yes it's a serious question. I was hoping for some more concrete reasons than those listed.
Disable the EGR system the (mostly) Toyota way (3 Viewers)
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yes it's a serious question. I was hoping for some more concrete reasons than those listed.
- Thread starter
- #22
I'd say melting your engine wiring harness is awful concrete to me, but maybe you disagree.
I agree that the possibility of the EGR effecting head gasket failure is somewhat nebulous, though I'd argue that there's a lot of evidence that supports that.
Hmm....as for other reasons, here's a few that I can think of.
- Mr. T added the EGR system as an afterthought, the 1FZ was not designed with it in mind, so by disabling the EGR system you're reverting back to the original design.
- For those who don't have to deal with emissions (or have easy emission tests to pass) it's an inexpensive way to deal with EGR codes, which may or may not be easily solved. There have been many cases of people throwing part after part at the EGR system in an attempt to fix it.
- Free up a bit of room in the engine bay (not a big benefit).
- Simplify your engine, one less thing to break.
Really the wiring harness and the strong possibility of it effecting the head gasket are the two biggest reasons for me.
my wiring harness has 230k on it with out any issues and not all HGs fail at the #6 cylinder.
Blame the EGR if you want but I'd more likely blame the dead spot in the temp gauge and an engine running for long periods of time at an elevated temp without the driver realizing it.
This happened to me this spring. I was running down to NC for a trip and my modded gauge was running a little warm in the mountains. Turns out that the radiator was shot. When I am saying warm it was probably around 210*. well within the dead zone of the stock gauge. With the stock gauge things would have needed to get a lot worse before I would have been made aware of it.
Justify this mod any way you want but selling it as a HG or harness deterrent to failure seems like a stretch to me.
Blame the EGR if you want but I'd more likely blame the dead spot in the temp gauge and an engine running for long periods of time at an elevated temp without the driver realizing it.
This happened to me this spring. I was running down to NC for a trip and my modded gauge was running a little warm in the mountains. Turns out that the radiator was shot. When I am saying warm it was probably around 210*. well within the dead zone of the stock gauge. With the stock gauge things would have needed to get a lot worse before I would have been made aware of it.
Justify this mod any way you want but selling it as a HG or harness deterrent to failure seems like a stretch to me.
alia176
SILVER Star
Although it's too late for lot of wiring harnesses, that EGR pipe does wreak havoc and that has been proven on this board countless times. I was the victim of this three years ago, unfortunately. Definitely can't hurt to disable the EGR from that aspect and to keep the intake cleaner. Having to scrape the pistons of the varnish (PCV + EGR) was no fun.
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- Thread starter
- #25
And both my trucks have 150k with no issues. I've seen trucks with 300k on them with no issues.
But it still doesn't mean that it's not a contributing factor, or it can't be a danger. You may not mind it, but I'm not real fond of the fact that if a single plastic clip fails it can wreak significant amounts of havoc, because Mr. T ran an incredibly hot pipe next to the harness.
It's simply a poor design, and anyone who looks at the EGR system will admit that. 99% of what Mr. T's done with the 80's are absolutely wonderful design, and I'm constantly amazed at how little of it can be improved on. The EGR system, however, fails that miserably.
Nope, but the vast majority do. In fact cdan doesn't even want any more blown headgaskets to add to his collection unless they're not in the usual spot, because it happens so rarely.
I absolutely agree that the dead spot is an issue, and RT's temp mod is on my list of things to do
Two very different mods for two very different purposes.
And some of your justifications for some of your mods seems like a stretch to me. How about we just leave it at that, and let everyone else decide for themselves?
You know better than that, Rick. A vast majority we've seen on this forum fail at that spot.
From prior discussions on the board, it seems that head gasket failure is not nearly as common in Australia, where they have no EGR. The fact that the failure most often occurs at #6 and the location of the EGR is simply a coincidence to you, I take it?
IdahoDoug's rigs and many other have failed with meticulous maintenance. While I'm sure overheating will accelerate HG failure, I'm not convinced that every case, or even most cases, are due to this.
Personally, I don't find the harness or especially the HG deterrent to be a stretch at all.
most everyone who has replaced their HG has also left their EGR system in place and haven't had another problem. It would seem to me if the demon EGR was the culprit of HG failures it would continue to do so.
I tore down a 1994 engine with 280k on it and the original HG was in perfect shape. So what does that tell you?
I tore down a 1994 engine with 280k on it and the original HG was in perfect shape. So what does that tell you?
alia176
SILVER Star
I suppose you have to wait another 10 years or so to see if the same engines blow HG in the same spot
Rick is just annoyed because HE didn't come up with this idea in the first place, is my guess and now he is going to argue for the sake of arguing.
This has been beaten to death.
EGR, unless needed for emmissions, is a waste of space..Ive always disabled EGR systems, and never had any problems on countless makes and models. On top of that I live in the hottest spot in the USA, and preignition is a non issue on 87 pump gas.
Take a look at 350 chevys for example: do you really think it matters to the engine if your running a EGR system or not? How many emmissions configurations has GM built them in over the years? Doesnt matter. There is little to be gained either way. I'll take the head gasket insurance by disableing the EGR anyday.
EGR, unless needed for emmissions, is a waste of space..Ive always disabled EGR systems, and never had any problems on countless makes and models. On top of that I live in the hottest spot in the USA, and preignition is a non issue on 87 pump gas.
Take a look at 350 chevys for example: do you really think it matters to the engine if your running a EGR system or not? How many emmissions configurations has GM built them in over the years? Doesnt matter. There is little to be gained either way. I'll take the head gasket insurance by disableing the EGR anyday.
- Thread starter
- #30
I suppose you have to wait another 10 years or so to see if the same engines blow HG in the same spot
Correct me if I'm wrong, but isn't the replacement HG a slightly different design?
alia176
SILVER Star
Basically if you take the terminals out of the connectors, and hold them side by side, you will see what I'm talking about.
Pics will come when I get my truck back from getting the new exhaust.
Let's see some pics boy
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- #32
Yeah yeah, it's on my list of things to do. Company and work take precedence. I argued that my truck should, but I "let" the 
win that one. 
win that one.
My only problem with the JBWeld is that I want to be able to return the system to stock in case I run into any particularly anal emissions checks. Has anyone thought of an easily reversible way to do this?
I don't get the JB weld thing on the modulator.....and I don't know why you need to block off plate the system.
If your worried about emissions checks, then simply leave all the parts in place and and disable them by taking the vacuum lines off and cap off the ports on the throttle body. Your system is disabled. The only reason to start pulling off parts would be to clean up the look of your engine.
This isn't complicated.....I have been running mine like this with the resistor mod for 2 years now with no issues, and its a simple re hook-up for our testing.
If your worried about emissions checks, then simply leave all the parts in place and and disable them by taking the vacuum lines off and cap off the ports on the throttle body. Your system is disabled. The only reason to start pulling off parts would be to clean up the look of your engine.
This isn't complicated.....I have been running mine like this with the resistor mod for 2 years now with no issues, and its a simple re hook-up for our testing.
- Thread starter
- #36
Yup, you can easily swap vacuum lines to disable it.
I didn't want to do that, so I went a different route.
I didn't want to do that, so I went a different route.
alia176
SILVER Star
I'd like to which vacuum lines you're plugging? I need to see a pic pls! The EGR modulator and the EGR valve has three lines. I'm mostly curious about the P & R lines.
thanks.
no pics....just pull the 2 lines off the TB that go to the modulator and cap off the nipples on the TB...thats it..or you could loop a 3" line from one nipple to the other like I did essentially capping them off.
The egr system recieves it vacuum from these 2 ports on the TB so you have disabled the system by doing this and the egr valve can no longer recieve any vacuum required to open it..
you can leave everything in place if you want..even all the lines its up to you...
of course you will be getting that dreaded CEL shortly after doing this....thats where the resistor mod or something to trick the ECM comes into play..
The egr system recieves it vacuum from these 2 ports on the TB so you have disabled the system by doing this and the egr valve can no longer recieve any vacuum required to open it..
you can leave everything in place if you want..even all the lines its up to you...
of course you will be getting that dreaded CEL shortly after doing this....thats where the resistor mod or something to trick the ECM comes into play..
alia176
SILVER Star
Sorry to belabor this point, but I'm a visual kind of guy. I can see the need to plug of the two lines at the manifold (P&R) but shouldn't the third line be plugged as well (arrow on the right side of pic)?
3FE..OK. That line goes to through the manifold to the VSV right? If so you can plug it off or leave it as is..it doesn't matter, as the only vacuum the system is using comes from the TB. The VSV is simply a blow-off so to speak for the vacuum coming from the TB...it just acts as a simple on/off switch for the system when at idle, cold or at WOT.
Hope this helps.
Hope this helps.
