Condensation on oil cap and dark oil

i have a 2003 nissan altima with 99288 miles on it. i just got it changed yesterday and one of the tech’s showed me and said there was condensation on the oil cap and the oil was dark. he recommened an oil system cleaner. is this accurate or is there something more i should worry about? he also said i was 1/2 qt low. last time i got my oil changed at the same place he said my oil was 2qts low and recommened a semi sythenic blend to flush things out, which i did do. i usually get my oil changed about every 4000 miles or so, i try for 3000 but not too successful. i also drive 1/2 hr to and from work every day at a min.

The oil is supposed to be dark. That’s normal.

It sounds like you’re going to a “quickie” oil change place. These places make their money by “up-selling,” or talking you into things you don’t need.

Your car DOES NOT need an “oil system cleaner,” whatever that is.

The oil is the cleaner. That’s why it’s dark, it’s cleaning the dirty stuff out of your engine.

It’s not uncommon to have a small amount of condensation in the winter. Unless it’s severe or persistent, and you’re losing coolant, I wouldn’t worry about it, especially if most of your driving is in stop-and-go traffic.

Check the owner’s manual for the recommended oil change interval. You may be wasting money changing it too often.

I recommend letting your regular mechanic change oil if you’re not comfortable doing it yourself, rather than an oil change franchise. Too many horror stories from these places.

that’s kinda what i thought. i figure as long as i was loosing oil where i had to add it frequently it was alright. i would do it my self just don’t have the right tools and most of the time, time to do it. i would also have my mechanic do it or consider the dealer (but they are so effing expensive and most dealers like to fix every little thing that needs to be fixed i shy away from them, my wife has a honda and has everything done at the dealer, like all scheduled maintance ect. and her oil changes are like $50 but she also get’s free road side assistance by having the oil change done there so i guess it isn’t too bad) but since i work 6am to 530-6pm mon-fri and 30min from my home it makes things really hard… so since this “quickie” place is 2min from work i’m able to stop in after work since they are open late. i know i should be more like my wife and have the factory recommend maintenance done but i really don’t and my cars have been lasting into the 100,000 plus range. my old car that my dad now has is around 160,000 + and is now giving him a lot of problems…

They Sell Tools At Sears, Home Depot, Lowes, Advance Auto, Auto Zone, Hardware Stores, Wal-Mart, Etcetera. You work 5 Days Out Of Seven. I’ll Bet You Could Figure Out How To DIY If You Were Inspired.

i would do it my self just don’t have the right tools and most of the time, time to do it.

I agree, the condensation can be normal and dark oil is good. Stay away from any place where car sharks circle your car whenever they smell money.


An additional thought to consider is replacement of the PCV valve.
Even though I do believe that the “tech” was trying to unnecessarily talk her into some “upselling”, the condensation could be the result of an old, gunked-up PCV valve.

If the valve is not replaced every 3 years or so, it is possible to run into lots of engine problems, ranging from condensation/dilution of the oil, to leaks, to oil burning. For just a few bucks spent on a new PCV valve, you can eliminate those possibilities.

You might consider having the crankcase ventilation checked as a problem with that can cause. (PCV valve and hoses, not a big deal)
Personally, I would skip the system cleaners and the BS about synthetic blends flushing things out.

From the tone of your post it also sounds like you are not personally raising the hood to ever inspect the oil level and you’re relying on the oil level to remain at the FULL mark no matter what. Two quarts down is not good and eventually this policy is going to leave you with a trashed engine.

This policy is also something that appears to be reaching epidemic proportions based on the similar posts lately.

“Even though I do believe that the “tech” was trying to unnecessarily talk her into some “upselling”, the condensation could be the result of an old, gunked-up PCV valve.”

Her ?

" . . . my wife has a honda and has everything done at the dealer . . . "

I think it’s a guy, unless it’s one of those life partner things or whatever they’re called.


Well, as it turns out, you are correct, CSA.

I failed to read the OP’s update from 7:19 AM, simply because HE did not bother to break it up into paragraphs.

I usually avoid reading any post of more than…6 lines or so…if it does not have paragraph breaks, and his “update” post was one of those that is simply too long to be written with no paragraph breaks.

As the others have said, changing oil is usually rather simple. That does not mean everyone should change their oil. I say if you don’t want to get dirty and messy, and don’t mind paying a little more, then that is a good reason to have it done.

Also like VDCdriver, I did not try to read that mass of letters. My old eyes need a little help and proper page and paragraph breaks, make reading a lot easier.

I would also question whether or not the engine was REALLY two quarts low at the OP’s last oil change. It’s pretty easy for them to “check” the oil and leave the dipstick pulled out an inch or so.

If you don’t know how, please learn to check your own oil between changes. It’s in the owner’s manual. It will save you a lot of grief in the long run.

Take a look at this:

You didn’t mention if your '03 Altima is a 4 cylinder engine, or the V-6 engine.

If it is the 4 cylinder engine, you need to have a mechanic remove the catalytic converter, and inspect the catalyst to see if it is coming apart. If it is coming apart, replace the converter.

You need to do this soon, because your car is right at the mileage point where the converter comes apart, and destroys the cylinder walls, due to this engine design using valve overlap camshaft phasing instead of an EGR system. There is a time when both valve are open and the vacuum created by the intake stroke can pull a small amount of the debris from the cat. The debris will damage the cylinder wall and create an excessive oil consumption.

And since you have already reported the excessive oil consumption, I highly recommend you only change the oil every 3k miles from now on, and would probably even recommend switching to a 0W-40, or 5W-40 weight oil from now on, instead of the 5W-30 oil Nissan recommends for all its engines.

Good luck.


Here’s my advice. Get one of these for your Altima:

I put them on my cars (well, I’m down to one now, since I replaced the other car, and the new one comes with free oil changes for life). My mechanic is about 2 miles down the road, but with this valve, I can change my oil faster than I could drive there and back. I literally pull the car into the garage, slide the pan underneath the valve, open the valve, and walk away. 10-15 minutes later go back out, close the valve, spin off the old filter, spin a new one on, and refill the engine with new oil. I need NO tools to change my oil other than the drain pan…