# Mk3 Jetta Idle Problem



## knuckk (May 12, 2010)

my mk3 jetta jumps around form 400 rpm to 1000 rpms then dies out even when the vehicle is warmed up and running its been getting worst and worst lately and tonight it just died out not sure whats going on with it im new to Volkswagen so please excuse the dumb questions its probably a common question but ive search and haven't gotten a straight answer  

can anyone help me out? at leas some ideas where exactly to check and what i should be looking for?


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## germancarnut51 (Mar 23, 2008)

Before you touch a wrench, buy the Bentley VW Factory Service Manual for your car and read it. 

Since you recently got your car, I suggest doing all of the normal maintenance first. You'd be surprised by how many problems get fixed by simple repairing replacing and adjusting things according to the Factory Maintenance Schedule. Camshaft timing belt, and belt tensiponer, OEM Bosch silver or copper spark plugs, Bosch distributor cap and Bosch ignition rotor, inspect the ignition wires, clean the battery connections, clean the MAF and the throttle body with the correct chemicals, repair all vacuum leaks by replacing any vacuum lines that even looked cracked, make sure that hose clamps are tight enough, check to see if the UIM (upper intake manifold) seal is inplace (check to see if it's leaking by spraying a squirt bottle of water around the seal while the engine is idling to see if it changes drastically), and change the motor oil (10/40 or 20/50), replace the oil filter with a German oil filter (Mann, Mahle, Kenelt(sp?)), check the air filter, replace if dirty, check the big rubber intake hose to see if it's loose or split, and replace if damaged. 

Fix all oil leaks: oil cooler seal, oil pressure sensors, valve cover seal, oil pan gasket, PVC (pressure regulating valve) if it's broken (common breakage from people yanking on them), it's grommet and the hoses connected to it. 

By the time you get the maintenance done, you'll probably find that the problem is solved.


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## madbeachjetta (Apr 5, 2009)

There's all that advice from the first poster. But that behavior sounds a lot like the idle air control valve is having problems. Maybe the wiring is frayed or damaged, the connector may have some corrosion or the valve itself may be gummed up. It's attached with one-time hose clamps so you'll need to use zip ties or similar to install it if you cut them to clean the internals.


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## bearing01 (May 27, 2004)

What year is the car? 

If you unplug the mass air flow sensor (the electrical plug next to the air filter box) and start / run the car does it run better?


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## knuckk (May 12, 2010)

its a 97 but not sure but ill def. check when i get home ill keep you guys updated thanks for all the info guys !:thumbup:


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## Alfa164S (Apr 11, 2007)

usually putting a large brown banana in the tail pipe solves all problems


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## knuckk (May 12, 2010)

Alfa164S said:


> usually putting a large brown banana in the tail pipe solves all problems


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## PoorMansDub (Nov 28, 2010)

I would go to Autozone and have them read your computer. Just because the check engine light doesn't come on means nothing. The bulb could be burned or worse (dare I say) the person you bought it from disabled it from illuminating. 

Sounds to me like the idle control device or other possible sensors, although Germancarnt has very valid points especially concerning vacuum leaks and other tune up procedures.

Lastly, don't rule out poo poo fuel pressure regulator.


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## VincentVr6 (Jun 3, 2011)

mines doing that too, i have a 95 jetta with 60k on it, vr6, i take out maf sensor n its good for about a day or two n goes back to fluxuating idle, and just earlier td it shut off on me, idk what it is


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## mrhys388 (Feb 14, 2011)

I actually have a 98 jetta vr6 that has a weird idle and it feels like i have no power when I give it a lot gas at higher rpm's. I replaced my sparkplugs and plug wires which were in pretty bad shape. Still have to change the coil pack. Got an oil flush and new full synthetic oil. This car has cam work and tune done to it (may be a result of a little different idle). Just ran into another problem that is electrical. Dash starting smoking after a drive on the highway from Troy to East Lansing. Car actually started the next day, but had it towed home. This thread actually helped me out a lot because I never thought it could be the idle control valve. Not saying that's a fix to the electrical fires, but a fair warning to get all the maintenance done on these cars! GOOD LUCK!


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