Warm start rattle solved on my car!

[Bluedoggiant]

I’ve got the 40v belt 4.2 and I’ve developed a brief rattle on cold start, NO rattle on warm start, NO chain rattle when opening the throttle when engine is cold, brief rattle when opening the throttle when engine is warm (~oil temp 200F)

The genuine chain tensioners are not that old, so I did the check valve replacement. My old ones looked okay (fully closing) but did the repair.

I still have the same rattle described above.

Outside of starting the engine, does anyone have any possible idea why I get a brief rattle when opening the throttle ONLY when the engine is warm? I would think it would rattle more when the engine is cold

Been stumping me for weeks

[Rol-co]

I’ve got the 40v belt 4.2 and I’ve developed a brief rattle on cold start, NO rattle on warm start, NO chain rattle when opening the throttle when engine is cold, brief rattle when opening the throttle when engine is warm (~oil temp 200F)

The genuine chain tensioners are not that old, so I did the check valve replacement. My old ones looked okay (fully closing) but did the repair.

I still have the same rattle described above.

Outside of starting the engine, does anyone have any possible idea why I get a brief rattle when opening the throttle ONLY when the engine is warm? I would think it would rattle more when the engine is cold

Been stumping me for weeks

Intake manifold flapper?

[jag212]

NEED HELP. so ive gotten the timing chain rattle on warm starts after an oil change and when temps got high here in cali... happens every single time and don't know if it's a coincidence with me changing the oil/oilfilter or temps reaching about 80 degrees outside, i replaced the upper driver side tensioner from where the rattle was coming from... after the tensioner was replaced the rattle wasn't as harsh but it's still there on warm starts even right after turning it off and on. the rattle/tick stays for 5+ seconds unless i whack the throttle then it goes away instantly. do you guys think this could be a chain stretch issue or should i address the check valves and go from there?

[EvoRam]

It’s always hard to say. I basically had rattle (cold & warm) even after doing timing, check valves and everything in between…until recently when I had to do cam phasers, replaced the cam solenoids & upper cam adjuster guides. I’ve had the car almost 12 years. This is just my personal experience with rattle. My Rattle never bothered me at start up even when warm. But my rattle was just for a second at startup.

[Rol-co]

NEED HELP. so ive gotten the timing chain rattle on warm starts after an oil change and when temps got high here in cali... happens every single time and don't know if it's a coincidence with me changing the oil/oilfilter or temps reaching about 80 degrees outside, i replaced the upper driver side tensioner from where the rattle was coming from... after the tensioner was replaced the rattle wasn't as harsh but it's still there on warm starts even right after turning it off and on. the rattle/tick stays for 5+ seconds unless i whack the throttle then it goes away instantly. do you guys think this could be a chain stretch issue or should i address the check valves and go from there?

Wat oil u use now? 5w30?
When you look in the oil filter housing, both valves are ok?
Checkvalves already done?
Clacking at startup, could be the adjusters, the intake manifold flapper, did you move the lever already or disconnect the vacuum and plug it?