forgot oil cap!

Messages
11
Location
Canada
I have a 87 Nissan Pathfinder 3.0 V6. When filling up with gas I topped up the oil (0.5L) and drove about 3000 miles before filling up with gas again. Upon checking the oil again I noticed the filler cap was missing!! I drove all that way with no filler cap. I know that no oil came out the filler hole because the engine was clean. I wonder what kind of crap entered my engine and if I did any damage. I plan to change the oil in the very near future. It was 5W30 Valvoline maxlife.
 
Messages
1,151
Location
Clovis, CA
Yeah, 3000 miles on one tank ? Don't let the oil companies know that....they might send a hit man after you. But as far as I'm concerned, mum's the word.
 
Messages
47,765
Location
Duvall WA - Pacific NW USA
Seriously - you only check your oil every 3000 miles? Yet, you are concerned with leaving the oil cap off? I'm not saying this to flip you some choda bits, it's just a very strange dichotomy, that's all. As for your oil - I'm absolutely sure some nasties entered (let alone the pollution factor). Will these nasties damage your engine? Your filter will catch the large chunks. Please do a used oil analysis immediately to confirm. Order the kit immediately from a vendor of your choice or find a local lab. Take your sample midstream while draining. Post the results on this site. My bets are that your engine will be OK in the mid/long term.
 
Messages
63
Location
Texas
You are very lucky there weren't more serious consequenses especially if there was a lot of oil thrown around the engine compartment.
 
Messages
7,409
Location
Austin, TX
quote:
When filling up with gas I topped up the oil (0.5L) and drove about 3000 miles before filling up with gas again. Upon checking the oil again I noticed the filler cap was missing!!
Your penace is 3 "Our Fathers" and 3 "Hail Marys". [Cool]
 
Messages
2,513
Location
Richmond, VA
An engine usually has a little suction at the oil fill. Verify by placing a dollar bill over the fill hole with the engine running. There should be enough vacuum to hold the bill against the valve cover. My guess is that you sucked in some dirt, so I would change the oil.
 
Messages
11
Location
Chicago Area
I did that once when changing the oil. I don't remember what vehicle it was, but when I started the engine to verify oil pressure, oil came spraying out the filler hole. There was oil all over the place (the hood, engine, walls). Another time, I added coolant and forgot to put the cap back on. That was a much bigger deal. When I drove it the next day, after about 5 miles or so, the temperature gauge started raising and I smelled a sweet smell. Luckily, I was near one of those Oasis things with a gas station. I stopped there and bought some coolant and water. The radiator cap was still under the hood. I drove that car for another 50,000 miles or so before I traded it in because it didn't fit our needs anymore.
 
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