Light Gray Oil With Gas Odor - Team Camaro Tech
Troubleshooting Diagnosing problems done here.

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post #1 of 13 (permalink) Old Dec 9th, 01, 02:34 PM Thread Starter
Join Date: Aug 2001
Location: Lawrenceville, PA, USA
Posts: 13

I have a 79 Z28 with a rebuilt 350. The car has been sitting for about 10 years. I got it out of storage this summer to do body work. The motor has no street time on it, only initial break in, tuning, and idle time, maybe 15 hours total over the past 10 years.

I changed the oil when I got it out of storage. The old oil looked fine. Now the car has been sitting for about 3 months without being run. The oil is a light gray in color and has a gas odor. My radiator is low too.

When I checked the oil dipstick I noticed the odd color of the oil. I then checked the radiator and noticed it was low. So I assumed water/coolant in the oil.

The car has been sitting for a few months without being run (I was doing body work) so I figured the water would probably have separated out and be on the bottom of the pan. So I drained about 1 cup of oil out of the oil pan. It smells of gas and is very light gray in color.

Any ideas? I have a Holley Blue electric fuel pump, a Holley 4bbl with vac. secondaries and dual feed.

Could the fuel have leaked out of the carb and into the oil?

Would fuel in the oil give it this color?

How about the color with antifreeze?

Where would antifreeze come from? Cracked block (I hope not)? Head gasket? Intake gasket?

How would I troubleshoot this?

If it's fuel would it most likely be the carb leaking fuel out of the bowls when sitting? The carb has been on the car for 10 years. It was rebuilt with a Holley trick kit but that was 10 years ago, so it's possible the gaskets have dried up.

Any ideas?

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post #2 of 13 (permalink) Old Dec 9th, 01, 03:46 PM
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Location: niagara falls ny
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well how low was your antifreeze and was it low just when u took it out of storage too or full then went low after u changed ur oil because after a long enough period of time in the right climate u can get condensation in your oil as for the fuel smell i dunno hopefully not a head gasket or cracked somthing letting ur coolent into ur oil
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post #3 of 13 (permalink) Old Dec 9th, 01, 04:24 PM Thread Starter
Join Date: Aug 2001
Location: Lawrenceville, PA, USA
Posts: 13

Thanks for the reply.

Unfortunatley I don't remeber the level of the coolant. It is really low though. I can see 5 or 6 cores down and I know it was never that low. However, I did reconnect my heater core, I had it bypassed for a while. So this may account for some coolant loss. But the motor has not been run since I reconnected the heater core so the coolant would not be able to circulate and fill the core.

I am just not sure why the oil is gray. I've had a motor (Ford 302 cracked cylinder wall) with antifreeze in it before and the oil was never gray, just black with a green slimy tint.

Any other thoughts?

I use Pennzoil 10W30 just in case anyone was wondering, so it's not gray because of any synthetics or additives that I puposely put in the oil.
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post #4 of 13 (permalink) Old Dec 9th, 01, 07:25 PM
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How high was the oil level? If it was way over full than I would be worried. Your best bet is to drain the old oil and coolant. Then refill and try to fire her up. You might want to pull the plugs and squirt some oil in the cylinders and mabye even prime the oil system and rotate the engine by hand.

70 camaro 307 (350soon) /350th
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post #5 of 13 (permalink) Old Dec 10th, 01, 02:54 AM
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Why would you be worried if the oil was way overfull? Can you expand on your comments?


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post #6 of 13 (permalink) Old Dec 10th, 01, 03:09 AM Thread Starter
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I believe the oil was at the full mark. It did not appear to be overfull.

I assume an overfull condition would suggest more fluid, such as coolant, made its way into the oil system.

I plan to drain the oil and coolant this week and replace the oil filter.
Tonight I am going to pull the plugs/screws on the fuel bowls to see if there is still any gas in the carb. Would the fuel in the bowls evaporate over time?

The color of the oil looks like chocolate milk. It also poors really easy compared to normal oil, not nearly as viscous.
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post #7 of 13 (permalink) Old Dec 10th, 01, 02:04 PM
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Try to get a cooling system pressure checker from a friend and see if the system holds pressure, even overnight if you have to, to see if theres a slow leak. Chances are that all the fuel has evaporated from the float bowls, and that oil change isn't a bad idea at all.
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post #8 of 13 (permalink) Old Dec 10th, 01, 03:30 PM
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You definitely have more than just condensation in your oil if it is grey / brown and loose. You should do a compression test and a radiator pressure test. Probably a head gasket. And if I'm not mistaken in regards to your post, oil would stay on bottom, not water so water would come out last. The gas smell in your oil is the least of your worries. It may just be leaking down from your carb. through the cylinders. That is the easiest fix. Good luck.

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post #9 of 13 (permalink) Old Dec 10th, 01, 03:41 PM
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It could be the intake. If it has a bad gasket or isn't torqued down properly it may have caused the problem.

As for the checking the oil level if you had 5qts of oil in the pan and add a qt of water or other fluid, it will indeed show more...

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post #10 of 13 (permalink) Old Dec 12th, 01, 06:43 AM
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(phel69) Water will come out first, oil is lighter than water and will stay on top.Now back to origanal question if you have gas in your oil it probably is from a bad diapram in fuel pump letting fuel to run into crankcase this will make your oil look gray. If your getting water in your oil it will look milky. Hope this helps
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post #11 of 13 (permalink) Old Dec 13th, 01, 05:24 PM
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Sounds like a headgasket is out..
I just blew out my headgasket on my everyday driver and I notice the same as you....Greyish oil, low coolent, ...The gas in the oil is from gas leaking from the carb as timemechines hafta do a compression check to be shure of the gasket..
post #12 of 13 (permalink) Old Jan 6th, 02, 07:47 AM
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Location: London, Ontario, Canada
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I had this problem with a motor, But only when i wasn't driving the car. My ex drove it, revved the **** outta the motor and shut it off while it was still turning 3000+ rpm, which kept the cyl's loaded with fuel, it drained down the cylinder walls, and into the pan.

So it's most likely leaking through the carb/intake somewhere...I don't think the oil would smell like gas if it had coolant in it.

79 Malibu - 355/th350
83 Camaro - 406 going in, with fireball heads & a real nasty camshaft
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post #13 of 13 (permalink) Old Jan 7th, 02, 03:59 AM Thread Starter
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Location: Lawrenceville, PA, USA
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I did a radiator pressure test last week. I got a test unit from AutoZone.

The first test I did was check my radiator cap. It held pressure.

Then I hooked the pressure gauge and pump up to the radiator and pumped it up to 12psi. I had hose leaks everywhere. So I tightened all the hose clamps and got rid of those leaks. I then put 12psi on the radiator again. I let the system set for 30 minutes and the pressure gauge never moved.

I released the pressure and started the car. As the engine warmed up the pressure started to rise, as it should. I never saw any pulsing on the pressure gauge.

From this test it appears that all is good with the cooling system and gaskets.

I still need to do a compression test.

Can I rule out a head gasket and intake gaskets after doing the cooling system test?

Could the water have been from condensation?

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