That irritating ticking sound is hard to ignore, and it’s especially irksome when you are not sure if you should continue driving or take it to the shop.
Continuously driving a truck with a bad lifter will damage the camshaft and could result in total engine failure.
In this post, you’ll learn why you should fix a noisy lifter as soon as you hear that telltale ticking noise and why ignoring it could be very costly.
What is a Lifter
Lifters come in two forms solid and hydraulic; we’ll look at the hydraulic type since it’s the most common type today. Broadly, a lifter is a small metal component located in the valvetrain between the camshaft and the valve. It may be acted upon directly by the camshaft or indirectly via a pushrod, depending on the engine design.
Its function is to aid in opening the valve at the correct time and by the correct amount. Each valve has its own lifter, so at least two lifters per cylinder.
The hydraulic lifter acts as a self-adjusting cushioning shim. It’s cleverly designed to adjust automatically to the correct clearance, somewhere around .006” between the camshaft and the valve.
In a cold engine, the clearance between the valve and camshaft tightens as the engine heats, and as an engine ages, the clearance between the valve and cam naturally increases. Hydraulic lifters make allowances for these changes automatically.
Older engines with manually adjustable lifters are prone to noisy lifters on initial engine starts but quieten as the engine warms. However, old-school lifters do require regular manual valve adjustment as the engine ages.
The hydraulic self-adjusting lifter solves both these problems using a clever mechanical valve and some oil pressure. Engine oil routed to the lifter fills it with oil causing it to expand, which fills the clearance between the cam and valve. As the lifter is compressed by the camshaft, the oil is trapped momentarily inside the valve, causing it to lock and act on the valve, opening it.
The lifter acts as a sort of shock absorber, quieting the mechanical process of the camshaft pressing on the valves.
Why Lifters Fail
Lifters fail mostly because of age but an engine with a poor oil service record or incorrect oil type will for sure shorten lifter life.
But there are other reasons why a lifter may not be working; not all, by the way, are the lifter’s fault.
- Dirty, poor-quality oil
- Excessive oil level – Too much oil can cause aeration of the oil, which prevents oil pressure from building inside the lifter.
- Low oil level – Self-explanatory
- Faulty oil pump – Poor oil pressure caused by a faulty oil pump means oil pressure isn’t reaching the top of the engine where the lifters live.
- Worn-out engine – In this case, worn lifters aren’t your biggest concern.
Mechanical debris in the oil will destroy the lifter seals and cause them to fail.
Why Do Lifters Make Noise
Lifters make noise because they aren’t expanding to take up the available space between the valve tip and the camshaft lobe. Wear and tear is a common cause o lifter failure. The valve doesn’t last forever; the seal eventually gives way, which means the oil-filled valve no longer cushions or fills the gap between the cam and lifter.
This allows the cam lobe to hammer the lifter on every revolution, which causes the ticking noise.
How to Diagnose a Faulty Lifter
Engine ticking noise is usually a good indication of a faulty lifter. In the shop, we use a stethoscope to determine which cylinder is to blame. Having the engine idle while placing the probe above each cylinder in turn and carefully listening for the noise to increase or decrease as we check each cylinder.
On a V engine, the stethoscope will at least determine which bank is at fault; it then requires rocker cover removal and checking for the loose rocker to determine which lifter has failed.
Of course, it may well be that you have more than one faulty lifter, and in many cases, that is exactly the case. When one lifter fails, the others may soon follow. Remember, your engine has a lifter for every valve, so you’ll have at least two lifters per cylinder.
Symptoms of a bad lifter vary by engine type and how bad the lifter is; common symptoms include the following:
- Tapping noise – top of the engine
- Banging noise – top of the engine
- Misfiring engine
- Power loss
- Engine light on
- Rough idle
- Stalling
- Bad gas mileage
How to Fix a Noisy Lifter
Lifters depend on oil to perform; low, dirty, or wrong oil type can cause lifters to make noise, and if ignored, can then cause the lifter, camshaft, and valve to become damaged.
Since oil plays such an important part in lifter performance, it is worth trying an oil inspection. Check the level and quality. As said earlier, low oil levels, excessive oil levels, poor quality oil, wrong oil type, or bad oil filter will all affect lifter performance.
It is work changing the oil and reassessing lifter performance.
If an oil change doesn’t help any, then it is likely your lifter is faulty, and the only repair is to replace it, and likely better to replace them all. As said, once one fails, likely, others may too.
How to Replace Lifters
Replacing lifters on most engines will require a fair deal of engine stripping. Some engines will require head removal, and others may require cam removal, depending on the engine. But do check the net for a creative way to replace yours; there are some hacks for overhead cam engines that don’t require cam removal.
If your engine requires head removal, you’ll need new head gaskets, head bolts, manifold gaskets, plenum gaskets, rocker gaskets, fresh coolant, and an oil change.
How Much To Replace Lifters
Prices for replacing lifters will vary by the make, model, and type of lifter. Some engines with cylinder deactivation may use two types of lifters, and prices for those types of lifters are more expensive.
Take, for example, the Chevy 5.3, a lifter kit may run in the region of $500 to $600, and GM say to replace one bank expect about nine hours of labor, with labor running at $80 per hour, you are looking at a bill in the region of $720 for labor assuming all goes smoothly (no broken manifold bolts, etc.).
Doing both banks, then you can double up that labor cost and add the lifter kit for a total price in the region of $2000.
What Happens if You Ignore a Noisy Lifter
Ignoring a faulty lifter can be an expensive one to fix. And sadly, it’s one I see pretty regularly because, in the beginning, the truck drives just fine, and in the beginning, the noise goes away after a short while as the engine warms up. Increasingly as you become accustomed to the noise, you fail to notice it takes longer and longer to go away. That’s usually when the real damage is done.
The ticking noise is the camshaft lobe playing pin pong with the lifter, the camshaft or valve usually comes off worst, and they are both expensive to replace when compared to the lifter.
It also causes metal filings to pass through the engine, which can cause the cylinder head and camshaft n wear which in older engines means they are beyond economical repair.
Sun Up
A ticking noise is a common sign of worn-out lifters; that said, poor quality oil or low oil level will prevent a good lifter from operating correctly. If a lifter is faulty, changing it immediately will prevent camshaft damage and significant additional expense.
Ignoring the faulty lifter will eventually result in engine failure as metal filings from the lifter and camshaft will act like sandpaper on the engine’s innards.