Possible fix for the blow by smell in HVAC

[sag2]

Well I obviously have too much free time, because I tried a fix for the crankcase odor that comes in the cab when you stop. And save the posts about how stupid an idea this is. I already know the down side of oil residue in the fresh air side. Besides, I get a new truck at least every year. I still contend this is a normal condition (the price for less emission controls) but with some of the posts from people who think it is the worst thing imaginable, I thought I would give it a try.

I got eight feet of 3/4 heater hose, and routed it behind the pan, along the frame rail, up to the radiator and inside the fender next to the headlamp. I turned it into the air box, and cut it off about half way inside. Well the good news is the smell is gone, and I await the bad news, the air filter plugging with oil.

For now I will keep you posted. The truck has 800 miles and the filter is nice and clean. I will monitor it and see how fast it gets oily. The factory oil seems to smell more than after a change, and based on the 03, the smell should be gone in about 2000 miles anyway.

 

[lschultz]

And I thought I was a idiot. I had to say that. Question how is the oil gonna run up hill? Or does it? Did you put the hose on where it comes out of the valve cover or did you tie onto the end of the existing hose?

 

[NSperduto]

Have you tried checking what this guy checked?

http://www.rounsevell.com/blowby.pdf



Nick

 

[sag2]

I just put the hose on the end of the existing hose. The oil can't run up hill, but the vapor can. Based on the fact that after 40,000 miles the 03 never dripped one drop from the hose, I trust the oil separator on the valve cover works good.

I will have to check mine for the holes the guy found in his 03. That would be better than soaking the air filter.

 

[Elite1]

Originally posted by NSperduto

Have you tried checking what this guy checked?

http://www.rounsevell.com/blowby.pdf



Nick

I couldn't get the pics to work from that site... . anyone else able to see them?

 

[NSperduto]

I had no problem, just did it a second ago, but it does take awhile for it to load.



Nick

 

[ttreibel]

It's a PDF file you may need to upgrade your browser with adobe acrobat software



And thanks for the hose routing idea this will be my next BOMB as soon as I get a dry day off... ...

 

[Vaughn MacKenzie]

Sag2 since you live in a mild climate your setup will probably work OK. Guys living in cold climates shouldn't do this because the vapor can ice up or conglomorate as it cools and plug the tube if they have to travel very far. A number of guys with 2nd Gen trucks added extra length to their hose or had them run uphill and had them ice or plug up. Your engine will start blowing oil out around seals and leak all over (and potentially damage the seals) because there is no way to vent blowby gasses.



Vaughn

 

[ttreibel]

After reveiwing all the information it seems that the breather tube must let it's gasses out right next to the leak in the air box.



This truck is my first diesel that has had so much diesel smell in the cab. My past diesel a 240d and a 1990 ford 7. 3 idi would only occassionally get a diesel smell usually when the wind were not in my favor.



I like the idea of routing the breather to the air-box but I am concerned with both a chance of icing in the hose and also a chance of having the oil vapor coat the inside of the inter-cooler over time thus reducing it effectiveness.



I would like anybodies ideas on this I know we can come up with a good permanent fix if we put our heads together. From what I understand most if not all the third gens suffer from this problem.



With all the rain ice and snow we have in these parts I am not sure that plugging up the cowling holes is a good idea either. I am hoping on coming up with the best place to vent the breather tube... ... .

 

[sag2]

Well, I have a little over 1000 miles on the modification. There is just a bit of oil residue on the filter, and none in the air box. Vaughn has a good point about freezing weather.

I would say that the blow by smell is about 90% improved. I can occasionally smell just a bit when I come to a stop. I also thought about adding a "T" for a drain at the low point with a small hole for any oil to drain out. I will keep you posted on the progress. I don't plan on changing the oil until about 5,000 miles, so it should be just about gone about half way to the change.

 

[sag2]

I know, the hose is red, but it was free.

 

[geusterman]

I still have a kit from one of the performance catalogs that routes the breather into the exhaust pipe downwind of the turbo. It has a light checkvalve. It is for my 02 which is now for sale as 04 is ordered. I may install it there. geusterman

 

[NSperduto]

I haven't bothered to check anything on mine yet, but I'll tell ya, I just did the first oil change and the truck surely smells at idle now.



I'm hoping to pull the cowl tomorrow and see if there's any open holes like the guy above. If there is, I'm going to check with Dodge and find out if the holes are supposed to be open or closed.



NIck