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Discussion Starter #1
Occasionally, my idle bogs down from 800 to 500-600. I thought it was just my TB needing a cleaning.

This morning, I rolled up my windows, and it bogged. I hit the switch again, and it bogged. Everytime I clicked on the window up. It would fall and feel like it was going to stall.

I have noticed it does this with some other electronics like the lights when I first turn them on or my AC.

Is there a electrical problem? Grounding issue? What is it? :mad:
 

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Did you clean it or not?

If not, it is just getting dirtier, and dirtier, and dirtier.....so the symptoms get worse and wor...you dig?
 

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Clean the TB, its always good to do that. The idle bogging sounds strange, I would check the grounds first and run a VAG to see if it picks up anything.

You checked your battery, alternator etc already right?
 

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'Preppie's theory 1 (probably not the case because it doesn't really cover the AC issue):
Maybe an alternator issue? Try it at night, do your headlights or interior lights dim?

Mine do just barely noticeably on my '99 GLS with a 8 month old alternator, but the power drain isn't enough to make the engine bog down with the extra energy that the alternator has to provide.

If your alternator is weak, then it it might not have any trouble putting out energy on a normal load, but when the load goes up some, it might be having trouble keeping up.

'Preppie's theory 2 (which I like better because it covers AC and power draw issues):
The AC and alternator are run off drive belts that connect to the crank pulley. When you start your AC (or draw more power from the alternator), it puts more drag on the crank pulley which forces the engine to compensate by supplying more fuel to keep things running. If the TB isn't reacting fast enough to supply more air then the engine could bog down for a moment.

Just another thought as I ramble on, the power steering pump is run off of a belt/pulley. What happens when you turn the wheel from lock to lock? Do things bog down? How about when you turn it to one lock and then try to go just a little bit further for a second or two (this always caused my old saturn to bog down)?
 

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Discussion Starter #5
NotAPreppie said:
'Preppie's theory 2 (which I like better because it covers AC and power draw issues):
The AC and alternator are run off drive belts that connect to the crank pulley. When you start your AC (or draw more power from the alternator), it puts more drag on the crank pulley which forces the engine to compensate by supplying more fuel to keep things running. If the TB isn't reacting fast enough to supply more air then the engine could bog down for a moment.

Just another thought as I ramble on, the power steering pump is run off of a belt/pulley. What happens when you turn the wheel from lock to lock? Do things bog down? How about when you turn it to one lock and then try to go just a little bit further for a second or two (this always caused my old saturn to bog down)?
I think if I do turn my wheel it causes it. HHHHMMMMM!!!!!
I can check. If so, I guess I need new belts? :???:
 

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Possibly, if the belts are slipping, but it's still hard to tell.

Belts aren't too expensive so it would be a good first step. Cleaning out the throttlebody isn't a bad idea since it's fairly cheap (a can of carb cleaner is typically around $5).

If I understand idle v.s. engine load correctly (I'm sure Sharky will correct me) this works something like this... As you increase the amount of load on the engine (turning steering wheel, turning on AC, using high drain electronics) the computer senses this and allows more fuel and air to enter the engine to cope with the extra power needs. If you have a gummed up throttle body, there could be a significant lag between the time the increase in load and additional power to cope with it.

Do you hear any squealing or belt whine? If so I might be suspicious of maybe a pulley, roller or tensioner going bad too.
 

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NotAPreppie said:
Possibly, if the belts are slipping, but it's still hard to tell.

Belts aren't too expensive so it would be a good first step. Cleaning out the throttlebody isn't a bad idea since it's fairly cheap (a can of carb cleaner is typically around $5).

If I understand idle v.s. engine load correctly (I'm sure Sharky will correct me) this works something like this... As you increase the amount of load on the engine (turning steering wheel, turning on AC, using high drain electronics) the computer senses this and allows more fuel and air to enter the engine to cope with the extra power needs. If you have a gummed up throttle body, there could be a significant lag between the time the increase in load and additional power to cope with it.

Do you hear any squealing or belt whine? If so I might be suspicious of maybe a pulley, roller or tensioner going bad too.
He understands it correctly.

Clean and re-adapt the throttle body.
 

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My car does the exact same thing. And i dont think it's the TB because if the windows are all the way up, and then I try to roll them up some more, the car will bog down. I'm thinking it's the battery are alternator. Anyone have this problem yet and resolve it? This Bouncing idle thing is getting on my nerves!
 

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hernandez,
when you try to roll ur window up farther there is still more power going to you window motor to try to move the window up farther, i believe it is still the same amount of power as if the window was actually being rolled up, so the same thing should happen if there is a problem somewhere else. the TB cleaning is a good idea anyway and cheap, and if that doesn't work still, try belts, cause thats also a good idea and cheap anyway, then alternator cause thats more expensive. unless you just cleaned the tb and changed the belts or something :crazy:
 

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My 98 does the same thing, its lights also dim when i use any other electrical components at night. When i rev the engine at night the headlights dim, then go back. Today as i was driving my abs light flickered and then went off. Also today my subs wich are powered off of an amp connected to the battery would turn off and on but the regular inside speakers wich run off of my deck would work fine. Once in a while my stereo would turn off and then on. And lastly, the light fort my boost guage turns off and on when ever it feels like it. I am pretty sure its an alternator prob, and yours might be too. i think i am going to take it to Sears day after tmrw for a free alternator check. Ill let ya know if that is what the prob is.
 

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You too???

It's your battery my has been giving me problerms for a while. When I put my A/C on full, stereo, heated seats the car would just about shut off. Th idle would drop down and lights would just about shut off. The ABS would also start flickering. I have been told by a Tech at VW a trusted Friend that the batteries are the worst in the industry. They could not have put a worse battery in there. I have 70,000 on mine and it just went on me. I'm ordering a Optima does any body have the Part# for it?
I don't think it's the alternator. I did a volt test on it and it's putten out plenty of juice. It's the battery's ability to take the load with all the accesorries on which it can't.
Scott
 

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All of those problems were due to a weak battery...i changed mine today and all the problems went away...includiny my car running in limp mode for some odd reason :crazy:
 

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I was looking at my tach as I was waiting to turn with the turn signal ON and I could barely see the RPM's going just a hair up and down along with the turn signal light. I just found it funny ... since it's just by a few RPM's.
 

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This all makes sense that it is the battery. I noticed the exact thing happen on my car. Even just a flick of the power windows will dim the lights a bit and idle will bog down. I have 54,000 kms on my car now.
 

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Discussion Starter #16
Really the battery. :???:

Even the turning the wheel. It bogs when I turn the wheel.

If it is the battery, anyone know the Optima battery that fits are car and setup.
 

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is it actually the engine bogging down, or just power being cut from the dash. so no power to the rpm needle which would cause the needel to drop looking like engine dropping rpms. when my sub hits my entire dash dims and the rpm needle bounces, but the engine def isn't running ruf. I have gotten out to listen to make sure of this. The engine runs fine, the dash blinks kinda and bounces
 

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It does seem like the same thing mine was doing, and mine was the battery. I suggest you take your car to Sears to get a charging/electrical system check for $9.99. They will tell you whether or not you need a new battery.
 

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These cars need new batteries when you drive them off the show room floor
 

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Someone correct me if I'm wrong...but if the alternator is pumping out ~14 volts, why would the battery be a problem? You only need the battery to start the car, not to keep it running.
 
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