chevygirl

iTrader: (69)

Does anyone know if a torque converter can affect the idle and make it rough or unstable?

C5XTASY

Kind of depends on your cam and brand and style of converter. The smaller diameter converters can be quite a bit lighter than the stock converters. As the converter acts as a flywheel, an aftermarket cam's idle could be affected somewhat, dependent on idle speed.
Ed

chevygirl

iTrader: (69)

I was wondering if the torque converter is not working properly or locked up could it call the idle to be rough?

waterbug1999

iTrader: (3)

Are you referring to your other thread about when its in 3rd and give it gas it shakes and shimmy's? Or at idle?

jimmyblue

iTrader: (11)

It will make idle "hunt" because of the low flywheel mass,
if the idle settings are not good enough to be stable on
their own. It will also allow any raggedy idle characteristic
to show more plainly. But it won't cause these things in
and of itself.

Now if you had a real mechanical problem up in there
you could have other weirdness (like a cracked flexplate
or a busted off converter mounting ear or whatever).

But plain old crappy idle, that's just "garbage in, garbage
out" on wheels.

98A4LS1

iTrader: (1)

Sorry to get off topic, but I noticed '98 flexplates being installed on later model years. Is there a difference between the '98 flexplate and later years?

chevygirl

iTrader: (69)

I just wondered about the converter causing my rough idle problems. No one has been able to fix it in 21 months. This shudder has become very bad and I just had my second new engine installed. It is probably 2 seperate issues. Mechanic thinks it is a fuel problem now. Maybe lean but the idle cuts in and out when you first start it up and it is cold so I don't know.

tinytimsolderbrother

Yes it can ... a converter with a internal failure will effect idle

i used to think i had a miss at idle and when i put my new

converter in it was gone... and hasnt returned.. even a ac

compressor that starting to bind up internally can do that or

a overcharged ac system!

chevygirl

iTrader: (69)

I got a new ac system (everything) I had the idle problem before and after so I will rule that out for now. How can you diagnosis an internal failure? Can the torque converter be replaced without needing to replaced the trans. oil pump or anything else? Labor is like 6 hours on a new torque converter so I want to figure this one out before I dump alot of money. Mechanic looked at the converter about 8 months ago and said he didn't see anything wrong with it but that was before it got real bad in 3rd gear when I am driving it. Also said he disconnected it and ran the engine without the converter and it did not change or fix the idle problem.

tinytimsolderbrother

are you talking about a torque converter or a catalytic converter?!?

you lost me for sec with your last responce!

chevygirl

iTrader: (69)

I was talking about the torque converter the mechanic looked at it some time back.

tinytimsolderbrother

I wonder how he disconnected it?!? that doesnt make sense

he must of meant the catalytic converter

chevygirl

iTrader: (69)

He said he ran it with out the torque converter and transmission hooked up with it on the rack to see if it affected the idle.

jimmyblue

iTrader: (11)

I think your mechanic is taking advantage. Without the
converter the engine would have no flywheel mass, and
I bet not idle for ****. I bet he went and bolted on a
spare M6 flywheel he happened to have laying about.
Yeah.

Selling someone a new engine for idle quality problems is
downright suspicious too.

I think there are some people in TN who are capable of
helping you out. You're way past "second opinion" time
with Dr. Wildguess. Go put out a shout in the appropriate
local forum for shops or people who could give a proper
try at diagnosis without swapping entire assemblies.

chevygirl

iTrader: (69)

The engine was sold and installed by another company when it was smoking and had an irratic idle. After replacing the engine with a new one the idle did not get fixed by him. I took it to another place and they could not figure out want was wrong. I took it to another dealership and they said it was just a normal rough idle???? It got worse so I took it to this guy I am using now because he said he would work on it until he figured it out and 3 of my friends recommended him. One dealership said he was the best engine guy in the city. He works on show vehicle and people come from all over to let him work on their vehicles. The engine was replaced again because they saw signs that there was a coolant leak internally so GM gave them another engine and they thought it might have fixed the idle problem too but it has been there a long time and we really didn't expect the engine to solve that problem. This guy has actually done alot of work and he hasn't been paid for his time. I don't understand why he said he ran it without the converter if you can't do that. I wish I could figure it out and fix it myself but I haven't had any luck for almost 2 years.

ChocoTaco369

has anyone thrown in the possibility it's not a hardware problem but rather a tuning issue? converters are known to need a tune afterwards. have you tried bumping up the idle 100 or so rpm's to see if that corrects the idle? have you adjusted shift points? have you raised your lock-up mph?

chevygirl

iTrader: (69)

I don't know if he tried that. I will check to see if he can tell me. The idle seems to be a little high now. It may run okay for a minute and then it starts messing up.

spy2520

iTrader: (3)

thats funny, so many different motors and still the same problem. i would have swapped out the converter or got into the tune to see if anything changed by now...

chevygirl

iTrader: (69)

The converter is going to be 6 hours labor so I need to make sure.

ChocoTaco369

6 hours of labor to install a TC? doesn't that seem a little high? header installs don't take that long.