CarTalk.com Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Do I really have an oil leak?

At the risk of sounding like a complete idiot, I have to ask what I imagine might be a pretty obvious question:

Short of bringing the car in for a second opinion, how do I know for sure if I have an oil leak, if I see no obvious signs of one, but was told by a mechanic that I have a major leak requiring the replacement of the oil pan and gasket?

Here are the details of my conundrum:
I have a 2000 civic that I rarely drive which has about 137k miles. About 3 weeks ago, I realized at about 7pm the night before a road trip from Boston to NYC that I was 1000 miles overdue for an oil change. I took it to the only place still open, which was a national tire/repair chain. The mechanic there told me I had almost no oil in the tank, and said I have a major leak. As evidence, he showed me how greasy the parts around the oil tank were. (Which of course looked normal to me…I thought the underneath of my car was always a little dirty or greasy.)

Since I’m relatively inexperienced with car upkeep, I tend to usually trust the opinion of my mechanic and heed their advice/suggestions. However, I am hesitant to go ahead and pay for the replacement of these parts, for the following reasons:

  1. My car gave no indications of any problems prior to the oil change (when he said there was almost no oil); the engine sounded normal, it drove as smoothly as it normally does, etc.
  2. In the 3 weeks since the oil change, I’ve checked the oil level several times and found the level to be a little above the 2nd notch in the dipstick every time. I haven’t noticed the level change at all.
  3. I haven’t found any drips or spots of oil underneath my car.
  4. I recently saw an expose on a similar national repair shop, which showed them acting in very bad faith.

Are these signs that I don’t have an oil leak? Are there more subtle things to look for that would indicate there is one? And lastly, if there is a leak, and it is the oil pan, would it make sense to just tighten the bolts around the pan first before replacing the entire thing?

Any thoughts or advice on this topic is very much appreciated!

How many miles AND how many months had you driven the car between this oil change and the previous one?

I ask because it is not unusual for a car (especially after it passes 125k miles, and especially if it is not maintained properly) to burn ~1 qt of oil every 1,000 miles. So–if you had driven for…let’s say…4,000 miles, it is possible that the crankcase (there is no “oil tank”) could have had very little oil left in it.

If you had driven…let’s say…5,000 miles or more, it is very possible that there was almost no oil left in the crankcase. This scenario is why it is vital for a car owner to check the dipstick frequently, and as the car ages and racks up the miles, it is important to check the dipstick VERY frequently.

That being said, it is also possible for an engine to have an oil leak that is only noticeable when the engine is running, and as a result, not much oil is lost when the car is parked. IIRC, this car’s crankcase holds–at most–5 qts, and may only have a capacity of 4 qts, so there is not a whole lot of room for error when it starts to consume or leak oil.

If there is a leak in the oil pan gasket, it would be a good idea to at least attempt to retorque the bolts before attempting anything more expensive.

Via cyberspace, the only way we can attempt a diagnosis is to get full disclosure from you!
So–in order to respond properly to your question, we need to know:

How many miles/months between this recent oil change and the previous one
How often you checked your oil dipstick during that period of time.
How often (in terms of both miles and elapsed time) you normally change your oil
When the PCV system was last cleaned or when the PCV valve was last changed

It is possible that you were low on oil as suggested above, and the mechanic just assumed you had a leak. Continue to drive the car normally, and check the oil at least every week. If you don’t lose oil, then you don’t have a “major” leak.

The idiots are the ones who DON’t ask.

If you’ve been driving this vehicle for 137,000 miles without ever checking the oil level, than it would not surprize me if you have oil usage problems…including a “leak”, but not as you’re envisioning it, and not as can be fixed with a new oilpan gasket.

It’s crutial to check your oil level routinely. Allowing it to run low means the same amount of suspended diilutants and contaminants as would normally be contained in 4 quarts is contained in less oil, in this case apparently 1 quart or less. That makes the concentration four times or more what it shoudl be. It makes it gunk instead of lubricant.

Gunk doesn’t lubricate well. So the engine wears faster. Even in a healhty engine, some amount of combustion gasses pass by the piston rings (the effect is called "blowby) and dilute the oil. In an engine with excessive wear, more blowby occurs. This dilutes the oil, further affecting the gunk’s poor ability to lubricate. And it tends to “wash” the cylinder walls, reducing lubrication even more and acceleratting the already excessive wear.

As a matter of fact, so much combustion gas can get blown by the piston rings that it can pressurize the crankcase. That can force oil past gaskets and seals that have been compressed for 11 years and have lost some of they sealing ability. That squeezed-out oil makes a mess of the bottom of the engine. If the “pressure relief system (my words)”, the Positive Crankcase Ventilation system (PCV) valve is also gunked up, the problem gets worse. The pressure builds higher.

In short, I suspect you have excessive internal engine wear due to neglect, getting rapidly worse due to neglect, and that’s allowing the crankcase to pressurize and force oil past your gaskets and seals. And you may have a clogged PCV valve as well.

I’m going to suggest changing your PCV valve (they’re cheap), changing your oil every few thousand miles for a few times, perhaps even using some additive to flush gunk out, and perhaps doing a compression check of the engine. Then learn to monitor your oil level and other fluid levels routinely.

And get a new shop.

Wow, thanks for all of your responses and advice. I actually bought the car used about a year and seven months ago. I had the oil changed when I bought it, and then exactly 3,000 miles after that, and then I am ashamed to admit that I went around 5,000 miles before bringing it in this most recent time. I also neglected to check the dipstick during that time (although I did take it in to the shop for a few small unrelated repairs.) Anyway, I will try to make-up for my months of neglect and check the PCV valve and make sure to continue to check the dip stick.

Even if you don’t drive the car much, you still need to check the oil level as you have been doing since the last oil change. It seems there isn’t a problem with the car, so just check the oil level once a month at a minimum regardless of usage. That way if some oil is leaking out you will know it and can add some oil.

Some oil brands burn off quicker than others. This means you might not need any oil between one oil change at 3 or 5K miles and the next oil change need to add one or even 2 quarts of oil between changes. Needing some oil doesn’t always mean a leak, or a big problem. But using some oil does give you reason to keep an eye on the oil level to find out if there is a problem; which is exactly what you are doing. You can check for leaks by putting some dry/clean cardboard under the front of the car where you park it overnight. Oil spotting will be easy to see then.

5000 miles between oil changes is nothing to be embarrassed about. (3000 miles may be an outdated recommendation, depending on the car. Oil change frequency is like religion around here, many different strongly held opinions.) But do remember to check it in between changes.

IF you have an oil leak, it is NOT likely to be the oil pan gasket. all of the usual suspects for a leak in a Honda are above the oil pan, but of course, the oil leaks down to the rim of the pan, then travels around the edge before leaking from the low point.

A mechanic on duty on the night shift at a tire dealer, I think not. You got an oil change “technician” who is not a qualified mechanic. Even worse, he might get a commission for any extra services he sells. In any case, I would be suspect. Either way, I don’t think he was qualified to find an oil leak, if you actually have one.

Now that you are regularly checking the oil, continue that and make it a habit. You should check it every time you fill the gas tank. If the oil level remains normal, then the next time a service technician tries to tell you this story, you will know the real story.

If you do find that you are losing oil at a rate that you are not comfortable with, post back and we will try to help you find the true source. Honda’s are not known to be oil burners or leakers, unless they were severely abused.

“5000 miles between oil changes is nothing to be embarrassed about.”
That is true, but if it took…let’s say…almost a year for the OP to accumulate that mileage, then the OP is going far too long between oil changes. And, as we all know, the sludge that tends to accumulate when a car is used for mainly short-trip local driving and has infrequent oil changes is…damaging and can easily lead to excessive oil consumption.
How long does it take for the OP to accumulate 5k miles???

And, then, we have the following nugget of information:
"I actually bought the car used about a year and seven months ago."
So, unless the car came with full maintenance records, this car could have been subjected to very poor maintenance during its first 9 1/2 years or so. Again, engine damage/excessive wear could have taken place in this engine if poor/infrequent maintenance was the norm with its previous owner(s).
Did the OP get full maintenance records when buying the car?

So, in regard to…“Honda’s are not known to be oil burners or leakers, unless they were severely abused.”
Yes, that is true, but, based on the very slim information that we have so far, this car could have been abused by its first owner(s) and/or by the current owner.

Can the OP supply some of the missing information for us?

Well, yes. She drove 8,000 miles in 19 months. Millsie, you’ll want to change your oil (in this or any car) every 5,000 miles or every 6 months, whichever comes first.

Thanks again for all of your responses. Here is some additional information that might be useful:

I purchased the car from my hometown mechanic who is a honda specialist, and who sold me my first car which was also a ten yr old civic which was still running well when I sold it with 250k miles on it. Unfortunately, I don’t know anything about the previous owner, and neither does my former mechanic I bought it from. The car was bought at an auction, it had been in a wreck, and he refurbished it. It’s possible it wasn’t treated very well in its previous life.

Although most of what I use the car for is short trips to the grocery store, I also use it for short road trips of ~300 miles every couple of months. I think it took me a lot longer than 6 mos to accumulate the 5k. The most recent trip prior to the oil change, and likely when it was low on oil, was through a mountainous area in NH, with a lot of extra weight in the car, which forced me to push the car a little harder going up all the hills on the highways. I’m assuming that probably also contributed to some of its abuse. For some reason I was really concerned about the tire pressure on that trip…next time I’ll make sure to check the dipstick first.

One last thing. There is a little “maintenance required” indicator on the dashboard that turned red a week or so before I brought it in for the change. I looked this up online and found an overwhelming number of people who said not to pay attention to it, that it is just a routine maintenance reminder. But now I’m thinking it could be more than that…

What year is your Civic? My '03 has a “maintenance soon” light which is basically a reminder to take the car for an oil change. It is “reset” when the oil is changed and seems to go back on in about 7,500 miles on my Civic. It is nothing like the “Check Engine” light which means you have a problem that needs attention when the CE light goes on.

Suggestion

A. Read and become familiar with your 2000 Honda Civic Owner’s Manual.

B. No manual ? Get one and then return to A, above. Manual ? Proceed to C.

C. Follow the manufacturer’s recommendations and instructions.

This does not have to be read in one sitting (too boring, possibly), but becoming more familiar with your car could make it last longer, possibly save her life, and take some of the mystery out of her proper care and feeding.

http://www.helminc.com
These folks have a brand new 2-door 2000 Civic Manual in stock & a brand new 4-door 2000 Civic Manual in stock ($34 & S&H). A manual came with this car. This manual doesn’t cost, it pays !

CSA