Hey Scotty,
My 08 Corolla with 190,000 miles rattles for maybe 1 or 2 seconds on only a cold start. I change the oil religiously every 5,000 miles. The car runs great doesn’t burn any oil and gets 37mpg. I’m no mechanic but I believe mabe something called the VTT-I gears are at fault. Do you think this will become a big problem if gone unaddressed. And if I do replace them do you know if Toyota addressed the problem in the replacement part or should I expect this again after replacement? Thank you for you time and thank you for fixing our Chevy blue van 30 something years ago.
Jason!
Use synthetic oil and see if it goes away.
Yea tried that no change. Good suggestion tho.
This is a common problem, my 09 Matrix had it until the VVT-I repair kit was installed. Here's the Toyota Technical Service Bulletin on it for 09's
https://www.tsbsearch.com/Toyota/T-SB-0087-09
Thank you for this Glen! This is very helpful!
I don’t think it’s the timing chain because it almost goes away immediately. Hence when oil pressure is positive the vtt-I then stops rattling.
The hydraulic and spring loaded chain tensioner is beginning to fail, IMO and experience.
Thanks Doc wouldn't hurt replacing it anyways while everything is opened up.
If equipped, that's likely the VVT sprocket.
If it gets worse, replace the sprocket with the entire timing kit - usually they last the same.
Thank you for you opinion Dan. Thats what I’m thinking as well.