Tongyong19

Hello All

Just bought a 1999 LS 400 with 120k miles. Great when driving, very quiet and comfy. My only concern right now is at initial start up and idle, the engine is a tad loud and just want to see if that's normal for the car to warm up+ higher mileage. I have a 08 Toyota Highlander that sound very similar during warm up as well.

Thanks in advance

timmy0tool

iTrader: (7)

the car holds the revs higher when the engine is cold to promote a faster warm up time. this is normal as you pointed out in your highlander. it should eventually idle to the regular speed once warm.

the LS is very well insulated so you shouldn't be able to hear much unless at the upper RPM range, so i hope you don't have an exhaust leak. it's very unlikely that that mileage.

Tongyong19

Ran a can of SeaFoam through it and the engine is quieter during idle now. Thanks for the reply.

Losiracer2

you could have a bad thermostatic clutch fan spinning off the engine. Mine was seized or almost seized and it wouldn't disengage the fan even when cold, So my engine basically sounded like a mac truck when started with the fan blowing hard.

it should be easy to spin when cold or when the engine is off. if it isn't then you know the fan clutch is no good anymore.