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Is this normal for a 15yr old 2.5 with 100k miles?

1.6K views 15 replies 3 participants last post by  garyakirsch  
#1 ·
On cold starts im hearing a knocking sound from inside the car but it dies down when fully warm up
. Im using 5w30 oil and its full and its getting close to winter in my area so i don't think i need heavier oil but idk. Some ppl say the valves are slapping normal for old engine or belt tensioner doing the knocking. I need more advice, help b4 i go to a shop. The car runs fine and has decent power and good gas mileage.
 
#2 ·
It usually isn't valves on an aging QR25, piston slap is more likely. If so, they can do that for a very long time without any other ill effects, provided you keep up with good maintenance. My '04 beater with 160K+ has greeted me with slapping every morning since I got it, but with 3K oil changes, it will probably pass 225K before it gets bad enough to matter.
 
#5 ·
Not strictly, although stepping to 10W might quiet it down. That goes for most mechanical noises an engine might make. You probably don't want to go thicker than that, the IVT may start throwing codes. If the problem is slap, it happens because of wear in the piston skirts that allow them to "slap" the cylinder walls until the piston warms slightly and expands them into the bore. That's why the noise quickly vanishes after the engine starts and runs.
 
#16 ·
It may not be the engine. WHEN I bought my 09, every engine mount, the transmission mount, the dog bone torque arm, and catalyst flex coupling were all dryrotted and torn. After replacing them all kinds of ticking and banging noises went away. Download the manual so you can find and inspect the mounts.