Cold-weather startup rattle revisited

Preventive maintenance. It can't really hurt, and it seems it does more good.
This is why the oil is changed at certain intervals. You change it BEFORE it breaks down,
and the engine is destroyed.

 

You should monitor the egr pipe before calling 50K the official cleaning interval. It can be way clogged even before 50K and by the time you reach the interval, engine may be near kaput.

 

No knocks then but knocks finally now?! Oh no, climate change has affected our cars!!!

 

If I did my math right, it only takes 3 tablespoons of fluid to hydrolock a cylinder. Doesn't take much to bust a head gasket!

Pixel XL ?

 

Where's that fluid coming from?

@danlatu 's saying PCV:

Oil Catch Can, Eliminate that knock! | PriusChat

 

This is what I am deducing so far:
"The Atkinson cycle effect is allowing some of the unburned, intake charge to be returned to the intake manifold rather than being compressed" (un-burnt fuel) +plus+ Condensation due to cold weather on the plastic manifod and some comes from EGR due to Exhaust Moisture/condensation that comes back through the EGR passes the cooler and the change in temp creates more moisture +plus+ whatever makes it in from the PCV (or passed the catch can if installed).....

So there is a lot of gunk mixing at the bottom of the intake. even with a OCC and clean EGR.
Some of the moisture and gunk cling to the walls of the intake ports and manifold (especially if the engine is cold) then get sucked in to the combustion chamber.

Only some engines experience the start up knock or rattle with or with out.....................
There are some prius owners that claim to have over 300,000miles and no OCC and never clean the EGR and never had knock or rattle.
Then some owners report they have under 100,000 and DO have this problem.

Remove and clean
1. EGR system (brake clean the cooler, valve and pipes)
2. Intake manifold (use brake clean in a tray and scrub the inside including all the ports)
3. Throttle body (use shop towel and throttle body cleaner spray hold the butterfly open with your finger to really get in there)

Replace PCV valve (22mm socket)
"Install Oil Catch Can"

At every oil change include emptying the OCC and looking under the throttle body (just move the butterfly and shine a flashlight down) to see if there is Liquid.
If there is liquid use a towel or turkey baster or syringe to extract.

Note: sometimes every thing is always clean and dry, if you still have rattle or knock, do a compression test... Could be a head gasket issue.

 

Yes those with over 300,000 miles are usually taxi drivers or couriers who drive long distances. Their engine fluids are always up to temperature and condensation does not have as much of a chance to form in the EGR cooler, intake manifold, and engine oil.

Empirical evidence on the forum, from those who donated experiences on PC, suggest that lots of short trips can cause condensation and build up before 100k miles. Those who drive the average or above average mileage can expect problems delayed beyond that.

 

I remember a recent post that a Prius owner had a blown head gasket at 40,000 miles. Engine temp not reaching operating temps for sure

 

The 2 Oil Catch Cans just showed up.
Going to install them in both cars

 

What name are those?

 

Tasan Racing Universal Aluminum Baffled 2-Port Oil Catch Can/Tank/Air-Oil Separtor Black

 

mishimoto copy for 15% of the original price /

 

Cleaned out the Intake manifold.
Drove about 40 miles then
Took off the Throttle body
and


No Oil Catch Can installed yet.............
But the liquid is not oil.
It is Gasoline.!!!

Very Interesting. (Just documenting) No problems.
I was just curious how fast stuff builds up.

 

If you are new to this thread and trying to figure out why your Baby is Rattling/Knocking, It could be a easy fix.
READ your Owners manual from cover to cover.

I wonder how many Prius owners have Clean EGR and Oil Catch Cans and still have that rattle/knock.
They might also want to make sure they have "OEM Iridium Denso Spark plugs" (the gap is pre set)
I have heard that there are a lot of counterfeit Plugs being sold out there.
Also check for air leaks in the intake after the MAF.
And make sure your air filter and fuel injectors are not clogged.
Check your Connections to your Coils and Fuel Injectors.

So tune your baby up:
Clean the entire EGR system, throttle body, Intake Manifold, Fuel Injectors, PCV tube (and Oil Catch Can if installed)
Change air filter and PCV valve
If 120,000 miles change spark plugs with OEM. (In some cases they could go bad sooner)
Perhaps change your engine coolant maybe the thermostat

---Anytime your Engine Starts, make sure it fully warms up before you shut it off---

Did I forget anything?

 

Yeah, forgot that no one reads that here

 

My fully warms up at 153 F with app monitoring temp, how does one figure that out w/o an app?

 

Is it just me, or does that sound like instructions to the babysitter, for the problem child...

 

It's true, some of them are.

 

Is 153 thermostat temp setting? - typically in the 190 range.

 

It will be interesting to see if a car without a pcv system connected to the air intake manifold anymore will ever get a cold weather start up rattle.