I've been having a problem that's getting worse and worse. The car has developed this very hard jerk when I go from coasting to giving it gas and vice versa. Could this be vacuum related? This weekend I plan on taking apart the iacv and the upper intake manifold and cleaning it out. Could an axle be bad? It feels like slack in the drivetrain. I'm about to take it somewhere because this really sucks! Anyone??

Oh- No codes either

Thanks

 

I assume the coasting in in 5th gear? what speed?

Cleaning the manifolds and such could help some. I found when I beld my clutch, and got out all the old dirty fluid, engagement was butter smooth. Do your cleaning, try a bleed and see what happens. How much milage on current clutch and tranny?

Are you litterally stepping on the gas like trying to floor it almost?

 

Thanks mdeezy, no, it happens in all gears, mostly going under 60. It does it when I gently tap the gas and when I hammer it. The tranny and clutch are less than 10K since being rebuilt. This has been more noticable since the rebuild and new clutch. It has gotten worse since I replaced a clutch hose, I bled the line but forgot that line by the strut tower. I will bleed the clutch some more and cross my fingers.

 

The one by the strut tower is where I got just about all of my dirty clutch fluid. Clutch was properly broken in right? Try the bleeding, if not a slight adjustment of the grab point can do some wonders also.

 

Ok, I'll try that. Thanks.

 

Car jerks hard?? Did anyone else read the title and start laughing? Or am I the only immature one?

 

and you're 24??

 

do you REALLY want us to answer that?

 

well look at his name - pat deez nuts, needless to says he's probably not very mature...



either that or loves **** and fart jokes.

 

Everyone has a differnt tastes on humor, his are obviously different than yours.

 

Yeah the title of this thread is funny, but I couldn't describe it any other way!

OK, I bled the clutch some more, I got the old stuff out for the most part. But the jerking is still there. My car jerks and jerks! It does it when the clutch is fully engaged when on and off the gas.

Throttle cables?
IACV?

 

Motor mounts guy. It's your engine rocking back and forth because the broken rubber motor mounts are not holding your engine as still as it should be. Very common in our cars.

 

When I say motor mounts I mean the front and rear mounts. Not the side mounts, they don't wear out much. Either the front or rear could be bad, most likely both are torn though.

 

You know, I was thinking about that but when I rev the engine, it doesn't seem to rock back and forth very much. I will definitey look into this.

 

http://www.mr2sc.com/websites/tech/SolidMounts1.htm

McMaster urethane can be found here.
http://www.mcmaster.com

8644K11 - for the juices

 

Motor mounts make sense. This has to be where the slop is coming from. I'll have to attempt this another day though. I'm sick of my car jerking all the time. Good thing I don't have internet in the car!

 

Thanks MDeezy/Nealoc187!

 

Your engine won't move very much if you are just revving in neutral... there's no load on it. Put some load on it with broken motor mounts and it can move like 2-3 inches.

 

how do you adjust the grab point?

 

I've got Energy Suspension polyurethane motor mounts in my turbo maxima and I like them alot. I reccommend them. They were like $85 plus whatever it costs you to get them pressed in, and installation if you can't do it yourself. Avoid the place racing mounts (I don't even know if they make them anymore) they increase vibration a TON.

 

Ok. My car just started doing this after this weekend. I'm assuming this is also my problem. Makes since.

 

Just ordered the urethane casting compound from mcmaster.com... The order should be here tomarrow $27.04. I ordered the softest stuff 60A, that should be good enough. This morning I called Napa to see what they would sell mounts for- $140 front and $86 for a rear mount. I'll try making my own first.

 

Please let me know how this turns out. I will be trying this.

 

$140 for a motor mound is quite alot when you can spend $30 and make quality ones yourself. The only down side it is need atleast 2 days to cure, before it goes back in. Some say its best to wait a week, results will vary. I'd like to hope you'd be fine with it curing for 2 days because I'd like to do my when I do my tranny and I wont have more than a weekend for downtime.

 

I've been having the same problem for the last few months and it is very annoying. Just by looking at them from under the car the mounts look to be OK, but they're very difficult to see.

Please keep us informed in what you find...

 

I find it hard to believe this will arrive in 1 day, that would be fast. I may have to wait till monday because I need to be able to bring this back to the dealer on monday morn because of the ac compressor acting up(was replaced last fall)....I'm just worried about getting all of the bolts off of the mounts and hopefully using the softer urethane -60 won't be too soft, I don't need any more vibrations otherwise I would have used the 80 urethane.

Tensile strength on the different urethanes-
60A........1250psi - I ordered this one
80A........1725psi - recommended but can add vibrations/noises
94A........3120psi - really stiff

 

Check to see if the butterfly valve in your intake is sticking. Very common if it hasn't ever been adjusted. If it sticks, then that's just a sign of some wear and tear and you need to adjust the stop screw very slightly (turn it clockwise) until it doesn't stick. You'll have to readjust the idle speed after doing this. Make sure the throttle body is clean before you do the adjustment. It can make a huge difference in driveability. Check that before guessing at replacing motor mounts.

 

I'll do that. I did that the other day but I will do some more adjusting on that screw. When I cleaned out the TB I could see way down in there that there was a ton of nastiness back in there that I could not reach so I plan on taking off the upper plenum and throttle body on Friday so I can clean out as much grime as possible. . then when it's back together I'll make more adjustments with that screw.

 

The black poop may be making it stick, so clean it first, then check for sticking. It's not too unusual to have that happen since the butterfly valve moves so much. A small tweak is all it should take. Also check where the throttle linkage attaches to the throttle body. Take the cable off by rotating the TB clockwise, and clean both the cable and where it rests when attached. That area tends to collect stuff, and the cable tends to get greasy after a while. Don't even think about the motor mounts before trying this easy job! good luck with it.

 

Well, I tweaked and tweaked but nothing changed, TB is clean and all the black poop is way back in there where I can't reach it, no where near the TB. Nothing sticks, everything is smooth. BTW the urethane is not here yet, I kinda wonder if it will really get here in 1 day. I called some of the biggest junk yards around here and NOBODY has motor mounts, so I have to use the ones on the car anyway. Damn.

 

i have the same problem with mine
if you touch the gas untill it barely gives it any gas itll give a big jolt, u have to be reaaly light leting on the gas and letting off.
i just got used to it, bieng so gentle
its the motor mounts......could it be the transmision mounts?
not sure...
when i rev the engine, it doesnt move or under load..so im guessing it could be transmission mounts...or something of the sort. i also get a creeking sort of noise when direction is changed from front to back. sounds like a quick tap, like something moving enough to ..tap somethign.

 

Wow I never thought it could be the throttle body. I will clean mine this weekend too. However, Im almost sure it's my mounts because it started doing it right after a hard launch.

 

I also get a click/tap noise. I hear it sometimes when I push in/let out the clutch and sometimes when the jerk happens.

 

well if you fix the problem with new mounts pls post. thatd be a big help

 

Definitly, but this will have to wait till Monday afternoon. The front mount looks easy but the rear mount looks difficult to get at. Right now the whole upper part of the motor is on the floor of the garage. I took it all apart and cleaned the hell out of the upper plenum/intake. Biggest job I've ever done on this car, I showed some poeple the engine all taken apart and they were like WTF?! But there was sooo much oil caked on. I'll get this back together today and see what difference it made.

 

Sorry guys, I just haven't gotten to this yet. I'm going to make an attempt at this on Wed.

 

Cleaned my throttle body. Still herkin and jerkin. Got some nice acceleration though....

 

OK! Engine mounts have been poured as of 8pm. I suggest to anyone doing this DO NOT get this stuff on your hands. I had to use brake cleaner to get it off. Both mounts were in tact, nothing unusual looking and on our mounts there is only a small slot that you can fill so I don't know how much this will help.

 

igntion coils

 

Dont want to be the berror of bad news, but if the mounts looked pretty decent when you filled them up, it may not be the culprit. keep your fingers crossed.

How long are you going to let it cure?