April 12, 2013 by quirkyuncle
Some BMW six-cylinder engines from the mid-2000s exhibit an intermittent and annoying lifter (tappet) tick. If your BMW is ticking, solving the problem might be easier than you think.
Variants of the BMW six-cylinder engine are consistently rated as one of the top automobile motors. It is a proven design that has been in use for many years, evolving steadily over time. It is a really great engine, which is why the whole ticking lifter problem is so unusual. You can hear what it sounds like here.
What are lifters?
Lifters are used to open the intake and exhaust valves in most gasoline powered cars and trucks. The valves are held closed by strong springs and pushed open by elliptical lobes on a rotating camshaft, allowing the air/gas mixture in and the exhaust gasses out of the cylinder at precisely the right time. The lifters fit between the camshaft and the valves and transfer the force needed to open the valves. Lifters are of two basic types: solid and hydraulic.
- Solid lifters have no moving parts and must be manually adjusted as part of routine engine maintenance.
- Hydraulic lifters (BMW calls them Hydraulic Valve Adjusters or HVAs) are self-adjusting, making them a good choice for use in most vehicles. The hydraulic lifter has upper and lower sections that are held apart by oil pressure. The oil is pumped into the lifter while the engine is running to push the lifter halves apart, leaving no play between the camshaft and valve.
Why do lifters make a ticking noise?
Lifters tick when they are out of adjustment.
All solid lifters tick when the engine is cold and get quiet once the engine gets up to temperature, causing the lifters to expand to their normal running size. If solid lifters tick when the engine is hot, you need to adjust them. Adjustments are made when the engine is cold by setting a precise gap between the camshaft and the lifter that will close predictably to specifications when warm.
Hydraulic lifters are self adjusting. They will tick when something causes them to lose their internal oil pressure. Pressure loss can occur if the internals of the lifter become dirty from not doing routine oil changes. It can also occur if you don’t use oil of the proper weight, causing it to bleed out of the lifter when the engine is off or not pump in fast enough when you turn the engine on. Pressure loss can also be caused by a malfunction of the lifter, where it becomes unable to hold pressure. Keep in mind that when an engine stops, at least one valve inside of it will be open, meaning that the camshaft is holding is this valve open against strong spring pressure; this spring pressure, in turn, tries to force the oil out of the lifter. If a lifter is not sufficiently pressurized when a motor turns off, it loses its pressure more easily and ticks more readily when the engine turns on.
What is the official BMW solution?
BMW does acknowledge that these lifters are ticking. They consider it somewhat “normal,” which in all honesty is half true, as you will see below. Note that “normal” does not mean the condition should be ignored.
The first thing BMW does when a car is brought in with ticking lifters is perform the lifter bleed procedure, given below. From what I can see, the bleed procedure seldom yields a permanent solution. Next, if the customer pushes hard enough, BMW will replace all the lifters in the cylinder head. Lifter replacement is a costly repair and BMW is quite reluctant to do it. From what I can see, lifter replacement only solves the problem in some cases. Lastly, if a customer continues to pursue the problem, BMW might replace the entire cylinder head with one of a new design. BMW hates doing this, because it is super expensive. Replacing the cylinder head will, however, solve the problem every time.
Lifter bleed procedure:
BMW SIB 11.09.07
Metallic Ticking noise coming from engine? – BMW 3-Series (E90 E92) Forum – E90Post.com
SI B 11 09 07 Engine
This Service Information bulletin supersedes SI 11 09 07 dated April 2008.
Intermittent Hydraulic Valve Adjuster (HVA): “Ticking” or “Rattling” Noises
All E82, E83, E85, E86, E88, E60, E61, E70, E90, E91, E92, and E93 with the N51, N52 or N52K engines
An occasional ticking or rattling noise from the HVA elements may occur during cold engine starts or frequent short-distance driving.
In these situations, the HVA elements may not yet have been supplied with sufficient amounts of air-free oil. This condition will not cause any damage to the engine, and usually remedies itself with a longer driving distance or operating times at full operating temperature.
In the event of a customer complaint, please perform the following the HVA bleeding procedure.
The bleed time may take anywhere from between two minutes and (in rare cases) to a maximum of 30 minutes. This procedure is to be performed on a level surface with the vehicle stationary, and in a properly ventilated area.
Engine oil level correct – neither underfilled nor overfilled
Engine running at operating temperature
1.) Bring the engine up to an operating speed (no load) of 2000-3000 rpm and maintain this condition for three minutes (bleeding procedure).
Let the engine idle for 15-30 seconds and reevaluate whether the noise is still present or not.
2.) Engine quiet – procedure is finished.
3.) Engine noise is still present – repeat the procedure; perform steps #1 and #2 up to a maximum of 5 times.
4.) Only if the noise remains after performing the bleeding procedure 5 times: proceed by performing the procedure for a final time, also at an engine operating speed of 2000-3000 rpm, but for a total time duration of 15 minutes.
Covered under the terms of the BMW New Vehicle Limited Warranty.
What did I find out?
My 2007 Z4 3.0i started ticking intermittently just over a year ago, after it was out of warranty. The problem would come and go, seemingly at random. If it started ticking, the problem would go away after my 25-mile commute or after performing the lifter bleed procedure. It really did annoy me, though, so I did a bit of research.
At that time, the problem could be found all over message boards for BMW user groups in the USA. When I located some user groups that were in Europe, I could not find a single mention of the lifter ticking problem. Not one. I thought this a bit strange.
From what I can tell, the engines used in the US and Europe are the same with regard to cylinder head design. BMW also specs the same oils for use in the US and Europe, although I suspect many people are not using the correct oil in the US unless they have the change done by their BMW dealer, or are really careful about purchasing oil that meets all BMW specs. (You can find the correct oil through local retailers, if you look for it. The correct oil just costs a bit more.)
So, what is the difference between Europe and the US? I think it’s the way we drive.
Personally, I found a correlation between rises in gasoline prices and re-occurrences of lifter ticking. When gas prices go up, I drive more sedately to save fuel, and suddenly my lifters get noisy. Hmmm…
Could it be that folks driving BMWs in the US need to drive them harder? I think this is the case.
- Think of the home markets. In the US, we grew up with big, lower-revving 8-cylinder engines: in Europe, there have been a lot of small, high-revving 4-cylinder engines for years. Europeans have a tendency to rev their cars up higher.
- Think of buyer demographics. In Europe, BMWs are a domestic brand with a higher level of performance. The police drive them, as do regular people who like to drive spiritedly. In the US, BMW is a status brand, with many buyers purchasing them to impress and not necessarily for the awesome driving experience they provide.
- Think of the roads. Autobahn vs rush-hour urban traffic. Enough said.
So, I did an experiment
- Part 1: Keep the RPMs at 2000 or above during normal driving, with routine gear changes in a higher RPM range (above 5000 RPM). You are able to easily accomplish this, even around town, without violating any laws. Result: no lifter tick, at all, for months.
- Part 2: Purposefully drive at lower RPMs. Within a few days, the tick was back. It magically vanished as soon as I returned to the higher RPM driving style.
Lifter tick, or lack thereof, was never impacted by the age of my oil, which I always change at the 7500-mile interval. I will admit that my gas mileage did drop around town by about 1 MPG when driving the car harder. It’s not a big deal and you can more than offset it by switching to a more efficient air filter (see Review: aFe Pro Dry S Air Filter
I don’t know if driving more enthusiastically (obey all laws!!!) will stop your lifters from ticking as well as it does for me. Give it a shot. It is pretty much the ultimate no-cost fix.
Remember, this topic is only discussing lifters that tick intermittently. If yours tick all the time or if the bleed procedure does not make them stop ticking, this could be indicative of a bigger problem. If in doubt, talk to your mechanic.
Good luck! If you try it, please leave a comment and let me know how it works out for you.
But, wait! There’s more!
I’ve discovered that using a motor oil certified as meeting BMW LL-01 specifications also eliminates lifter ticking in my 2007 BMW Z4 3.0i. See DIY – Choosing the correct motor oil for your BMW for details.
Updated 24 June 3013: Added link to Review: aFe Pro Dry S Air Filter
Updated 10 September 2013 – Added ‘tappet’ as alternate term for ‘lifter’.
Updated 15 September 2013 – Added info about oil.
Category Automotive, DIY | Tags: BMW, E60, E61, E70, E82, E83, E85, E86, E88, E90, E91, E92, E93, HVA, hydraulic lifter, hydraulic tappet, Hydraulic Valve Adjuster, lifter bleed, lifter knock, lifter noise, lifter tick, lifters, N51, N52, N52K, tappet, tappet bleed, tappet knock, tappet noise, tappet tick