UnsanePyro

My mom came home today and told me that her car has been sounding a bit funny lately, and sometimes starting a bit hard. She drives a 2000 Toyota Solara (V6). I took her car for a drive, turned off the radio and the heat, opened the windows, and put it through some paces, accelerating, slowing down, turning, forward/reverse, and some combinations. I couldn't find anything that stood out as a bad sound though, the engine has a different sound than mine, but thats comparing apples to oranges, an I5 to a V6. She said it sounds different though, I believe her.

Brought it home, told her I had no idea what was up with it, and went back outside to bring it into the garage. It started a bit rough for me again, though not as rough as when it had been sitting for about 30 minutes. I immediately turned it off, waited a few seconds, and started it again, it started fine. Brought it inside, and saw a case of oil sitting on the shelf in the garage, and then I had an idea.

Her car reccomends 5W-30 for oil, but my dad put in 10W-40 a couple weeks back. Durring these weeks, the temperature has dropped, and now its down to around 30.

Now, is 10W-40 thinner then 5W-30 once it is up to opperating temperature? My understanding is that the first number is the 'thickness' of the oil, and the second number is how many 'points' that it will 'thin' once up to temperature, and 10W-40 would end up being slightly 'thinner'.

With having this different (not reccomended) oil in the car, would it be safe to assume it is the cause of these symptoms she is having? I believe it is, but my dad (great with wood, not with cars) just wants to run some injector cleaner or something through it, and hope it goes away.

SilverUA5

You should always put what the manufactuer recommends but you can have it a little different like 5W20 vs 5W30, but not 10W40, I think you should drain the 1040 out and get a can of engine flush and flush out the rest of it, then put some Mobil One 530 in. I also think that 1040 is sort of a all season oil but since you are now down to the 30's, it might make a difference since 530 will protect better.

savageTL

First 10-40 is THICKER than 5-30. The heavier oil, colder temps and tight engine could well be the issue, any "unusual sounds" will likely be apparent on cold start up. Drain the 10-40 replace with the correct oil (no need to flush, thst is WAY overkill), cheap way to prevent any cold start wear that might be happening. Plus given this is the start of winter is kinda crazy to have heavier oil than recommended in the engine, even if it isn't the source of the current problem.


Spend a few hours/days on bobistheoilguy.com you will learn more than you ever need to know about oil. The guys on the forum section rceally know their stuff.

Vandy

Pure Adrenaline

iTrader: (2)

The second number indicates the viscosity of oil once it's warmed up to operating temperature, I believe.

Yeah, definitely drain the 10W40 and get 5W30.