Cleaning EGR Hole behind throttle body....

[cosmic_splatter]

Took apart the throttle body today to clean the EGR Hole. It was definitely bad!


Here is the backside of the throttle body. Pretty dirty as well...


Should the throttle body gasket be put back with a sealant or dry? Put a few small surface scratches on the gasket surface. The old gasket seemed welded onto the throttle body. Will try to clean that up some with 3m pad.

thanks,
John

[fixkick]

i think dry,
there are 2 types. just paper and with built in sealant (like all Honda's ,for ages have)
that blow gasket above looks like with built end sealant

i used that tacky type, just to hold it. type.
or light film of old type Permatex 2b? looks like tar.


that was one nasty , port !
the PCV cloud hits EGR cloud and bam ,rat nasty.

[cosmic_splatter]

Fixkick,

So what sensor actually throws the 51 code? Is it the sensor on the EGR main valve? Or is the vacuum side that tells the EGR Main to fire? How does the sensor determine there is a problem to fire the CEL?

I think my issue is the clogged port. It looked totally restricted. I took off the sidewinder pipe when cleaning since I didn't want the carbon to drop back down into the pipe. That pipe is a bit of a trick to get out. It feels like you may break a post when pulling it out and putting it back in.

John

[fixkick]

on your car the EGR main, thermprobe (see 2 wire there) is too cold.
easy, engine gets hot, and you drive and the ECU opens the EGR, and then this 51 monitor fires off and check the probe, if it read 300k ohms its cold if 10k ohms its red hot and passes.
if cold it fails. just a single test.
if the stall test passes and you can see it open gunning a fully hot engine, its working and the probe is packed in carbon.
yes, that sidewider is funky fit, my guess its best removed from rear first.
be sure to not lose the SST gaskets. or it sucks air and messes up idle.

if the stall works, and the probe gets hot , 10k ohms , (meter it) and the ECU opens the valve hot, it will pass.

[cosmic_splatter]

Thanks fixkick! I didn't clean that probe since I started to turn the sensor from the nut and it wasn't budging so I stopped. I didn't see a way to clean it from the engine port side. That could still be an issue, but I think mine was the clogged port since it failed the stall test. I should have it back together in a few days and will be able to tell. I'm half tempted to pull the head and have the valves redone, but I think I'll wait until I pull the engine for a rebuild and new clutch.

I'm wondering if the engine at some point had a bad 02 sensor and was failing to go into closed loop and running rich causing all that carbon to build up. It was really jammed up in there! Or, could be ethanol gas?

John

[fixkick]

its not easy to clean,that probe and most dont want to budge.
that is bingo , not in closed loop , makes carbon and packs probe and all.
getting it clean is not easy. and the whole thing is like 300 bucks. so that not cool..
you could attack it with 16 penny nail, jabbing it ,until its not impacted, or make have someone bead blast it out.

[cosmic_splatter]

I'll see if I get another CEL after opening the intake port. If I do, then I will probably have to try to clean that probe. Do you have to reset the computer or will the CEL clear itself now that the port is open? Not sure how the CEL lights are programmed. If they don't go off until a dealer/technician resets them? Or, they will self clear when the problem is taken care of?

---

Here is one for around $100, but there is no temp probe.
http://www.ebay.com/itm/EGR-Valve-ACDelc...87&vxp=mtr

[fixkick]

the cel can take many driving cycles to clear, i never do that. ever.
i pull the dome fuse , and it clear the NVRAM memory in the ECU, and forgets all stored DTCs.
its very very simple design this, you dont have a scan tool but the dome fuse always works, if not then leave the fuse out for 5 full minutes. (caps can take a bit to discharge in side memory bank)

yes ,all DTCs can self clear but there is no reason ever do let that happen, its a waste of human effort. and fuel... big time.
CEL glows., fix cause.
dome fuse out, then back in. (reset)
CEL flashes 12s now.
drive see if CEL fails to hold 12s (12s is happy feet)


on the 96 we know the conditions for 51's (P0400s) but the 1995, im not sure,
i think its hot engine, light cruise.
im not sure a 95 will set 51s, parked gunning the motor., never tied that.
it is very easy to fool, a 10,000 ohm resistor in place of the thermoprobe fools it.

the ECU does not check for a change in temperature there, dumbly, it just goes, gee, is this thing hot NOW. oh, yes it is, pass.
simple and dumb it is and is the most easy to diagnosis. unlike all other types used.

[cosmic_splatter]

From what I saw, the check engine light went on immediately with a code 51 when the vacuum line was kinked to the egr solenoid. That happened right at idle. After I fixed that issue, I drove it for a couple of days with no issue, then the check engine light came back on while on the highway again code 51. So, it appears the vacuum side triggers right away, but the EGR dump process takes some driving. At least that's what I think is happening. Hopefully, after the cleaning, it should take care of it for another 100k miles.

[fixkick]

that 11mm hole , the EGR mono port
with a rubber hose.
can you blow air with lips from there. to the EGR port (removed) freely, if not , that path is blocked too.
on my 97, every single path was blocked, a small horror. but engine was in 100s pieces so... was easy to fix.
some folks just drive it with 51, for ever. now you see why.

if the stall test works hot, 800 RPM and drops to say 400, its working , or, stalls.
i use a laSer RPM gun (i uses this because it works on ALL THINGS)

i use a $1 bottle of liquid paper, ask mom. "typewriter days, omg"

and paint a dash on my damper pulley
and read RPM real. with this pointed.
http://www.amazon.com/Digital-Photo-Lase...B000EUT9ZS

i say this for folks not knowing 800/from 400. the RPM cuts in half or stalls.