My car stutters!
 

Help... I thought of posting this in Tilted Motors, but that forum seems to be dedicated to obiesance verses maintenance...

Can anybody diagnose my car problems so that I don't spend a lot of $ on a garage telling me something expensive?

Basically I have to discernable problems:

1) my car stutters badly. even idling, it is jerky, like it's missing a cylinder. rough sounding. It's been doing this for about 3 months now, and doesn't seem to get worse or better. Sometimes, if it is rainy, it seems to be worse.

- does it need a tune up? is it the spark plugs that are gummed up?
- does it need a new fuel pump? It's got its original (1997 VW) pump
- is there something more sinister ($$$) happening?

2) there is a grinding sound coming from under the car when I accelerate. It doesn't happen when the car is cold, but after about 5km of driving, if I accelerate I hear it. Not when coasting or stopped.

At first I thought the differential was shot. but after looking under the car, I realized that front wheel drives have no differentials. So it's not that.

The heat shield is loose, and rattles, I suppose I could take it off, but I think I know the rattle that it makes, so no worries there.

I thought it may be the bearings in the rear wheels (the sound seems to come from behind the driver's seat) but when I switched my winter tires to summer tires, I tried to jiggle the wheels, and there was no play.

Could it be the muffle is full of rust?


Thanks in advance!

make? model? engine? transmission?

Uneducated Guy Says:

Lose spark plug?

is it all in the engine compartment, or does the whole car move when it's jerky?

the whole car moves when it is jerky. It's like you are sitting in bumpy ride.

Make: VW jetta, automatic transmission, 4 cylinder, 115 hp, 1997 model

I'm guessing it has more than 100k-120k miles on it?

when my mechanic hears 'jerky at a stop' with an AT, he blurts out (quite involuntarily it seems) torque converter. Which, since I'm sure you're curious, is not cheap (for a shop) or easy (for you or the shop) to fix.

If you have an AAMCO around, take it there. They do free diagnostics for transmission problems (although you may have to bring the coupon from their website).

Yes, it has 130K Kilometres on it. I'll have to do a conversion... about 82K miles I think?

Might be something simple like a fouled plug or bad wire.
Could be the timing is off too.

My best guess for the grinding sound would be something with the drive wheel.

I'm no mechanic but On the SE corner of Greenwood and Mortimer is an OLCO garage that I take my '03 Tribute for everything since I moved not too far from there ~2yrs ago. Ask for Maurizio (sp?) and the best time to drop the car off for work is Tues 9am and they'll be done by 5pm the latest as long as you go before hand to find your problem and know what parts to order.

Just to give you an idea of my cost comparison, them vs "other place", not including taxes:

Front rotor and brake pad replacement; I tend to let the pads go metal on metal...my bad...LOL!
$400 vs $600

Alternator; I go through one every year and a half...crappy placement @ bottom R/F of engine...salt slush eventually kills it
$350 vs $500

HTH

These types of things are almost impossible to diagnose over the internet. My thinking is leaning towards transmission (and, more specifically, torque converter) as well, but without a hands-on diagnosis it's hard to be sure.

Get it to your mechanic. Costly, perhaps, but there's no automotive problem that will fix itself. It's almost always cheaper to deal with the problem sooner rather than later.

--- Actinic, I could walk there from my house (I'm on Glebeholme). I know about dealer's costs. I took my '07 Rav4 to the Inn on the Park Toyota last month, just for its warrantee checkup (itself was $115) and they had me doing machining rotors and new pads on all 4 wheels (30K km !!) at $355 per axel, hepa filter ($80) air intake filter ($159), I was going to spend 10 x what I was already grudginly going in for. I only gave them permission to do the front brakes, but I also complained that the wear indicators on the brake pads were not providing any warning. Blank stares, I think I will phone them back about that.


-- Fotzid, what is the drive wheel? you mean the wheel that is connected to the drive train? That would be up front right?

- Martian - yes, you're right. Actually you sound a lot like my wife! I'm just trying to ride out an already expensive spring with the bills and all. torque converter's come up a couple of times now. I'll goole it to see what it's about.


But now that you guys mention it, there is another symptom: when you give the gas, sometimes there's a lag before the transmission engages. I haven't been able to check the transmission fluid, because the friggin VW's don't have dipsticks. They force you into the shop just to check the fluids. Do you think it could simply be low on tranny fluid? I don't trust the idiot lights, because they seem to be tempramental as well.

My guess is timing as well.

join a forum for the type of car you have. more likely than not, someones had the same problem.

just to be on the safe side, check spark plugs and fuel filter

We're pretty close...I'm on Frankdale/Sammon. I pushed the Tribute there last summer when the alt went...LMFAO!!!

The dealer was asking more than what my the friend of a friend's ("other place") mech was charging but he's out in Kipling/Queensway. I'd gladly pay a bit more for honest work but I lucked out w/the Olco guys around the corner. I was weary at first but after chatting w/the guys in the beginning I was pleasantly surprised w/what they charged and the following brake work. Hopefully I don't need a new alt this winter ;).

Jerkiness and stuttering that doesn't get worse or better says "disconnected vacuum line" to me. Even if you're uneducated, pop the hood, and take a peak and see if any of the small black lines (somewhere between 10 and 30 mm diameter) seems to have come loose...they've usually got little hose clamps on them, but they occasionally come loose, and make the engine run like hell.

Most of them connect to the intake manifold, but I'm not familiar enough with Jettas to point you towards it...if you can see the throttle body, (or the air filter) the intake manifold is between it and the head.

ive got a feeling its the fuel line...but thats my hunch. i had a silimar problem and it was my fuel filter

For the jerking:
Replace fuel filter, vacuum leak (use a can of carb cleaner and spray around the hoses, if engine speed picks up you have leak.) Replace spark plug wires, distributor cap and the rotor.

For the transmission issue, try changing that filter. It's a little bit of work, but is always forgotten.

my ford taurus has this similar sounding issue. the garage I took it to said fuel injector issue. I haven't had it fixed yet because I want a second opinion, but my instincts say your car is probably suffering near the same issue. fuel injection somewhere.

so, I've resolved some things:

I started the car, opened the hood and listened. I heard a sparking sound, and searched it out. The air intake manifold (I think that is what it is called) swoops over the spark plugs on top of the engine, looking under it I saw a spark coming from the 3rd plug away from the distributer cap.

Looks like that cylinder was missing as the spark was arcing.

I pulled the air intake off, pulled the plug (sounds simple, but required a lot of effort and McGyvering) to find that the plastic cover was ripped. so I pulled it and wrapped it with electrical tape and reassembled everything.

so, now it runs smooth. But apparently the unburnt gasoline vapours were travelling down the exhaust, and exploding inside the muffler which has caused the baffles there to disintigrate. thus the grinding sound.

I am on the lookout for a single plug replacement for cyl #3 and will take the car into Speedy muffler to have the muffler replaced as per their warrenty.

It also appears that my transmission fluid is low (although with the VW, there is no way to check due to the lack of dipstick) so I will have to eat the cost of a checkup.

thanks for all the input!!

---------- Post added at 01:29 PM ---------- Previous post was at 01:28 PM ----------



Fuel injection of a sort: the fuel being injected into the cylinder was not being sparked..... check your plugs if you haven't done so yet!

Sounds like you found at least part of the problem but this:

Worries me. That's exactly the type of behavior you'd expect to see with a torque converter failing. Be wary, and know that your mileage is probably borrowed. At some point you'll be accelerating hard and it'll just pop and go into neutral, and never go back.

yeah... that's got me worried too. So I asked the guy at the muffler shop if he does VW transmissions, and he said that he would check and top up for $40. Best deal I can find, so next month...

Oh yes, he replaced the muffler under warrantee, but claimed that the resonator also needed replacing as well as the pipe assembly. $288plus tax in total. I squawked at that, and he cut off $60 of installation charge. so that's done now.

Replace your spark plug wires (one at a time) making sure to snap them into the litte clips that keep them seperated. They can short out right through the insulation. do the plugs while you are there.

Don't be too cheap. Replace all of the spark plugs and the wires... and the air filter, while you're at it. You should be good to go for another 80K+ miles (if the trans holds up). It's called "maintenance" and makes your car your friend. Plus, it's a lot cheaper than repairs.

check your crank sensor and your cam sensor cuz for one everything that you just said points right to it check then get back to me

I enroled in college on a 'know your car' course. Taught us simple things like brake pad changing and supposedly gave us a basic idea of whats happening. Prior to going, I would ask such questions as - 'why does my car sound like the crocodile coming after captain Hook when I put the indicators on?'. I am lucky I guess in having eventualy found a garage that is very cheap. When the lads change my tyres, I give them a packet of sweets, and when its the mot I leave them a bag of muffins. They dont sem to mind my asking them questions, and will have a look if I have a problem. I went through my post mot advisory list, and they just said ignore this, dont worry about that - did need to get the new tyres and my tracking checked - uneven wear - and put right. Sad bit is, there were all these young lads some still at college when I started using their services, and now these middle aged men who look strangely familiar are wandering around the place. I would start with checking your leads and work your way in - could be just a spark plug - always hope for the simple. Do you have a regular service.
See you checked your sparks. My emissions were high for mot test. In the end, they did a service, and got the emissions down - but it seems that because I neglected this routine stuff, I took out the catalytic converter box which had been replaced a few months earlier - but they kindly replaced under warranty and told the manufacturer it was duff. Its a bit of that old horse shoe nail stuff, regular upkeep will help avoid major bills.

All this contribution is appreciated. So to update: after I had dealt with the arcing plug, I found a replacement harness at the local junk yard ($50) as opposed to the retail cost north of $400. It was fine after that. never did resolve the slipping tranny, and had to replace a piece of muffler pipe (cross over pipe?) for $780 a year ago.

In the end, I couldn't resist Mazda's 0% financing for 60 months & $0 down offer in May/11. I went and traded the 14 year old Jetta for a new Mazda 3 Sport.

that Jetta is SEP now (Somebody Else's Problem).


:)

How are ya liking the Mazda3? I got the wife one back in '08 but I cringe at all the dings and scratches she's put on it. A fun car to drive :).

I strongly suggest getting winter tires for the Mazda3. The Goodyear Eagle RS-A that came with the our Mazda3 get squirrely when it gets cold and a white knuckler when it's cold and wet going down Pottery Road.

Of all the winter tires that suit our driving style, ContiViking Contact3 is an AMAZING winter tire. They are now called ExtremeWinterContact by Continental here in Canada/US.