Author Topic: 1.6td idle drop  (Read 3778 times)

November 07, 2015, 02:41:56 pm

sean_caton666

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1.6td idle drop
« on: November 07, 2015, 02:41:56 pm »
I was driving down the road and was coming to a stop sign. I took the car out of gear and as soon as i did the idle dropped down to about 350 rmp. I have no idea what is causing this. Could it be the head gasket? If I keep my foot on the gas its all good. Still starts right up, just the super low idle. Please help

Reply #1November 07, 2015, 07:07:01 pm

vanbcguy

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Re: 1.6td idle drop
« Reply #1 on: November 07, 2015, 07:07:01 pm »
Any air bubbles in the feed line to the pump? Have you tried adjusting the idle speed?
Bryn

1994 Jetta - AHU M-TDI - Jezebel Jetta
2004 Jetta Wagon - 1.8T - Blitzen

Reply #2November 07, 2015, 08:20:02 pm

libbydiesel

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Re: 1.6td idle drop
« Reply #2 on: November 07, 2015, 08:20:02 pm »
Could it be the head gasket?

I'm not going to say it's impossible that a low idle would be caused by a head gasket issue, but I've never seen or heard of it.  Most common cause I've seen is that the idle screw locknut has vibrated loose and the idle has adjusted itself. 

Reply #3November 08, 2015, 10:47:27 am

sean_caton666

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Re: 1.6td idle drop
« Reply #3 on: November 08, 2015, 10:47:27 am »
thanks you guys ill check on that stuff today

Reply #4November 08, 2015, 01:50:50 pm

air-cooled or diesel

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Re: 1.6td idle drop
« Reply #4 on: November 08, 2015, 01:50:50 pm »
id say in this situation, unless idle screw locknut came loose, its either air in inlet/pump, or try changing out fuel filter, prime from inlet

Reply #5November 09, 2015, 03:10:15 pm

sean_caton666

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Re: 1.6td idle drop
« Reply #5 on: November 09, 2015, 03:10:15 pm »
there is air in the line, would a new fuel filter take care of this?

Reply #6November 09, 2015, 08:53:13 pm

Dakotakid

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Re: 1.6td idle drop
« Reply #6 on: November 09, 2015, 08:53:13 pm »
Probably not. What shape is the fuel line (which connects to BOTH sides of the fuel filter) in. Over the years, they tend to crack on the inlet side.

Also, have you removed the old plastic fuel separator box ahead of the passenger front wheel (bottom of car)? THOSE suck air as the plastic breaks down. I just removed my last one (off a car which has been sitting out of service for several years) last week. This is a common problem and you need to address it before it leaves you stranded on the road or in a bad part of town (where you score yer junk?).
The mask and the shot(s) are actually an IQ test. If you are wearing or circulating, you just failed the test. I can't feel sorry for you.

Reply #7November 11, 2015, 12:30:03 pm

sean_caton666

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Re: 1.6td idle drop
« Reply #7 on: November 11, 2015, 12:30:03 pm »
did you just remove it, or replace it?

Reply #8November 11, 2015, 02:45:16 pm

fatmobile

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Re: 1.6td idle drop
« Reply #8 on: November 11, 2015, 02:45:16 pm »
Water separator gets removed and replaced with a piece of 5/16" metal tubing.
 Remove the check valve in the line after it too.
 The tank will drain if you remove the hose because it's lower than the tank.
 You'll need to check the fuel pickup screen too, check for clogging.
 Do that first so the fuel line is disconnected from the water separator.

 Then change the filter, ha.
Tornado red, '91 Golf 4 door, with M-TDI 12mm pump, south bend clutch, VNT-15 turbo, 02A trany
MK4s: 2000 TDI jetta, 2003 TDI wagon, 2000 golf 2.0 gasser.
'84 Rabbit with 1.7TD KY block pistons bored to 80mm, VNT-15
'84 GTI with stock 1.6TD starion intercooler.