DupermanDave

What's it mean when the EGR modulator has fluid inside of it? Recently I dumped a load of water on the intake manifold to find a leak (found it and fixed it) Now I'm only getting an EGR code and I checked the modulator and its filter and it's wet. It's not coolant, definitely water (or water evaporated from coolant?)

I let the filter dry out and replaced it, and it keeps getting wetter every time I drive it. it starts out moist, and then gets soaking wet.

DJ99

Sounds like the rubber diaphram may be broken, letting exhaust gas come up through to the filter side. Exhaust is made up of CO2 and water. Is the filter dark and dirty? It should be white. Check it by removing it and blowing through the bottom port. If any air goes through, it's toast. There are other checks for the vacuum modulator in the FSM.

DupermanDave

Eeek. I actually did that last night, removed the modulator and blew air through the bottom. If i remember right, I could nto blow air through it, but i could suck air out (was trying to get all the water/moisture out of it)

The filter was all black, but it's pretty old. I'm looking for a new one.

DJ99

Sounds like you found your problem! It's not just the filter, but the whole part (old rubber!).

I got one off ebay by posting the Toyota part number. Make sure to check the "search title and description" box to get the best search results. I felt that I was lucky to get one for $38.49 shipped.

Good luck to you! Please let us know how it goes. I think this is an overlooked common Toyota issue.

DupermanDave

So I shouldnt be able to suck or blow air through the bottom port?

looking on amazon and partsgeek.com looks like i can pick one up from $35 to $47 (all new)

DJ99

Ha ha! NO, it's a rubber diaphram. Do you want to get pregnant?

The exhaust gas presses up on the diaphram via the bottom port and changes the vacuum to the EGR via the top ports. Basically, the EGR should not be open except when the truck is cruising, where it lets some exhaust gases recirculate. The diaphram just moves up and down according to the exhaust pressure. If you can suck air through it, it has holes in it, which leads to a wet filter. It should never be!

Post your part number that is on the modulator and I'll help you find one on the net if you want.

DupermanDave

knew someone was gonna crack about the suck/blow stuff. Was easier than saying "I can apply a vacuum and get a flow of air" and "I can forcibly push air into it."

I'm going to order it from partgeek. $47 isnt too bad, and they've been quick in the past. Gonna get new tires first and then worry about the EGR. I was just worried I blew a headgasket or something and this was a symptom.

DJ99

Good job. At least you know it's bad. I bet your truck runs better after this quick and easy replacement!

Please let us know. Maybe some other poor Toyota owner will be enlightened.

DupermanDave

you sure its faulty? i was checking the fsm yesterday and doesnt it require a vacuum on the lower port?

DupermanDave

yup, i double checked the modulator and it says you should be able to blow air through the bottom and come out another port (which mine is able to do)

DupermanDave

I tripple checked the FSM and tested the modulator as per the FSM. It looks like it is working properly.

Anything else to check? Should I check the EGR at the cylinder head? We did the head gasket about a year ago, and during that time I cleaned the EGR very thuroughly. But it could be gunked up again.

NYChopshop

yes. Look over the entirety of the hose system for your EGR and vacuum system. I just did that on mine and found 2 busted to hell hoses needing replacement and a new PCV valve because I was getting oil in my intake. If you pop off your intake at the throttle body and run your finger around the inside and find oil, you need a PCV valve. Another cheap part to fix a huge PITA.

DupermanDave

my PCV valve is about 2 months old and also just has a new gromet (as of 5 days ago)

NYChopshop

attaboy! still, check the entire spiders web of vacuum hoses under that sucker. You may just need to slide one back onto the nipple, or do nothing at all, but its always worth a look. Did your bad EGR system give you a loud grumbling at cold startup like mine did? I couldnt for the life of me figure out what the F-nuts the noise was actually coming from. There was a 90 degree bent hose going from part of my EGR system to the intake manifold on the passenger side that had eaten it bigtime, and the PO had apparently just cinched up a little and prayed noone would notice. The hose had totally popped off since. I fixed it today in class (I'm studying to be an ASE certified master collision repair technician). Happy day.

abecedarian

Water in the EGR 'filter' is a byproduct of being 'normal'.
If you assume EGR functions are 'on', when the VSV for the EGR valve turns the EGR valve 'off' or 'closed', the vacuum that was in that tube to the EGR valve (what was holding the EGR valve open) has to be released, otherwise the EGR valve will be held 'on' forever (or at least until the engine is shut off). That means that outside air has to come in to the system to fill the vacuum- hence the need for the filter: to keep crap out of the EGR diaphragm. If the filter is wet, it's because it was wet to begin with.

DupermanDave

i checked all the hoses and pulled some off, but I supposed I could check again. All the hoses to the modulator are tight fitting. all the other hoses on the vacuum rail are almost new and not cracked, and I can't find a leak anywhere.

is the code 71 caused mainly by the EGR (with sensor) on the back of the intake plenum, or the EGR setup on the head?