athens7 Posted July 14, 2008 Share Posted July 14, 2008 Saturday, I attended an autocross on a fast, clockwise course. The last sweeper was fairly fast, with a full throttle exit from a late apex. On this section, the car started emmitting blue smoke and exhibited a crackling misfire. As far as I can tell, this didn't occur anywhere else on the course, and I saw no smoke on the 90 mile drive home from the event. When I got home, I found the car had used almost 1/2 quart of oil. In the 1800 miles since my last oil change, the car has used less than 1/3 quart, and it was full when I checked it Saturday morning before the event. The car is equipped with an SVT Zetec with a Raceline wet sump, and the block and heads are stock, save a camshaft upgrade and some tuning changes (no porting, polishing, or other modifications). The motor was new when I acquired the car, and now has 3700 miles on it. I have been to several autocrosses with the car, and not had this problem, but I have also never run on a course with this particular direction/speed/g force of curve. What causes should I be looking for, and what are the possible cures? Link to comment Share on other sites More sharing options...
pksurveyor Posted July 14, 2008 Share Posted July 14, 2008 My SV with the 147 hp Zetec emmits blue smoke under the hood on very late braking full throttle hard right hand turn. I added a catch bottle at the end of the rubber hose connecting to the crankcase. I also added a hold down spring on the dip stake to keep it from coming up and venting engine oil when pushing hard. Does your blue smoke come out of the tail pipe or under the hood? My engine will misfire when the ECU gets hot. Link to comment Share on other sites More sharing options...
WestTexasS2K Posted July 14, 2008 Share Posted July 14, 2008 I have seen this issue a few times myself with an Ultralite. When you are in full rev vtec engaged and get out of the throttle vtec dumps massive amounts of oil in the valve cover. A sharp right hander soon after vtec dump can cause the instant vacuum increase from the intake to suck oil thru the PCV valve. A catch can should elevate the problem. Link to comment Share on other sites More sharing options...
athens7 Posted July 15, 2008 Author Share Posted July 15, 2008 The smoke was from the exhaust. A catch can seems the popular solution. Can it be integrated into the existing PCV system, or must it eliminate the return to the intake? Link to comment Share on other sites More sharing options...
Boxologist Posted July 15, 2008 Share Posted July 15, 2008 it would be fine either way, but if i end up needing to do thins i will try and run a return line to the orginal pcv location. Link to comment Share on other sites More sharing options...
athens7 Posted July 15, 2008 Author Share Posted July 15, 2008 Pros and cons of keeping the PCV system intact, with an in-line catch can vs. plugging the hole at the intake and ending the PCV system at a ventilated (filtered) catch can: Lower intake air temperature/cleaner intake air/more power Less plumbing vs Correct emmissions Scavenging effect from intake pulling gas from crankcase (?) ECU used to vacuum in PCV system, won't work correctly otherwise (?) I don't care about the ECU throwing a code, just that the engine runs correctly. Any thoughts on this? Link to comment Share on other sites More sharing options...
pksurveyor Posted July 15, 2008 Share Posted July 15, 2008 My Zetec does not have a PCV system. The rubber hose on the valve cover goes to nowhere. It is pointed to the ground before I put a plastic bottle at the end. Link to comment Share on other sites More sharing options...
WestTexasS2K Posted July 15, 2008 Share Posted July 15, 2008 catch can be put inline with the PCV valve. Link to comment Share on other sites More sharing options...
BobDrye Posted July 16, 2008 Share Posted July 16, 2008 Pros and cons of keeping the PCV system intact, with an in-line catch can vs. plugging the hole at the intake and ending the PCV system at a ventilated (filtered) catch can: Lower intake air temperature/cleaner intake air/more power Less plumbing vs Correct emmissions Scavenging effect from intake pulling gas from crankcase (?) ECU used to vacuum in PCV system, won't work correctly otherwise (?) I don't care about the ECU throwing a code, just that the engine runs correctly. Any thoughts on this? The pcv system results in better piston ring seal. Delta P> Link to comment Share on other sites More sharing options...
athens7 Posted August 3, 2008 Author Share Posted August 3, 2008 The catch can is now installed, retaining the original PCV system. http://www.usa7s.com/aspnetforum/upload/247258019_DSC01726.JPG http://www.usa7s.com/aspnetforum/upload/1435903119_DSC01725.JPG http://www.usa7s.com/aspnetforum/upload/1519233423_DSC01724.JPG The catch can had to be upgraded, as it would not hold a vacuum, which caused the car to run VERY unevenly. Once this was corrected, the car runs as if no modification was made. Now for a hard right-with 2 autocrosses this coming weekend, hopefully I will get a chance to test for a positive result! Link to comment Share on other sites More sharing options...
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