1997 VW golf P1582 engine light
fixed my car tonight, and it’s running like a new unit. for years i’ve been driving this thing with a screwed idle, which began the day i picked it up from southern VW in waldorf MD after a 30,000 mile “preventive maintenance” schpilk*. never again. fuck maintenance by people who aren’t personally vested in the outcome. seen it too many times. nothing like taking a perfectly operating vehicle in, paying hundreds of dollars, and having the “mechanic” make it run like shit. thanks!
if you happened upon this page because you have a ’97 or comparable VW golf GL or jetta with a p1582 error code, here’s what i have to say to you, assuming you’re lost and this hasn’t been done recently: take off the throttle body, clean it, and put it back on.
don’t do like so many fools on the internet (and sometimes on the can of cleaner) recommend, which is spray a pint of nasty shit into it while it’s mounted on the air manifold. here’s the process, and — assuming you’re not a total fuckup working on cars — it’s worth doing right.
[note: since, far as i know, nobody will ever use my bullet lists here, i'm not gonna go crazy proofing and worrying if i left out a step or something. you'll figure it out. as always, don't blindly follow steps; rattle 'em up against yo' head for corroboration.]
my standard technique for such jobs (skip this block if not a newbie):
- have all known supplies and replacement parts bought and standing by. think through the whole job before downing your ride.
- arrange ready alternate transportation in case of screwed pooch.
- leave time to do the whole thing, including surprises, without rushing.
- always loosen and tighten bolts in stages when torque is up, when possible jumping in an X-pattern instead of to adjacent holes (whether circle, square, whatever). not unusual for me to hit all the bolts 5 times, in pattern, when finally torquing a part. important for correct alignment, torque, and lowest stress. changing torque on one bolt usually changes it on the others — another reason for multiple circuits when at the tight zone.
- except in cases where you know that all bolts/screws/nuts/etc. are identical, note original position and store each so it can be installed in the same hole. cardboard and a sharpie are great for this, since you can punch the bolts through the part you drew on the cardboard (labeled if necessary). in most cases, however, laying them down somewhere in relative position will suffice.
- do not overtorque. always bear in mind the lever moment, since your hand will feel much different based on this, obviously. BTW, i don’t use a torque wrench, and pretty much swear by feel. for lug nuts you can calculate torque by using your known weight to stand on the breaker bar at the correct point — assuming you’re not grilling them into torque afterburner with impact wrench set on “kill” (á la most garages).
- cover critical disconnected parts (e.g., hoses, electrical connectors) using plastic wrap and cable ties or whatever. label if you might forget what’s what and goes where.
- if disconnecting the battery, retrieve radio anti-theft code first when possible.
- have adequate lighting. because i needed to repair my car at a location with no electricity (long story), i just bought this, this, and this. like all three, but recommend them in the order listed. LEDs are the way to go, bitch!
parts/supplies needed for usual job:
- new throttle body gasket. after enough fuckups doing it otherwise, i almost always buy parts like that at the VW dealer. pat yourself on the back as you roll up the armored car to deliver payment; you’ve made the correct decision. same with relays, oil pressure switches, etc.
- if small hose on throttle body is crimp-clamped (no screw), get replacement clamp from VW or neighborhood generic parts place. okay to replace with a screw type; definitely do that if you don’t have the special crimp tool. you could clean the throttle body fine without removing the small hose, but it means you’re hanging over the hood the whole time and bending the hose back and forth.
- can of throttle body cleaner. this stuff rocks. normal auto parts place should have it.
- clean rag and at least 50 Q-tips.
- air filter if timing’s right; may as well slap in a new one while you have the big hose removed.
procedure for cleaning throttle body:
- loosen clamp and disconnect big hose going to throttle body. look inside. nasty in there? kickass! your cleaning will likely drastically improve engine operation. if it doesn’t look so bad, consider aborting and reassembling everything. move the throttle plate manually from the throttle linkage (i.e., not pressing plate directly) if in doubt. the visible edge of the plate should be clean. not much tolerance on those edges, so if it’s not sparkling, may as well do the job.
- assuming you’re continuing, loosen clamp on other end of big hose and remove it entirely, easing off the remaining connection (midway, no clamp on my vehicle) and being sure not to drip oily scum which may be inside.
- remove electrical connector attached to throttle body.
- loosen or, if crimp version and you have replacement, break off clamp from small hose going to throttle body. don’t cut the rubber while wrenching off the clamp. slow and easy.
- carefully remove throttle cable from throttle body linkage. don’t kink it. work gently, moving throttle plate manually via linkage to slack the cable.
- remove throttle body bolts, then throttle body. it’s expensive as fuck, with sensitive bits on the side, so don’t toss it around like a wheel or something.
- in adequately ventilated area, spray a first layer of cleaner in either side of throttle body (intake or outtake). flip it over and spray from the other side. let sit for 30 seconds or so. spray some more. start Q-tipping that shit out, being gentle with the throttle plate. gonna take a lot of cycles, cleaner, and Q-tips, but congratulate yourself for removing the throttle body and not sending all that bilge into the air intake (insane, IMO).
- when clean you should be able to see a definite circle of light shining through the throttle body, around the throttle plate. that’s the reclaimed air passage that will raise your idle to the correct range and, hopefully, ditch the P1582 code and that goddamned engine light. makes a huge difference, that little ring of clearance. super-bitchin throttle plate gap pictures here (ignore that it’s a VR6). move throttle manually via throttle linkage to get those plate edges shiny. shouldn’t be a speck of anything in there when you’re done.
- Q-tip out the small hose line attachment on the throttle body, then finish up the interior with a clean rag. set aside.
- clean inside of big hose if necessary. if grimy, that can be a 15-minute job.
- as able, clean with Q-tips and rag the two other places (on my car anyway) where big hose connects.
- put everything back in obvious logical order, using new throttle body gasket (definitely), and new clamp on small hose (if it was a crimp-clamp before).
- assuming you don’t have VAG-COM gizmo, ensure you have anti-theft code for radio, then disconnect the ground strap from the battery. there may be easier ways around this part, but it works fine for me. i do something else for 10-15 minutes, just to make sure the computer’s lost its prior settings.
- reconnect battery ground strap and tighten properly.
- make a last check for loose tools, then — assuming you’re in a place where you can run the car for a while without dying — start the bitch up.
- all things correct, the computer should adjust to the new conditions by itself. i let the car idle until warm, in case that might help the computer.
- engine light? dunno. maybe it’ll go off by itself eventually, assuming throttle body scum was the problem. i’d already bought a cheapo code reader/zapper, so i killed the light that way. unlike all previous tries, this time it stayed out. yayyyy!
- enjoy, if it worked.
damn sure did the trick on my vehicle. no more occasional stalling when maneuvering in parking lots. no more A/C or headlights stalling the car. no having to rev the fuck out of the engine before unclutching on a green light. no more stalls simply because i let off the gas too quickly while in neutral (or with the clutch in) and the compensator thing couldn’t kick in fast enough.
removing the throttle body is no big deal if you take your time and have the replacement gasket/(clamp) as noted above. you’ll get it much cleaner (including the side you can’t to when it’s installed), and won’t be goosing foul schmooze into your engine so you can save 30 minutes.
* for those questioning this weirdness, here’s my theory (ignorant, since i don’t know electronic ignitions for shit) for how a gradually worsening dirty throttle body could have resulted in a sudden idle problem after the supposed preventive maintenance from southern VW, assuming that the mechanic didn’t introduce — accidentally or not — foreign matter into the throttle body. only thing i can think of if the throttle body was the core problem back then:
while i was driving the car from new to the 30,000 mile check (done very late), the throttle body was worsening normally. during this period the computer was adjusting the idle up and still hadn’t reached the max of the adjustment range. then my theory requires that the mechanic ran some tune-up procedure that bypassed or otherwise altered the fucked up throttle plate artificially, and in that procedure crossed into a range the max auto-adjustment could no longer hit. so even though the throttle body hadn’t been fucked with, the tune-up was made assuming an ideal throttle body. best i’ve come up with so far. the part that’s not so much of a stretch is for the mechanic to have seen this shit behavior and handed it back to me so i could later come back and they could say “oh, you need a new throttle body” (way over $500, from what i hear), and that’s why it couldn’t be tuned up, blah blah blah. no shit, i think that over 50% of the time i have someone else work on my car (very rare), something gets screwed, or the service pusher says something needs work/replacement that doesn’t. even tire/wheel stuff is screwed far too much.
so many mechanics are outrageous scum. whether there was mal intent at southern VW, they definitely turned my vehicle from running perfectly to running like bullshit, hesitating on every acceleration from stopped. that may not sound like a throttle body problem, but if the reaction time of the compensator thingy wasn’t designed for the profile necessary leaving a red light, it’s plausible. same reason i was stalling in parking lots despite giving extra throttle. considering the deepness of the problem, i suspect dynamic changes to the mixture, though that might be wacky talk. engine reacted much like a recip airplane engine when you briefly yank the mixture too lean — just nothing to work with coming out of idle, even if in emergency i floored the pedal. VW geeks, please sound off if you’re into the subject. would love to hear better theories.
BTW, why was i able to fix this problem myself, not throwing my wallet and vehicle to the mercy of the dealer fucks? internet, baby. the internet. thanks to all you fuckers who talked about this issue — this thing i’ve been avoiding for so long. ya made it a pleasure to deal with finally.