Noise at Start Up

[Tedward]

I'm noticing a noise when starting my 2010 4Runner, it's immediate and quick and only happens when the engine is cold. It almost sounds like an engine knock, thinking oil pump? maybe timing chain? anyone else experience something like this? I can let the vehicle sit for an hour or so to try and re-create it but it seems to occur most when sitting for multiple hours which leads me to believe it's oil circulation related. No other symptoms other than when starting. 126K for mileage, nothing major needing to be done to date, just routine maintenance, tires, brakes etc.

 

[Biggcrisp]

I'm noticing a noise when starting my 2010 4Runner, it's immediate and quick and only happens when the engine is cold. It almost sounds like an engine knock, thinking oil pump? maybe timing chain? anyone else experience something like this? I can let the vehicle sit for an hour or so to try and re-create it but it seems to occur most when sitting for multiple hours which leads me to believe it's oil circulation related. No other symptoms other than when starting. 126K for mileage, nothing major needing to be done to date, just routine maintenance, tires, brakes etc.

Thank you for sharing your mileage. My 4runner start and immediately gets shifted into drive to pull out of the garage. Then it sits in the driveway for a few seconds idling. As a comparison; mine has zero knocks, ticks or strange noises currently at 26k miles.

FWIW low end knocks are slow(ish). Lifter ticks are faster. Exhaust manifold leaks can sound just like a lifter.

How many miles on your current oil change? If close to needing changed that could be the place to start if it is a lifter bleeding off.

I believe a Toyota could run for many thousands of miles even with a constant knock. Just saying…

 

[Tedward]

Thanks for the reply! we're about 6K into the last oil change, I do them at 7500 mile intervals now instead of the recommended 10K. I will check the exhaust manifold to be sure. Like I said, it's very quick but once over there's no other knocking. Agree on going thousands of miles, we had a Tundra with over 200K before we purchased this 4Runner.

 

[jordan_tm]

My '06 Tacoma started making knocking noises (primarily in the winter months) after it got over 100,000 miles. It would continue on until the engine warmed up completely. I had it checked by a couple of places and no one could ever find anything wrong with it. It never affected the driving or anything but it was enough to annoy. Even after I traded it in for my T4R nothing was found to be wrong.