Loud engine sound at start-up

I am in California - so coldest is around mid 40’s early morning. I have had no differences is MPGs in using 40 weight. I use Mobil 1 which tends to be on the thinner side of oils.

Toyota allows the use of 30, 40 and even 50 weight oil in some other countries. There have been post on Priuschat of photos of the service booklets showing these higher weights.

 

I would not mix the oil weights, you should do your oil changes at 5,000 miles as well. I also let the car go through the first warm up cycle (a few minutes) before driving it.

 

Been a Taxi Driver most of my life (recently retired from that, frackin' Uber)...so the 5k Oil Change is like a religion for me.

I run with my phone display on & connected to ODB...and let the coolant temp top 100f before I take it out of park.

Gotta say, I love TorquePro.

 

My most recent cold start "engine knock' at 189k miles turned out to be the dreaded head gasket issue. Throwing misfire codes in cylinders 2 & 4. $3k to take it apart to "see what the problem is". Traded it in...

 

Just to recap: EGR and intake never cleaned?

 

At your next oil change I would run BG EPR for twenty minutes beforehand. That should clean your piston rings and all of the build-up from elsewhere in your engine. 44K should help a little with the rings, but it does most of it's work elsewhere. I would also use BG MOA with your fresh oil. See if that all of that helps with the oil burning.

 

No clue. Just got the car a bit over 2 months ago.

But...judging by the condition of the oil when I did my first oil-change...I'm betting that maintenance has been minimal to non-existent.

 

If you end up taking the head off for head gasket, does cleaning the pistons of carbon get any easier? Not sure. It's a major $ undertaking unless you DIY.

Attached TSB details piston replacement. Alternately you can purchase new short block for under $2K USD I think.

 

weird about how do don't get tired asking this question. in my case (and The Critic, too), HG failed despite over-maintaining the car and preventive IM and EGR system cleanings. so, that myth is debunked.
but, if this is your ideology, no facts can change it.

 

I'm just trying to solve this jig saw puzzle.

 

Correlation doesn't equal causation.

Can something happen despite preventative measures? Yes
Can something NOT happen, despite lack of preventative measures? Also yes.

You may go a million miles without cleaning the EGR & never pop that HG. Or you may clean it, put it back together...and blow the HG because of something totally different.

 

totally agree with this part. hence, it's irresponsible and/or insane to preach here (as many do with no proof) that dirty EGR blows HG in prius.

 

However, from the flipside of that argument...if this is a suspected source of failure, then preventative measures are a good idea, both to do...and to preach for.

 

It's neither. There's a strong correlation: the EGR system is acknowledged as a way to keep combustion chamber temps within spec. When owners pull out the cooler and intake manifold and are greeted with a carbon plugged disaster, they tend to prosletize.

 

i would like to see the data on the said correlation. do you have any?
prosletize what? that it's nice to have the EGR clean? agree with only that.
for the record, when i cleaned mine, there were no drivability or MPG improvements. no benefit for my HG either.

also, mine was not clogged at 113,000 either, it was up to 50% restricted. i was a big proponent of EGR cleaning too, and did it too, only to discover it doesn't prevent HG failure at the lowly 125,000 miles.

 

Wow, I begin to think I unintentionally dropped myself into a minefield on this subject.

...can anyone point me in the direction of the easiest path to safety?

 

And clogged EGR is definitely not the circumstance the engine is planned to work in.

 

At 50% restricted all or most of the metal is coated in carbon, yes? That would decrease the EGR cooler's cooling ability as it is conductive. It's still a mystery to everyone except maybe Toyota engineers of why the third gen head gaskets fail, but recommending the maintenance of a part to help it do its job is neither irresponsible nor insane. Especially when logic dictates that the part and the common problem would imply that they could be linked.

And as with most things, personal experience and anecdotal incidence is almost never indicative of overall reality.

 

This happen to my car 2012. But the weather was hot all day. I turned it on at night for a drive. Just like everyone else, I turned the car off when noise came on. Turned back on and it was fine. However when I reversed it off the drive way it made that noise again. So I parked did reveres a few times. But noise was gone. Is this a conman thing is Prius? It’s my first one.

 

How many miles? Ever cleaned the Exhaust Gas Recirculation system?