10K oil changes are BAD! ??

Off Topic....

Thanks for the link.
I have now joined the EGR Delete Club this morning!
I'm at 153k miles. I know I should clean the EGR system someday....
And the way I drive I never have two tank fulls the same MPG. It might be hard for me to quantify any difference.

 

Doesn't that discredit the theory that a clogged EGR system will fail a headgasket?

 

I could come up with some reasons, but I think your mind’s made up.

 

No one has 100% found the exact reason. I personally believe it is a combination of things.
And at times, certain things. And it seems those who do mostly city driving have issues
sooner and more often than those who do mostly highway driving. And also HOW it's driven.

 

It's just the opposite.
It's implying that without an EGR system to get clogged in the first place, Prii in Brazil do not routinely have a head gasket go bad.
Of course this is Hearsay without actual data to back that statement up.
Only the Brazilian Toyota mothership knows what the Toyota dealerships report in the way of repairing head gasket failures.
Of course, just like here, Toyota doesn't know the extent of HG failures because a lot of the repairs take place in independent repair shops.

 

I found it interesting that the water pump impeller on your high mileage car was in good shape whereas other folks are saying theirs were badly deteriorated at much lesser mileage. That tells me they haven't been changing the coolant at the prescribed intervals or used inferior coolant. I think poor maintenance practices contribute to the headgasket life. Corrosive coolant is going to eat the headgasket and water pump and raise operating temperatures and cause overheating. Of course driving practices contribute as well.

 

of course, the maintenance schedule has quite a long interval for coolant changes, and no rec for testing.
dealers aren't helping ether, and toyota europe claims it is because of faulty waterpump speed software.

 

90% of my driving is highway. So they engine temperature is more steady.
With city driving, it changes. So that's likely part of the reason it fails, it's plastic...

 

Seems like a strange reason for an electric water pump with a plastic impeller to fail.
Its duty cycle is always changing RPM. I'm hoping the latest and greatest SW update addresses the duty cycle to help with the head gasket at high speed/power duties.

Do you recommend changing the entire pump assembly at X miles, preventatively? Can the impeller be changed separately?

 

Apparently. Of late there’s been a lot of impeller-only offerings. There’s a thread here with some discussion.

 

Google "Aisin WPT-190 impeller". Apparently not hard to replace either; a circlip of some sort needs to be removed and out it comes?

 

I wondered about that. It seems that most of my cylinders drained to empty overnight (I think one cylinder still had some solvent in it after an overnight soak) I wondered if I was getting any significant cleaning of the expansion "spring coil" under the oil scavenge ring or not. I suppose if I were to really try doing a better piston soak, I'd have to refill cylinders frequently (as you note) and also tip the car different directions (to get soak to run down different sides of the rings). What a pain.

Hoping that little springy coil under my scavenge rings is still not gummed up. Did not know about that before and talked with Gasket Masters about this.

If car starts burning oil, I'm guessing those are gummed up beyond hope. I don't know if it is or not yet. Gasket Masters says "Change oil every 4k miles!" They report that prevents oil burning problems and might resolve minimal oil burning after a few changes.

Wow. Every 4k seems excessive...but no doubt we have a varnish-in-the-scavenge-ring expansion-"spring"-thingy issue.

 

Tried finding the impeller with no luck (also tried "rebuild kit" with no joy). Aisin pump is all that comes up. Not too important, just wondering if I should think about replacing my impeller to keep my head gasket in optimum condition. I'm kind of worried about head gasket failure and would obviously like to prevent, rather than have to deal with it whenever it happens. Does anyone have a sense of how many Prii get to 300+ withOUT a head gasket failure. Any estimations on percentages?

EGR recently cleaned out (again) and oil catch can helping a lot, but tempted to go the EGR delete method now. Bill Norton has me almost convinced. If Mendel goes delete, I'm definitely doing it! (Ha! Mendel has TWO catch cans!...and he doesn't seem to want to change anything Toyota-designed without great caution...so if he goes EGR delete, I'm following for sure!)

I called Gasket Masters as I have a reason to travel to San Bernadino (from AZ) anyway: Asked specifically if anyone changed head-gaskets prophylactically, and they reported a "ton" of customers do that. They have people drive from nearby states (and northern CA) all the time, by their report and have done a lot of preventive head gasket replacements (to FelPro) to eliminate this problem.

Anyone heard of this? Thoughts?

 

Two Moroso cans. Ultra pricey, but I had an extra one (long story), so why not. Second typically collects greater volume, but about 4/5 water. Still, that’s stuff that otherwise would be messing up intake manifold, ports, valves and so on.

I would not do an EGR delete. Cleaning it you’ve restored car to factor condition, at least in that regard.

 

Saw that video. Absolutely something other than oil-change-interval causing that. No way does a valve-train look like that with 8k mile oil-changes, without something else going on. According the the implication of this video, you're entire engine and valve-train are full of sludge because you went 8k between oil changes. Not a chance. There's just a ton of gunk/sludge in that valve-train. Valve-trains with MUCH more mileage than that one, and 10k oil-change-inervals often look very clean. Maybe some sort of emissions-control recirculation or pump issues? Anyway, that's not a normal valve-train for 10k mile oil changes, let alone 8k.

 

Thanks Mendel. EGR delete on the shelf for now. I'll keep cleaning EGR occasionally. I had a feeling you'd say that

 

Just gassed up today, gauge was down to to half full. Took 17 liters (maybe 4.5 US gallons). Distance since last fill up was around 350 kms (maybe 220 miles). Entering it in my fuel consumption log (and Fuelly, badge below), see last fill up was mid-July.

that’s where we’re at, both retired, lots of amenities within walking distance. Just about kicking the car habit. That said, we mostly do longish drives; todays was over to son’s, help him patch drywall, and visit. About 50 km round trip.

I don’t think I stand a chance of getting to the head gasket “fun”. It helps hanging out here, seeing what others encounter, further down the road.

 

Frequent oil and coolant changes on THIS VERY FLAWED engine makes good sense, especially if it’s not an oil burner now. Preemptive hg changes is the only way I would do it - otherwise change the engine when it fails.

Again, some of these engines get sludged up. People these days don’t check the oil much less change it for $75. So it happens and could have happened to that lease car in its first 50k undocumented miles.

I would do an egr delete in a minute if there was a way to eliminate the check engine light.

 

You could take it apart and clean them up and reinstall them.
But it's risky. The rings will not be in the same spot, not that it matter at this point.
And the cylinder walls are scored, not round. You can hone them....
But if you are going that far, and the cylinder walls are okay, put in the updated
pistons and rings.
If you don't drive a lot, or far, and have AAA, you can probably get away with just cleaning up
the pistons and rings and reinstalling them.
You do what your wallet allows you to do...

 

I agreed with you right up to 'Change the engine'. What? For another unknown used Prius engine?
What's so bad about waiting for the first tell-tale signs of a leaky head gasket before doing a repair?

Anyways, I'm one week into driving with an unplugged EGR valve. At first I saw a big increase in MPG, but it turns out that was from putzing around town. It was above 50 MPG for a while!
Once I started using it normally on the interstate the MPG was the same. But it's always ± in a 4 mpg range....

But, what I think I feel is a new smoothness in driving easy around town.
Does anyone else feel a vague non-response or slight stumble going really easy adding or removing power? Just a second of 'something/nothing' before it starts to accelerate?
I feel the car is noticeably smoother when adding light throttle and removing throttle. Quicker, smoother responses to small pedal movement.

Maybe it's just Placebo.
I asked a friend to help test this with me and him driving and testing this theory.
He would,, or would not,,, disconnect the EGR valve and I would do a few test drives like that, where he raised the hood between each test.
Then he would see if he could feel anything while I dikked under the hood.

As for the Check Engine light... an app and a $20 OBD reader will clear the code. Maybe it will clear by itself once reconnected, I don't know yet.
And if you really hate just seeing the light, a small piece of tape can fix that!