Loud engine sound at start-up

going to arbitration with Toyota about noise, any comments?

 

all the best? you could be setting a precedent.

 

FYI
It's that time of year to start posting about the knocking at cold start ups.

I had a cold spell in one morning and the car had an ever so slight hint of rattle.

Basically I moved the car a small distance, in the driveway, under battery and jumped out to do something and as I walked away the ICE turned on and I did a double take to catch the mini rattle, like two cycles at best than smooths out.

So I am changing to higher octane which has helped me to keep it away, IME.

I'm at 82,000 and still original intake manifold.

I'm also adding a can of Techron since I have not added/done anything since last winter.

 

high octane usually does the trick. at least the price isn't outrageous right now.

 

Hey thanks for the vote.
I hope the higher fuel octane can help people when they search for suggestions on what to try for themselves for the issue.

Remember YMMV

 

My car has 26,768 miles her and after I started it at work and drove to the pharmacy about one mile, I turned it off and when I got back in to go home, I put the car in R and then D and a horrible metal rattling came from the driver back seat area...I thought I had forgot to take something out and it sounded like two metal pans hitting against each other. I drove home and checked my car for the reason for the noise....nothing was in my car....I keep it clean and not a thing was in it to make the metal rattling noise.....crazy...I was in ECO mode

 

For what it's worth, I had this issue for the first time today on a 2014 Prius II. No recent oil change, well maintained, low mileage. Similar to what others have mentioned, prior to the issue I had started and stopped the car before it finished the initial warm up cycle and the car was sitting overnight in temperatures around 35-40 F.

 

don't do that!

 

My 2013 prius has the same cold start rattling issue. Found out this August after two weeks of vacation.
I took it to dealer try to fight for a solution, but no luck. Service adviser said there is no recall, warranty services, or anything related to this issue in my year model. Or i can pay $120 upfront to let the tech diagnosis...**** that, I'm gonna contact Toyota USA or even write email to Toyota HQ in Japan to see what can they do about it to recent year models.

 

nothing. don't waste your time. see henry holders post #41. over a year, and no result.

 

Sadly everybody's like that these days: service calls for household appliances, specialty dentists, they all want an up front "cover charge" before they'll even budge.

 

Engine noise on start up while engine is cold, its going common day by day, i faced the same issue, sounds which comes from.engine its too horrible. I consulted my mechanic, he told me that its beceause of fuel pump, when engine is cold, it needs time to supple the fuel, furthermore he said, if you r having this problem then disconnect your battery terminal fora nighy amd then connect it again in morning, i did the same and issue solved, if anyone having this problem try this method or must visit the workshop to change the oil filter and plugs of car...
Regards

 

I got this on my 2014 Prius C, only does it some time. my car DVR record this.

 

To fix the cold start rattle. Clean out your entire intake manifold. Remove all the oil and carbon build up. Then install an oil catch can. I have not had a cold start engine rattle for 2 years on the 2010 prius my gf drives. I have one on my 2011 aswell. The knock you are hearing is oil being burned in the combustion chamber from your pcv system. If you continue to run your car with this knocking, you will blow the head gasket.

Oil catch can thread < click on this

 

Does this sound like the dreaded problem?

Just had (what I think) was this last night. OP was right, if you've never heard it before it will freak you the hell out. Sounds like the engine was gonna fall out of the car.

2010 Prius 3, 130k(ish) miles
Ambient temp around 44f

Around 10pm (I go to work), I went to start it, and the most god-awful sounding rattle. I immediately shut it off (maybe 3 seconds).

Wait a minute or two (actually, honestly, I was panicking and running in the house to be comforted by my wife, as this is my work-commute vehicle).

Second start, exactly the same. Shut it off after 2-3 seconds.

Ended up having to take my wife's truck to work, as I'm on a fairly tight schedule to make it to work (45miles away)...so no time to deal with it.

Woke up this afternoon, temp's around 75f. Went out to start it..."that noise" lasted for all of one second before starting to "settle out". In about 10 seconds it sounded almost normal. Drove it around the block a few times to let it "warm up", drove fine, engine sounds normal...although a high-pitched whistling noise I can't pinpoint has been there from day one (anyone know if that's normal?)

Checked TorquePro, which shows a "pending code" of P0304, which does NOT light up on the dash. Odd.

The wife HAD started the car yesterday afternoon to move it down the driveway, but can't remember if the engine fired up, as it only took seconds.

PS: As a side-note, that noise when I first start the vehicle (for a second or two) is the noise the AC makes on this vehicle. Is that a normal sound for a Prius? I'm a fairly new Prius owner, had this one for about a month & a half.

 

If your moving the car around you gotta let the motor turn off on its own before shutting it off. This will happen many times from not allowing the motor to warm up at about 100 deg F and turning it off when the engine shuts off by itself first. Also, you probably need the EGR cooler and pipe cleaned as well.

 

Thanks for the advice.

Yeah, at 130k I kind of figured as much (on the EGR). It's on my list of things to tackle (or have tackled, I'm not the most mechanically inclined).

Also on the list are:

• Oil change (done, the oil was ATROCIOUS!) I was losing on the order of 1/2 quart per fill-up (that happens every week).
• Change from 0w20 to 5w20 (done, recommended for above oil loss)
• 2x cans of BG 44k (for above oil loss as well, I'm due for my second can at this fill-up. I've been told this will hopefully clean the crap off the ring lands?)
• Air filter
• EGR cleaning

What else should I watch for? Brand new to Prius World.

 

I run 0w-40 weight oil with a Toyota filter since around 60k miles and have no oil usage. I would suggest you go higher weight than 5w-20.
If you don’t have the history on the car you should do the fluids as well as the trans fluid and spark plugs.

Unfortunately the oil usage is hard to stop once it has begun. You will probably need to continue to add oil even with higher weight oil, but it should help.

 

I live in Texas where it rarely gets below freezing...should 5w work in Winter? Not sure where you live. I'll look at -40 for my next oil change...which should be in about 3-4 months with my current 45mile daily (each way) commute. What effect (if any) have you seen on fuel economy (or anything else) with pushing the thicker oil around?

Fluid, tranny, spark plugs added to "The List"

 

Currently using the 5w-20 version of this oil. No reason to "mix" the viscosities, right? Just wait 'til the next oil-change to put in all-new thicker oil?

EDIT: Huh, it won't let me link it...it's just Amazon Basic "Full Synthetic" ($25 per 5-quart bottle)