85 300D Blowby and Engine smoke
 

Hello everyone,

Blowby: Plugged the valve cover tube stub and after 15 sec. elapsed, the idle RPM drops but the engine is still running. After 30 seconds, same results. Releasing the plug results in a pressure release from the valve cover. Is this an indication of "bad" blowby or "normal" operation. I know it doesn't really matter in the whole scheme of things, but this is mostly for piece of mind. I will not hook up a hefty bag to it though and measure the volume of trapped air with respect to time though . . . :eek:

Engine smoke: I installed a K&N filter on my 300D with a mandrel bent aluminum tube from the turbo to the filter. Looks really cool and frees up tons of space in the engine compt. I ripped out the stock airbox, and installed a oil breather (kragen mod) to the valve cover tube stub. After the modification, I am seeing the breather smoke like crazy (visible at stop lights from under the hood) and it drools oil on the intake manifold. Any suggestions? I'm thinking of running a oil catch can (no breather) from the valve cover to the aluminum intake tubing. Any problems with the smoke/particulates entering the combustion chamber?

Thanks in advance for your help and ideas for solving. :bulb:

did the same last night
 

I crimped the vent line from the valve cover to test last night.. my engine died in about 10 seconds .. i'm thinking thats not too good. I'll wait to hear what other people say about your times.

The longer the engine can remain running after pressurizing the crankcase, the less the blowby. The fact that yours won't stall indicates that the accumulated gases are escaping from leaks in the system at the same rate as the gases are being produced.

It's not a test that you should be doing, however. You put quite a bit of pressure on the main seals and gaskets in the pan for no good reason than to satisfy your curiosity.

With regard to the K&N, there is more than enough data to show the K&N performs poorly when compared to the stock filter. It may look good, but you sacrifice some clean air to achieve it.

You also notice that you have lost the entire oil recovery system and now must cobble up a suitable replacement to prevent breathing crankcase fumes every time you drive it. :(

Yes, I do have a suggestion that should stop the oil dripping, smoke and also do a much better job of protecting your intake and combustion system, without sacrificing performance or spending more money: reinstall your stock air filter system. If you still don't like the way it looks, paint it your favorite color.

While the head is off, I realized that I didn't like the way the stock filter housing looks. The small areas of surface rust on the housing and the cover were starting to bother me.

So, I painted it my favorite color: black ;)

Thanks everyone for your responses . . . I reinstalled the stock airbox, and what a difference!!! I should've never spent the $ on the K&N filter for it made my engine run hotter, rougher, and louder. The turbo sounded cool, but got annoying after a while. I never thought it would make that much of a difference, but anyone who's reading this, and is thinking about swapping the stock airbox for a K&N filter, I wouldn't recommend it, at least for an 85 300d Turbo california edition.

Good man. ;)

I'm glad you switched it back. Your car will last so much longer that way. Since you had it on there for only a short time, there should be no real significant damage done.If you do a search (and you are probably much better at this than me) you will find some excellent test data that someone posted about filter performance and especially the K&N. I was shocked at how much particulate matter the K&N let through. After spending about $2000 in parts and a lot of my careful labor, I wouldn't let a K&N NEAR my car. It angers me when I see stuff at the cheapo auto parts store where K&N has a prominent display. there should be truth in advertising laws that impact that stuff. Ironically, it's right next to the R134a stop leak, another product that has no business being on a retail shelf.