for 20-30 minutes following the install. Looked normal.

2. Changed it again after about 300 miles. Looked a little darker than I expected and smelled a little odd, like some sort of chemical was in it. I chalked that up to excess engine lube getting dissolved.

3. Changed it again after 1000 miles, because it looked darker on the dipstick than I wanted. I noticed the same smell from the oil. I thought, " That seems like an awful lot of lube was in there, if that's what this is."

4. Just checked it again with about 600 miles on this oil change. It's nearly black and I've decided that the oil smell is likely from gasoline in the oil. Not a lot, but enough to change the smell and make it a little pungent. Now I'm concerned.

My first thought is that the rings aren't sealing and I'm looking at excessive blow by. That would explain the dark color and the odd smell.

Anybody had this experience and can confirm this or else steer me towards another possible cause? Thanks.

 

Dirty oil is not necessarily a bad thing.

Some oils have more detergents than others and clean your motor better.

If you had excessive blow by your dipstick would come popping out all the time. Check to see if this is happening.

I use Quaker State oil BECAUSE it comes out dirty. If I use certain synthics it comes out clean. Meaning all the crap is still in the motor.

Check your air fuel ratio. Make sure you aren't running extremely rich.

Check your oil for coolant and your coolant for oil. (Head gasket leak)

 

i had the same problem with my 383. when i changed the oil after 800 miles, it was completely black. it looked like if it was driven for 8k miles without an oil change. i check oil level regularly and the oil on the dipstick is still clear after 200 miles. i dont know what causes it but hope it fixes itself like mine did.

 

I know I'm running rich. Pretty dang rich (thanks PCMFORLESS).

So running rich, how does that much fuel get into the oil? It still seems like it would have to be some blow by.

BTW, thanks for the posts. Another healthy 383 doing the same thing is reassuring. I need to get the rich condition cured and see if that does it. I'm probably slightly paranoid on the new engine A few grand spent on a motor will do that to ya'.

 

Don't just guess, I would suggest getting an oil analysis done as that can help pinpoint potential engine problems, as well as telling you how your oil is performing. Oil can look perfectly clean but be full but be worn out, or vice versa, it can be black as can be, but still be suitable for continued use. You just never know until you get it analyzed. Blackstone Labs is very good if you live in the US, for Canadians, I like Wearcheck.

 

My oil is black after 400 miles and 17 strip passes. I just run 20-50 NAPA brand. It has been doing that since the motor was new.

 

I am far less concerned by the look than I am by the smell. I would defiantly get the over rich mixture taken care of. There aren't many ways that gas can get into the engine other than past the rings.
Did you break in the engine using dino oil?
Leaking injectors might cause this too. Hows the start up?

 

As I have said many times on this and other boards. The type of oil you use is far less important then changing it at the recommended interval.
But I have to say, this is the most illogical reason I have ever read for not using synthetic.
You can not gage the effectiveness of your oil by looking at it! And no, the crap is not still in your engine.
Whether you choose to except it or not, science has proven synthetic oil to be far superior to dino in all aspects of engine protection.

 

except in breaking in a new motor, dino is still best for that. I dont care what any scientist said, i will break in any new motor i build or have built on dino, and after a few thousand go to synth. Just my .02 cents but im young what do i know

 

I recognize that engine...

I'm glad you met your goal of walking away from Vette's and LS1 cars. On to the problem at hand - if it smells like fuel in there it probably is. With your computer setup do you have a way to check air/fuel ratio while it is running? Typically if the rings are not seated then you would end up burning oil as it is the second ring (a glorified oil scraper) that is the last to seat. If it is not burning or using oil then I would guess that excess fuel is getting in there by either running too rich or possibly a leaking injector.

How is that computer program you have set up for tuning rich/lean conditions? Have you tried to smog it yet?

On a side note, give me a call at the shop and we might be able to work something out to dyno your car at my friends chassis dyno. - Daryl

 

This is the exception that makes the rule. The reason you use dino to brake in the engine is because it's not as good. Synthetic is so good it does not allow the rings to seat ie. ware-in.

 

I used synthetic for 7 yrs. After 2 oil analysis I found Quaker State to clean better and produce less metal particles.