Lifter noise is usually a message from your vehicle. “Hey, I need some attention”. Ranging from fairly minor–to go straight to the mechanic. Here are 7 noisy lifter fixes. You can easily take care of the first 3 yourself–quickly and inexpensively. The fourth option requires more time and effort. Numbers 5, 6, and 7 will probably require you to be a pretty good weekend mechanic–if you plan on tackling them yourself.
First, a little information on what lifters are, and why they make noise.
Noisy Valve Lifters
A faulty lifter usually signals itself with a quick, rhythmic tapping sound coming from the engine. It is easiest to hear while the motor is idling. The tapping noise will speed up when you increase engine RPM because the cylinder is firing more rapidly.
Quite often you will hear tapping when you first start the vehicle. Give it a few minutes to warm up and get the oil circulating before panicking. When the vehicle is sitting–specially for some time–your oil drains into the pan and while everything is getting lubed again, metal is moving against metal. If the tapping continues, then you might have a lifter problem.
Note: By the time you start hearing it, the lifter has probably been wearing out for some time.
What are Valve Lifters?
Valve lifters are also known as tappets or cam followers. They convert the camshaft rotation into a vertical motion to open and close valves. For more information please see Tappet – Wikipedia.
Valve lifters are finger-sized cylindrical parts (usually hydraulic) responsible for transmitting camshaft movements to the pushrods allowing valves to open and close as required. Which lets fuel into the cylinder and exhaust out of the cylinder. Nothing important. Right? They are also meant to quieten motor noise.
Hydraulic, self-adjusting lifters should last well over 100,000 miles. Mechanical, or solid, lifters need to be adjusted about every 30,000 miles–or sooner if they are making noise. These adjustments are needed because of wear in the valve train.
Note: Overhead cam engines do not use pushrods, therefore do not have lifters. If your motor is an overhead cam unit, you will have to continue your search for the tapping sound.
Why do Lifters Make a Tapping Noise?
Lifters can be noisy for a number of reasons. In no particular order:
- Low on oil
- Low oil pressure
- Dirty oil
- Incorrect type of oil–too thick or too thin
- Damaged push rods
- Improper lifter adjustment
- Worn lifters
Fixing Valve Lifter Noise
As with virtually all automotive repairs, your owner’s manual will be your closest friend throughout this process. It will give you:
- Oil type and weight
- Oil change schedule
- Maintenance schedule
- Parts numbers
- Schematic diagrams
Many vehicle owners have never opened the thing. You should not be one of them if you plan on tackling some, or all, vehicle maintenance on your own.
1) Change the Oil
Manufacturers recommend oil changes at regular intervals for a reason. Longer engine life. Less maintenance. They also recommend certain types of oil for the same reasons. No one saves money by going 20,000 miles between changes.
Note: It is not essential that you always use the same brand of oil–as long as it meets the manufacturer’s specifications. Some of us believe the truck will quit running if we don’t use our favorite. Mine is Quaker State 5W-20. Truck has never tasted anything else.
Hydraulic Lifter Noise
Hydraulic lifters have a small hole in the cylinder body to allow oil inside the unit. Oil is virtually non-compressible, so it is perfect for hydraulics. Dirt in the oil–usually caused by poor maintenance–restricts the free flow of oil. It can even clog the lifter hole. Without enough oil in the lifter, you will hear metal on metal tapping–especially on start-up. Get the motor hot, drain the existing oil, fill the motor with new oil, and take it for a drive. Quite often magic occurs, and the tapping will have disappeared.
Solid Lifter Noise
Although solid lifters need to be adjusted more often than hydraulic lifters, they also require clean oil for optimum quiet operation. There is not much point in taking off valve covers and adjusting them if you do not do the easy fixes first. Get the motor hot, drain the existing oil, replace it with new, clean oil recommended by the manufacturer, let it cool. When you start it again, listen for lifter tapping, and see how long it takes to go away. Solid lifters usually make a little noise on start-up. Especially if the vehicle has not run for some time. If the noise continues, you will have to move on to something else.
2) Flush the Engine to Clean the Lifters
Flushing and changing oil is a little bit of a chicken and egg thing. Which one first? If you are changing your oil regularly, you probably do not need to flush the motor out. (There is one school of thought that believes a chemical engine flush is never a good idea.) Before doing this, it is a good idea to consult the manufacturer, or dealership.) If you decide to use an engine flush like Liqui-Moly Engine Flush, be prepared for the possibility of oil leaks. Quite often, the sludge in your oil has formed on gaskets providing a secondary seal. Once the motor sludge is dissolved, gaskets that have never leaked before could start. Make sure to follow the instructions.
One way to avoid the leaking problem is to use a double oil change to flush the engine. Make sure the motor is hot, drain the old oil and change the oil filter, add new oil, run at high idle for 15 minutes (or take it for a short highway drive) to make sure it has circulated though everything. Drain the oil again and change the oil filter again, add new oil, and listen for any tapping noises. (Note: Let sit overnight so the oil all drains into the pan–then listen when you start it.)
Note: If you think the sludge and varnish build up is particularly bad (such as a vehicle that has only been driven around town for years), consider adding Marvel Mystery Oil (about 40% by volume) to your first oil change. The second oil change should always be the product recommended by the manufacturer.
3) Oil Additives to Eliminate Lifter Noise
One of the easiest, quickest, and least expensive options to quiet lifter noise is an additive like Liqui Moly 20004 Hydraulic Lifter Additive. It is formulated specifically to quiet hydraulic tappets. Works on virtually any vehicle including those with catalytic converters. Use one 300 ml can (just over a cup) per 1.5 gallons of oil. Works best when added with, or just after, an oil change. Take your vehicle on a short highway run after you have added it to ensure good mixing. The tapping should quiet down fairly quickly–and stay quiet, although you might have to add more after 3000 miles if the noise returns.
Note: Make sure you do not overfill the motor. I know that a couple of cups does not sound like much, but even in my Hemi that adds over a pint (about 7%) to the oil volume. And too much oil creates more pressure that can lead to blown gaskets and seals. The motor will also eventually whip the oil into a foamy froth that loses the ability to lubricate.
4) A Weak Oil Pump Can Cause Lifter Noise
A weak, or worn, oil pump will not provide sufficient oil pressure to allow the most efficient motor operation. Lack of sufficient oil can cause lifter noise from both hydraulic and solid lifters. And with many vehicles providing about 48 idiot lights instead of gauges, you may have to get an oil pressure test kit for a proper reading.
Note: Before cleaning, or changing, the oil pump, or even testing the oil pressure–make sure you have tried the first 3 options of changing oil, flushing out the engine, and using additives to try fixing the tappet noise.
Before doing a pressure test, make sure you check the oil first–cold and level vehicle. (You do not want to go to the trouble, then find out you are down a quart.) If the pressure is low, you will have to remove the oil pan to get to the pump. Assuming the pump screen is clean (allowing free flow of oil), you are probably going to have to replace the pump. Make sure you get the matching pump (see owners manual) and oil pan gasket. The job is not tough, but neither is it for the faint of heart; so if you are concerned about your abilities, take it to a mechanic.
Lifter noise can be caused by too little oil. If you have an oil gauge in the vehicle, and it is reading lower than normal, the problem might not be the oil pump. It may be too little oil to bathe every part of the motor. So, even if you are absolutely certain your vehicle does not burn, or leak, oil, check the level regularly when cold. You may find that keeping the oil level up to the mark solves your tapping problem.
Note: Being an old curmudgeon, I am convinced that you have about 5 minutes to get stopped after the idiot light comes on–before parts start coming through the hood, or falling out of the bottom. Of course, I might possibly be wrong, but I like gauges on the dash to give me an idea of what is happening, not a light telling me what just went wrong.
5) Adjust Lifters to Eliminate Noise
Solid lifters have a small space between them and the rocker arm–around 10/1000th of an inch. (The space is necessary to prevent motor parts from binding as they expand as the motor heats up.) This gap is known as valve lash, which when not adjusted properly, leads to lifter noise. To adjust the valve lash you will need to remove the valve cover to access your lifters. Your owner’s manual should tell you the amount of gap required. You will need a feeler gauge as you make adjustments to get the proper gap. Solid lifters will likely need to be adjusted by the time you get to 30,000 miles because of wear.
When replacing the valve cover, make sure you buy a new valve cover gasket or use liquid gasket maker to prevent oil leaks. And you have cleaned both cover and motor block well. (Installing a gasket on a dirty or oily or lumpy surface is just inviting leaks and a re-do.)
Note: The contact area between the cam lobe and lifter can have a pressure of 200,000 – 300,000 PSI (Pounds per Square Inch). So it is fairly important to use the proper parts and the recommended oil.
Hydraulic lifters are self-adjusting. They are designed to have no valve lash. Hydraulic lifters should last over 100,000 miles, but stuff happens; so they may need to be replaced before you hit that milestone. Because there is no way to adjust them, replacement is the only option if they go bad.
Note: My Hemi just passed 340,000 miles using the original lifters with no tapping, so I can attest to the ‘over 100,000 mile’ claims.
6) Replace the Lifters
If you are contemplating doing this job yourself, you probably know more about mechanics than I do. It is definitely not something you want to do without quite a bit of knowledge and a fairly wide assortment of tools. There are YouTube videos showing lifter replacement for almost every type of motor. Here is one for a Dodge Caravan. The job is relatively simple because the lifters are at the top of the motor under the valve covers. Many other lifters are down inside the motor–like my Hemi–which involves not only removing the valve covers, but the intake manifold, and virtually all accessories on top of the motor. Then replacing it all so it works.
Parts cost of replacing either solid liftersor hydraulic lifters will range between $200 and $400. Labor, if you take it to a mechanic, will be between $1000 and $1500 (probably 7 – 10 hours). So, if you are truly comfortable taking on the job, there is a significant savings involved.
7) Replace Damaged Push RodsPush rods are fairly tough and do not damage easily. But a person can do it–specially if she/he has a heavy foot on the gas pedal combined with a lousy maintenance record. Then they can be bent, which means the valves will not open, or close, fully. Meaning that performance and fuel efficiency are negatively affected. Also, you will probably hear tapping coming from the motor–either the rod hitting the the walls of the block, or the lifters tapping because the valve lash is too great when a bent rod is shorter than it should be.
Replacing push rods is essentially the same program as replacing lifters. It involves removing and replacing quite a few motor parts to access the rods, then replacing everything properly with new gaskets. (And maybe new bolts to replace the ones you broke taking it apart.) Here is a short YouTube video. Push rods are not terribly expensive. It is all labor again, if you are getting a shop to do the job. If you are doing the job yourself, it is a matter of having the time, a sheltered location, the tools, and of course, beer.
Take it to a Mechanic
If you are not mechanically inclined, just take it to a professional. The first 4 suggestions are fairly simple for a vehicle owner to accomplish. The last 3 require more time and effort. If you are not even certain about the cause of the noises you are hearing, it is best to take it into a shop and have it looked at. The mechanic may just put in an additive to quiet the lifter noise, or he/she may recommend new lifters. But at least you will have a better idea of your needs and costs. Which should, hopefully, make it easier to decide on what to do.
Even if you end up paying a shop $50.00 or $100.00 just to pour in an additive that works, you come away with some peace of mind.
Benefits of Fixing Noisy Lifters
Eliminating or reducing noise is not the only benefit of fixing lifters. Here are a few more.
- Combustion. Valve lifters help control the entire combustion process. If an intake lifter is not working properly, the correct amount of fuel mixture will not get into the cylinder. If it is the exhaust lifter, the explosion residue cannot all get out. Either problem will reduce gas mileage and performance.
- Related Damage. Ignoring lifter noise for too long can lead to other damaged parts connected to the lifters, such as rocker arms, valve tips, and push rods. Which, of course, has the potential of causing more damage.
- Financial Damage. Faulty valve lifters tend to be a ‘pay now or pay later’ issue. Pay now can be expensive and/or time consuming if replacement is required. Pay later can be really expensive and/or more time consuming if there is added damage.
This is just a personal rant. Other sites I have looked at tend to suggest that changing lifters and rocker arms is not much tougher than changing your underwear, and pass it off as ‘just change them’ in a couple of paragraphs. I do not believe this is helpful to the reader. Changing lifters and rocker arms can be long, involved jobs requiring time and talent. Not to mention a fair bit of cash if you have it done professionally. You should know that.