Few General Questions

[PCGUY112887]

All of these are for my 96GP sedan with the 3100 and almost 110k miles.

 

1. High idle.

Sometimes when I start my car, it will idle high, usually about 1300-1500rpm's. Once I put it in gear it goes down to about 1000 and after driving for a bit and it getting warm it idles normal at about 800rpm's. I replaced the PCV valve and ran some fuel injector cleaner, still does the same thing. It doesn't seem to casue any problems, but any ideas on what I should do about it? (if anything? I tried the PCV valve just in case but it didn't change a thing)

 

2. Seemingly rough idle.

If i'm sitting at the light, sometimes I can "feel" the engine through my seat, like it's shaking ever so slightly. It doesn't do this everytime... i'm not sure if it's normal or not but I can't feel it when i'm moving and it doesn't take off hard or anything. Maybe the mounts are just going bad or something?

 

3. Timing belt.

My friends VW is getting a new timing belt because he was told that at 90k he really needs to have it replaced otherwise he's running a high risk of a piston poping from the hood or out of the oilpan. We talked to someshops and the VW dealer and all of them told him that he's 10k miles lucky (100k car) because it's going to break at any day and someone needs to replace it right away.

 

Why do I never really hear of people replacing the timing belt/chain on the 3100 if it's so important?

 

4. Part of PCV line.

OK when I was chaning my PCV valve I managed to snap the hose right under the plate that holds onto the TB. I went to autozone and got a repalcement but it wasn't a direct replacement, had to rig it on there with this rubber piece that came on it and such. Right under the black plate in the PCV line there is some type of fitting that goes into the upper manifold. When I rigged this line back in there, it's sorta crooked in there and doesn't fit down very well. Is this going to cause a problem? Note the above issues existed before this.

 

I think there is something else but I can't remmeber so i'll stop for now, thanks!

[Regal_GS_1989]

1 I'm not sure of the weather by where you live, but this is most likely just the cold idle routine. Its normal

 

2. run some top end cleaner through it, cant hurt. IDK when the last time you had a tuneup was, maybe one is in order.

 

3. 3100's dont have timing belts.

 

4. As long as it is not leaking, should be no problem

[Prospeeder]

Timing chains dont ever break on any of these motors, most chains live longer than the motor itself does! but Turbosedan has his break at 227k or so on a Turbo motor reving it up and snap! did some valve bending i belive. But TIming belts always wear out every 60-70k on any Timing belt having engine,

[19Cutlass94]

sounds like the high idle is simply cause its cold. Mine does the same thing.

[PCGUY112887]

I bought some seafoam and a funnel to run some through, i'll probally do it tomorrow.

 

I've been wondering, what exactelly is involved in a "tuneup"? Just the general 100k things (plugs, wires, some injector/top head cleaner, oil, coolant) or is a "tune up" something more?

 

Thanks.

[Prospeeder]

sounds like the high idle is simply cause its cold. Mine does the same thing.

definalty, mine idles at 1500 or so on cold days untill it gets a little warm then drops down a bit till its to about 900 rpms

[19Cutlass94]

plugs, wires, fuel filter, air filter (if just the paper filter and not K&N)

[PCGUY112887]

Fuel filter is layin in my car waiting to be installed, and i'm doing a CAI as soon as I order the filter.

 

Thanks again.

[Crazy K]

#1 it does seem slightly high, my bros 94 CS doesn't run that high by my 95 Cs does.

 

and #1 may relate to #4. I think you have pointed out a possiblity, if the gasket on that hose is bad and/or leaking it may allow air to be sucked in and be the cause of a high idle.

 

with regards to #3 the 3100 has a timing chain. basically it 'should' last the life of the engine. BTW I do not know if the 3100 (or 3.1) is a non-interference engine, should the cahin actaully fail. anyone know?

 

BTW interference is what the vw engine has, when the engine valves and pistons travel through the same spot, but miss striking as long as the the timing chain or belt is functioning. A failure can mean cosmic collison.

[19Cutlass94]

If an engine has a timing chain, it should never fail. It my stretch over time therefor worrant (sp?) a replace but shouldnt break.

[GutlessSupreme]

but Turbosedan has his

 

*chain

 

break at 227k or so on a Turbo motor reving it up and snap! did some valve bending i belive

[Prospeeder]

but Turbosedan has his

 

*chain

 

break at 227k or so on a Turbo motor reving it up and snap! did some valve bending i belive

 

yea i reworded it, i knew it was a chain, just how i arranged that paragraph

[PCGUY112887]

Guess I could ask this in here... I was considering going ahead and changing the head gaskets becuase I know it'll go sooner or later and if later i'll have a big shit mess. What all is involved in doing this?

 

Thanks.

[19Cutlass94]

If your not having a problem with em right now dont even bother. Save your self the trouble. And of course if your gonna change the head gaskets you better to the UIM & LIM as well.

[Crazy K]

If your not having a problem with em right now dont even bother. Save your self the trouble. And of course if your gonna change the head gaskets you better to the UIM & LIM as well.

 

x2 unless you have a known problem you should not touch them.

 

The most likely thing i have seen the needs for headgaskets for is a badly overheated engine(usually also requiring heads), or when the coolant passages have eroded because or low quality or just plain bad coolant. Expect 200 to 250k before the headgaskets would have to be replaced, assuming normal use with proper maintence, IMO.

[THe_DeTAiL3R]

No need to replace the headgaskets. It is alot of work, probably 10+hrs if you've never done something like that before. You will MOST LIKELY need to change the lower intake gaskets eventually though, cause they DO go bad. Keep an eye on your coolant level and around the lower intake for and wet spots indicating leaking gaskets.

 

As for your original post:

 

1. Yes that's normal. The IAT (idle air temperature sensor) is that wire that goes to the intake hose. It senses that it's cold outside so the engine RPMs go higher to warm up the engine.

 

2. Somewhat normal to an extent, or: you may have bad gas, dirty fuel system/injectors. Also the possibility of the upper mounts may be a possibility. I'd run some fuel injector cleaner/ top engine cleaner and do a tuneup if you are worried about it.

 

3. The CHAIN basically lasts the life of the engine, as others stated

 

4. I know that vacuum line you are talking about. I just replaced mine cause it was old and cracked causing a leak (idling about 200RPM too high and SES light came on). The GM one I bought came with 2 or 3 other vacuum hoses that I didn't need and cost $40 with my discount. :| . If you got it rigged up with something else and no leak than you're fine. All they do is put the poluted air from inside the crankcase back into the engine to be burnt up (through that skinny hose on top of the throttlebody) thus not poluting the air and such.