Thread: Provent 200 outcome after 150,000km

We've debated this before. Here's some of that rare commodity known as "evidence".

Vehicle: 2014 Gen 7 Hilux (KUN26R) with the 1KD-FTV motor, 150,000km
Use: Overlanding around Aus, then hunting and general rural lifestyle in NZ.

At least half the mileage has been towing a camper trailer or quad & bike, the remainder carrying a constant full load, with a great deal of hard off-road driving. Air lockers front & rear, lots of other off-roady mods.

There were four options to prevent the infamous diesel engine intake blockage:

1. EGR blanking plate (complete blank or 7mm hole)
2. Fit a catch can
3. Do both
4. Do nothing

I wasn't happy with blanking or restricting the EGR for various reasons, that I'm not going to debate. Don't bother trying to tell me to blank / delete the EGR, I'm not going to.

So I fitted a Provent 200 when the vehicle was brand new. What I expected from the Provent was for it to stop the build up of the rock solid tar around the EGR valve, in the elbow behind it and down into the intake manifold. This because the catch can would remove the oil vapour from the crankcase vent. Therefore, the hot recirculated exhaust gas carrying diesel particulate "soot" wouldn't mix with oil vapour and coagulate and harden over time, building up an ever increasing restriction in the intake. When that happens, the intake restriction can cause significant detrimental effects - power and fuel economy both suffer. The black, hardened tar is also a complete bastard to remove, requiring solvents and lots of scrubbing. A bad case in the intake manifold is a bitch to rectify.

The result was exactly what I expected, and wanted to see. Only a slight decrease in the valve internal diameter, loose, soft, easily removable soot. Very pleased with the outcome. I've not noticed a performance loss, fuel economy has remained constant since new. No codes or any other bother. I can see from the amount of soot that just fell off as I removed the valve, that a lot of this is removed by air flow into the combustion when you give it the berries. The "Italian tune". I give the old Hilux a boot up the ass once a week up the hill on the way home, holding it at 4,000rpm for about 15 seconds.

EGR valve as it came off the vehicle:



A better view of the soot deposits:



Lightly pulling one of the wife's cutlery around the inside of the valve:



Better view of the removed soot on one side:



The soot is really soft and crumbly and comes right off with zero mechanical effort. A couple of passes of the kitchen knife yields a pile of soft soot. The elbow is still on the vehicle and doesn't show any difference in texture or hardness. I'll take it off tomorrow and clean it and the EGR up properly. On this evidence, there's no need to remove the intake manifold.

The lesson is that a catch can will stop the hard deposits forming that build up layer by layer over time and cause the severe restrictions. There's not much in the way of evidence of this out there - what there is is a lot of guys arguing without any evidence. So if you want to see what a catch can does over a decent mileage, now you know.

Cheers