Blocking EGR

[pjorek Advanced Member Find all posts View Profile Close pjorek]

Sorry guys but I've read the lot and one thing I don't understand (not a mechanic), on the D4d do we need to clean up this gunk/EGR from time to time? If so when do we do it or how do we prevent it from forming up?

[phantomintel Lurker Find all posts View Profile Close phantomintel]

I have placed a blanking plate on my 1kz and noticed already a pickup in acceleration and more responsive on and off the pedal.

[xpro Lurker Find all posts View Profile Close xpro]

Hi All,

A quick update:
I have finally modified my egr system as per my previous post, i blanked the Egr exhaust port on the block and welded an additional pipe onto the egr cooler,to allow intake of fresh air instead of exhaust fumes.
Good news, everything works perfect, engine runs sweet as a nut with no engine lights as all the sensors work perfect.
MAF readings are normal,no interference with air flow most importantly. ( previosly with blocked egr only, maf reading were above the limits, and fueling was excessive).

Also as Skywalker previously explained, egr also act as a turbo pressure relief valve, and he was right. ( blanking the egr fully is not a good idea, nor unplugging the vacum pipes to stop egr from working properly)
I ran a few tests prior to connecting all the pipes just to see how and when does the egr operate, and i could hear turbo pressure being dumped, and also the loud sucking noise mostly in low rpm, and cruise, but never under any loads.
Generaly speaking egr doesnt seem to work alot, only in low rpms, cruise and never under any sort of engine load.
So with my modification i dont think there will be any problems, NOX levels might be increased but thats about it. In normal conditions egr valve operates only in low rpms and light cruise, if theres any sort of load its switched off, and in reality thats when the egt temps would be at their peak, quite opposite actually.

I have a rubber hose attached to the egr cooler which is connected to a small filter that will prevent water and other particles from entering the intake manifold, and also remove that suction noise from egr valve.
Anyway, some pics below for you all to see.
Cheers


before


after

[SWR Banned Find all posts View Profile Close SWR]

Gday xpro

Very nice weld job on the EGR/Turbo heat-exchange pipe!.... Very Profesh!

Apart from your heat-exchange and a few other things being slightly minorly different from the 1KD-D4D's here in Australia they basically appear to be the same set-up!

Wonder if someone here in Australia will give it ago as i reckon its the bizz! (I personally am not brave enough to give it ago!).... RTA down here make me nervy. (Equivalent to the MOT in the UK).

I'm am guessing that you will now be like the 1KZ's here in Australia with the blocked-off EGR! Cleaner engine oil/ No more fouling of the intake system with a more responsive accelerator pedal plus smoother idle with an improved fuel consumption! ..... For that i am jealous!

......... Still not sure about the long cruising temps! Especially when pulling a heavy load?

Cheers

[xpro Lurker Find all posts View Profile Close xpro]

Haha, welding job wasnt that good, sort of a rush job, i even had to used mild steel wire on stainless cause i had none left, but i gave it a coat of zinc spray to stop the rust. I think the MOT tester might not even spot the modification, looks very OEM with black hose and the filter unit. ( unless they start testing for NOX levels)
The EGR heat exchanger i used for testing wasnt actualy mine, i got it from a crashed landcruiser from a scrapyard so i didnt mind doing a bit of experiment, i still have mine that i can always reinstall if things dont work out. But it seems to be working ok,so im leaving it in.

After i had everything installed and bolted back up,just for testing i ran a big garden hose trought the bulkedhead straight into the cabin and i went for a spin to see exactly when the egr valve operates because i could feel the vacuum trought the hose when the egr was on, and aswell the turbo dump when letting off the throttle. ( previously when testing it trought the obd diagnostic, i think there was a slight delay and the readings were confusing aswell, so i couldnt get a good picture of the egr operation)

To be honest, the egr valve isnt on that much,its on anywhere below 2k-ish rpm and ONLY when off load, light cruise or deacceleration.
The second you put your foot on the throttle the valve shuts off, so if there was any load present there was no suction, and the egr remains shut.
I personally cant figure out how is the egr valve suposed to lower the combustion temps when its only active during light cruise and deacceleration, and never on when under load.
For example say if you were driving uphill for the next 10 miles, you car would be under constant load and the egr would stay shut, so how could that help with lowering your temps when the egr is off..

Its more of a venturi effect, as pressure decreases the velocity increases, so if the valve stayed open during loads you would lose the boost

Anyways, thats my theory but i will have to monitor it for another while to make sure everything is ok. So far so good.

@Dhjupi

Yes the egr valve is now blocked beetwen the cylinder head and the the EGR heat exchanger. I used an aluminium gasket.
As you can see from the picture below, all i did was i blocked the exhaust outlet on the cylinder head, and drilled another hole to allow for fresh air instead, so technicaly the egr system remains unaffected.
I would say i did about 500km with this setup with no warning lights, and will do some more over the weekend.

Thanks

[timmo23 Lurker Find all posts View Profile Close timmo23]

Forgive me if this is stupid but the way I see this system working is that being a diesel with no vacuum the EGR relies on the valve in the manifold closing to create a vacuum to draw the exhaust gas into the intake manifold through th EGR valve so if you were to disconnect the vacuum hose to the intake manifold valve actuator there would be very little exhaust gas drawn into the engine without any other modifications to the system while still having the boost pressure dump side of things working.

[SWR Banned Find all posts View Profile Close SWR]

Gday timmo23

This was mentioned earlier by adrian5800. Click the link below.
http://www.pradopoint.com/showthread...l=1#post325267

You will reduce EGR flow due to low vacuum by removing the shut-off valve (Butterfly flap) but you will also have an engine jumping around violently when you switch it off!

Don't know how much the engine-mounts are worth for the 1KD-D4D but i know they are very expensive each!

Cheers

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

I know the ones for the D4D prados are just over $100 each so not to bad, been vacuum controlled on the prado I was expecting alot more, not sure if the hilux has the same setup but I know they are common on the D4D prados to need replacing and some at very low klms....cheers Steve

[timmo23 Lurker Find all posts View Profile Close timmo23]

Gday timmo23

This was mentioned earlier by adrian5800. Click the link below.
http://www.pradopoint.com/showthread...l=1#post325267

You will reduce EGR flow due to low vacuum by removing the shut-off valve (Butterfly flap) but you will also have an engine jumping around violently when you switch it off!

Don't know how much the engine-mounts are worth for the 1KD-D4D but i know they are very expensive each!

Cheers

I asume that the valve in the manifold closes when the engine is shut down to help stall it out preventing the violent shaking of the engine so there is no reason you couldn't set it up to close when the engine switched off still just not when EGR valve is open.Wouldn't be too hard just anouther VSV (vacuum switching valve) like the one already used to control the valve would work.

[SWR Banned Find all posts View Profile Close SWR]

Gday Steve M

Quote: I know the ones for the D4D Prado's are just over $100 each so not to bad

Answer: Wow!! I didn't know or realise that they was that cheap!! That is good to know given that i am now out of warranty

Quote: timmo23 - I assume that the valve in the manifold closes when the engine is shut down to help stall it out preventing the violent shaking of the engine so there is no reason you couldn't set it up to close when the engine switched off.

Answer: Yes! the valve slams shut on shut down to choke the engine for a smooth shut down.

I believe that it is not so easy to set it up to close when the engine is switched off as the butterfly flap is controlled electronically by the ECU via an electric motor not a solenoid! (I believe motor + Worm gear as it also has to semi close the butterfly flap to increase manifold pressure). I am not even sure that you could get away with removing the brass disc as not sure if the motor uses the disc to acknowledge its stop position? (resistance feed back from the motor). (1KD not 1KZ).... You could easily over-come the prior problems simply by drilling a hole in the actual disc! Say 10mm.... Maybe bigger??. #1 This would reduce the manifold pressure and in-turn reduce the EGR gases being drawn. #2 It would make the engine shut down smoother than if no disc at all and not interfere with the butterfly positioning.

Cheers

PS. @ xpro

I run a turbo boost gauge (Directly to the intake manifold after the butterfly flap for true manifold pressures) and noticed whilst cruising @ 110KMH (68MPH) that the Boost would drop off then when i twitched the accelerator pedal the boost bounces up instantly!... I am lead to believe that the ECU watches RPM/Speed/EGR sensor switch but most importantly the manifold/Turbo boost pressures. I believe it works out the stable cruise speed then decides when to open and close the EGR. Hence the vaige EGR operation.

[xpro Lurker Find all posts View Profile Close xpro]

@ Xpro
what Year is your D4D, Have the EGR a Positionsensor and have the EGR 1 or 2 vacuum hose.
my Prado (Landcruiser) is Year 2009 and have EGR with Positionsensor, and 2 vacuum hose. (1for open and 1for Close)

Thank you, and i found you did a great work.
so long,dhjupi

Hi,
I have a late 05 model. And yes there is 2 vacuum hoses attached to the EGR and also an electric position motor on top.

@skywalkerrun

going off topic now Did you notice any difference in boost pressures since installing a high flow cat?

cheers

thanks

[SWR Banned Find all posts View Profile Close SWR]

Gday xpro

Quote: Did you notice any difference in boost pressures since installing a high flow cat?

Answer: I installed the hi-flow catalytic converter back in April-09 ($420 supplied/Fitted) Way before fitting the turbo boost gauge.... I can say that the turbo spools quicker which did make a noticeable change in engine response and i still have the original exhaust system fitted.

Cheers

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

05 is the 1kz, are you guys referring to 1kz or D4D for this modification ??? Cheers Steve

[SWR Banned Find all posts View Profile Close SWR]

G'day Steve M

Oops! A valid question!.. Xpro's truck is of the europian model which is a 1kd even though it is an 05 model and we was both referring to the 1KD

Cheers

[DocK Member Find all posts View Profile Close DocK]

Following this with some interest - couple of questions for xpro.

1. How does the rubber tubing stand up to the heat of the exhaust gases or overboost?

2. Could you post a picture of the filter set up and how do you propose to keep it out of the way for water crossings etc?

My assumption is that when the overboost comes back thru the EGR it will go out thru the air filter to atmosphere, and you need to stop water and dirt getting back in throught the filter into the intake. So it has to be able to tolerate the pressure of the overboost 14+ psi as well as what ever the manifold pressure needs to suck back in. So...

3. How resilient is the filter to the changes imposed on it both in and out?

Thanks
DocK