PeachParts Mercedes-Benz Forum - View Single Post - Engine blow-by test, Blow a bag of blow-by

Jeremy5848 · #9 07-09-2007, 05:54 PM

Here are the results of the test for my 617.

Conditions
1. Air temp 80F
2. Engine warm after driving 20 miles in city traffic with a/c.
3. Car is 1985 300D-T, 617 engine, CA version w/trap cat, EGR disconnected for testing. Main vacuum line not blocked off. Car has 223,000 miles, original unrebuilt engine, minimal oil useage between changes and no smoke.

Results (see pictures)
The bag filled in 90 seconds. This is half the time that it took to fill the bag on my '87 car (603 engine). Given my '87's penchant for using a quart of oil every 1000 miles or so and smoking (oil smoke) upon acceleration, I was not expecting these results. (The problem with the '87 is probably worn valve guides and/or seals -- that will be confirmed later this week. Other possible sources have already been eliminated.)

There must be more here than meets the eye, ear, nose, and throat.

I'll try repeating the test with the main vacuum line blocked off to see if there is any change.

Let's see someone else's results posted here.

Jeremy