Prius Issues. Advise Needed

If that coolant hose let loose, the intake of engine air snorkel is not that far away, might have sucked some coolant in.

At this location (flagged by arrow):



there's no hose clamp, by design. I'm not sure why, but that's the way they all are. I think someone mentioned that hose, and the plastic intermediate piece at it's right end, are a single part no. FWIW, the clamp on the continuation says "19", and the OD of the left side hose, pushed onto the spigot, is 19 mm.

I wonder could there have been excessive pressure in the system, causing the hose to blow off. I've got a vague recollection of someone with a similar problem, that hose blowing off. He kept installing clamps on it, but there was a problem elsewhere in the system that was the root of the issue.

 

"The process of recirculating precise quantities of exhaust gases back into the combustion chamber has a number of advantages. In petrol engines, it helps to lower combustion temperatures and reduces the chance of spontaneous combustion, also known as ‘knock’."

Understanding EGR

The concern with EGR is not about plugged or not plugged. If the EGR hasn't been cleaned recently deposits gradually form that insidiously and slowly raise engine temperatures.

Also air in your coolant system can cause a hotter running engine which can lead to knocking.

Thread: Need help! Gas engine overheating

 

"Also something to think about, these engines are pretty reliable in general. Meaning most go the junkyards with plenty of life left in them. There just isn't demand because the engines aren't exploding left and right like american vehicles. They may use more oil, but they do work. "

I beg to differ! These engines EAT head gaskets. Mine was diagnosed at 116K. It should be able to go twice that before even thinking about a head gasket. I, too, have had all my service done by my dealer just because I'm getting old and it was one of our first 'new' cars. My Service Manager says its because Toyota uses them 'Stretch to Yield' head bolts, and is normal for these engines. (only in Prius and CT200H, not in Corollas, BTW)
Why there is not an extended WTTY or a class action on this I'm not sure!

 

There will always be a few lemons, that's why reliability curves are just that, curves. But overall, your experience is rare.

It is common for the Prius engine (Gen-2, Gen-3, and not sure about Gen-4 yet) to start consuming oil. And as long as you keep ontop of that, no damage.