2010 Prius Engine Rattling. Should I be Concerned?

Welcome to Prius Chat .

Some questions:

• Is this the first time you’ve noticed the behavior?
• Is the coolant level stable for the engine?
• Does your Prius consume oil?
• Has the egr circuit been cleansed?

Good luck and keep us posted .

 

It's not the battery. Hopefully, it is not too late to clean the entire EGR circuit. Your head gasket may be at stake, as per @Raytheeagle 's comments.

 

Mafs, map, and throttle body being dirty or oil saturated will cause these issues also especially at idle. Seen it many times when oil was overfilled or the pcv is stuck open

Posted via the PriusChat mobile app.

 

worry? no. concerned? yes.

 

@JJC123 what's your situation, are you mechanically inclined, doing some maintenance yourself? Or strictly dealership serviced? Somewhere in between. Let us know.

The aforementioned Exhaust Gas Recirculation circuit was introduced in 3rd gen, and had a major revamp with 4th gen, likely to address shortcomings. Specifically: that the dang thing inexorably clogs up with carbon, and as it does engine temperatures climb, head gaskets fail.

Also mentioned above, the Positive Crankcase Ventilation system tends to dump a lot of oil and gunk into the intake manifold, possibly accelerating the the EGR clogging.

The EGR also has passageways going through the intake manifold, and they clog as well.

 

It's getting to where the only way third gen ownership is viable is if you're a game DIY'r. Ok, one alternative: a reasonably priced shade-tree mechanic who makes house calls, and is willing to learn. Or, an evangelistic Priuschatter that holds EGR "clinics". On the west coast @Raytheeagle has been coaching people through this, has it down to a 4~5 hours for the EGR. And maybe 2~3 hours for the intake manifold.

The dealerships and Toyota have effectively turned their backs on the EGR issue. Have a read and check out the links:

The simplest way to see where you're at, is to check the degree of carbon build up in the EGR pipe, a stainless steel connecting pipe between the EGR valve and intake manifold. Watch @NutzAboutBolts video #16 here:

Nutz About Bolts Prius Maintenance Videos | PriusChat

Two or three other videos linked there too, for the full cleaning of the intake manifold, full EGR clean, and Oil Catch Can install.

Good thread:

EGR & Intake Manifold Clean Results | PriusChat

Another:

Oil Catch Can, Eliminate that knock! | PriusChat

Some tools worth having:

E8 Torx socket (mandatory)
E6 Torx socket (optional, but good to have, to remove the throttle body studs from intake manifold)
3/8" ratchet wrench, regular and long handle, flex head, you can never have enough (or 1/2 plus reducer)
1/4" ratchet wrench, or 3/8" to 1/4" reducer
Ratchet extensions: you can never have enough
Long needle nose piers, straight and bent tip
Ratcheting 12mm box wrench (optional, but makes disconnection of the EGR cooler from exhaust easier)
Torque wrench (3/8" and 1/4" both good to have)
Floor jack and safety stands (or ramps): basically some method to raise front, if you need to take underpanel off, which you may need to, both for access and to recover dropped items.

 

with no dash lights on?

wow, congrats!

 

just got home thanks to EV mode. After a 8-9 min drive, picked up my order, waited in park mode 2 minutes or so, then as soon as I started to move, the engine started to rattle and shake. I thought it ll pass after a few seconds but it hasn't. I pulled over and charged the hybrid battery and was able to get home with hazard lights.
No engine lights on
The s.plugs changed in summer ( no egr cleaning that time)
Is it EGR do you think? I also consider misfiring but this never happened so far. Only thing I can say that it sometimes rattles on low speeds for a second or so
Checked the oil, it's fine and same as before

 

Your symptoms sound consistent with engine misfire. There are many things that could cause misfire - ignition coils are near the top of the list, but that's just a guess. Using a scanner to check data or codes in the engine computer would be a first step.

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