Hey guys, I'm planning on cleaning my intake manifold on my 2010 gen 3 prius which is approaching 150k. My question is, since theres coolant lines involved, should I also drain and replace the engine coolant during the cleaning? I wanted to replace the coolant anyway, and I figure it would make sense to do it at the same time. Just curious if there is a reason I shouldn't do it at the same time as cleaning the intake manifold.
Perfect time to do it. Every time I clean the egr circuit, I changed the coolant . Keeping the engine coolant fresh I feel is another key to success at high mileage.
If you're just doing the intake manifold, you need to remove the throttle body, but there's no need to disconnect it's coolant lines. They can remain connected when you lift the throttle body off. If you're doing the EGR you do need to disconnect coolant lines, but if you drain a couple of liters into a clean container before starting, the coolant level will drop below the EGR components. Just be careful when lifting the cooler off, there's a little bit of coolant trapped at the lower back corner. After the EGR is reinstalled, pour the drained coolant back into the reservoir. It'll be a little high, but should settle back to normal with a bit of driving.
Hmm so glad I asked! I was planning on cleaning the egr pipe in a separate round, being that it seems a little tricky and time consuming. Is the egr cooler different from the egr pipe?
Yes. The cooler is composed of many small fins where the carbon deposits collect, making this easier than the pipe to clog. I’d add that to the list for cleaning.
Here's the EGR components: Watch @NutzAboutBolts videos, pinned at top of 3rd gen Maintenance sub-forum. There's one for just cleaning the pipe, and another for cleaning the complete EGR system. (Yet another for intake manifold cleaning.) Also read through this thread on EGR cleaning, lots of info: EGR & Intake Manifold Clean Results | PriusChat Some relevant Repair Manual excerpts attached:
Thanks guys! I wanted to do the intake manifold and egr cleaning as separate items, being that I want to take my time and not get stuck in the limited daylight we have now in the fall. This definitely helps determine that i could do the intake manifold without the coolant replacement, then do egr with coolant replacement on another day.
Ok guys. I have the instant cleaner for the intake and cooler. You HVAC guys will be smacking your head, but Nu Calgon, evaporator cleaner made my intake and cooler crystal clean after soaking for an hour. For you non HVAC guys, this cleaner is what your AC guy uses to clean your outdoor AC unit. I used NuBrite, the blue stuff mixed 3 to 1. Incredible results; soak, rinse, done. The cleaner was black and the intake and cooler look like new.
Interesting, here's a link: Nu-Brite Nu-Calgon Description says it's alkaline. Accordingly I'd say no problems using it on EGR cooler which is 100% stainless steel , but on intake manifold if you use rinse VERY well. I'd be cautious using it on EGR valve, which is mostly aluminum, and has some electrical internals. Alkaline cleaner residue can react with ferrous bolts, inserts. And alkaline dulls aluminum quickly. My 2 cents, just use on cooler, and use brake cleaner on the rest.
