Do Hydraulic Lifters Bleed Off???

[Biff2252]

Hello! I am wondering if the hydraulic lifters bleed off after time? I have an 02 Z28 and when I get into the upper RPM's when I am really getting on it, it really bellows smoke. I would hope it is just valve guides, but this may be wishful thinking. I think the guy who had it before me ran the pi$$ out of it and/or sprayed it, and def did not disclose this to me :thumbdn: What I am wanting to do is a compression check on the car so I can pinpoint what exactly is going on. I am wondering if I can just let the car sit over night and the lifters bleed off allowing the valves to close. This may be an idiotic question but I was hoping this would be the case. If not do I have to crank the motor over on each piston to DC? and make sure it is on the compression stroke and not 180 out? and if not, just a generalized question if hydraulic lifters are rigid then whats the difference between a Hydraulic and Solid Roller? I dont exactly understand the mechanics of the hyraulics, sorry :dunno:

[keliente]

Before you start thinking internally, try adding a catch can. I would put money on that fixing the problem.

I put my car on the dyno last week and it just poured blue smoke out the back at wide open throttle, it made me so nervous. I went and got an air/water seperator from Lowe's and integrated it into my PCV system - now absolutely no smoke comes out of the rear. The can has caught a small bit already that would have otherwise been digested.

[Biff2252]

Hmm, that suks because I already have one on it. I was really wondering though if that thing did much good. It does collect a significant amount of oil though, probably about a teaspoon amount every 2k miles or so, just rough estimate......what else could I possibly check before I start pulling my hair out? (if I had any)

[Jon B.]

The hydraulic lifters are not solid. They should bleed off the oil in them if there isn't any oil pressure. I have limited knowlege on the subject, I just know that they have oil that runs through them and when it's pressured up the car is obviously on. So you shouldn't have a problem with it off and sitting overnight and then checking them.

Jon

By the way, how would I make one of these catch cans for my newly acuired TA? Any good links?

[keliente]

Yeah, search for catch can on this site.

[Biff2252]

Well thank yall for the help. Looks like I will be doing a compression check this weekend. Yay! haha

[Hi-Po]

Maybe this will clear things up for you about Hyrdrualic lifters. they maintain ZERO lash and automatically adjust to parts wear, and maintain thier adjustment for very long. The lifter is filled with engine oil suppied by the oil pump. Pressure pushes a plunger up inside the lifter untill no play(lash) in valve train. A check valve inside traps this oil(since liquids cant be compressed) and the lifter acts as a unit to open valve. Also, if you want to check your lifters you want a leakdown test not a compression check.