Valve Cover Gasket Leak

A TrustMyMechanic fan contacted me recently about his valve cover gaskets. He had already replaced them THREE times over the last two years, and they are leaking again. Talk about frustrating! What he didn’t realize, and what I’d like to explain here, is that the leaking gaskets are probably not his problem…just a symptom of what is really going on that needs to be dealt with.

Valve Cover Gasket Seepage

The first thing that I advised him to do is to determine if he has a “seep” or a “leak” of oil. If the car has what we call a seep, you will notice a slow seepage of oil over time that isn’t enough at one time to actually produce a drop. You usually won’t find any spill areas on your driveway, and the oil level won’t really fluctuate between oil changes. What you will notice is a burning odor or even smoke as the oil seepage gets on hot engine or exhaust parts. An oil seepage is usually a problem that doesn’t require an immediate repair.

Almost every car that has been driven over 30,000 miles can experience some oil seepage as normal wear and tear. As the oil gets dirt and dust stuck to it, it will get more obvious, but isn’t necessarily the sign of a problem. I just took a look at both cars in my driveway, and both have signs of seepage around the valve cover gaskets. These automobiles have less than 40,000 miles on them and don’t have any problems that would indicate I need to replace the gaskets.

Of course, if I were to take either vehicle in for other repairs, the service manager would probably draw my attention to this seepage and advise me to replace my valve covers. It’s an add-on item for his bill, and he’s not incorrect or being dishonest in saying that my valve cover gaskets are “leaking.” But if the car isn’t showing any of the signs of true leaking we just went over, I wouldn’t go through the expense of having them replaced.

For higher mileage cars, I would advise that you monitor your valve cover gaskets a little more often and be sure to follow the recommended preventative maintenance for your car. Should you notice a problem or the beginnings of a true leak, replace the gaskets.

Additionally, if your car has a V6 or V8 engine, the valve covers sit at an angle. This design causes the oil to pool at the bottom of the valve cover. Any oil that seeps or leaks from this area is going to heat up from the exhaust system directly below it and cause a burning oil and possibly smoke.

On the other hand, a true leak will produce noticeable signs of dripping oil on the pavement where the car is parked. The leak will continue to drip oil while you are driving the car, which can cause a burning odor and possibly smoke, and if it isn’t attended to, can cause your oil levels to drop low enough to damage the engine. An oil leak should be corrected as soon as possible, and make sure to watch your oil level carefully until it can be repaired.

Valve Cover Gasket Leaks

So if this gentleman’s car has a true oil leak at his valve cover, let’s help him figure out what is causing it. The valve covers are on the top of the engine and provide protection for the valves and rocker arms. The gasket resembles an egg carton and is made of rubber or cork.

valve cover gasket

As the engine runs, oil is pumped to the top of the engine to lubricate the valve train, and it pools in the valve covers. The oil drips back inside the engine slowly through the drain-back holes in the cylinder heads. Then the oil is pumped back to the top of the engine again.

If you don’t keep your oil changed frequently, the sludge buildup in your oil can restrict the drain-back holes and drastically slow the draining process. This thicker excess oil will pool in the valve cover for longer periods of time and can create extra pressure on the valve cover gaskets. The Positive Crankcase Ventilation (PCV) valve’s job is to help relieve some of this pressure.
PCV valve

The PCV valve is built into the valve cover and vents excess pressure just like the valve on top of a pressure cooker. As pressure builds, it starts shaking back and forth allowing small amounts of steam to escape slowly and safely. Should your PCV valve become restricted, the pressure can cause a blown out oil gasket or seal.

PCV valves should be replaced as recommended, following the suggested maintenance schedule for your car. This is a critical safety component protecting your engine, and is inexpensive and easy to replace. A reputable shop will replace these valves as standard practice during a tune-up, and they should also be inspected for restrictions during all maintenance visits.

I hope this quick synopsis of oil seepage and leaks has been helpful. Hopefully most of you can rest assured that your car is fine, and if it does start showing signs of a true problem, you will be able to recognize it and correct it quickly.

Blessings,

Austin Davis

Posted in: Oil Leaks

About the Author:

Austin Davis, consumer car repair advocate. "Hi there! I love to help people solve their car repair problems and I hope my site was helpful to you today. Thank you for stopping by."
  • Ricky Harris

    I have an 2002 Kia Sedona that is leaking out from a black cap sealer on the side of the valve cover. Once the car is started and idling for about 10 minutes the pressure under the valve cover pushes the cap out and causes a huge oil leak. I’ve replaced the gasket and cap, even put silicone around the cap (not knowing if it needs silicone or a gasket), but it still pushed out. Could it be the PCV?

  • Diane Tompkins

    I have a 99 Toyota Camry with 198,000 miles on it. Took it in to the Toyota dealership for a service and they said I need a battery and valve cover gaskets. The following week I took it back in to have the battery and gaskets installed. When I got in the car to go home the inside had a strong odor and when I went to turn on the defroster it would not switch over to defrost or anything but blowing directly out. Air conditioning is working it just won’t switch over to anything else. Also,when you turn the air up now it begins to make a loud humming noise. None of this was going on when I took it in. Could replacing the battery,valve cover gaskets and spark plugs have interfered with my air conditioning system?

  • Morgan

    I have a Ford Taurus 2004 with over 200,000 miles on it. I just took my car to the repair shop and had the Valve Gasket Cover replacedas well as the PCV Valve & Assembly. I am still smell like something is burning or hot. The same smell that it was before I took it in to the shop. They said they fixed everything. Well they said they were 90% sure that it was fixed. They mentioned something about another leak? I dont know whats going on? Can somebody please tell me whats going on with my car? I know I need to replace it but how can I ise this as a little trade in value if it doesnt even run right?

  • Jack

    Hi I have Toyota camry 2007 with 86000 miles. I do my own oil change with mobil 1 extended protection. Recently, I received a letter about excessive oil consumption in camry. I noticed this because in just 4000 miles after oil change I get oil sign indicating low oil in my car. Going under my car, I didn’t see any oil leak coming out. I thought it must be excessive oil consumption covered under warranty so I took it to toyota today but they said my car has valve gasket cover leak and power steering hose leak. Without fixing these two, they can’t do under warranty maintenance of oil consumption test. They quoted me a little over $500 for these two repairs. I was wondering if the valve gasket leak is major and requires immediate repair? I was thinking of filling in oil whenever I get oil pressure sign while also doing regular oil change. I just want to keep this car for around 6 months. Would this be ok or it will result in major repairs if I don’t get leak repair?

  • Austin Davis

    Wellll……is the oil leaking bad enough that it is dripping on the concrete, or is this just a small seep a mechanic noticed? If its leaking bad enough to drip on the ground, yes, I would repair it now. The valve cover gaskets are a very common source of leaks, the intake not so much so I would be a little surprised to see the intake gasket leaking…or leaking substantially. I would ask the mechanic to tighten all valve cover and intake mounting bolts first, sometimes they become loose over time and just tightening them up stops/slows the oil leak.

    The vehicle is old, although with few miles, but all the components are old and tired. But, I think you could probably spend another $300 or so and still have made a pretty good investment if you like the vehicle. I don’t think I would spend much more than that. You could sell this car on Craigslist to get your money back then go buy a 2 year old (lease trade in vehicle with less than 30K miles) Kia or Hyundai and use the money as a down payment, and finance the balance….both are fantastic vehicles.

  • Kelly

    Hi:

    Due to financial constraints, I bought my aunt’s 1991 Cutlass Supreme. I though $1000 was a great deal for it since it only has 59,000 actual miles on it. Then the fun began. Needed new tie rods nd oil filter $440. New tires $350. Now it is leaking oil. I went to two mechanics. One said oil gas get cover and the other said oil gasket cover and I think he said intake gasket. The first one didn’t mention intake gasket, yet. The second one said it could be more things as well but would start with these two. Labor and parts on cover $350 and intake $500. What do you think I should do? Throw more money at this car? I don’t have much right now and wish I had known this before I also spent $300 for title, sticker etc. Thank you for your help!!

  • Austin Davis

    Well, the timing belt should be replaced about every 80,000 miles or so and they might have to remove the valve covers to gain access to the timing belt. So if the valve covers are the culprit of the oil leak, AND you are due, or close to being due for the timing belt replacement the second mechanic is looking out for your best interest.

    Doing it his way, you get the valve cover gaskets changed, the timing belt replaced as maintenance and when replacing the timing belt its a good idea to replace the water pump (the timing belt drives the pump) and there are timing cover seals inside that should also be replaced at that time. $1,300 sounds like a pretty good deal, and the $1,000 quote seems pretty high just for valve cover gaskets. My suggestion would be mechanic #2.

  • Susan Loyd

    Question for the experienced mechanics.
    I have a 1995 Lexus LS 400. It has 140,000 miles on it and has had the transmission rebuilt. I have an oil leak and the dealership tells me that I need to have the gasket covers replaced for approx $1,000. In an effort to save some money I took the car to a regular mechanic who says I need the covers replaced, a new timing belt and a new water pump for $1,300. I don’t know who to trust. Is it smart to replace the water pump and belt if you are already in there? Thoughts anyone?

  • Austin Davis

    Possible. The valve cover gaskets can leak oil that runs down the side of the engine and INTO the starter motor, which will damage the internal electrical parts. I would ask to see the old starter and see if its covered in engine oil, and have them show me the valve cover leak and see if its at the same location as the starter.

  • Tina

    I have a 2002 kia sedona van. Pep boys is replacing the starter which they had done 7 months ago. They say it is because I have a valve cover gasket leak. Can this be true?

  • Austin Davis

    Not sure, oil can leak from many places, but since its a BMW it will cost about 4 times what it would cost with a Honda, Toyota, Ford etc. get the quote for repair so you know, then I would decide to keep and repair or cut my loss and re-sell it.

  • Penny

    bought a 2006 325ci bmw 3 weekes ago lady said it was great has had it serviced runs like new. well !! thats not true the same day engine light came on had the thermostat replaced, the mounting bushing replaced on right front and now took it in for brakes and oil change . didn’t have any leaks under car til now , have oil leak took back to mechanic and he put dye in to see where leak is coming from how much more will this cost me ?

  • Austin Davis

    Valve cover gasket leaks are pretty common starting at around this mileage interval….although usually they just “seep” a little oil onto the engine which causes a burning smell and maybe a little smoke under the hood. If they are actually leaking/dripping oil then its time to replace them. I would expect to see oil on the driveway if they are leaking, but sometimes the leaking oil tends to accumulate on the engine itself and only really drips when you drive on the freeway and the wind blows it off the engine onto the ground.

    I would have a mechanic look into this farther, and will usually require the engine to be cleaned off so the source of the leak can be identified. There are many seals and gaskets on the engine that can leak and make it difficult sometimes to identify the source when everything is covered in oil. Any repair shop should be able to fix this for you, and probably cheaper and faster than the dealer would.

  • Stephanie

    I have a 2008 Ford Fusion SEL with between 77,000-78,000 miles on it. The last time I took it to the dealership (Sticker on windshield states that it is due again this month or 81,000 miles)for my regular oil change they advised upon pickup that my valve cover were starting to leak. I checked my oil this morning & notice that it appears very low and I have recently (past day or so) noticed a burning oil smell. I see no visible leaks in any spots that i have parked my car in. Any suggestions?

  • Austin Davis

    Not really Andy, replacement is what is needed…although I would take a wrench and “snug up” the mounting bolts first and see what happens. They have a tendency to loosen up over time and just a little tightening can work wonders

  • Andy

    So I guess a can of oil leak stop would not really do much good for valve cover leaks?

  • Austin Davis

    No probably not. The jerking could be a problem still with the transmission or it could be an engine miss, like from a bad spark plug or spark plug wire type of problem. I would take a wrench and LIGHTLY tighten up the valve cover gasket mounting bolts, which can loosen up over time and cause the gasket to leak. The noise, could just be low on P/S fluid.

  • ericka

    i jus had my transmisson rebuilt on my 2002 ford focus n its makin lil jerks only goin 45mph n now makin a noise like the power steerings whinning noise wen accerlerating plus havrnt had an oil change n over 6000 miles n now i have oil on my valve cover gasket that i got replaced a yr n mth ago could n e of these resons b because of the jerkin

  • Austin Davis

    Hi there. I have not heard of this EXACT problem on this EXACT vehicle, but have seen similar issues with oil leaking onto sensors (like the speed sensor) and causing problems. I have not worked enough on the older Optima’s to know how much money we are talking about to do the repair. if the repair is more than $300 I might suggest you get a second opinion.

    Any oil leaking on any sensor is not good for the sensor and can cause sensor failure though. I do agree that a bad speed sensor can cause transmission shifting and check engine light problems.

  • Alisha

    Have a 2001 Kia Optima SE. Having problems with transmission shifting. Had car put on check engine light machine. Codes came back for Speed Sensors. Was told Pcv valve cover gasket and cam cover plate had to be replaced because oil was leaking onto speed sensors. Have you heard of or seen this problem before? And if so, what exactly do I need replaced?

  • Austin Davis

    First thing I would do is put a wrench on all the valve cover mounting bolts and see if you can snug them down just a little…just a little, not too much. Those bolts can work loose and the gasket under the valve cover can get squished and become thinner over time.

    Then I would buy a can of CRC Brakleen from your local auto parts store and spray down the area around the valve covers to remove the oil that has spilled on the hot engine..producing the smell. The product drys instantly and is non flammable and uses no water.

    See how long those ideas last until you notice the smell again, or can see fresh oil leaking

  • Carmen

    I was told that I have a really bad valve cover gasket leak last time I got an oil change, and I do sometimes smell a burning odor when I’m driving. From what you wrote, it would be considered a “seep” and not a leak (no puddles or variation in oil levels, etc.) A friend who knows about cars told me I don’t have to get it replaced, but the burning odor is new, and I wonder if that means I should replace it now. What do you think?

  • Austin Davis

    Thank you, glad it was helpful to you.

  • Matt

    Great info and suggestions!