Hey guys. Just about have my car running as it should after doing a lot of work on it.

When I was putting it back together after an intake manifold change, it had a massive vacuum leak causing pouring fuel into the throttle body. I could get the car running but only after letting the injectors put some fuel into the manifold, then unplugging them so it wouldn't add more fuel. Once I got the leak fixed, the car would crank and run on it's own, but had a horrible knocking sound. Checked the oil and it had about 10 quarts in it, with the extra being gas. I figured all of the start attempts with the vacuum leak had put so much fuel into the cylinders that it ended up making its way through the piston rings and down to the oil.

Fresh oil change fixed the knocking. The oil has less than 100 miles on it, but it already looks thin again. Car was still overheating due to a leaking heater core, and it did get very hot at one point but no blown heads or gaskets. Changed the heater core, now the car is warming up and not overheating. When cold, oil pressure is up around 30psi when I first crank it up. As the motor warms up, the oil pressure seems to decline. Car still runs and drives fine, but the low oil pressure on the gauge worries me. Here are my theories for the thin oil:
Maybe the fuel hasn't completely made it's way out of the motor yet?
Did the overheat break down the oil prematurely?
Is it possible that my oil pump is going out?

I'm going to try an oil change but wanted to get some opinions of what else this may be.

I've attached some pictures. 1 is oil pressure at idle, another is oil pressure around 2700 RPM's, and another is what the oil looks like on the dipstick.
(Also, the SES light on the dash is giving me code 15, which is Coolant Sensor Circuit Low or Open. Not sure why I'm getting that, CTS has been replaced.)


Any input on this would be greatly appreciated! Thanks again!

 

Oil doesn't work when it has gas in it, if your lucky and got it early it could be as easy as putting in a new set of bearings for the rods n main if they are within spec and ya got good compression and a fresh oil pump. [though ya hope the cam bearings are still ok, not as easy to change by mostly removing one part like the pan.]

But you won't know till the pan is off, and you can see what happened.

Id also change the oil a few times.

But either drop the pan and look or just drive it fingers crossed


Id put some 20/50 in there BTW

 

It didn't run long with gas in the oil like that, maybe 5 minutes on a total of 2 or 3 start ups. That knocking kept me from wanting to keep it running. I was suprised at how quickly the fresh oil stopped it.

Since I'm still getting good oil pressure at higher RPM's, do you think there are any issues with the pump? I'll definitely change the oil again and see what happens from there. Actually been thinking about going full synthetic, but don't want to pay that price if my pump is going out and I'll just need to drain that high $ oil back out to change the pump. Maybe try putting conventional 20/50 in it to see if pressure builds back up, then change to synthetic after 500 miles or so?

Thanks for the input!

 

I don't like synethic in my old gen V8 engines, tried it, didn't like it, just change your dino oil more often is what I say.

your could be fine, thats up to you.


A pan drop isn't that bad to look for any burn marks then pull 1 or two caps n see what things look like.


I lost half my oil psi in my V6 using Rotella for only 100 miles, high detergent oil. Either it gunked up the oil sender passage or it washed away to much gunk. nothing I did brought it back, but still runs fine. [yet to drop pan n check or change pump on it ]

 

10 lbs per 1000 rpm is ok.... change oil..... use 30w reg.oil.... if you pick up any pressure...you might be okay....let's hope