EGR cleaning

Have you, by chance, collected the EGR flow test value from before cleaning, so that can be added, with your mileage, to our data collection?

If you did not, was that because you knew about it but decided not to, or because you didn't know about it?

If you didn't know about it, can you identify the threads here where you read about EGR cleaning and got the idea to do it, but which did not mention getting the flow test value first? There must still be a few of those around, and it will be good if we can fix them.

 

I think if you remove bot the side studs, the two at the exhaust manifold can remain on. And bonus: the rear gasket will hang up on them, not drop.

update please, when you try it.

 

See how that goes, in particular with the EGR cooler. If the carbon is stubborn, try concentrated solution of "Oxi-Clean Versatile Cleaner", with hot tap water. Plug one end, fill with the solution, let it sit about an hour, drain/rinse/repeat. About 5 sessions should have it like new.

I would not use that solution for any of the other components, say the EGR valve of intake manifold; it's moderately caustic, will react with them. It's fine for the EGR cooler though, which is stainless steel.

 

I just removed the lower EGR cooler stud, left it off.

 

My EGR cleaning with Oxi starts here, then several more posts follow:

EGR & Intake Manifold Clean Results | Page 4 | PriusChat

 

Well, Techstream is a Windows app, so for starters you need a Windows laptop or tablet or something, and a J2534 dongle to connect it to the car. Those dongles come in a range of prices, from around $495 for the DrewTech one that Toyota tests and endorses and supports, down past around $170 for a decent one from an outfit in San Francisco that does their own design work, $80-ish for another cheaper one that is legit as far as I know, and sometimes as low as $20 or $30 for dongles that are blatant counterfeits of a real one that was sold years ago and whose maker was driven under by the counterfeiting.

Along with the choice you have to make about the dongle (how much to spend, and how you feel about counterfeits, and undermining the small number of legitimate makers we still have building the things), you also get a choice about the Techstream software itself.

If you download a legit copy, you'll only pay for a $65 activation key, good for two days, any time you want to use it, and that beats pretty much hands-down what you'd pay at any dealer to have diagnostics done, especially if you are actively tracking something down during those two days and repeatedly going back and collecting different data. At the dealer, that would run into money.

The other option involves copies of Techstream from other sources that might be modified to forget to check the activation key. You get to figure out your own comfort level with that.

Incidentally, you don't need Techstream to retrieve EGR flow values. It's a standard OBD-II "mode 6" monitor test, so any scan tool that allows you to pull up standard mode 6 test results will do the trick.

 

And, pretty obviously, you can hang the rearmost gasket on the studs. And alignment is then a walk in the park: getting it all assembled without the rear studs on, getting the gasket and rear flange aligned and the studs through, was a royal pain.

 

2010 Prius overheating



My 2010 Prius with 136000 miles showed an overheat condition twice within the last two weeks. The pump had been changed and I changed the thermostat. After reading quite a few situations on this site where owners cleaned the egr system to alleviate the overheat I tacked the job. Pain in the rear but I got it finished. Found out that after removing the wipers and cowl it was a lot easier to get at the bolts. Proof of the fix is that I took a digital temp reading of the reservoir coolant before and after. Before the coolant would read 165 F. After the temp. read 155 F. Thanks for all the info on this site my Prius should be good for another 70k.

 

That is interesting, but might not be telling us all that it appears to. Both of those temperatures (165 and 155 ℉) are below the engine's thermostat-regulated temperature of 180 to 185 ℉, and far below where an overheat light would appear (around 248 ℉). Essentially, they look like measurements taken during warmup, where a lot of things can be contributing to that observed difference.

 

Keep an eye on the coolant level for the next little while.