Slack in the drivetrain

[jesus_man]

School has started again so my commute has become a lot more stop and go (pissed), but such is life in the big city. Being that my car has a 5spd it's not that fun to drive in traffic, but it seems as if there is a LOT of slack in the drivetrain. There always has been and I have tried to tighten it up. I have a new clutch, new motor mounts, even the expensive one, and made sure things were tight.

If I'm in either first or second gear, and traffic is speeding up and slowing down, thos transitione between on the gas and off make it look like I am just leanring to drive a car. Especially in first gear. I *really* have to ease into the throttle to not get this bucking. Slowing down isn't bad, but going from coasting to excelerating is where it's teh worst. But if I push the clutch in, just before I speed up, it is much smoother. I am pretty sure the CV axles are good.

What else should I be looking at? I'll be changing the oil this weekend, so I'll be double checking tightness of everything again.

Thanks for your help and suggestions!

J.D.

 

[BlackCherry06]

This is basically what it's like to drive most M/T cars from my experience. You have to feather throttle and sometimes slip the clutch when traveling below engine idle speed in 1st gear or you can expect it to buck like a wild horse. Easing off the gas is as important as easing on it, and using the clutch in conjunction with that is how you get smooth transitions. Any car is going to act that way if you leave the clutch out and get on and off the throttle at low speeds.

 

[jesus_man]

Thanks, glad it's not just me. however, I have a lot of experience with many cars and not all do that. In fact, none have done it this bad. My last commuter car was a 95 subaru with a 5spd. It did not do that. My previous truck and current truck were both standards and didn't do that either, when stock. I modified the drivetrain on the previous truck and this slack got more noticeable, but it wasn't nearly as bad as my Protege. My wife's VW doesn't do this. And I've had experience with other cars, not just mine.

The car has 122k on it so I expect things to be wore out, but I thought with the things I replaced, it would have gotten better.

It seems like something in the drivetrain is a torsion bar. Like the axles allow for a lot of twist, and then catch up once momentum is established.

Maybe it's just something I have to live with. or maybe crawling under it this weekend will show me some loose items??

J.D.

 

[jesus_man]

Ok, bringing this one back from the past. My issue has been getting much worse lately. What I have done:
Got a CEL a couple months ago. Codes were P0660 and P0037. Had the codes cleared, but the CEL came back the next day. Had the codes read again and P0037 came back. That happens to be the second or rear O2 sensor. I am patiently waiting on that from Protege garage.

I also ordered one of the new motor mounts from Medieval (sp) and hoping those are being shipped out soon as I think a lot of my slack is due to the motor mounts being too soft.

However, this morning, my car was REALLY bad. I don't know if the rain had anything to do with it, but as I left my driveway, the car started bucking very badly, like I was mashing the gas to the floor and letting off and back on again. now this has been happening, but not ever this bad. As I drive more his morning, I find that the car just does not want to accelerate from a low rpm. And even if I hold the rpms at 4k+ and slip the clutch to get going, I still have the bucking issue, it's just more tolerable that way. Keep in mind the car seems to be idling fine and will travel at 30mph+ fine, but the issues only arise when I attempt to take off from a stop, or a slow roll in either 1st or 2nd gear. It literally felt as if the car has lots of water in the fuel, but the gas cap is securely on and it doesn't appear that water should be able to get into the filler neck. Plus rain has never affected it before.

So about 1/2 way thru my 25mile commute, the car straightens out and was running good. Good as in, the normal slack in the drivetrain and not severe bucking like the previous 12 miles.

I get to work, pop the hood looking for where water might have gotten into the intake or something like that and there is no clues. Everything appears to be dry.

Recent mods:
K&N stock replacement air filter about 4 months ago
Synthetic oil change about 3k or 3 months ago.

Any ideas? I am anxious to see how the new motor mount helps, but I don't think the O2 sensor will do anything more than make mt CEL go out. Thanks!

J.D.

 

[martispeed]

One thing i can think of is maybe a vacuume leak. Check all hoses and what not after the MAF sensor. I know My MP3 did this and i was freaking out, but i popped the hood and saw that one of the couplers on my SRI had dried out and cracked allowing air to enter after the MAF and mess up the A/F ratios... Hope that might help

 

[martispeed]

By the way it was exactly the same as you are describing

 

[jesus_man]

Thanks I will start there. The Similar threads section below had me reading thru another thread where I might have a warped flywheel. I really hope not because I have a new clutch (20k old) and a surfaced flywheel. A cracked hose will be much better.

I took it for a spin at lunch and the bucking issue was back to normal. Was your problem intermitant or constant until you fixed it? Thanks!

J.D.

 

[martispeed]

It was constant til i fixed it. But that makes no sense how it can be really bad in the morning but normal in the afternoon. Maybe a bad sensor connection with the maf of iat???

 

[jesus_man]

I will at least unplug and plug those sensors back in. Also I have a mechanic friend of mine run diagnostics on the P0660 and this is part of what came back

"3. Turn engine off. Disconnect vacuum hose from VICS solenoid valve. Connect vacuum pump and apply vacuum to hose for 5 seconds. If vacuum holds, go to step 5 . If vacuum does not hold, go to next step."

I have no idea what this stuff is and I am hoping it doesn't have anything to do with the way it runnning, but maybe one of those fluke codes. But it may very be the problem... Still probably easier to fix than a flywheel.

J.D.

 

[martispeed]

Yea that might just be your problem. I think the VICS solenoid has to do woth the ammount of air allowed through your intake manifold. I don't know much about this kinda stuff, but i have read some of kens (Captain KRm P5) posts about this and he seems very knowledgeable on this topic. You might want to send him a P.M. explaining your situation and ask him what his opinion is.

 

[jesus_man]

I think I found it, in fact I am 99% sure. I was taking the air box loose to spray the MAF down and clean it. Upon doing so, I found a huge crack in the accordion section of the intake tube. So that crack was allowing unmetered and unfiltered air in. So I duct taped the duct and it will hold until I decide what I am going to do from here. I will probably just replace it with another stock one, but I may look around for an aluminum one. Anyway, I still know that the motor mounts are too soft, so I will still be replacing the front and maybe the rear with aftermarket. Thanks again for the help, I hope this helps someone else!

J.D.

 

[edumspeed]

that problem happened to me when I bought my pro home. that rubber hose cracks 99.9% of the time. I used black rtv silicone to fill the crack and beyond it and it worked waaay better than the tape it had. It lasted till the time I made my custom intake. Also, if the cold weather issue continues, you may have a bad MAF. I replaced mine with the 2000 Celica unit as most of us 1.6'ers have done when the maf dies or put a cold air intake to remedy the bucking and no power at low rpm.
Happy wrenching!

 

[jesus_man]

Got my new factory intake tube in from Mazda Parts Zone. They had the best price and even tho the part was on backorder, it was still shipped quickly and it was an exact replacement. No surprises. It also looks like I gained fuel mileage with this fixed as well. Maybe even the best ever. Long love the mazda!

J.D.

 

[martispeed]

Glad to hear everything turned out good, and good luck with the future projects

 

[jesus_man]

One last update: I bought the front motor mount from Medival (sp) and installed it over the weekend. It helps a lot with the slack in the drivetrain and although I waited months for it to arrive, it's very good quality. My only beef is that at idle and start-up it transfers a lot of engine vibration. Especially when the AC is going. That may be because the motor is lugging a bit, so I may raise the idle just a hair and see if that helps. I just hope this is it for repairs for a while...

J.D.