2008 2.4 Camry
 

So I have had my 2008 Camry for quite a while and I started getting this blue/white smoke on startup after the car had been sitting for a bit. If I leave the car to sit for over a day, the next time I start it, it produces a puff of smoke. I will also note that there is currently a leak in the flex pipe, but I don't think that would cause the smoke. I have read everywhere about what it could be, but I can't get a definitive answer on what the issue may be. The car also seems to run really loud after it is started for a minute or so then it settles down and idles fine. Does anyone have any ideas on what this issue may be?

Louder as is in more engine mechanical noise or exhaust noise?

Any loss of coolant (need to add more)?

How is the oil consumption?

Smoke at cold start is typically worn valve stem seals.

The exhaust leak can cause future emissions troublecodes.
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It sounds like the loudness is coming from the exhaust but it is hard to tell. I know that when an engine starts up, the first few seconds it runs loud to make sure everything is moving correctly then the noise drops down, but I am not sure if this is a related issue to my issue. I haven't seen any loss of coolant or oil. I do the oil change every 3000 miles and it seems fine. Check the oil every 300 miles and it seems fine. This smoke issue has been an issue for around half of a year so I have been trying to track down where the issue might be. Is there a way to easily see if the valve stem seals are bad without too much work, or would it be best to just take it in for that? How much would you estimate the fix to be for fixing the valve stem seals? I also plan to have someone weld on a new flex pipe. I don't want to have to replace the whole exhaust system with the catalytic converter and the flex pipe cause it is a lot of money.

Use a section of rubber hose as a stethoscope to determine where the noise is coming from. The timing chain area can rattle at cold start.

Engine is also know for excess oil consumption and blown head gaskets (loss of coolant) due to failed head bolt threads.

Can't really check valve stem seals. They are extremely labor extensive to change. Need to either remove the head to remove the valve and seals. Or use compressed air in the cylinder with head on to keep the valve from dropping into the engine when the seal is changed.

If not using synthetic suggest changing to try avoid possible future oil consumption issues. The oil return holes in the piston sludge up causing greatly increased oil consumption.

Is there really any other possible reasons why there would be white/blue smoke coming out the muffler on startup other than the valve stem seals. At the steep price of valve stem seals, I don't want to get them replaced and it not fix the issue. Is there a possible short term solution to this problem or is the only real solution to get the valve stem seals?