Car idle goes up and down..

[DaveLS]

Hey guys, I've done some research before posting this but I did not find anything that really answered my question.

I currently have a 04 LS v6 and I have noticed that my idle (at the car's normal operating temperature) seems to go up and down a little. For example, at a stop my car idle at about 800rpm and at the next stop the idle is at around 600rpm. A couple months ago, I replaced all my plugs/coils and when I was screwing back in my Intake manifold bolts I snapped of them (this is probably the reason my car's idle is not always the same). I do know this kind of problem is usually due to a vacuum leak. Other than that though, the cars runs fine.

So, my question is : should I be overly concerned about this problem or is it a kind of problem that can be left as it is without creating new problems or increasing my car's idle ups and downs ?

Thanks !

 

[LS4me]

Hey guys, I've done some research before posting this but I did not find anything that really answered my question.

I currently have a 04 LS v6 and I have noticed that my idle (at the car's normal operating temperature) seems to go up and down a little. For example, at a stop my car idle at about 800rpm and at the next stop the idle is at around 600rpm. A couple months ago, I replaced all my plugs/coils and when I was screwing back in my Intake manifold bolts I snapped of them (this is probably the reason my car's idle is not always the same). I do know this kind of problem is usually due to a vacuum leak. Other than that though, the cars runs fine.

So, my question is : should I be overly concerned about this problem or is it a kind of problem that can be left as it is without creating new problems or increasing my car's idle ups and downs ?

Thanks !

Sounds like un-metered air is entering the system, i.e. the snapped intake manifold bolt.

 

[joegr]

...So, my question is : should I be overly concerned about this problem or is it a kind of problem that can be left as it is without creating new problems or increasing my car's idle ups and downs ?

Thanks !

So, keep in mind that the unmetered air that is going into the engine is also unfiltered. A long while back, there was a guy on here with a manifold leak. It sucked a little sand in and destroyed one (or more) of his rings. The only solution then was to replace the engine (it was the V8). With the V6, you can probably find the parts needed to rebuild it instead. Still, that seems drastically more expensive than removing the broken bolt and replacing it.

 

[DaveLS]

Yes indeed I'm better off removing/replacing the snapped bolt. Is it possible to remove the snapped bolt without removing the intake manifold itself (drilling threw the remainder of the snapped bolt ) ? Im asking this because removing the IM on the v6 is quite a long job especially if I go to a garage its gonna cost me lot of $$. Also, one of my friend told me that some sprays that seal vacuum leaks existed and it MIGHT solve my problem or at least temporarily solve it. Any thoughts on that?

 

[joegr]

Magic spray is more likely to do harm than good.
Yes, if you are really good and have the right screw and bolt out bits, you can get out without removing the manifold. If you mess up, you'll wish you had just removed the manifold. I'd be really worried about getting any bits of metal from the drilling process into the intake. It just takes one to scratch the cylinder wall or damage a valve or valve seat (although it may not).

 

[DaveLS]

Ok thanks for the heads up !