Ok so I'm a little confused here. I've been having this problem lately, and until recently I though it was the transmission slipping, but now I'm not so sure.

This is what's going on:

The car acts normal until I am cruising and want to accelerate. If I hit the gas to about 50% throttle, the car downshifts and the front end kind of stutters, or vibrates. It feels alot like the front tires are breaking traction for a second before they grip, or something in the tranny is grinding().

I was inclined to think it was slipping, but when the car does shift, at part or full throttle, the shifts feel solid and firm. I have a DR mod but have checked it and double checked it, and it is working fine and only at WOT.

I've been trying to isolate exactly when this is happening, so I can narrow down what it is, and all I can say is that I first noticed it while turning, and that it doesn't seem to do it at night when it's cool.

What do you guys think?

Slipping?

Engine or transmission mounts?

 

Your post is not very clear ...

I would start by checking the trany fluid, have you done that? The car needs to be running and in P when you do.

Next, I'd have someone sit in the car (e brake on, foot on the brake) and shift from P - R - N - D - and so on ... to see if you notice a lot of movement under the hood (if you do, it's likely your trans mount).

Could also be a TC (torque converter) issue and from what you describe, I'd bet that is it. Does the car move if you take your foot off the brake at a light (level ground)? Or, does it take 2k rpm's to get it to start moving? Signs of a bad TC if it doesn't at least start to pull forward when you take your foot off the break. (or low trany fluid)

 

The car actually noticably jerks when it's put in gear, especially Drive.

I'll have to check on the fluid and TC

thanks for the tips, this has me baffled

 

if you hit the gas in neutral, does it still do it? Sounds like a mount....

 

it really sounds like a mount ... i agree

 

ok than that brings me to my next question

If I plan on doing all the mounts at once I'll need 4 in total right? front and rear, and left and right?

like this?
http://cgi.ebay.com/ebaymotors/NISSA...mZ380065697555

I still have my suspisions about the gears, but 1 thing at a time I suppose lol

 

If you're going to do all the mounts, I'd look at poly mounts ... much much better quality. Why not just do the trans mount tho ... why do all of them? If the engine mount bushings are not bad, why replace them? To do the front / rear mounts, you'll have to pull the X member and that is a PITA! You can pull that trans mount (and not even have to worry about supporting the engine / trans) and replace it in no time at all. I will give you a heads up though ... pull the center pin first or you'll play hell getting to the right hand side bolts (mainly the front left hand bolt). They should be 14mm (all of them) and you'll have to remove a couple clips (10mm) (spedo wire / shift selector switch wire). A gear wrench comes in very handy on those 10mm buggrz. lol Hope this helps.

Why do you question the gears? Does the car slam in and out of gear? I thought you said it shifted smooth .... if it's slamming, it could be mounts, dirty filter, needs trans flush. If not ... and it's just when you let off the power, I'd say mount for sure.

 

Are there poly mounts available for an auto? I thought I read something on here that said they weren't. I think I will start with just the tranny mount for now, I just assumed it was a "do them all at once" kinda deal

I'm having a really hard time describing the problem....I will probably just have to wait till it gets worse unfortunately

Something is off, take turning off main roads for example,

I brake, let off the brake while turning and then press the gas again.

When I press the gas, something slips or grinds, it's hard to explain but like I said it feels almost like the tires are slipping. In almost all other driving situations the car acts totally normal, including harsh up and downshifts

what originally made me think of mounts is the fact that it's WAY worse when it's hot out, so I thought maybe the rubber way getting softer in the FL heat

The jerking when I put it in D should be fixed by the tranny mount, which it won't hurt to replace reguardless

thanks for bearing with me

 

We'll get it figured out ... the .Org that is.

Have you checked the 1/2 shafts ... it could be an inner joint problem. Go to an empty parking lot and stop, turn the wheel all the way to lock one direction and let off the brake, slowly accelerate (not looking for speed here, you're listening for a 'clicking' sound). You don't need to go very fast, 5 - 10 mph maybe. Do the same thing turning the other way and listen. If you hear any 'clicking' that could be a part of the problem too. Only reason I mention this is because you said "when turning" ... It could be a combination of things, mount + inner joint .... dunno. Heat can affect the 1/2 joints too, not only the rubber for the mounts. Have you looked at the mounts, do they seam dried up, cracked, REALLY hard ??? If any of the mentioned ... time to replace them.

Just doing the trans mount will save you some money too .... I accept PP ... Just kidding!

Cheers mate!

 

lol thanks so much for the help

I will update soon

 

Almost willing to bet its a mount.

 

I think I have the same problem as him, just worse. Before it used to be unable to switch to 3rd gear when getting on the highway, especially at around 40 mph, it would stutter when u gave it gas, as if the gear is trying to switch up but slipping. This would not happen ofter, and now a year later, its doing it on almost all the gears. I do too have the hard **** when switch to D. Now just off the start when pulling out with the car warmed up, it stutters as its trying to accelerate and u can see the RPM bounce up and down as its trying to switch to a higher gear; it feels as if i keep tapping and letting go of the gas pedal but I am just holding it steady at low RPM. Also when the car is in D and holding break pedal, on a red light for example; I can see the RPM arrow trying to fall while giving the pounding noise coming from under the hood, as if someone is hitting the engine with a sledge hammer. This is so hard to explain because its all about feel and sound, but you know it idles on D at about 0.6 RPM, and the arrow drop to 0.4 RPM and it keeps bouncing with the pounding feel/sound. Recently trying to fix this problem, I have replaced all the spark plugs, new air filter, fuel filter, and cleaned out the throttle body. Have no clue what it might be but since it keeps giving me problems on every gear I am thinking it must be the transmission. Do you really think a bad tranny mount or tranny fluid can do so much damage?
Thanks guys for any information, much appreciation.

 

I wonder if you have a bad MAF....

 

Cold .... you let this go for a year? You deserve what you have gotten IMO. You probaly need to fix it if you want your car to continue to get you from point A to point B. I don't understand why people let crap go and then wonder why it isn't working at all now ??? Or, it get's worse and they know it's getting worse and don't get it fixed.

Sorry to be so harsh, but ... what, you thought it would just go away or fix its self? As for low trany fluid, have you even checked it? A bad mount is easy to diagnose (see posts above) and trany fluid is so easy to check that it is silly not to. If you checked it and it was low, why didn't you add any? Great that you did a tune up and all, but maybe you should take your car to someone - let them tell you what they think it is, maybe even get a second opinion if you're not sure, then get it fixed (either you do the work, or take it someplace you trust).

All I got to say ... end rant

 

Heh, yeh I going tomorow and spending the whole day on it just to figure out the problem, its not that I let it go on, just that every time it would do it, I would go to mechanic and while his drining it, the car was acting fine. It only got worse in the beggining of September and the car stood for a while cause i was at school, now that I got a day off, I am going to use it to fix problem. Oh and my Service Engine Soon light came on, with 2 codes, one being 3rd O2 sensor is bad and Knock sensor is bad, can this be the main sourse of this problem? I am sure it contributes, reguardless; im going to get new sensors tomorow anyway. Will updated on what happens tomorow. Thank you!

 

First thing to do is to replace the O2 sensor and the KS, then clear the codes. I don't think that either of those would affect your trans in the least btw. And for the trans, it's probably on it's last leg I'd say. You could try to take it to a shop and have them do a trans flush on it (take out the old fluid, put in new) and maybe a filter ... but it will not be cheap (~$120 - 180 or so I'd guess). Might fix ya for a while, it might not ... who knows. G'luck

 

Ok guys just got back from mechanic, so heres the update. The code for knock is still there, I didnt have money to fix it but should be done sometime soon, it doesnt affect the driving, and the O2 sensor code didnt show up this time, so didnt replace it. Turns out the transmission was completely fine, and one of the cylinders was misfiring and causing the whole car to jerk. So got all new spark plugs and the number 2 ignition coil, that was the faulty one. So now the car runs perfectly fine. Cost me $130 with tip. Thank for everything guys, you're all awsome.