ClubLexus - Lexus Forum Discussion

Lexus IS/GS: Why Does My Engine Crackle When I Start My Lexus?

A common issue with the Lexus IS and GS is a crackling noise. Learn what this might be and how to fix it.

By Brett Foote - January 5, 2015

This article applies to the Lexus IS and GS (2005-2014).

Does the engine in your Lexus IS or GS make a crackling noise when you start it? This is a pretty common issue that unfortunately has several possible causes. Some of them are directly related to an issue with the cam gear (which caused a recall), the exhaust or catalytic converter, and other engine-related problems. Here is an assembled list of potential causes that can cause a crackling noise upon starting your engine. Take a look and see which one might be the cause of your particular problem. Depending on the root cause of the problem, this could be a free repair.

Step 1 - Try a different engine oil

The solution to an engine that crackles could be as simple as changing the type of oil you use. Some forum members have reported switching from conventional oil to synthetic and noticing the problem disappear. With maintenance contracts, dealers will often use conventional oil in these cars to save a few bucks. It's also important to use the proper weight of oil. A heavier-than-recommended oil will cause problems with the hydraulic lash adjusters that can lead to noise upon start-up.

Figure 1. Remember: use synthetic 5W-20 oil.

Step 2 - Check for recalls

If you have a third generation Lexus GS, there are a couple of recalls you should be aware of. There are two additional recalls that could be causing the crackling problem: one for valve springs and one for VVT cam gears.

Some models had issues with valve springs. They were prematurely fatiguing and breaking, causing a drop in compression in that particular cylinder, which causes a lot of noise as well. The cam gear recall was issued because its bolts were backing out over time and rattling around behind the timing cover. This throws off the vehicle's timing and makes a lot of noise as a result.

Either way, take the vehicle into the shop if the noise is coming from the valve train area.

Figure 2. 2GR-FSE with removed valve cover.

Step 3 - Check the exhaust

Many users who have installed aftermarket exhaust on their Lexus report that they have a crackling noise, particularly in cold weather. If this is the case with your car, it is completely normal. As cold air is sucked back into hot tailpipes, there is going to be a bit of crackling. The same goes for catalytic converters, which have a habit of making a crackling noise when they are warming up. This is not a cause for concern.

Figure 3. View of the exhaust and catalytic converter.

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