Hi, I have a 2010 Corolla with 85,000 miles. So, on a cold start, the engine makes a brief rattling noise. It goes away after 2 seconds. Scotty said previously this is fine as long as it does not continue. It has always done this since I have bought the car in December 2020. 0W20 full synthetic was put it. Now, in July of 2021, there is a rattling sound in drive/reverse if I am at a stop. It goes away in neutral. I had an oil change done in August 2021 and full synthetic 5W30 was put in. It’s a thicker oil so I thought it might stop (both the startup noise and idling noise). Now, the startup rattle is likely fine, but is the idle rattle related to the startup rattle? The startup rattle just sounds like a diesel starting. The idle rattle sounds similar, but a weaker sound. More similar to a rattling heat shield, except from the engine. Anyway, just wondering whether the idle rattle is a normal thing with age and if it is fine to let it continue. It goes away once I start driving and press the gas pedal, but it does it in drive and reverse when I just let the car move itself or if I am sitting still in drive.
First of all, do not change the oil viscosity. Stick to the manufacturing recommendation. Second of all, do you know if the previous owner changed the oil frequently? If not, you may need to change the timing chain to fix the issue.
It was changed yes. The 5w30 synthetic was put in without my knowledge. I called the shop and they said it'll be fine and won't change it. I'm in college so I can't do it myself in the university parking lot. How quickly should I change this and are you sure? The rattle whilst in drive/reverse with my foot off the pedals just letting it move only started recently. It goes away if I step on the gas and sounds different than the cold start rattle. Which made me thing it was a bearing of some sort.
You should take care of it sooner than later.
This is clearly a timing chain replacement issue. It's best to do it before it destroys your engine.
It is the timing chain on startup I realized. but it does go away. The other rattle sounds different and is only if I let the car move on it's own from being put into drive/reverse. I thought it was the timing chain overall too, but now I am thinking it is a bearing or something.
That noise could just be something loose in the exhaust system hanger system or worn cv joints. Might even be a loose CAT heat shield.
The cold startup rattle in that gen Corolla/Matrix comes from the variable valve timing gear. It's pretty harmless, but there is a TSB if you want to address it (I had mine done under warranty). The rattle AFTER cold startup is something else, very likely a timing chain or a heat shield rattle as discussed above.