Awkward Idling

So i searched high and low before i made this thread to ensure that this wouldn't be a double. My apologies if it is. Yesterday i got my regular maintenance done on the car. Oil change, fluids all checked, coolant swap, the whole 9. later on in the day when i got home i was just sitting in my car just to enjoy the glory of it, and i noticed that it wasn't idling right. it would go to about as low of RPM as it could without stalling and then boost up to about 1500 rpm... and its constantly doing that now, in about 3 second intervals....it would do it before the oil change but only once every few minutes and it would spike only once. my A/C was not running or anything. it has continued to do this for the last 24 hours, any ideas?

It really could be a lot if things.

What exactly was done at your service place and what place did the service?

Didn't you have some mods done to the car recently? What was done?

no major mods on the car atm, only stage 1 91 cali oct map from ap on it... and sigh... i got it all done at jiffylube..... all they did was check levels of everything, replaced coolant and gave oil change... car only has 52k miles on it

I know they will take the air filter out and try to up sell a new one. Check the filter box and make sure there is one in there. Make sure the box is sealed. Make sure the maf wiring hasn't been messed with. Give the engine bay a really close look. I can't stand places like jiffylube cuz they seem to fark things up by just being near a car.
(Used to work at a quick lube place when I was teenager... let me tell you)

We'll start there since this is coincidental.

MAF good, filter in place...im not certain how the seal for the air filter was cuz i just pulled it off to check but its all tight and in place now if it was before....and yeah i will never be going to jiffylube or the likes of them again....not impressed with their service, they are vaginas about doing things....they wouldnt check my diffs because one of the peices is alluminum and they were too afraid to break it.

Probably best they didn't check it.

I gotta check out for a bit, Father's Day stuff to do. I'll think about it and get back later. Maybe someone will throw some ideas in the meantime

thanks man

Man, i really need to get my shit together, I haven't owned a vehicle in 4 years and most of my basic knowledge has escaped my mind, it took me almost 40 mins to change my alternator belt this afternoon. i need to start getting more acquainted with simple preventative maintenance and basic things around this car.

so oddly enough, i changed the alternator belt, and the idle problem went away, its back the way it was. the belt was crap and needed a new one.

I'd suspect a boost/vacuum leak at this point. Check the plumbing pre turbo, pre and post maf. Turbo to IC and IC to throttle body. BPV flange and plumbing. Intake manifold flanges and anything that attached to it. Check any other vacuum lines. While its running you can use a gasoline soaked rag or ether (starting fluid) to check for idle changes. (Idle should go up) pay particular attention around couplings and flanges.
Be careful cause you can start a fire easily with this shit. Keep a fire extinguisher handy. Soapy water may also help to find leaks. Or you can have a boost leak test done at a shop.

NESTI said:

so oddly enough, i changed the alternator belt, and the idle problem went away, its back the way it was. the belt was crap and needed a new one.

Click to expand...

Uh, ok. Lol