1999 Pontiac Montana Repair Question
I have a 1999 Pontiac Montana, It started having idle problems and hesitation in park and drive.
The Idle Air Control Valve is the best place to go from here. It is located on the intake manifold near the throttle body.
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Have unplugged the IAC sensor as well and it seem not to idle up or down.Or take the hesitation and shake out. I will try a new one and see.
When you replace also clean out the prots with brake or carb cleaner. I prefer brake cleaner because it is easier on rubber and other platics. Also, make sure to spray from the outside in towards the intake manifold so you don't push deposits further towards the IACV and further clog the ports.
You Should also run a can or 2 of BG44K. You will have to go to a car dealership to get it and it is around $20 a can, but nothing else comes close to working like it does. It cleans deposits out of the entire fuel system and even removes carbon from the tops of pistons. All of the deposits end up in the oil so after running the 2 cans, use a full tank of gas without any BG and you might expect some things to act a little funny as deposits are removed. The oil will need to be changed if the engine is really dirty since the deposits will all collect there.
Just curious, can you also do it through the brake booster and pcv valve vacuum lines as you can seafoam?
I do not reccomend that as it is a, "quick way" that some say works as well. It also creates a tremendous amount of smoke and I am not comfortable with the possibilites for top end damamge or wear.
To truly be safe with this stuff, and I know SEA FOAM is good but BG44K is better, you have to have a full tank of gas to use a can. That should tell you something about how strong the stuff is.
I do not reccomend doing that at all. Use the cleaner as reccomended and it will give a deeper cleaning, remove more deposits and get to more places than the, "quick flush" will do.
I have used sea-foam as indicated on about every vehicle I have and have never had a problem with it hurting or damaging the top end. As for the sea-foam it states to use it in oil, fuel and vacuum, about a 1/3 of can in each. Going in through the vac line gets to where it would not get just by running it through the fuel also. Anyway I have the upper intake off and it's in soak right now to get all that junk out. Would it be wise to go ahead, since I can get to the cam sensor to replace it while I have the chance or to at least ohm it out. I checked the torque on the lower intake and all seems fine there to. No leaks indicated either! Just trying to cover all my bases before I put this back together.
That sounds like a good plan.
All you can do is see how it runs. I would let it run 10 minutes before I made any judgements.