Jeepjeepster wrote:
The air box in the crd cannot be the same as the 3.7 b/c my intake comes in the bottom of the box which would never let water get to the filter. If i stood there and poured water in the intake with a water hose it wouldnt fill up. There are holes in the bottom of the box that lets the water go out. Sounds to me like all you need to do is make the holes bigger? Dont know why this is getting so complicated for such a small issue. It doesnt take an engineer to figure this out. Maybe it has something to do with the crd pulling so much air it sucks all of the mist up into it?
From what I've seen it's the exact same intake (with the exception of the lid). It's not an isssue of drainage but an issue of draft. The diesel draws over twice the air volume than the 3.7L (according the DC tech rep). Twice the volume will produce twice the intake velocity. When pulled through a tight opening through the front grill as with the Liberty it will create a significant vaccume. Most likely enough velocity to draw rain and road spray directly into the filter element which is less than 12 inches from the grill face. The first clue I had this happening was I literally had road salt in the filter element (coated & w/rocks) and the inside of the airbox was lined with salt. More recently found the filter element completely saturated after driving in the rain.
Getting an intake constriction is a serious problem on a turbocharged engine, especially a diesel. Have seen this on some larger diesel vehicles with pneumatic systems sharing a common airfilter box for both the engine and the air compressor head. The draw of the turbo is so strong that it starves the air compressor head for fresh air. When this happens it literally pulls crancase oil past the compressor rings, contaminating the pneumatic system with oil. I believe there is a similiar problem with the CRD but involving the turbo seals and the CCV. A minor and temporary constriction caused by a damp filter would be sufficient to pull oil through the turbo seals into the CAC and create sufficient crancase vaccume (through the CCV) to pull additional oil through an unfiltered CCV. When I witnessed my first incident, it pulled atleast 1 qt of oil through the turbo seals in @ 2 tanks of fuel (800 miles). It also pulled hard enough through the Provent to clean-out the accumulated sludge from the dirty CCV line, depositing it in a wad of sludge in the top of the Provent can.
The solution is to allow expansion room or create a baffle to reduce aiflow velocity so moisture has a chance to drop out before it gets to the filter element. The modification I did to mine opens both the diameter of the intake hole in the airbox and the intake tube along with adding a baffle. The larger diameter intake tube also allows for some leakage so a small amout of intake air is drawn from behind the headlight where it is dry. Have been running this in heavy rain for three days, thus far it appears to be working.
And you are correct, it shouldn't be this complicated. It's something a DC engineer should have known and corrected long before mine was ever built.
Login
Register
FAQ
Search
but trust me the intakes are different I have a 3.7 and a CRD sitting in my driveway and I have directly compared the two the big advantage for the 3.7 is that the intake is much higher off the road then the CRD by 6 inches or so that by itself would keep a lot of water and stuff out of the box in the first place also it could be my imagination but the 3.7 airbox itself seems to be a little larger but the actual intake seems to be smaller.
