EGR Confusion

[znelbok Member Find all posts View Profile Close znelbok]

Hi all

Trying to get all this turbo diesel stuff straight in my head - just upgraded from an old 3L 2.8 diesel to a 1KZ-TE 120 series Prado.

From what I have read so far, the EGR outs a lot of crap into the intake system and needs to be cleaned out. To overcome this I was under the impression that a catch can or blocking the EGR would work.

A bit more reading shows that the EGR valve is one one side of the block while the catch can would be installed between the pipe from the rocker cover to the intake side of the turbo.

How does a catch can help reduce the problem of the crap building up in the intake. It makes more sense that blocking the EGR system is actually going to make a difference.

What's the link I am missing between the two.

If the pipe between the rocker cover and turbo is recycling the oil mist that forms at the top of the engine, then that would mean that the intercooler most likely has a lot of oil collecting in it as well. Would the intercooler benefit from a good clean out as well?

I was thinking of just putting in a catch can, but I now think that I need to block the EGR instead - or should I do both?

Thanks for any clarification.

Mick

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

General consensus is don't block EGR. The EGR can be cleaned on high mileage vehicles. The EGR isn't super critical to good economy. Install catch can to prevent/reduce oil mist into air intake. Inter-cooler will have oil residue build-up right through. Keep reading, there's a ton of useful info and opinion within these threads.

[Mule Member Find all posts View Profile Close Mule]

I own a D4D but have not had a close look at this particular engine in regard to a catch can and blocking the EGR. I have had some experience with other diesel engines in this regard. To perhaps save you a little time the quick answer is that a catch can will remove oil and oil is fuel for a diesel. The concern is that if there is some over fill of oil or if excess diesel somehow gets into the oil then a fair amount of it will enter the intake through the rocker vent and this will fuel the engine and this can lead to catastrophic and uncontrolled run on and engine destruction. This has been known to happen to just about every make of diesel. A catch can will stop this getting back into the intake and fuelling the engine. I suspect that the oil mist may even help clean the intake and intercooler so other than a catastrophic event I see it as no problem under normal circumstances.
The EGR as far as I can tell is to reduce nitrogen oxides which are a major pollutant causing smog. It also helps just a little in smooth running of the engine when cold. Yes it does cause sooty residue to build up in the intake side. Blanking the EGR is a common but controversial mod. Those in favour claim it will keep your expensive engine from premature failure and some go as far as to say increase performance with better breathing of the engine.

[adrian5800 Advanced Member Find all posts View Profile Close adrian5800]

1KZ-TE - block the vacuum line or install a plate to block the egr
1KD-FTE - install a catch can

Reason being the 1KD has a variable vane turbo without a waste gate and these motors rely on the egr to limit boost.