Timing Chain Wear

New Technology Offers New Opportunities To Excel

Timing-chain wear is the latest challenge facing the industry.


Back in March (2018), I told you about a problem surfacing among some turbocharged gasoline-direct-injected (T-GDI) engines: timing-chain wear.

Experts think soot is to blame. Although most people associate soot with old-fashioned diesel engines, a modern T-GDI engine can produce more soot than an older diesel not equipped with a particulate filter.

Life is often a series of trade-offs, and engine design is no exception. The industry is willing to accept a little soot in exchange for improved fuel efficiency and performance.

Well, a little soot is turning into a big problem for some drivers.

Soot can accumulate in the motor oil in T-GDI engines. The tiny particles can agglomerate into larger wear-causing particles that cause problems inside your engine before the oil filter has a chance to capture them. These particles appear to be causing accelerated timing-chain wear on some vehicles. In fact, Ford* issued a technical service bulletin (#14-0194) that acknowledges timing-chain wear as a problem in certain vehicles equipped with its popular 3.5L EcoBoost* engine.

If you’ve never seen an automotive timing chain, they’re similar in design to a bicycle chain but far more robust.

Close-up of Timing Chain Links

A series of links are connected by pins on which they pivot. Soot particles can lodge in the tiny clearances between the links and pins. They slowly scour the metal surfaces as the engine is running, enlarging the clearances.

After a while, the timing chain stretches. It doesn’t “stretch” like a rubber band; instead the enlarged clearances between the links and pins create slack, effectively increasing the chain’s diameter. Soon your roughly 43-inch
(109.22-cm) timing chain becomes a 43.1-inch (109.474-cm) or larger timing chain. While the tensioner can take up some of the slack, it has its limits.

If the chain stretches beyond the capability of the tensioner, the camshaft and crankshaft sensors can trigger an engine code and even send the engine into “limp” mode.

To combat this problem, the industry has developed a test specifically to measure an oil’s ability to resist soot and fight timing-chain wear. It’s scheduled to become part of API SP and ILSAC GF-6, the next generation of motor oil specifications. Those specs aren’t slated for introduction until 2020, however, and don’t be surprised if they’re delayed (again).

Well, we don’t wait around for the industry to catch up to problems – we develop solutions now. The current Signature Series Synthetic Motor Oil formulation is a prime example. We kept timing-chain wear in mind when we reformulated it last fall.

Even though passing a chain-wear test wasn’t required at the time, we subjected Signature Series to the Chain Wear Test at an independent third-party lab anyway. Although the test was still under development and hadn’t been finalized, we wanted to run it anyway to get out front of timing-chain problems. The test used a Ford 2.0L EcoBoost engine run a total of 144 hours for 54 cycles. The timing chain is measured prior to installation, after break-in and following the test. Results are reported in percentage of change in chain length.

How did Signature Series perform?

Bear in mind that the test and the allowable limits are still under development, but I’m happy to say Signature Series allowed just 0.05 percent change. It beat the proposed standard by more than 50 percent. By the way, the chain image shown here is the same timing chain we tested. You can see how great it looks.

This is yet another example of how we’re pacing the industry. We were one of the first, if not the first, with oils that provided 100 percent protection against low-speed pre-ignition (LSPI),1 another problem plaguing the industry. We introduced the new SEVERE GEAR® easy-pack, an industry first. And now, while the industry wrestles with the problem of timing-chain wear, we already have a formulation on the market that helps solve the problem. That’s just another example of why AMSOIL is “The First In Synthetics®.”

1 Based on zero LSPI events in five consecutive tests of AMSOIL Signature Series, XL, and OE 5W-30 Motor Oil in the LSPI engine test required by the GM dexos Gen 2 specification.

This article from the October 2018 issue of the AMSOIL Dealer Magazine.

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