Thinking of replacing PCV Valve- Who has done it on the 3uZ?
 

My LS is about to turn 64k. It runs like a champ. Just recently, the car has developed a slight tremble at idle. I put a bottle of techron in the tank, but have yet to go through it. The car still has over 3/4 of tank left so it's going to be a while.

I'm thinking of replacing the PCV valve as this may be the culprit to the trembling. My car averaged 27mpg on my last highway trip with no traffic however, so maybe I just got some bad gas recently and I just need to let the techron do its thing.

Is it something that I should leave alone? (If it aint broke dont fix it) or should I change it out just for preventative maintenence? It appears to be metal. It just screw out I'm assuming? I'm also a little nervous about letting the grommet get too old and becoming rock hard and causing it to break off into the engine while trying to remove it. It may already be rock hard at 65k anyway. It would be nice to know. I have not checked it out yet to confirm.

Is it easier to change the the PCV on the 3uz because it has screw threads? I'm thinking it's more bark than bite. Words of wisdom?

I've never had a problem with one, they are pretty easy to change... that being said, they rarely ever go bad, and when they do, they cause the opposite of the problem you are having, they plug up and let crankcase pressure get a little too high causing leaky valve cover gaskets and what not...

if your check engine light isn't on, probably not much to worry about... if it was bad fuel and you have added fuel since, it may be worthwhile to pull the battery terminal or ecu fuse to reset the ecu to let it relearn fuel trims and such... it may actually run worse at first, but should clear up after a few minutes / miles... Assuming there isn't anything else wrong...

I also assume, since you didn't mention it, that the check engine light is not on... if you have access to a decent scantool, you can see if there are any codes pending that just haven't shown up yet...

Yeah, CEL is not on. The last tankful was one that the dealer put in my car for me as a courtesy when it was in for service. Chances are it was no name 87 octane that they filled it up with. They only have one pump as far as I can tell and would bet that it's regular and not premium in their. But hey, it was free gas and I was grateful they did that. I will see how the techron goes. Don't have access to a scanner.

Take it to autozone...they have OBDII Scanners that can read the code, and they will do it for free. Once you get the code, come on back here (could be an O2 sensor, sometimes they can mess with the idle) and let us know what it is.

And I like your Sig...Maintenance before mods. People dont do this enough! At 64k, I would go ahead and replace the PCV anyway. I do mine every 40k. As Cody said, they can plug up and cause leaks. Its like a $10 part, and I change it once every 2-3 years. Cheap insurance.

I've got one little addendum to the maintenance before mods, because I truly believe in that too... HOWEVER... if you can turn maintenance into a mod, or vice versa, then you are really winning... For example - don't replace the OEM air filter, instead, replace with a K&N, or a cold air intake... :)

Agreed. :thumbup:

I have and changed the PCV on a 2003 LS430 which should be the 3UZ you are talking about.

I don't recall any screw threads, so just have at it with a pair of needle nose pliers and pull/wiggle/pull. Same with the grommet, if you choose to replace that.
Be sure you bought the replacement parts before monkeying around

The PCV are a PITA to remove. Not impossible but can be done.

? I actually had no problem, far from impossible. On a difficulty scale, this would be a 1 wrench out of 5. same as changing an air filter or changing a tire.

The first time I changed one, I supposed it seemed more difficult due to fear of damaging something. If you try to pull by hand it probably won't come out.

But use pliers and don't be afraid of damaging anything and it comes off fine (I suppose depending on the size of your pliers).

I'd draw the comparison to trying to unscrew an oil filter. First time you ever changed a filter, maybe you try doing it by hand and seems impossible. After you get the hang of it, you get a tool and just crush the sucker and twist it off.