EGR Mod

[poppy986]

My old truck failed the MOT because of the emmissions were to high Poo !
I have had my old girl for 6 yrs now and have only just got
around to do the EGR mod , took a bit of locating the thread but only
took a few minutes to do .
Re moted her today , passed the emmissions with flying colours
the truck seems to run a lot better also ? but there you go should have
done that ages ago ha ha .A link to Bushwackers original post for anyones
interest
http://www.hiluxsurf.co.uk/forums/at...1&d=1155739046

Cheers me dears another year of surfing

Chris

[smiffy]

Top modificaton if not the cheapest!!!! I had to do it yo my Surf for the same reason. Aint this forum just the bestest ever

[internetsurfer]

running veg oil through it will bring emmissions down too i suppose .

are there any after effects blanking that pipe off , like loss of power or excessive fuel usage etc ???

[Koi]

I did my first Surf and other than less smoke, a bit more low down grunt, the MPG better. I did a lot of research on the EGR before making my mind up, heres my post from a couple of years ago


Alot of people have done the mod and noticed no difference, thats probably because the valve is already knackered and failed shut.
I did a alot of searching when this subject first came up a few years back and the following is my take on the info I found.

Exhaust Gas Recirculation Valve
Exhaust gas recirculation (EGR) systems were introduced in the early '70s to reduce an exhaust emission that was not being cleaned by the other smog controls. Oxides of nitrogen (NOx) are formed when temperatures in the combustion chamber get too hot. At 2500 degrees Fahrenheit or hotter, the nitrogen and oxygen in the combustion chamber can chemically combine to form nitrous oxides, which, when combined with hydrocarbons (HCs) and the presence of sunlight, produces an ugly haze in our skies known commonly as smog.

So basically it recirculates some of the exhaust gases back in to the block to reduce NOx. It says in doing this it reduces the operating temperature of the block, I have read many many articles on this topic. Some written by the Green/environment people who advocate you should never disconnect the EGR because of the detremental effects it has on your engine, of course they would, nothing to do with the environment of course.
Some by Profs. of motor mechanics, who don't deny in disconnecting the valve it raises the NOx levels released to atmosphere (our MOT laws in England don't test for NOx). They also claim that lowering the operating temperature is not a bad thing except the recirculated gases cause hot spots and on cast heads thats not good. The recirculated gases are reintroduced into the block on one side, so cooling that area not the far side of the engine, one side hotter than the other.
The other down side of the EGR is, in reintroducing the gases back in to the engine, this will place an even greater demand on engine oil performance through increased soot generation and acid levels. So you need to make sure regular oil changes are strictly adhered to.
The EGR also comes with another downside slight loss of power and decreased MPG.
The very early valves (like on the early surfs) were single diaphram valves that open on positve pressure (some open on negative pressure) these early valves entailed a mass of vacuum hoses within the engine bay. They were not that reliable, hoses can rot, split, the diaphram within the valve can perish, become perforated. All this leads to a non or poorly operational valve.
This system had many problems. It would often open to much, which caused a hesitation on acceleration as massive amounts of recirculated exhaust hit the combustion chamber. The peak temperature NOx is produced at only occurs when the engine is under full load, not all the time so with older style valves it recirculated all the time.
The newer valves are controlled by solonoids, so control the recirculation better only reintroducing the gases when the engine is under full load. So are more reliable don't effect performance so much or the MPG.
I have disconnected my EGR, I personally noticed more low down torque on my surf and better MPG. Yes my head has cracked 1 year after I got the motor and 10 months after disconnecting the EGR.
There are some who's heads have cracked and have never disconnected the EGR.
After replacing my head I reconnected the EGR for three weeks. Its diconnected again, couldn't stand the smoke it throws out the exhaust, the less grunt on acceleration and the worse MPG.
I hope this answers your question with an unbiased opinion, there are the greens who write articles on the EGR saying how great it is and mechanics who write articles saying the early valves were poor.
Thats the info, you make up your own mind.

[poppy986]

Wow Nigel , that was comprehensive .

It seems to be running smoother , with a bit more response , the black smoke
on hard accellaration has gone , as said should have done that ages ago .


Chris

[POPEYE]

I removed mine dureing my fiddleings, it does seem a bit better without it, blanced off each end but i left the wireing plugs as was and capped off the vac tube, one good reason for doing it for me was the state of the inlet manifold when i removed it, chocca with black oily gunge,good report nigel, wish id seen that when i was asking, it did'nt come up in searches.

[Ski_Extra]

Koi, are you suggesting that there is a connection between doing the EGR mod and the head going?

My head is going, replacing it at the weekend. I would LOVE to reduce the amount of black smoke it pours out but not at the risk of cracking the new head (when it arrives and I fit it!)...

[Koi]

Koi, are you suggesting that there is a connection between doing the EGR mod and the head going?

My head is going, replacing it at the weekend. I would LOVE to reduce the amount of black smoke it pours out but not at the risk of cracking the new head (when it arrives and I fit it!)...

No, no suggestion what so ever. Just stating the facts that my head went after doing the EGR mod, but then most heads have gone and have never done the EGR mod.
As we now all seem to know heads going was due to a bad batch or faulty heads were the metal between the valve guides and water ways was to thin so not dissapating the heat correctly.
The above fautly dodgy heads is a fact, use a micrometer and measure the thickness between the old and new redesigned heads that Stevo sells and the new ones have a thicker wall between the guides and waterways, not a lot but a difference.
My write up is after spending hours trawling the net finding out about the EGR, as you see some Prof. of motor mechanics in fact believe that the EGR on early models contribute to heads cracking. Due to hot exhaust gases being re introduced to one side only causing hot spots which aint good.

The write up is purely a summary of my findings after reading many many posts and sites on the EGR, I make no claim that the EGR causes heads to crack or by disconnecting it it will cause a head to crack.

PS. I ran my surf for another 18 months after I replaced the head with no problems with the EGR disconnected and sold it on and was still running good a year later, then sold on again.

[animal]

from what i can see, that post is actually saying that blocking off the egr can help prevent the head cracking, its says that by recirulating the exhaust gas(leaving it as it is) it can cause hotspots due to the hot gases going back into the system and increasing the overall running temperature.
im definately doing my egr valve today, didnt realise it was that easy to do

[coolsv650]

I was a motor mechanic at the time EGR valves first appeared, quite a few mechanics never saw the point of poisoning a nice clean slug of air with exhaust gasses and carbon!

I've disconnected my EGR valves on every diesel I have had (1 fraud escort, 1 fraud mondeo & 2 surfs!) just because working the engine oil more can never be a good thing for your engine, not to mention the goo that ends up in the inlet manifold and turbo.

As koi stated it cant be confirmed either way weather it has affected the cracking of heads, but bearing in mind most surfs that appear in the country have been running for a number of years with it connected what we do would probably have little effect.

The really stupid thing is the people that pay up to £5 on flea bay for "a cure" that they can do for nowt (ok so th cost os a cable tie or bolt!!)

[MadcapMagician]

It definitely has more low-end power.

Not tested the mpg yet - will have to wait and see.

[darkdezigns]

ok my head hurts lol,mines a 3.0 td,do i/how di cable tie/use bolt,or blank the pipe?god i miss petrol lol

[plumb bob]

Any or all of the above

[darkdezigns]

ok,which works best?

[stormforce]

ok,which works best?

just use a cable tie.thats all i used anyway