Weird lump in drivetrain - Update: Problem Solved!!!

[Grand Moff Joseph]

UPDATE:

 

Just to follow up, since this whole saga got bogged down for a while, it looks like I have managed to solve the problems I reported earlier. I recently had the spark plugs replaced, replaced a broken vacuum line, put the engine through a total fuel system cleaning procedure, as well as a fresh oil/filter change. Now, the rough idle is gone, the power delivery and throttle response has smoothed out to perfection, and the tranny is shifting much nicer at highway speeds.

 

So, disaster has been averted once again. Thanks to everyone for your suggestions/tips!

 

-GMJ

****************************

I have a couple of anamolous problems that I need some help pinning down:

 

1. When driving at highway speeds, I feel a near constant 'lumpy feeling' in the drivetrain. The car only seems to do it after it kicks down into OD. As soon as I let off the gas totally/ push the gas harder, it stops. It's not a huge lump like the whole car is shaking, it's just this weird vibe I can feel coming from what I think is the tranny.

 

2. At moderate to highway speed, the tranny likes to shift into OD a lot, and when it does, it sometimes does so with a nice kick. When the gas is pressed harder, it illicits another smll kick to get out of OD. I'm kind of used to this, but it seems to have gotten a little worse lately.

 

3. Under moderate to heavy throttle, I can easily hear what sounds like a low knocking sound. No, it doesn't sound like a piston or soemthing like that. It sounds like it's coming from the exhaust system, but I can't tell. Under near WOT, it sounds really noticeable, but it dies down quite a bit when the throttle levels off.

 

Any ideas folks? I'm planning on taking the car in to get checked out, but I want to have some clues before I go.

 

NB: My tranny is a remanufactured "Accu-shift" tranny. Engine is a stock 3.1L

[DaveFromColorado]

1) sounds like you've got a CV shaft starting to go out - those are typical symptoms of the INNER joing (where as the outter has a loud clicking on turns)

 

2) I'd say the TCC (Torque Converter Clutch) Solenoid is going bad, and keeping the TCC locked up durring those shifts.

 

3) Time to start running premium gasoline - what you're hearing my friend is detonation - almost sounds like you're running with marbles in the engine I bet.. typically associated with a knocking sound in the exhaust too.

 

--Dave.

[Grand Moff Joseph]

Dave,

 

I think I'm gonna have to disgaree with you on #2. When I firstgot the car in late 2003, it had the horrible problem of dying when coming to a stop after driving at any moderate to high speed. Every shop I went to said it showed classic signs of a bad torque converter, so I had to entire tranny replaced. In the process, the cat and the alternator died, and I had the EGR cleaned out.

 

Anyway, long story short, the problem was finally traced to what was described to me as the "electric solenoid that controls the lock up on the torque converter". I can only assume that this is the same thing as the TCC you mentioned. That part was changed, and the problem was solved.

 

It's not that the shifts into/out of OD are missed or hard, it's just that it tends to kick down into OD a lot at cruise speeds, and when it does, the engine seems to have absolutely no response or power left in it, and I have to goose the gas to get it to pick up again wheen needed.

 

As for #1, is the CV shaft part of the tranny itself? Better yet, WTF is it?

[DaveFromColorado]

The CV Shaft (or constant velocity) is the actual axel that transfers the power from the transmission to the wheel hub - when those go bad, it's usually the outter that goes bad, when transmissions are replaced I see a lot more inners go bad due to mishandeling when it's disassembeled, or durring the disassembly process - it happens all the time.

 

the TCC solenoid (the electric solenoid that controls the Torque Converter Clutch lockup) may still be the issue, but from what you're describing I'd almost think that again, your engine doesn't have enough power because it's detonating due to cheap gasoline or a bad tuneup - I'd try upgrading the fuel and that may get rid of problems #2 and #3. Also, a fresh tune up may be in order, new plugs, wires and such. You could also look at the coils see if they are going bad and not generating enough power to produce a good hot spark - that too can cause detonation and lack of power type problems.

 

--Dave.

[Grand Moff Joseph]

Well, I replaced the plugs and wires last year with platinum tip plugs and performance wires, so they're all good.

 

I'd love to take you up on the higher octance gas, but it's just too damn expensive right now. In truth, my grandparents pumped 93 octane into it from day one, and whn I got it, I continued to pump 89 in it, until it got to be too expensive to stick with it.

 

Is there a way to check the CV shaft for obvious signs of failure/near failure? How much could that possibly cost to replace? Also, I assume the coil packs are different then the spark plugs??

 

Sorry for the noob questions, but when it comes to repairing cars, I am quite the n00b.

[digitaloutsider]

Weird lump in drivetrain

Maybe it fdfsfsdfwerwerwer

 

At any rate, pull the platinum plugs out, ASAP.

 

(Sorry, had to edit it out. That was totally tasteless)

[ShockTherapy]

lol, Shaun, you're going to hell for that one !

lol

[Grand Moff Joseph]

I'm glad I wasn't around to read that... :shock:

[DaveFromColorado]

Platnum plugs are NOT happy in the 60 degree V6 family.. (2.8/3.1/3.4/3100/3400 engines) stick with stock AC Delco plugs and figure to change 'em about every other year (at least that's what I do if I own a car long enough)

 

Anyhow, to check the CV joints/shafts climb under the car and give 'em a shake, if they feel like they are moving more then say 1/16 of an inch, they are most likely bad. also look to see if the boots are ripped or if there's CV Grease everywhere (trust me, you'll notice it if it's there) - the replacement part is only about $120ish (IIRC) but there is a core charge (money you pay them for your old rebuildable part) you get that money refunded when you return the part (same idea for brake calipers, alternators, water pumps, things like that)

 

Changing a CV shaft is quite a bit different - you may have to research it a lil' as I know it's been discussed here a few times (how to's and such) but it's a fairly simple process.

 

I'd recomend saving up a little bit and getting a tank full of 93, just to see how it performs in your car, if the symptoms go away, you know where the problem is (and you may be able to correct it with new plugs) - or you can replace the plugs and hope for the best.

 

here's an other question - when's the last time you changed the air filter - it's a simple thing that most people forget about when working on their own cars - if it's cloged up, that too can cause issues.

 

Finally, the coils are what the sparkplug wires are plugged into on the other end - if they are damaged, weak, or otherwise malfunctioning, they will cause problems - testing procedures for the coils are located just 'bout everywhere on this site...

 

Good luck!

 

--Dave.

[19Cutlass94]

Before anything, Id change the plugs. Do what Dave said and just get normal Delco plugs. I think I might know what your talking about because I had a cylinder go out on me on my way home from work. Turns out it was a bad plug, but was it like your describing.

 

Also do you like to take the corners rather fast? If so, that will contribute to CV shafts going bad.

[Grand Moff Joseph]

Wow, I don't check the site for a couple days, and look how mahy questions I have to answer...lol

 

1. I changed the air filter around May 2004 by replacing it with a K&N drop-in filter

 

2. Once my current tank of gas runs low, I'm going to bump it up to at least 89 octane (and probably dump in a bottle of fuel system cleaner for the hell of it), and see what it does

 

3. I looked on AutoZone.com, and they list coilpacks for 19.99. Is that too cheap, or should I go to a dealer for authentic GM replacements?

 

4. I don't drive the Lumina like it's a rally car, but I do take some curves in a "sporty like" manner.

 

5. I've had the platinum plugs in for a long time (with new standard wires), and have had no problems.

 

BTW, would it be possible for someone to post a pic of their car's CV shaft/boots? I ask only so that I can verify that I am examining the right part...lol.

 

Thanks for the help guys!

GMJ

[digitaloutsider]

K&N filters don't last forever. They require being cleaned. Buy the cleaner kit from AutoZone, or whatever your local parts store is. It'll include a soapy substance and the red oil in spray bottles. It's cake to do.

 

Once again, this isn't because we have some sort of beef with platinum plugs.. they are NOT good for the waste-spark system GM implemented in the 60º V6's! PULL THEM OUT! Especially if they've been in there a while. They may be misfiring if they've been in too long and are simply too worn down to fire correctly.

 

Don't worry about looking at the CV shafts/boots until you change the plugs. I'll almost bet they're the cause. If you absolutely must have a "performance" plug, get some NGK/Delco Iridiums.

 

FWIW, your CV shafts are what deliver power to the wheels. They run from the differential to the hubs. You can't really miss them..

[19Cutlass94]

yeah like shaun said, pull the plugs and replace them ASAFP.

[Turbocharged400sbc]

I have a feeling that 1 and 2 are related...

though i would check the inner CV joints as Dave said,

problem 1, this sounds very similar to a problem i have encountered a couple of times involving Torque converter clutch slippage/chatter that usually happens at part throttle and goes away when you floor it (the TCC solenoid will unlock the TCC) and goes away at light/no pedal as there is alot less load on the TCC, the best way to determin this is iff you hook up a scanner and look for the TCC solenoid on comand when the problem is happening....then just ever so lightly press the brake (just enough to activate the brake switch which kicks the TCC off) if the shudder/chatter/lump disapears when you lightly press the brake at the time the problem is occuring, you may have a bad/incorrect Torque converter, I have had a newer car that had this issue and the problem was that the converter was for an earlier PWM TCC system that had been installed into a newer design that required carbon fiber clutches in the Tq converter...evidently the Carbon fiber Tq converter costs 250$ more and the tranny shop (cheapo customer) didnt want to spend the extra $, on the other vehicles most of the time it was the original converter flushed and reinstalled into the trans and the clutches were just worn out.

 

BTW the Torque converter clutch is inside the Tq converter and is activated by the TCC solenoid to lockup the converter (so there is no slippage/Tq multiplication) so that the engine crankshaft rpms and trans input shaft rpms are the same, where as with the Tq converter clutch disabled the trans input rpms will be lower than the crankshaft rpms. this system was designed to give better fuel economy as the engine/trans works more like a manual trans at light/part throttle cruise. the TTC is usually only enabled above 40-45mph and has to have certain conditions to engage, from zero to 50% throttle (in most cases), speed above 45mph, brake pedal switch off, and trans position switch in OD.

 

Problem 2 may actually be the TCC engaging/disengaging as you drive at cruising speed and change your throttle position and not the trans going into and out of OD (4th) gear.... this may be atibutable to a leaky TCC solenoid with a cracked seat (the aftermarket makes metal bodied solenoids to replace the factory replacment plastic housing TCC solenoid housing)

 

problem 3 does sound like detonation try higher octane gas and as stated previously change your plugs, while you have them out look at them in good light with a magnifying glass, look for little aluminum specks on the porcelin of the plugs, this is an idication that detonation has been occuring, but usually when you can see it on the plugs the damage has been done, detonation can toast your rod bearings as well as the pistons and rings....

 

good luck finding the problem

 

regards, James

[Grand Moff Joseph]

I don't think this needs a whole new thread, but would any of these problems be contributing to the observation that I burned almost 1/4 tank of gas driving 16 miles from home to work this morning? (or has my gas gauge gone wacko??)

[Turbocharged400sbc]

more than likely it is gauge issues....the gauge moves the fastest at the top and bottom 1/4 scale (the float arm moves in a arc = not linear

[19Cutlass94]

Well it could also be a lost cylinder due to a bad plug. That will make your car go through gas like theres no tomorrow.

[DaveFromColorado]

I'm gonna agree that it's most likely the gas gauge going funny there - as Turbocharged400sbc stated. However, if you are burning through that much gasoline then you may also want to check your catalytic converter, as I'm sure there's LOTS of unburned fuel entering the exhaust system, and may be actually overheating the catalytic converter.

 

You've gotta clean your K&N Filter about every 6 months to actually keep it flowing properly, any longer then that, and I'm sure you'll start losing performance and having drivability issues.

 

Here's a list of what I would do if it were my car ...

 

1) Change the plugs with AC Delco Plugs. (Iridium if you want performance plugs)

 

2) Clean the Air Filter with a K&N Recharge Kit

 

3) Fill up with a tank of Premium (92 or better octane) Gasoline

 

4) Oil Change with a can of 5 minute motor flush (read the instructions) Even if you just changed your oil - lots of unburned fuel in the system from a misfiring plug will surly wash the cylinders and allow lots of that gas back down into the crankcase.

 

I'd see how the car runs for a week before I'd start going into more depth with it - I already have a few more ideas if that doesn't work, but hopefully those things should fix your car, they're fairly inexpensive as in the longrun those little problems can become HUGE problems.

 

--Dave.

[Grand Moff Joseph]

Well, I brought the car into a dealership here to get checked out, and to get the plugs changed. I took the service guy's advice and started with a full inspection to make sure that the spark plugs were indeed the culprit, and to look for any other problems that may be associated with it. Unfortunately, the news I received was far worse than I ever imagined. Here's the short form:

 

1. Transmission pan is crakced and is leaking tranny fluid. The leak is not severe, but the pan needs to be replaced, which of course requires a total drain/refill of the tranny system

 

2. Power steering pipes are cracked in a few places, and are leaking PS fluid.

 

3. Left front drive axle seal is shot and is leaking at a slow/moderate pace

 

4. Confirmed that idle is somewhat jumpy, is probably a bad/cracked plug or wire.

 

5. Bad idle/weird engine sounds also traced to possible fuel injection problem; fuel injection service highly recommended.

 

6. AC condensor is leaking and is pretty much on its way to its grave.

 

So, basically, I am TOTALLY SCREWED! :x I was not expecting any of these problems, given the high level of care that the car has received over the years, and of course, this all happens when my wife and I are trying to operate on a budget.

 

What makes me even more distraught over this is the fact that this car means so much to me. Over the last two weeks, I have watched my hometown get destroyed by floods, and besides her house, this car is all my grandma (a NOLA resident) has left! Why the fark does this have to happen now!!!!

 

I'm half tempted to setup a donation bin to get the money to fix the poor car. I have to do something, because it would break my heart to give up on the car.

 

Sorry for the rant guys/gals...

[GP1138]

You can't fix any of that yourself? I've done transmission pan drops and filter changes, if the pan itself is broken, you can just replace that, and then refill the tranny. I've also replaced axle seals, that's not too awful hard either, and it's cheap too. Idle should be an easy problem to fix.

[Grand Moff Joseph]

Well, even if I knew what the heck I was doing, I still don't have the tools to fix these problems anyway. My tool collection is extremely small, and I have never had the money to go out and get a good set of tools. I'd love to fix as much of this myself as I can, but to be honest with you, I need someone with the tools & brains to help me out.

[digitaloutsider]

Really, you don't need an elaborate set of tools to do your tranny pan. In fact, all you need is a ratchet, and 10mm socket! The fuel injection "advice" sounds like bullshit to me. How exactly do you "service" the fuel injection system?! There's nothing to it.

 

On the note of the tools, you can get a pretty nice 120-250 piece set anywhere from $35-150+. You don't need the top-of-the-line brand name tools if you're not going to be using them that often. You can EASILY do the transmission pan yourself. It's a bunch of 10mm bolts, some transmission fluid, a new gasket and you're set. Hell, you could even take the time out to put in a new filter (also a cakewalk). Once you do a little work on your car, you'll realize it's a lot easier than it seems. About the only thing you can't do yourself in that list (legally, anyway) is your A/C condensor. It's illegal to let the freon out into the air (unless you've converted to R-134a, and then you don't have to worry about it).

 

Power steering lines are a bit difficult, but inspect them yourself to make sure the stealership just isn't trying to fuck you over. Same goes for the A/C condensor (they don't exactly have a wear-out period.. either they're good or they're not. Simple as that.

 

Axle seals are not the easiest thing in the world for a beginner, but if you're determined and dedicated, a good Haynes manual will help you out. If you want to throw down the money (and it really isn't a lot on eBay), buy a factory service manual. Those things are lifesavers, and describe everything a lot better than any Haynes or Chilton's manual. As a good rule of thumb, Chiltons is crap.

 

If the idle is jumpy and they think it's a spark plug or wire, hell.. change them yourself! It's NOT hard. Plus, it's a good beginner project. Spark plugs and brakes were the first thing I ever did mechanically on my car. Then came the alternator.. and water pump.. and power steering pump (x5).. and power steering rack.. and subframe.. and a-frame.. and left-side strut assembly.. FUCK GRAND PRIX'S! [coughs] Anyhow.

 

Really, you can do just about everything on that list if you're not scared to take a wrench to your car. Turning a nut the wrong way isn't going to make the car fall apart. At the worst, you'll have a stripped bolt and a hole or two that might need a good tap-and-die set. Once you do a project yourself, you'll be more confident, and you'll have that feeling you can only get from completing something you didn't even know you can do. 8)

 

Good luck!

[White93z34]

i agree with shaun here, its FAR cheeper to pick up a half decent metric socket set and a service manual of some variety then it is to pay someone else to do that work.

 

i know it seems intimidateing at first, but its not that bad. i started out doing simple stupid things, brakes, plugs, wires, now i can do just about anything related to the car, period.

[Grand Moff Joseph]

OK, I went and spoke to a very nice gentleman that runs a small auto/tire shop near my apartment. I told him what the dealership said they found, and he called BS, as did I. For instance, they said that they saw a leak in the tranny pan gasket...but in order to check that they would have had to take the pan down, which they did not do. Also, they said the PS line was leaking, but the PS fluid was constant and showed no signs of deteriorating.

 

Anyway, he said he'd check the car out, and look for the things that the dealership said they found. If he finds the same problems as well, then I'll figure out what to do. Both him and I feel that the AC compressor is not worth farking with. It's too expensive to replace, especially since I would have to revert to R134 from R12, which jacks up the cost further. I'll use the AC till it dies, then I'll dick with it.

 

As for the PS line, if there is a leak, it is a very gradual one that is not causing any problems for now. Unless the lines are badly damaged, I'll leave it for now. The only thing I am concerned with, besides the spark plugs, is the potential drive shaft leak. If he does find any drive shaft problems, I will get those fixed. I'll tackle the plugs myself.

 

One last thing, do you guys/gals think it would be worthwhile to change the coil packs while I'm at it with the plugs? Also, since I have a six cylinder, I need three coils right? (two plugs per coil)?

[GP1138]

Actually, the tranny pan gasket is somewhat diagnosable if you see it leaking out the side of the pan.