Wrapping EGR pipe?

[Red Merle]

So after much deliberation, I believe I am leaning toward letting stay my EGR system intact, even though I have the head off and now would be the time to make a swap. I really don't understand the wire jumping/resistor deal and I worry about being stuck in a pinch some day trying to explain what I did to a shade tree mechanic out in the boonies.

I did decide that I was going to wrap some of that fiber tape that can withstand 2000 degrees Fahrenheit for short periods of time on the wiring harness and when I put it all back together, I am going to tether it as far away from the EGR pipe as possible.

My question is whether I can wrap the EGR too? I know it deals with hot exhaust gasses, but if they are hotter, will that cause me an issue? The tape works both ways, obviously. If it keeps one thing cool, it must insulate the hot thing too, right?

I want to wrap the whole pipe and attach the tape with the SS zip ties that it comes with.


The truck is a '94, which I know matters for some reason due to OBDI vs OBDII.


Thoughts?

 

[math]

The pipe may need to shed heat - I suspect you'd increase the EGR temps doing that. I have no idea what the consequences may be. Also not sure how the tape would hold up to that.

 

[Red Merle]

The pipe may need to shed heat - I suspect you'd increase the EGR temps doing that. I have no idea what the consequences may be. Also not sure how the tape would hold up to that.

This is the crux of the question. It seems like hotter might be better, given that the motor is known to accumulate creosote-like deposits in the intake manifold and the EGR opening gets clogged as it goes into the manifold. Hotter temps might keep that from happening.

 

[jfz80]

Wonder what the temps are at that section of pipe. I slit a 2-3" piece of silicone hose lengthwise and opened it up to slide over harness.... you could do the same for the pipe if the temps wetent too high for the silicone

 

[math]

This is the crux of the question. It seems like hotter might be better, given that the motor is known to accumulate creosote-like deposits in the intake manifold and the EGR opening gets clogged as it goes into the manifold. Hotter temps might keep that from happening.

This is an excellent point, and the EGR pipe is easy to wrap. I'll let someone more knowledgeable chime in on this, because we also run the risk of melting something with super hot EGR gas. But it'd be great if it stopped the buildups in the clamshell.

 

[Red Merle]

Wonder what the temps are at that section of pipe. I slit a 2-3" piece of silicone hose lengthwise and opened it up to slide over harness.... you could do the same for the pipe if the temps wetent too high for the silicone

beno(Onur) thought they went up to 1000 degrees F in that area, but I think that is a good guess. I think the silicone would melt at those temps. I have an extra piece that I could try, but I don't see that working, knowing what I know about materials. The tape will definitely take the heat, it's the insulation factor that I would be concerned with. I don't want the pipe breathing fire down into my manifold unless that is better.

 

[math]

Do you have an infrared thermometer? That'd be an easy way to get the temp off the pipe. I'd also crank it up to 4,000 for a couple minutes and make sure that it doesn't do something crazy like get to 2500 degrees. Can't see how it would, but better to know.

 

[Red Merle]

This is an excellent point, and the EGR pipe is easy to wrap. I'll let someone more knowledgeable chime in on this, because we also run the risk of melting something with super hot EGR gas. But it'd be great if it stopped the buildups in the clamshell.

I actually worked as a chimney sweep for a while when I lived in Oregon back in the 90's. Cool air, hitting hot air with a lot of moisture and pitch(oil, tar, sap, etc) make for a clogged chimney. Lots of little fires burning in the pipe. A hot blast will clear it out, but you risk burning the joint down. Same principle has to be at work here, right?

 

[Red Merle]

Do you have an infrared thermometer? That'd be an easy way to get the temp off the pipe. I'd also crank it up to 4,000 for a couple minutes and make sure that it doesn't do something crazy like get to 2500 degrees. Can't see how it would, but better to know.

The truck is apart right now. I am not going to wrap the pipe if I don't do it before I put it back together. The fittings for this and the PHH should be dealt with now, my hands won't even fit back there if I don't do it now. This is a one time decision.

Get yours running and take a reading for me.

 

[Red Merle]

Bump.

Anyone else have an opinion on this?

 

[SmokingRocks]

I wrapped mine with lava rock heat wrap. I can't imagine that a foot of pipe is designed and moreover expected to shed heat, so I just did it.

 

[ZackR]

The resistor trick to disable the EGR is just a matter of unplugging the electrical connection for the temp sensor and plugging in a resistor. Once that's done the vacuum lines to the EGR can be blocked off and the EGR will never get hot again. The resistor is to trick the ECU that the EGR temperature is correct so that a check engine light doesn't come on. If EGR is later wanted or needed it can be reversed in a matter of minutes.

The resistor is a 4.7 K-Ohm, available in a 5 pack from radio shack (part # 2711330).

 

[greentruck]

My opinion? I don't think the hose is a good idea, but the tape sounds OK. I've always questioned wrapping the wiring tightly. The tape heats up, the whole thing is hot, the insulation gets soft, rubs through from vibration and you've still got issues down the line. To me, it makes more sense to wrap the tube. They can't be counting on that for heat dispersal. And everything I've read about EGR is hotter is better and it can't make it more than a little hotter in the short travel.

Course, I'd still put the infrared thermometer on it just to see what it does, doubt you find much different, but maybe someone with an unwrapped pipe can take a baseline reading to compare to. I'd do that, but ours is a 97 and I don't think that would be a good comparison.

 

[jay]

Sand which a block off plate an call it done the restiot goes between wire or find a resttor plug off a 93 the discontisold. solder the reztitor bring the two wires together

 

[jay]

82824 35020 93 only harness has reztitor built I plug easy 2 pin connector

 

[jay]

Cut wire on engr temp sensor an install resistor. Give false restiance values. That's if you dont want cut your harness an make a plugin in resttor off egr

plug

 

[jay]

take that egr connection. Snip it use radio shack part. Solder both ends together then plug that into your harness. It will give a false reading no egr needed an no hot pipe I have block off plates gotta get me a Paypal account 1st though.

 

[jay]

Egr is us spec non us spec dont have egr. Egr is for the feds the philth the control. Just smile at the Dmv with restior an block off plate an dummy egr replace intake egr gasket also. Cuz u wanna keep 14/1 gasburn no intake leak

 

[Red Merle]

OK, the part I don't understand is where people say to plug it in to the harness. Plug what into what? Do you take the resistor and bend it so that each end goes in one of the wire ports on the connector the car came with? Does it matter which end goes where, etc? The pics help, but it is still kinda fuzzy in my brain. This is why leaving it alone seems like the better option for me.

I like greentruck's advice. I think I am just going to wrap the pipe and see how it looks. I may wrap the wire harness too with the rest of the fiberglass tape.

 

[ZackR]

I bent the ends of the resistor and plugged it into the harness, then sealed it up with electrical tape. Be careful when bending the ends since they can break (having the radio shack 5 pack is handy in case you break one). No cutting of the harness needed. It doesn't matter which end of the resistor goes where since its just closing the loop.

A temperature sensor (like the EGR one) is just another type of resistor that the resistance changes depending on temperature. With the resistor in place the system is "seeing" a temperature that is within the expected range.

Irregardless of the resistor method make sure to secure the harness so that it doesn't touch the EGR pipe. As long as you have some clearance and the wires are safely within a loom they wont burn up. The point of the resistor method is to further protect the wires by not allowing the EGR pipe a chance to get hot in the first place.