at 150k miles the egr valve cooler assembly should be cleaned

Yes to this. It would need an air flow/pressure sensors and a computer to determine how plugged up this is. I suspect even this wouldn't work since the sensor could get gummed up.

 

I just got done cleaning my spare EGR cooler and removing the original cooler this weekend. The spare was so full of junk I couldn't see the steel fins inside of it. After 2 chemical soaks per day, using @danlatu 's wire drill technique and hours of flushing, a week later carbon stopped coming out of it. The difference was night and day.

The most difficult steps to its removal are:
1. The nut underneath it holding it to the engine. You can't see this. It's best to either look at your spare cooler or view its picture before attempting this.
2. Hose clamps. I purchased a couple of different long angled pliers to make this easier.
3. The bottom stud and nut on the back of the cooler connecting it to the exhaust manifold you need to get underneath the engine and loosen with one arm.

When you're laying over the engine bay be careful how you're supporting yourself. There are lots of electrical connectors.

 

How was your original EGR cooler's condition? Also, did your purchased cooler come complete with EGR valve? Either way, how is cleaning of the valve, easy in comparison?

 

I bought my spare cooler assembly on Ebay for almost $50 and it came with an EGR valve.

My original at 70k miles looked like it has the same amount of buildup. I can just barely see through one of the fin openings.

I also cleaned the EGR valve with carb cleaner and a rag. It is a super easy, five minute job.

Cleaning the PCV valve is even quicker and easier. Just fill with carb cleaner and shake. Use nitrile gloves

I'll try to post pictures later.

 

Thanks for that. It'd also be interesting to know: what this does to driveability, mpg, any differences you notice.

 

Question to those experienced with this: what did you do to the pipe on the exhaust manifold? I'm assuming to clean it with a pipe cleaner and using solvents. Should I be concerned about carbon reaching the cat or heat exchanger?

I'm hoping the carbon will just burn out of exhaust.

 

Wire pipe brush cleaner and solvent is what I used. Carbon deposits will reach the cat and egr cooler as they are "in line" with the exhaust effluent. I also did a visual and air flow test to ensure I got it cleaner than it was.

Key is to be aware and find a way to address it.

Hope that helps.

 

Oh? What should it be lubricated with? The temperature must be awfully high.

 

Are you joking? That valve gets subjected to intense temperatures. WD40 is a lightweight lubricant; it would get burned off in no time. It certainly won't last 40,000 miles.

 

The EGR cooler sits between the EGR and the hot exhaust. Anything moving through the EGR cooler is cooled down close to engine coolant temperatures.

Engine oil could also be used to lube the EGR

 

This is what a clean EGR cooler looks like. I could not see through originally since it was completely pitch black.

Clean_egr_cooler by mjoo posted Jun 7, 2017 at 10:49 AM

 

With the EGR cooler installation this weekend - I had to improvise on Toyota's FSM instructions. It was impossible to install the bottom stud between cooler and exhaust manifold with Toyota's sequence b/c the stud wouldn't tighten down. So I removed the cooler and EGR assembly completely, then torqued only the bottom stud to the cooler, then installed the cooler.

Also, the bottom stud between engine and cooler was not done - there was too much in the way. It may be possible with a magnetized socket tool. I've saved the stud for the next cleaning.

I can post a picture if interested

 

In the attachment I posted (in posting #9) theres a somewhat involved install sequence. Maybe that would help? I don't claim to understand it mystelf, but have a read.

BTW, the web site is in it old "early morning sh*t storm" state this morning. Doesn't seem like anyone cares much, never any explanations, it just clears up.

 

Yes, I had the Factory Service Manual (FSM) instructions in front of me during the installation.

 

I wonder if the US market will get this warranty enhancement. Seems like it should become a high mileage TSB for replacement at 140K. My vehicle is currently at 143K and I'm a little worried. I looked up the part on Auto Nation and it's $254.57 + shipping. An engine replacement or rebuild due to head gasket failure would be much more than that. I think I'll ask my service writer at my next oil change about this.

 

It must depend on how much city versus highway driving you do.

I recently bought a 2010 with 73k miles and I was getting the startup knocking. PC recommended I disassemble the intake and EGR and sure enough it needed cleaning. The EGR cooler flow was down to a trickle (tested with a garden hose). Like others have mentioned, the EGR to intake manifold pipe is the canary in the coal mine.

 

Geesh that's not a lot of miles.

Regarding your comment on city vs highway driving making a difference to clogging, which of those two are you (or anyone?) thinking is more clog prone?

 

I think it also depends on the previous owner and what types of experimenting they were performing .