2007 Suzuki Swift+ P0301 Shaking at Idle

[Arrakark]

Hello,

Let me tell you the story of my latest project car, a 2007 Suzuki Swift+. I bought this car literally less than a week ago for $500 CAD ($411 USD at time of writing). It has 251,074 km on it. Previous owner said that the battery was new, had new spark plugs, new oil filter and recent oil change. Everything else works.





View photo album here.

The main complaint was that the "car shakes while driving"...

So I get to the car and inspect it. For +251k km it is actually in immaculate condition. Very very little rust on the underside. I suspect it was stored in a garage. Maybe even driven indoors only. Only visible rust was on the windshield wipers of all places, and some peeling paint.

Suspension looks great. Tires have been replaced clearly and have tons of tread and no unsymmetric wear. I don't understand how this car can shake while driving. If it does, it has to be not shaking very much.

I go to start the car and.... the car start shaking. Best described as a "powerful massage chair". What they wrote in the ad was totally wrong, the car shakes at idle.

I decide that I hate myself and decide to purchase it.

On the drive home I burn through half a tank of gas. Surprisingly the temperature gauge maxes out at about half temp. I notice that the shaking is most noticeable at a stop. It generally goes away after about 10km/h or higher, and comes back at around 80km/h, but only when I give it gas. It doesn't shake much at 80km/h if I don't give it much gas. Generally very slow to accelerate, especially at higher speeds or when going up a hill. Very fun to drive though.

In short, the symptoms are:

• Car shakes a lot on idle and low speeds
• Car also shakes while accelerating at higher speeds
• Smell of gasoline from exhaust
• Terrible fuel efficiency
• Check engine light
• Start idling at 1k rpm, drops down to 750 shortly after
• Idle is smooth (does not fluctuate in rpm) and does not change much after initial startup

First thing I do is plug in an OBD2 reader (should have brought it to before I bought the car). Pulls up two codes:

• P0131: O2 Sensor Circuit Low Voltage (Bank 1, Sensor 1) (Upstream sensor)
• P0301: Cylinder 1 Misfire Detected

Focusing on the misfire, I replace the spark plugs. The spark plugs are worn (not new at all). Cylinder 1 spark plug is more charred than the rest of the plugs. Doesn't help.

I replace the ignition wires because I'm a dummy and I didn't realize you can test for spark outside the engine. But then again, sparks act differently under pressure and maybe it's a good time to change them anyways. No change.

I replace the ignition coil pack with a new one. No change.



I figure it must be the injectors. I take the injectors out along with the pipe that spread the fuel to them. I clean them up and attach a can of compressed carb cleaner to the fuel input. While pressing the button on the carb cleaner I apply 12V to each injector and collect the cleaner in a cup. This way I clean the injectors and verify that each of the four holes of each injector is not clogged.



I place the injectors back and verify their operation by placing a screwdriver to them and my ear. All of the injectors work.

Hmm.. okay. We have fuel, we have spark, do we have air? I decide to do a compression test:

• Cylinder 1: 175psi
• Cylinder 2: 185psi
• Cylinder 3: 200psi
• Cylinder 4: 185psi

Hmm. Not good but not terrible either. I do this for dry values only. Technically, all values are within 15% of the max, which I read somewhere is okay.

I read online that a faulty O2 sensor can cause this. I replace it for $120. Oof. P0131 goes away and I confirm that the O2 sensor outputs 0.1-0.3V roughly depending on how I drive. I thought I had an issue with the harness after I replaced the sensor because the ECM kept reading 0V. I confirmed with a multi-meter that there were direct connections to the ECM from that sensor (pins 28 and 43 of top connector I believe). I think reseating the connector a couple of times got rid of the issue.

Engine seems to run a bit smoother now at idle. But P0131 still keeps popping up, even after I clear it. Fuel consumption did not go down either.

I do a vacuum leak test with propane. I check the intake (I wrapped intake hose with duct tape because it had cracks in it). Can't find anything...

To summarize, here is what I did:

• Replaced spark plugs
• Replaced ignition wires
• Replaced ignition coil pack
• Replaced O2 sensor (make it run a bit smoother and got rid of P0131)
• Did a compression test
• Vacuum leak with propane
• Reset the ECM and codes several times after each change

Unfortunately, now I'm a bit stuck. It's clear that cylinder 1 is still misfiring due to shaking and poor fuel economy. Here is some of the symptoms I see now:

• Long term fuel trim is +2.4%
• Short term fuel trim is ~0%-5% depending on acceleration
• Coolant maxes out at 97C
• Timing advance is 0-3 deg on idle, up to 35deg on acceleration
• Averaging 20-30L/100km. Ooof.
• Still hard shaking at idle and P0301 code

I hope you enjoyed listening to my project so far. If you have any suggestions as to what to do next I am all ears!

[Arrakark]

I think my next course of action is to replace the timing belt as I suspect it may be the culprit. Even if it's not, this timing belt is way overdue for a replacement. My thoughts currently are that the belt skipped some teeth. While I wait for the parts (and tools) to arrive, I decided to send an endoscope down each of the cylinders.

Cylinder 1


Cylinder 2


Cylinder 3


Cylinder 4


Immediately I noticed that the first cylinder was very sooty, and that each cylinder also had notches on them that were indicitave of valve interference. However, since all of the valve notches seem to be the same on all pistons, and the fact that I found an aftermarket replacement pison with the same markings leads me to believe that these marks came from the factory and are not there because the valves are hitting the pistons.

[Arrakark]

Alright, I'm in the process of changing the timing belt. While I'm waiting for the belt to arrive, I thought it would be a good idea to take everything apart just so I have no issues when the belt arrives. Here's what transpired:



I jacked up the car and the engine. Then I basically followed this fantastic guide and this good video on how to change the timing belt. My notes on procedure to change the timing belt are as follows:

• To remove the main pulley for the main drive belt, some people said it could be done with a breaker bar while having someone press on the brakes. I tried this and the brakes offered no resistance to the pulley. Maybe I needed to have it in gear? Either way, I decided to go to the shop and pick up an air impact wrench.
  
• I also could not break the bolts on the motor mount with the breaker bar. Good thing I had that air impact wrench now.
• Some thread penetrator worked wonders on the 10mm bolts holding the covers in place

Once I got to the point of inspecting the belt, I found it to be in rather good condition... except for the fact that it has stretched way beyond its intended length. With the bottom mark aligned, I noted that the top marks were off about 1/2 a tooth as shown here:



And this was probably due to the belt stretching way beyond its intended limits. I took a look at the tensioner and found that it was essentially maxed out. As far as I understand, the two notches in this photo are meant to line up. They are way off.



I emptied the coolant and noticed that it was in rather good condition. I measured it to be 5.27kg in weight (for reference for buying). It was red; which I am going to assume is DexCool since it was also highlighted in the owners manual for some reason.

The belt was so loose that I was able to take it off without unscrewing the water pump. I did so anyways and was greeted with some coolant which leaked out. Oh well.

I marked the old belt with white out like shown in the reference video.



Next step it to replace the idler, water pump, tensioner, timing belt, serpentine belt (old one was very cracked), then put it back together. It has earned the nickname, "gutless".

I also plan to clean out the injectors once again after remembering that while I did clean the injectors, the spray pattern for #1 injector might be off from the rest due to some clogging I did not get rid off. This time I will remove the injectors off the rail and also do a backflush.

Oh I also redid the compression test and did a leakdown test without a gauge (just to see if I could hear any leaks). Compression in cylinder 1 jumped to 185psi, and I'm thinking the original reading I got of 170psi might have been due to not cranking it enough on that test. I could not hear any leaks at all on any cylinder at top-dead-center. Doesn't mean they aren't there, but it's a good sign.

[Arrakark]

Yesterday I replaced the timing belt, water pump, tensioner, and idler pulley. I found the process tedious. I didn't have a water pump pulley (Amazon lost my package??? That's a first), so I had to fabricate my own out of some aluminum.



While I know it's possible to do this without taking off the camshaft pulleys, I found it very difficult. Taking these off with an impact wrench (while locking them) threw alignment off, which took the better part of a day to get back in sync.



New water pump looks shiny.



I noticed that the lower timing belt cover was warped and interfered with the timing pulley (new and old pulley). This meant when I started the car for the first time again there was a lot of squealing and a plastic burning smell. After a short ride it went away though. I suspect the timing pulley melted/rubbed away about 1mm of the cover. Sadly, this did not fix the mixfire, but the car did run smoother still.

I decided to clean the injectors again. This time I fully took them off the fuel pipe. I was worried last time that I would break their clips and that's why I didn't take them off, but I figured that it was worth the risk. Turn out there was a layer of gunk on all of the injectors on their input! I'm not sure what had caused this; maybe a worn out hose or dirty enough gas, but I took some cleaner to it, and now the car drives fine!!

Wohoo!

I took it for a series of very long drives today and the car did not seem to be misfiring. Overall I estimated the fuel economy to be 9.55L/100km, which is a bit high, but probably normal for mostly city driving. Plus I'm not too sure about my estimate there.

All that's left to do is:

• Change the oil, power steering fluid, transmission fluid, and maybe the brake fluid
• Probably change the transmission filter
• Fix a snapped bolt in the valve cover (not me!!)
• Wipers
• Replace the front brakes
• Replace the serpentine belt; this one is super cracked
• Try my luck with repairing the clear coat with K2 and a good polish/fade into the old clear coat
• A good cleaning!

I'll keep updating this post. If anyone is also experiencing a similar misfire; make sure to clean the injectors!!

[Arrakark]

Alright, I have done the following things:

• Changed the steering fluid
• Replaced the air cleaner hose
• Defogged the headlights
• Buffed out some of the larger scratches and flaking clearcoat
• Washed and waxed

The old air cleaner hose had gigantic rips in it. I lucked out and picked up a brand new one from Amazon (last one!) for $20. Compared to Rockauto's ~$50.



I then defogged the headlights with toothpaste and a brush. While the immediate results were okay, they quickly dried out and went back to looking meh. I think I'm going to take some 1000-3000 grit sandpaper to them later, some polish, and apply a clearcoat, because they really need to be done since they make the whole car look new.





Then I got a stuck bolt out of the valve cover. Replacement bolts are M6-1.00 x 55mm with flange head. I couldn't find a flange head at a local hardware store, so I went with a machine screw and a washer.. Maybe not the best but it's temporary! Some penetrating fluid left for an hour made quick work of the stuck bolt.



I took some Ultimate Compound to the scrape on the front of the car next. Made quick work as well, but it didn't take the entire scratch off.





The clear-coat on the hood and side panels of the car was coming off. I thought maybe I could fix it with K2 clear coat, but now I am having second thoughts. I think that it would require painting the entire panel, which would then make the entire panel look a bit different then the rest. A wrap would take way too long to do on the entire car. I decided to chip off the existing peeling clearcoat, polish, and apply a liberal amount of wax. I'll go over the chips that got down to the primer/metal with a touchup paint I ordered later.



A quick wash and wax and it looks way better! Gotta say these hatchbacks look much better from the rear than the front.



Also, I changed the cabin air filter recently too. Looks like the old one was never changed...



Lastly, I got the rest of the kit this morning. Next steps:

• Change the oil, transmission fluid, and top up brake fluid (gotta figure out the level mark)
• Change the transmission filter and gasket
• Replace the front brakes
• Replace the serpentine belt
• Fix a small chip in the windshield
• Replace serpentine belt tensioner and idler pully (don't want this belt to fail anytime soon)

[LTPOWER95]

Great thread. Enjoyed reading through the whole thing and congrats on your nice Aveo. I like doing these things and my Aveo has a replaced engine a few years back that it runs a little quicker lol! Even after driving other Aveo's I noticed mine is quite lighter on it's feet, although it is slightly modded. I've got some mods in the futur and enjoy driving it. What I want to do is clean the injectors and do some paint corrections myself, no need for some of the other stuff for me, like filters here and there, fluids, seals and pumps, belts etc, because they're still in excellent condition from the swap back then, with new parts. �� Try getting a drill pad and buffing compound on the headlight and you'll clear them up like a window (just put masking tape around the hood and bumper to not cut the clear too much from contact) Then clean your car and put ceramic wax coating to keep the finish and headlights protected for some months. I'll let you know later which product I use and trust, and it works! I use it on my freshly built Corvette too.

[Arrakark]

Great thread. Enjoyed reading through the whole thing and congrats on your nice Aveo. I like doing these things and my Aveo has a replaced engine a few years back that it runs a little quicker lol! Even after driving other Aveo's I noticed mine is quite lighter on it's feet, although it is slightly modded. I've got some mods in the futur and enjoy driving it. What I want to do is clean the injectors and do some paint corrections myself, no need for some of the other stuff for me, like filters here and there, fluids, seals and pumps, belts etc, because they're still in excellent condition from the swap back then, with new parts. �� Try getting a drill pad and buffing compound on the headlight and you'll clear them up like a window (just put masking tape around the hood and bumper to not cut the clear too much from contact) Then clean your car and put ceramic wax coating to keep the finish and headlights protected for some months. I'll let you know later which product I use and trust, and it works! I use it on my freshly built Corvette too.

Haha thanks! How was the process for replacing the engine? Any special tools other than the crane needed? I imagine you had to take all of the fluids out including the transmission fluid? I thought of pulling the engine, but I thought that there's no way I'd be able to find a low-mileage engine for this old of a car lol!

Sorry for the questions lol, but how did you want to try the paint corrections? Yeah I was planning on getting a rotary tool and buffing with some 1000-3000 grit sandpaper and then going to the compounds. I put wax on them already but ceramic coat is probably a better idea. I thought of also just putting a layer of UV stable clearcoat, but not the good 2k stuff, just the 1k. Let me know what you use!

As for my update, here's what I worked on recently:

• Changed oil and oil filter
• Changed transmission fluid and transmission fluid filter
• Did the front brake pads and rotors

The oil and filter were very easy. Jacked up the car; drained oil, took filter off, replaced filter, then closed up the plug and put the new filter on. Made sure not to double-gasket the oil filter, and also replaced the plug as well. Tightened to 26 ft-lbs as per this post. I found that a rubberized strap wrench made the filter come off really easy; but only when I figured out how to use it properly! Hint: the strap has to go down towards your hand and not the side. I slightly overfilled the oil; but it's such a small overfill that I didn't bother draining it.



One note about jacking up the car, if you can, don't jack up at the recommended jacking points (located near the tires; they have little notches them). I found that mine would begin to deform!! I found the front and rear cross-members to be a much better place to jack. Putting a piece of wood on the jack would spread the force nicely since these areas are also almost perfectly flat.

Later on I realized that I didn't need to jack up the car to change the fluids. I was skinny enough to fit under the car to reach the oil pan, and the transmission fluid is super easily accessible near the front-left tire when you turn the steering wheel to the left. It's almost like this car was designed to have the maintenance done by regular people!



One thing I wish I did was accurately measure the oil while replacing it. I didn't have any spare containers to measure this stuff with, and the marks on my oil drain pan didn't have numbers and were on the inside of the container. What a bad design!

After that I went through the process of replacing the front rotors and pads. I found that the old pads and rotors were really rusted and most likely warped, since they didn't appear totally flat, brakes would squeak, and the car steering would oscillate when braking. I found that replacing these components fixed all that! I found that ChrisFix's video was almost a perfect guide on how to replace these parts.

First thing I did was remove the caliper. Two bolts with an impact gun. Thankfully, my pins and pin seals were in very good condition, so I didn't see a need to re-lubricate them. Make sure to pop out the brake line rubber mount to prevent strain on the brake line. I then took off the knuckle; two larger bolts.



I had two phillips #3 screws holding the rotors in place. I couldn't get them with a screwdriver, so I went out to the store and bought some impact bits. Got them out in a few seconds. I believe these are either from the factory, or have been reinstalled onto another set of rotors. If they are from the factory, that suggests that these rotors have never been replaced!



After a thorough cleaning with brushes and brake cleaner, I used anti-seize lubricant on the areas in the image.



Then it was a matter of putting everything together, while replacing the brake pads and hardware. A caliper spreader was needed to give enough room for the new brake pads. I placed medium-strength, blue thread-locker on all of the bolts. I believe the total cost of parts was just under $150 with shipping. Totally worth it though! Stops on a dime now.



Then I moved onto the transmission fluid and filter. Again, I used Chris' video as a guide. I was pleasantly surprised to see the pan in such an accessible location on the car. I used the drain plug to first drain all of the fluid, then I took the pan off to replace the filter and pan gasket. The filter came out with three bolts. The filter looked a bit dirty, especially on the outside of the filter!



I replaced the gasket that came with the filter kit and replaced the ATF with Valvoline MAXLIFE™ MULTI-VEHICLE ATF. I am having a very difficult time getting the fluid level correct. I kept either underfilling it or overfilling it. I think this was due to the fact that the new fluid is only very lightly colored and the fact that the dipstick tube had a bend in it. Every time I would pull the dipstick in and out (after cleaning) it would scrape the side of the tube and ruin my reading I think I have more than the necessary amount of fluid in the transmission, which over time can damage the seals . I'm going to look into other methods of measuring the fluid level. Any tips would be greatly appreciated!



I noticed that after changing the fluid level the transmission shifts to the correct gear faster than before. I didn't need to rev the engine quite as high to get it to shift. However, this came at the cost of a little more rumbling while driving generally. I think this was due to the removal of all the particles in the fluid, which probably helped the torque converter maintain grip. I'm not sure.

I also checked the brake fluid. I don't think it needs a change.

Things left to do:

• Replace the serpentine belt
• Replace serpentine belt tensioner and idler pully

• Inspect rear brakes; adjust and clean
• Fix a small chip in the windshield
• Glue passenger door handle back on
• Fix fogged headlights properly
• Spraypaint suzuki elblem
• Paint touchup

[Eg.h2o]

I’m glad you’re having a little fun fixing up the car. Enjoy!

[LTPOWER95]

I'm glad you're getting the car in tip top shape with simple maintenance, this gets cars running forever. A few years back I think mid 2017 (For some reason I just can't remember the dateL The engine was replaced by a buddy of my dad's who lived about 30 miles away. This man is a certified master mechanic with Toyota. We took the car over to him with a car dolly and after he came back from work say at 5. He did the whole engine swap that night lol! He had picked out an engine and all the parts necessary while at work, I'm not sure which exact car this came out of but it runs nice, and as of now probably has 85k miles on it, while the cars odo reads about 130k. So The next day it was ready, and it was all done right. And yes trans fluid level is important and can make a difference in shifting points and wear. Please see if you got things right in there. ChrisFix, I guess those are helpful vids, I have seen his stuff and he's grown quite a bit as a YouTube.
I did my brakes maybe 6 months ago with some nice pads, and the spongyness did go away from the previous brakes it had. But I'm getting slotted Disc rotors soon. If I were you I wouldn't put those screws in there it's totally unnecessary and most cars don't use them, especially sports cars, or expensive brake kits. Good call on using Loctite, you're doing everything right with the car down to ever point you've worked on so far.

Here what you can use instead of sanding paper man, get these at Harbor Frieght or online, mind you this cutting compound is quite strong.

And by ceramic wax coating, I don't mean like a 9h hardness ceramic kit that's like $80, unless you want to do that which is a better option. I actually meant ceramic wax, this is what I use. Works well and last a couple months before needng to add to the car again. Don't be hesitant to not be too generous with it. Use an applicator pad around the car then with a clean cloth wipe it off after it turns waxy. Make sure when applicating onto the surface to not totally rub it in way too much, as it will actually be rubbing it off, you want to have a nice layer that will soon harden before wiping it off

[LTPOWER95]

Sorry for the wonky image placement,s one is even sideways. I barely made this account and am getting used to posting.

Your car is checking out allot of marks, there is still a few things I'm looking to do to mine. As for my paint there is a place that bothers me and a hole near the fuel cap,, I want to take it to Macco for a cheap $500 paint job. As soon as I recover from my Vette's spending I'm about $25k in her, but that is my dream car. And I lied, my vette isn't quite freshly complete. I still have custom worked heads & manifold, custom grind cam 218 225, not that big, along with supporting parts like 1.6 scorpion sa roller rockers and hardened pushrods, and possibly ls7 Lifters if my originals are a little worn, which I doubt.

My 95' has 103k miles. Also have corsa catback, em headers, 58mm BBK throttle body, 2500 9.5" stall and some built to order wheels coming in real soon. I'll take all these things myself. I read with about 460hp and similar torque with those heads cam and headers. So that's nice. All these new parts are about 10k together sitting in the room. Car was a barn find and is almost all restored and modded perfectly
Here is my Daily Aveo and my Vette.

Sorry for all the pics but my vette is my pride an joy the Aveo I plan to have it autocross capable.