Prevent EGR troubles?

Welcome to Prius Chat .

Since the cooler is a heat exchanger, the engine coolant is the fluid that can be regulated. The exhaust side heats the engine coolant then is cooled by the coolant once up to temp.

After the mileage piles up, the cooler needs to be cleaned as it clogs with carbon deposits .

Clean that along with the valve, pipe and intake manifold and you’re good to go.

 

The exhaust of a healthy & well managed gasoline engine contains fine carbon particles. Some are going to gather and stick no matter what you do. Cleaning out an EGR circuit isn't specific to the Prius; it's just that the system on the Prius has a couple more parts and suffers more consequences than average when the system isn't clean.

 

I'd say oil catch can, and an ocassional cleaning, say every 60~90k miles (depending on your tolerance), before it gets to clogged. Which is a bit of a black eye for Toyota.

 

I keep hoping that my use of the vehicle almost always at highway driving speed will keep things blown out. I also keep hoping that Toyota will step up to the plate and eventually provide a cost effective (read affordable) solution to this problem. I know I could DIY a cleaning as a preventative, but I just don't have the time.

 

Over 90% of my driving in the 190k miles on our 2010 have been highway and I’ve cleaned it twice.

Still getting great gas mileage too:



Glad I did the egr circuit too.

 

I'd say a simple habit is to add some Techron to your fillup and let it run for a whole tank before doing an oil change. It should help clean out the carbon build up and help maintain some good mpg. Dump it out in the oil change.

This pic is from Subaru about their support for Techron. I'm sure other system cleaners work in their own way.

Techron Fuel Additive - Subaru



This won't reduce oil consumption if the piston rings are already worn out. But if it is not, I'd say use it as preventative measure.

 

From
Hydrocarbons and Particulate Matter in EGR Cooler Deposits: Effects of Gas Flow Rate, Coolant Temperature, and Oxidation Catalyst

"The results indicate that mass deposition is lowest at high flow rates and high coolant temperatures"

Use a block heater then?

Another link Optimizing fuel economy with EGR | PriusChat

For increasing the EGR flow rate according to the second link I'd guess that keeping the accelerator pedal away from the floor would help.

Also from another research paper I posted a year ago high RPM (on a different engine) dramatically increased soot production.

The OCC and injection cleaning were good ideas. Burning oil or bad spraying injectors increase soot production.

Pixel XL ?

 

Huh? Techron cleans the intake valves, injectors & combustion chambers. Whatever it knocks loose is going out the tailpipe, not the oil sump. And some of it will have to go through the EGR system to get to the tailpipe.

If anything, you want to do the techron treatment right before you clean the EGR so you don't blast freshly-loosened carbon crunchies into a just-cleaned EGR system.

 

There are some YouTube videos one by Chris Fix and another by Eric the Car guy that don't give these fuel additives very good marks.
I still use them but not very often. I will look for the videos.

 

Anyone know what dealers are charging for a full cleaning? Every 100k might not be too bad

 

Why are you taking an old car to a dealer? This is exactly the kind of situation where the local independent can save you big bucks.

 

Nice, anyone know what an Indy might charge?

 

EGR step position

At low acceleration EGR is wider (larger step position) and manifold vacuum is greater = higher EGR flow rates.

 

Are you saying my granny car egr might never need cleaning?

 

Independent mechanics may also have borescopes and willing to take before and after pictures of your engine chamber. So you can see how bad your chamber looks and if something like Techron works. I don't know how long ChrisFix ran his test. It should at least go through an entire tank. You can also buy borescopes on amazon, but the work is a bit to get to the spark plugs from what I hear with removal of the windshield wiper assembly.

 

@Raytheeagle is in a good position to throw out a number. He's gone through the procedure more times than you can count on one hand I think? He keeps an extra, pre-cleaned EGR cooler on hand, swaps it in, takes yours. How many hours labour would that be?

It's complicated by the need to take off the wipers, their motors and linkage, windshield trim and the metal cowl. I think one time he skirted that, and wished he didn't.

It's maybe a good idea to do the intake manifold clean at the same time, since it really is the last leg of the EGR circuit.

And the Oil Catch Can install, as long as you're in there...

The one comment I would add: if you drain a couple of quarts of coolant from the radiator at the outset, there's no need to clamp egr hoses, and with a little care nothing gets spilled. Just pour the drained coolant back into the reservoir at the end. And when pulling off the throttle body, the coolant lines do not need to be disconnected either.

Yeah we got ours installed at time of purchase, and I'd say almost without fail use it for a couple of hours, before the first cold-start of the day.

 

Ah the egr circuit cleanse, I know it well.

Just got 3 requests from locals out here for assistance, so once those are done, it’ll make 9 times I’ve done it. Almost 2 hands worth of finger counting.

I have done this procedure once with the windshield wiper cowling on, and it extended the time significantly.

The windshield wiper cowling is a 10 minute job to remove though and gives great access for this job. While some complain about part removal, this isn’t as fiddly as the lower but in the egr cooler.

As for cost, I’ve done the job in 5-6 hours, so ask the local independent his hourly rate. But if you have no clean spare parts, I’m sure the local independent will not clean them for you, so the cost of the job increases as spare parts will now be purchased.

But I do this job about every 50 k miles after the initial one at 120 k miles, so my spare valve and cooler get used.

Just clicked 190k miles pulling into the garage last night and still going strong:


Hope that helps.

 

Wow, that could be close to a grand! Maybe worth checking some dealers

 

It could be, unless you’re savvy and know someone.

A dealer you would get close to that.

Probably an independent won’t be too far off from that, but I’ve not priced it out. Maybe some members here have, but locally I would surmise that the well respected independent shops will fleece you as bad as the dealer.

Definitely not te most glamorous job, but necessary to perform.