Originally Posted By: Danh
Originally Posted By: TiredTrucker
Originally Posted By: ragtoplvr
There are diesels that have problems with intake tract deposits. Some BMW and VW will have to have the aftercoolers and intake mechanically cleaned. Some diesels, such as the Cummings have CCV filters. The intake tract deposits are mostly from condensed crankcase vapors and EGR. I would recommend that anyone with a DI gas engine add a ccv filter or catchcan. Best is a cool location that can be drained easily. It will not hurt and might help.
Anyone with a diesel not already fitted with a CCV might want to add one. Many folks use programmers to eliminate EGR, but this of course is illegal for on road
Well the ccv catch can or filter is probably also illegal, I will say that one of these has very little potential in increase emissions and is way better than putting in a road draft tube as some advocate.
DI is excellent technology, that will eventually be common and well accepted. The comment about early adopters finishing the R&D is well deserved.
Rod
A catch can on these is not illegal. It still retains the closed crankcase ventilation setup that is EPA required, it just provides filtering of any oil or particulates that come thru the PCV line so they don't enter the intake. I have used them on PI engines and am always amazed at the amount of junk they capture. For a DI engine, I would think they should be a first mod done to the vehicle.
You are correct, when commercial diesels started being required to have closed systems in 2007, the OEM's put filtration ./ catch can systems on them right from the factory. They knew full well the implications of having that junk mix with sooty EGR gasses. The automotive diesel OEM's didn't quite get their ducks in a row so well. Many VW and other owners have taken to putting on Provent and other "catch can" systems on their engines to negate the problems.
It is anyone's guess as to whether the OEM's even have taken this into consideration on the DI gassers. But they are so focused on trimming a dollar in production costs, and something like a catch can system would require additional maintenance and user attention, that it could be reasoned they just decided to not go with a setup like that. Just get thru the warranty and let the owner deal with it.
A catch can may be useful, but keep in mind many manufacturers have built these into their DI engines. For example, Ford has one built into the PCV system of its 2.0 na engines and presumably others. In this example, captured liquids are returned to the crankcase so there's no need to periodically empty a catch can.
The point is, don't add one without making sure you don't already have one. It could do more harm than good even without considering warranty issues.
+1 From what I've been reading about diesel engines in cars, PU's and SUV's [late model] is the catch can helps, but there's still problems with the EGR. In fact maybe even bigger problems, that aren't easy, or impossible to fix and keep it legal. Lets not forget the warranty.
It's a shame since diesel IMO is a great platform, crippled by the emissions system.