Tranny Problem

Well, I'm not sure if its actually a tranny problem though. The car was driving fine, then all of a sudden, when I hit 30mph and try to accelerate, something makes this clicking sound, but really fast, and somewhat loud. But, when I put it in neutral and rev the engine, I don't here it. So I think it may be the tranny. 94 Z28, auto.

does the sound come from the floor or the back of the car??? try and trace the location of the sound. i agree that it is definatly drivetrain related, but it could also be the rear end, or something else. way out in left feild im thinking it might be a ABS problem, but im still wondering what might be causing it.

Does it click while coasting in gear? Get up to speed (when it starts clicking) and put the car in nuetral, If the sound goes away, Ide say its a problem with the tranny..

Sounds like the noise my 700 made on its last few kms...

Just went out and drove it again. Under light acceleration, the car is fine, it has probelms when the petal is pushed anywhere from 1/4-1/2 way down. But if I push it 3/4 to all the way, the car acts fine and gets up and goes. So now, it happens at any speed, just depends on how much throttle I give it. It definately coming from somewhere around the engine. My dad took a look at it and drove it and he thinks its coming from somewhere in the intake manifold. He said that the sound can be compared to engine knock. And it is colder right now. About 23 degrees here in MO. May be the weather. Anyway, I hope this helps.

How is your oil?

yeah sounds like a tapping lifter or rocker arm.

I think I am a very lucky guy. I went out to eat with some friends...car still having problems. Then we leave and go to a friend's house. Same problems. But, after about 3 hours, I drive home with no problems at all! I accelerated at different speeds and at different rates, but no problems, no odd noises and no sluggish acceleration. Might have been the cold weather. At this point, I don't really care, as long as it doesn't come back. So, I'll see what happens tomorrow when I go to school. Thanks for the many opinions on my terrible descriptions. I'll keep ya posted.

sounds like your oil warmed up, id let your car sit at idle and warm up before driving it in such cold conditions. i always let my camaro idle until the rpms drop from 1700 down to operating speed around 700rpms before driving it in the winter.

ive had this problem before... the car would knock and stumble and skip, backfire, rock, and do everything wrong... Someone said it was a wrist pin, crank, lifer, rod.. it sounded so bad.. .like the engine was going to shake and distroy itself to death....and my god was it loud. It litterally made the chevy mechanics at the dealership go.. "my god" and shake their heads.. It turned out to be the cap and rotor... It was sending a spark to some of the cylnders early.. so it would fire with an intake/exuast valve still open... I Love opti-sparks.:(.. I replaced it.. and a week later its doing it again

Well, I spoke too soon. This morning on my way to school, it was doing it again. A first, about the first 5 minutes, it was fine, then on the going 50mph trying to accelerate to 60, it started again. I could also feel it in the gas petal. I checked my gauges and everything was fine. Oil pressures good, no check engine light. Now that I'm thinking about it, the first time this happened yesterday, my low traction light came on, so I let off the accelerator, got traction, and tried to accelerate again, and that's when this all started. But I had no reason for low traction, roads where dry. So, this afternoon, I'm going to take it into my mechanic so they can find the problem, because like I said, it only happens when I'm driving, can't feel it in neutral.

Ok, so I just got back from my mechanic. He didn't look at it, but I told him what was wrong and he said that the optispark is getting old and going bad. I was also planning on getting a tune up, so replacing the damn optispark and wires etc... plus the tune up, it will cost me about $1400. So, I'm somewhat depressed right now. There goes my modding plans for spring.

well to save some money, he probly sold you the optispark for around 650 bucks. tell him to keep it, and buy one off of www.GMpartsdirect.com its about 300 bucks less. also, i am very hesitent to sell work to a guy who hasnt even looked at the car. thats not professional at all. even when i KNEW what a problem was with a car, i still verified by diagnosis to make sure. shady business.

also, remember i said it might be ABS related, and now you are saying that the traction control light was on while it was doing it.

Have youre greasemoneky repairman run the codes in the ABS module and BCM if he knows how, youve probly got a bad vss or abs module that is activating at speed.

Yeah id definatly have someone check out the ABS and VSS modules before you replace your opti-spark?

Your low trac light comes on when the ABS is activated.. And that loud clicking you hear could be the ABS system..

It only clicks when I accelerate at a certain rate, so how could it be ABS related? I may bring that up next time I talk to him. He said that the distributor is firing off at random because its old and trying to find the least resistance...or something. But my dad and I have been going to these guys for about 10 years now because my dad knew one of the guys, so at this point, we trust them. My dad used to work on a lot of the old carbed cars when he was younger, but just doesn't have the knowledge that the newer cars require, but he said that the sounds made could be caused by the electrical problem. Besides, I really don't know where else to go to get a second opinion. Most of these other places around here are oil change places. Do you think it would be about time to replace the original optispark with around 92K miles on it?

if its the original opti with 92k on it, its very possible it will need to be replaced. but that may not be your problem.

The ABS and VSS are electronic parts, all it takes is one part to fail, or one wire to rubthrough, and it can cause any number of symptoms from the vechile.

for instance, a possible situation with your car is that you have a wire rubthrough on one of your VSS wiring harnesses, it may only come into contact at a certain speed or harmonic that is only present under acceleration. this may cause a VSS to read 0 at speed, while the others are at speed. the ABS will try to correct the situation causing the tapping sound, although i would assume there would be a difference in feel of the car. like i said, just one possiblity.