The reason I ask this is because in attempting to clean mine, I found a system so clogged that you could not blow through the cooler. I am not sure the plunger attached to the sensor even works. I pushed on it a little and it did not move. Before beginning the cleaning process the car worked fine and got 50mpg. I am sure my system is and was inoperable. What is the point?
The car has 272,000 miles. I am not a great owner. We bought the car new. I am much braver now as I have successfully change the brake booster assembly and reconditioned the HV battery. I know I should have cleaned it sooner.
I soaked the EGR cooler/radiator in oxiclean for about an hour (could not wait to try the pressure washer). The pressure washer blew out enough of the buildup to the point I could blow air through with little effort. I can not tell if all of the passages are clean so I am going to soak it for a while and hit it again with the pressure washer. I held the part with a vice. The part was lightly held and protected with several layers of cardboard. Does anyone know how to test the sensor assembly so that I can tell if the plunger will move? Thanks in advance for the help.
You might want to spring for a new EGR valve. The EGR valve because besides being carbon impact, there's an internal plastic "ramp" that get's messed up. No one's quite sure why, it could just be a poor choice of materials/design; I'd speculate with a clogging system it might be worked harder. With the EGR cooler, you might want to try a soak with strong lye solution. Lye, aka sodium hydroxide. The smaller of the EGR cooler ends is roughly 21 mm diameter: with a white rubber stopper installed, it'll take about a cup of solution. Prop it up in the corner of a laundry sink works good. Be careful as heck with that stuff, wear safety goggles and rubber gloves. The usual drill, soak for an hour, rinse, repeat. In the States it can be hard to find lye, but hopefully not impossible. I was going to say run a wire through to open it up, but it sounds like you're making progress. Has the head gasket previously failed, or no? How's the oil consumption?
The price for the EGR valve is all over the place. Toyota parts deal has it for a little over $300. 25620-37110 - Toyota Parts Deal On eBay, Manhattan Toyota has one for $153. GENUINE TOYOTA OEM 10-15 PRIUS, 12-17 PRIUS V, EGR VALVE KIT 04004-58137 | eBay There are others on EBay for as little as $100. Are some of these choices not to be trusted?
The ones on Ebay for $100 are probably used, might be knackered. Amayama has the replacement (25620-37120) for $280.65 CDN all-in, for me, on West Coast Canada: That converts to around $196.46 USD: Maybe disassemble what you've got first though, see how that internal ramp looks. The screws on the black cap are tough to break loose. I managed with a manual impact screw driver, and a heavy ballpeen hammer. Put a block of hardwood under the other end, to keep the studs from touching down, set the whole thing on a heavy, wood chopping block, pressed the impact screw driver firmly on and slightly counterclockwise, gave them good whacks. It did help that I had replacement screws on hand, in case I completely messed them up: Steel Head Socket Head Cap Screw M5x16 (Bought 50, still have 48, if you happen to be in Vancouver, lol) When I opened up mine: Need a crash course in EGR valve disassembly | PriusChat
I have not had to replace the head gasket. Thank you so much Mendel. I have a few more questions you might be able to help with. Should you be able to push the plunger of the valve assembly in? I can not push the plunger in. Will the car throw a code if the part is not working? If I was to put the car back together with the old part and decided to get a new valve, could I change it without taking out the cooler?
Buy the EGR kit for $154 on toyota parts deal. It comes with the new egr valve and all the gaskets. If you buy just the egr alone it’s double the price. Not sure why toyota does it this way. 04004-58137 Genuine Toyota EGR Valve Kit
You’re welcome! Glad I caught this thread early. Another thought for your EGR cooler. I’ve been tempted to buy a new one straight from Japanese sellers on eBay for about $150. Would save you a bunch of time. Also don’t forget the intake manifold and the 4 small egr passages. I soaked my cooler in hot water and a gallon of purple power for an hour, then blasted it out both sides with an electric pressure washer.
Yes. Though it’s been about a while since I had mine apart. Either jammed by carbon, or just seized. You’ve got the black plastic cover off? If so how does that ramp look.
I took a feeble attempt at opening it up. The screwdriver slipped and I had visions of a messed up screw head with no ability to put it back together. I will probably spring for the $150 part on ToyotaPartsDeal. My son needs the car on Monday. I am putting in an oil catch can, cleaning the air intake, cleaning the MAP and changing the PCV in addition to the EGR. If I can open the EGR valve up I’ll let you know what it looks like. I believe it may be frozen shut. I can not move the plunger.
The 4 narrow passages on the air intake seem pretty clean. I used brake cleaner. It sprayed through with no resistance. I’ll try your suggestion. Thanks
You want those 4 passages to be very equally clean. The only sensor the car has for EGR function is the single MAP sensor low on the manifold by the throttle body. It is an overall pressure sensor. It's capable of detecting problems with the overall system flow, but it can't detect a flow imbalance among those 4 passages. That can result in some cylinders getting too much EGR and others too little. A mild symptom would be rough running at mid-loads where EGR is used (but not at idle or high loads, where EGR isn't used). An inexpensive hand impact driver (the kind you twist with your hand and bop with a hammer) is just the ticket for taking out the screws that hold the EGR valve together. Without that tool it frustrates people.
A brush designed for cleaning reusable drinking straws is good for those passages; @ASRDogman has mentioned-gun bore brush. For some reason those passages tend to clog sequentially, commencing with cylinder one (left end as you stand at front facing engine bay). The adjoining wall between cylinders one and two is where head gasket usually fails.
I bought the EGR Valve from ToyotaPartsDeal. Unfortunately it has not arrived yet. When disassembling the EGR radiator/valve assembly, you take it all out in one shot. Is it possible to take the EGR valve out without taking the EGR cooler/radiator out? I am considering putting the car back together with the old non functional part. Only having one functioning car is difficult. I am hoping to be able to change the valve without taking the EGR cooler and windshield wiper assembly out. Is this doable? Thanks
Look at the photo. First, disconnect the connector. Then unscrew the two lower bolts (A), which secure the curved tube directed to the intake manifold. Then unscrew the two nuts that secure the valve to the cooler (B). The main thing is not to drop the unscrewed nuts and bolts. It is difficult to look for them in the compartment and get them out. EGR by MAX2 posted Mar 27, 2025 at 11:31 AM
