19/01/2024
Why Timing chains stretch??
Air filters could lead to timing chain stretch. We've been corrected multiple times in previous articles - "timing chain wear"- but the most common term people use is "stretched". With the combination of a poor oil filter or incorrectly specified oil, this really starts to reduce engine longevity.
In our timing chain series, we've gone over what a timing chain is, the reason why modern vehicles contribute to excessive or accelerated timing chain wear, the importance of the correct type of oil, and the importance of the correct engine oil filter.
Understanding filter elements and their performance is crucial for ensuring the longevity and efficiency of internal combustion engines. With that being said- air filtration for the engine is a concern if ignored. Let me explain.
An engine air filter's job is to keep dirt and debris out of the engine as it draws in air for it to function. Just like the oil filter, it's job requires it to filtrate at a micron level. A typical air filter will work with 99.9% efficiency and filter above 5-6 microns.
On our previous articles, we talked about oil filter performance and their ability to filter the oil in (best case scenarios) around 20 microns; and remember- a human hair is about 50-70 microns thick. We're talking extremely small particles here.
So let's take a 3 liter engine in a BMW. At its maximum RPM it'll consume 10,500 liters of air per minute. To visualize this better- Take a typical 2 car garage. That BMW engine will consume all of the air in the garage in a little over 10 minutes.
Obviously you aren't running the engine at maximum RPM all the time, but you can understand that cruising on the freeway for an hour it would consume that above mentioned garage's volume about 2 times.
So here comes a curve ball- The effectiveness of an air filter tends to improve as dust accumulates on its surface, reaching an optimal point just before the filter requires replacement.
It is crucial to let the air filter fulfill its function adequately and avoid premature changes. In essence, an air filter that completes its lifespan tends to perform better than filters that undergo more frequent replacements.
So in essence- A new air filter does ok, a used air filter does better, and a dirty/clogged air filter needs to be replaced.
Oil analysis reports (we've done hundreds of them) show a dirty air filter as a culprit to excessive engine wear. Compound this with the wrong oil and low quality oil filter and you've got a recipe for timing chain wear.
A heavily clogged air filter has shown negligible affects on fuel mileage- only about 1-2%. Performance on the other hand show significant acceleration losses.
On average, studies suggest an accumulation of 60 grams of dirt over 30,000 miles for the typical street vehicle.
Which brings me to a way of measuring how clogged your air filter is. I don't understand why manufacturers only install air filter restriction gauges on Domestic Diesel trucks.
This is truly the only way to know if the air filter is coming up to, or has surpassed it's useful life; by looking at the restriction of air through the filter WITHOUT disturbing it. Remember, disturbing the air filter and its housing will shake dirt and debris into the air intake tract, and by doing so essentially does more damage than good if this is done multiple times over it's lifetime.
Since I'm talking about Diesels- There is a term called "dusting". It's exactly what you think. Diesel engines rely on compression to run. When poor maintenance, a dirty air filter, or air tract leaks cause unfiltered air to get into the engine, it'll wear the engine enough to where it won't start.
The engine loses enough compression for hard starts in the morning. It may end up stop running all together.
So this is the final series of this set. To summarize-
Dust gets in the engine. The engine consumes it. The dust gets in the engine oil. The (low quality) oil filter doesn't clean the oil correctly..... and that's how an air filter can contribute to engine timing chain wear.
If you need your air filter changed, or would like to get service in the Workington area, please let us know or call us 07455387909 and we'll get you all sorted out.
