Can I drive my car if the engine has Hydraulic Lifter Ticking?
September 9, 2013 8:01 PM   Subscribe

The "tappets" or hydraulic lifters in my ten-year-old Hyundai Elantra have started making noise. tap tap tap tap tap tap tap tap tap tap.

People tell me to stop driving it completely, to sell it to the junkyard.

But does anyone with experience know, can the vehicle be driven even with the hydraulic lifter ticking?

And when the engine fails completely, how does it fail? Explosion? Leaking oil? Failure to start?

And if you are driving on the highway at 60 miles per hour when the engine finally fails, what happens?
posted by shipbreaker to Travel & Transportation (12 answers total)
It will throw a rod:

If it happens at 60mph, according to the second link it'll pop out of gear if manual or just start coasting if it's an automatic. Either way, you'll be stuck on the highway and the car will be dead.

You can drive it. It will just be a mess when it breaks.
posted by thylacine at 8:10 PM on September 9, 2013

I assume you've checked the oil level? The lifters will tick if the oil level is very low (like empty).
posted by ryanrs at 8:18 PM on September 9, 2013 [1 favorite]

That seems to be a little extreme of a conclusion to jump to immediately, thylacine.

It may just need a valve lash adjustment or a good cleaning with a high-detergent cleaner in the oil.

An old mechanic's trick:

Pour about a pint of automatic transmission fluid into the oil and idle the car until it comes up to operating temperature, and then let it idle for about 5 minutes. Change the oil (and filter!) immediately, and then again within 1000 miles.

This is effective for cleaning out sludge, etc, which can plug hydraulic lifters. It works because all automatic transmission fluid is is a very high-detergent lubricant.
posted by pjern at 8:23 PM on September 9, 2013 [2 favorites]

I had a timing belt fail while driving. It was an interference engine, so the pistons hit the valves. It made a pretty awful metallic breaking noise and I think I instinctively pressed the clutch. It happened on a surface street. I pulled over down the road and stopped with no drama or danger.
posted by ryanrs at 8:23 PM on September 9, 2013

2nd ticking often means you need oil, there is possibly a leak.
posted by catatethebird at 8:25 PM on September 9, 2013

do try changing and filling the oil first, might fix it, if not:

A tapping hydraulic valve lifter is no big worry. When they start tapping they have failed and what it means is that the rocker arm is hitting the valve stem (or something in the valve trim has too much clearance and is hitting something). Lifters are part of the system that opens the tappet valves in the engine but they are NOT timing belts, nor are they connected in any way to the rods or crankshaft. The 'hydraulic' part is that they fill up with oil from the pressurized oil system that lubricates the engine and take up the correct valve adjustment in the engine, solid lifters don't have this feature and the valves have to be adjusted periodically.

What makes them fail is usually either oil that isn't changed frequently enough or letting the car run too low on oil at some point. NOTICE: this doesn't mean it was immediate, maybe you, or some prior owner, ran it low or dirty at some point and it just now is failing.

Does the noise just last till the engine warms up? or is it constant? or just under load(like climbing a hill?) If it is only when cold or under load you are probably running too heavy an oil in the engine, and going with a lighter oil or a synthetic might fix it (worth trying anyway actually). What it means is that eventually that cylinder is going to stop working and you will then get a miss, and have to replace the engine (you can't really overhaul most engines in Asian cars for various technical reasons and it is cost prohibitive over a junkyard/second hand engine anyway).

Sometimes the tap, tap, tap can be thrown rod, but that is a usually a faster, deeper thrum, not a tap, tap, tap (although they do sound a little similar to the untrained ear). And either failure is usually traceable to the oil.

Either way, you can drive it till it stops working with no more damage to the engine than has already occurred (i.e. it needs replacement or major repair to fix the problem). You might find a mechanic willing to try to change the lifters, and if so make sure they change the head gasket, valve cover gasket, timing belt and water pump why they are in there, but also get a quote on putting in a replacement engine as well as compare the price.
posted by bartonlong at 8:43 PM on September 9, 2013 [1 favorite]

When the lifters start ticking it means the valves do not open as far as they did when they were working right. A hydraulic lifter is meant to diminish the "lash" or lost motion in pushing it, and the valve, by means of the lobes on the camshafts. Losing that valve action gives a minor decrement in performance only.

As stated above, it could be the lifters don't have an adequate oil supply. It could be from several sources. There could be gunk (sludge, or decomposed oil) in the small ports where the oil is meant to be replenished. In that case running a lighter, high-detergent oil is the ticket because those small ports might open back up. The mechanic's trick pjern notes works that way. It could be the oil galleries that bring the oil to the lifters are sclerotic because of the same kind of sludge.

There is a one-way or check valve in the lifter that ensures oil gets in but gets out only very slowly and those passages are tiny. Un-sticking them is not so easy, but you might get lucky.

As a risk/benefit trade-off I second pjern. A ten-year-old Elantra might repay a replacement engine, might not, but try running the ATF for a while, drain it, and replace with the lightest weight oil specified in the owner's manual for a few hundred miles. If the noise diminishes, you are on your way to a cure.
posted by jet_silver at 9:08 PM on September 9, 2013

Seconding that it's not necessarily a big deal. But some engine designs may, for reasons that I don't truly understand, tolerate this more poorly than others. However, I do know that classic SAAB owners encounter this and are typically told to defer it until there's something more serious that requires opening up the engine. And those are interference enginges--if the timing chain breaks you're in trouble.

My memory is hazy, but I think I received the same advice about some tapping/ticking in an early 90s Jeep Cherokee LTD (4.0L HO v6, selectrac).
posted by snuffleupagus at 9:51 PM on September 9, 2013

How do you know it's lifters banging around in there? Could be an exhaust leak -- ridiculously, they can sound like tapping noise. Could be any number of other things clattering around.

Probably won't hurt to try Pjern's trick, to clean everything up, though that could also clean up things that you maybe wouldn't want cleaned, like if the rings are sealed by glop and now all the sudden they're clean, could lose some compression.


Let's say you're my family member but in another city. I'd suggest that you go to Get the best mechanic they have in your part of town, the one with TONS of really high recommendations. Ask that guy for diagnostic on your car, what he thinks needs to be done, if anything. Buy him coffees and donuts for him and his guys if you go there in the morning, nothing wrong with a little bit of bribery between friends, right?

Good luck.
posted by dancestoblue at 12:26 AM on September 10, 2013

I would try a high detergent oil change and if that didnt work ask a mechanic. Replacing the lifters might be economically viable if thats what it turns out to be. It is unlikely but possible that the problem will cause extensive engine damage.
posted by BenPens at 1:59 AM on September 10, 2013

I've driven cars for months with ticking lifters, but with so little knowledge, how can you be sure that is it? As mentioned, exhaust leaks (at the headers) sounds like ticking, as does injector failure. If it is a light duty sounding tick and the oil level is fine, it is possible to drive it with no issues but there is no real way of knowing if it is ignorable without knowing what it is.

A ticking lifter (and it CAN NOT be adjusted if it is hydraulic) means it is running without the full range of travel. It may be that you can replace the lifter and all is well. If you leave it too long then the wear produced can create metal shards/bit/detritus that takes the rest of the engine with it. It's a gamble. If you are planning on junking the car soon, then check the oil and drive it and start looking for another car. If not, check teh oil and drive it as little as you can until you can get it diagnosed/fixed.
posted by Brockles at 5:37 AM on September 10, 2013

If it is a quiet tick, like tapping a metal filing cabinet with something metal, don't worry about it. Get a Hyundai branded oil filter and have the oil changed. That should shut it up. There is a known issue with non Hyundai oil filters in Hyundai engines.

If it is a loud tick, more like a large ball bearing dropping on granite, or tapping concrete with a hammer, I would take it to a mechanic.
posted by gjc at 6:20 AM on September 10, 2013

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