Rattling/Knocking on Startup

[lathamb]

Hi All,
This may have been covered but I didn't find a good thread when i searched. My '07 V8 (170K miles) has started making an occasional loud knocking or rattling noise right at start up after it has sat for a few days without running. Sounds like a freight train. I'm thinking it is a valve train noise as it disappears as soon as oil pressure builds, like 3-5 seconds at start up. Afterwards it runs like a top, no knocking of any kind. Its not the fuel regulator issue, as i have had that for years as well, just never got around to fixing it.

Anyone have thoughts on this? I'm using a Toyota oil filters and Mobil 1 5w30, but I'm wondering if there is a better filter/oil combo to prevent all the oil from seeping back into the pan over that time.

Thanks,

 

[randy88fj62]

I had this issue a few weeks ago and it happened on cold start up in the morning only. It was gone when the engine was warm.

I added half a quart of lucas oil stabilizer to thicken the oil and the noise has not come back since.

507,000 miles on the 2008 SE V8 motor and still going.