The 2014 Altima 2.5 at 95,000 miles has been shaking at start up first thing in am, and in reverse. When in drive eventually gets back to normal. All mounts changed, CVT filters and fluid replaced, plugs replaced and alternator belt. Have tried everything. No cel light on and no codes

Any idead

Sounds like a coil that's misfiring cold. That's pretty common on 2.5's and the ECM won't throw codes unless the misfire persists. Just make sure it isn't an incipient head gasket problem or a leaky injector. Pull the plugs while cold and shine a flashlight down there. The piston crowns should be a uniform black, if any are shiny then you're probably looking at a tiny head gasket leak. If there's liquid fuel visible then you have a bad injector or o-ring dripping fuel after shutdown. Either of those will cause a transient startup miss.

Thank you

The suggestions are pretty easy to check

Thanks again and I will report back

Update

Pulled all 4 coils and plugs. Took a peak (as good as I could) into each plug hole and saw black on top of each piston. Went the extra mile and taped a q tip to a wooden skewer stick and found no sign of a liquid (oil, fuel or coolant).

Checked gap on all plugs and were fine @ 0.44

Checked the resistance using the combinations of (1-2, 1-3 and 2-3) on each coil (red probe on number 1)

Coil 1 - (2-3 @ 2.67 ohms)

Coil 2 - (2-3 @ 2.73 ohms)

Coil 3 - (2-3 @ 2.84 ohms)

Coil 4 - (2-3 @ 2.72 ohms)

all other combinations read 0L with red meter probe on #1.

With black meter probe on #1, 2-3 combination same.

All other combinations with black meter probe ranged from 12.9 to 14.9

The manual just calls out + ohms for these so if taken at that all would be fine for (2-3)

An Autozone listing calls out Ohms for a new one at 0.84 ohms

96,000 on the dial.

Should I buy one new coil and see what happens ?

Thanks

Nissan COP coils (and any other variety of 3-wire COP) use high-voltage transistor drivers inside the coil, which means there's no direct connection between terminal pins through the primary. So an ohmmeter frankly doesn't tell you much. You're actually measuring the primary through the "body diode" of the MOSFET transistor, so it can tell you if the secondary has a problem, but it doesn't tell you anything about the primary, the health of the FET, or the quality of the insulation/isolation. With a startup miss like yours, chances are it's a failing FET. You might get an inkling of which one from a spark tester, chances are the offending coil will be weaker than the others even when warm. In the shop I'd recommend simply replacing all four, because you certainly don't want to pay me for screwing around swapping a coil from place to place and then letting the car get cold again to see if it's fixed. However, with DIY, you certainly have that option. For my own ride, that's what I'd do.

Thanks again

So much for Youtube

Could this have anything to do with the transmission ? Or the catalytic converter

Just wondering .

The reason I asked on the CVT, when its 90 F in the south we do not seem to have this issue

It would be really odd for the cat to go south without throwing codes, and the tranny can cause a lot of symptoms but shaky startups aren't one of them. I'd just get a coil and swap it one by one to each cylinder until you find the offender. If you go through all four and it still happens, then worry about other stuff.

OK

The top of the engine shakes by feel on the top left by the oil filler cap

When in the car you can feel it in the steering wheel and up through the seats

Once warm at a stop sign seems to settle down

One other thing I have noticed is that when going down a slight hill, the rpms go up without my pressing the gas pedal. I do not recall it ever doing that before

The coils are HITACHI, should I go back with that or Denso ?

Thanks again

Denso is good, and so are Hanshin (Denso's Chinese partner) and NGK/NTK. Some Nissan engines have issues with mix-and-match coils, but not QR25's.

Shaking from a miss will generally shake the whole engine regardless of which cylinder, where you "feel" it most depends more on your engine mounts than anything else. If it seems shakier on the passenger side, check your nose and dogbone mounts.

PS - Since you're new to Nico, you probably haven't seen this, but it's important:
keep-your-engine-on-the-ground-not-just ... 28130.html

At 96K your coils might just be suffering from retirement age, but there could also be a simple reason underneath the failure. It takes five seconds to find out.

Thank you again.

I will try the vdrop test and see what i find

One other thing we have noticed right after start up and placed in drive, the vibration seems to occur with the rpm at 1200. Even after warm up and running ok at say 30 - 40 mph, when it drops back to 1200 rpm the vibration is felt in the steering wheel

I had disconnected the battery for 24 hrs, then cleaned the throttle body. After reinstalling and attaching the negative terminal, relearned the throttle body per the youtube methods. Is there anything else that needs to be relearned ?

Regarding the engine mounts - all were replaced and torqued to spec

The one that I am reluctant to torque is the top plate that sits on the engine top and bridges over to the mount to the left. Those 4 bolts call for 37 lb ft of torque. Is that correct ? If I snap one of those off - yikes

So I jacked up the motor and set that plate exactly where the marks were from the original install marks where the original were. I set the torque to 37 yet when tightening down seemed pretty tight yet the torque wrench did not click. I mean pulling hard and no click.

Ordered up a new coil and new plugs from rockauto. The plugs i installed a few months ago were autolite. When i pulled these yesterday all were dry as a bone and minimal carbon. One plug appeared to be barely used

Close enough, 36 lbs/ft. The procedure is on EM-85 here, torque for the other fasteners is in the exploded diagram on EM-83:
https://www.nicoclub.com/service-manual ... 4%2FEM.pdf

I'm a little puzzled that they're not torquing, those bolts are pretty hefty and guys commonly nail them down with an impact wrench.

Greenwood$ wrote: ↑

Sun Feb 04, 2024 10:28 am

One other thing we have noticed right after start up and placed in drive, the vibration seems to occur with the rpm at 1200. Even after warm up and running ok at say 30 - 40 mph, when it drops back to 1200 rpm the vibration is felt in the steering wheel

That's also a little weird, coils don't usually behave that way. The tranny might, but that wouldn't give you a vibration at idle or out of gear. Drop-throttle vibrations are usually from an induction issue if they aren't from bad mounts, so you might be looking at two separate issues with similar symptoms.

PS - Never use Champs or Autolites in a Nissan, stick with the riceburner brands. The OE's are all Denso and NGK, and both are fine in any Nissan application.

Sunday Nite Recap

- rechecked all newly installed engine mounts, all look ok

- rechecked torque on the bolts for these all are either at a smudge above what is called out. for the sake of verifying, do you have the torque for the bolts that hold the largest mount in place. This is the one that ties into the engine top plate mentioned earlier today. The top nut I have set at 76 lb ft and the two long bolts at 37 lb ft. With the engine running in park, i can get my hand on that mount and do not feel any vibration at all

- ordered (4) new plugs and (1) coil for replacement and testing purposes

- the vibration comes through on the passenger side, up from beneath both seats. I had replaced both exhaust mounts within the last month

- A new observation, is that when I back out of the garage and turn the wheel, the rpm dips and the vibration to the wheel increases. When back straight and rpm rises slightly goes back to the new normal level

- wife says that even after warmed up, the vibration is felt especially in that 1200 to 1250 rpm range. Also occurs when lifting of the gas at say 20 mph to coast to a stop sign as the rpm decreases to that 1200 level and eventually down to 700...not as intense as when cold

- received and printed out ground test document, though admit that without a sketch not sure what I am doing and where the block ground as an example is located

Other things wife has chipped in

- from reverse to drive with brake on, seems to take a sec longer for drive to engage than what we have been used to

- she mentioned just today that when she was driving a few weeks ago, a warning message flashed for a second then disappeared. she did not see what it was for and does not exist now. Zone read for codes and none came up and no CEL ever on this since new

The vibration started last year in colder weather then when back to 70 deg and up disappeared

I am not a trained tech. I have worked on cars for 40 plus years. Our favorite of all time was the Mercury Villager van with the Nissan 6 cyl drive train. Timing belts and tune ups, a few cv axles and went to the JYD at 300,000 + miles

About the only thing that causes the MIL to flash without leaving codes is a transient misfire, so you're probably barking up the right tree with a coil issue. My '04 actually did something almost identical, although the culprit was a set of China-cheap spark coils and not aged ones. Dead misfire for several seconds cold, worse in cold weather, and every once in awhile it would blip the MIL at me. Replaced all four with another China-cheap set and now it's fine. One of the first set was simply defective.

If the car is your wife's DD, is she grandma or does she used the gas pedal? If the former, you might consider decarboning the engine. Heavy carbon on the crowns will raise compression and carbon on the intake valves will interfere with induction, so it can obviously contribute to misfiring.

RE0F10 series CVT's are all slow to engage going D-R or R-D, I'd say a second and a half is probably average. That's because R is direct drive and D is belt drive, so the stepper is retracting frantically for R and restoring pressure frantically for D. Cold temperatures and old fluid will both exacerbate that, have you changed it regularly?

PS - The Vdrop test is from any good metal on the engine block to the battery negative post. The block itself is a giant chunk of connected metal with very little resistance, so where you check is pretty irrelevant. If there was supposed to be a pic with your post, it didn't come through.

Thanks again

I changed the cvt fluid at 60,000 miles per the owners manual, and again at 95,000 miles using the Nissan (exxon mobil made) CVT fluid. The most recent also did a two time flush with fresh fluid and changed both filters. I let the transmission drain over nite and kept level. The canister like filter was filthy yet i guess to be expected. The pan/magnets did not have a lot of crud built up. I did not use any type of aerosol cleaner at all.

Yes it is the wife's DD and yes she is a lead foot grandma

Voltage drop test today

On prior nissan's i replaced fuel injectors and would back probe those for resistance. After the coil and plug change will look at these as well

The car has been reliable. Has had a few recalls yet has been good for close to 100,000

Voltage drop negative terminal to block showed no millivolts. Scratching my head here.

Was the car running? That's when you make the measurement, if the ignition is off then there's no current flowing to measure. If you did have it running, zero is impossible, so that's a meter problem.

Nope not running

Shame on me and will check in the AM when running

Thanks again

I set the multi meter to the 200 mv setting

From neg terminal to block with engine running read 9.2 - i assume that is in millivolts

If so, is that a good result

Yep, anything below 50mV is acceptable, healthy ones run a lot lower. Yours is fine.

Great

Vibration seems to have settled down a bit

New plugs due Thursday and one coil

NGK plugs

just another observation

Vibration at stop light at 700 - 750 rpm

rev up just a bit, no vibration

Received and installed the (4) four denso plugs today. These were pre gapped out of the box at 0.040 !

Drop them in and installed the new coil on the plug furthest to the right when facing the car

I am also too hesitant to declare victory, yet at stop signs and while driving - like a cream puff...well not quite but close. For the heck of it I may go ahead and replace the three remaining coils

When accelerating at low rpm from 0 mph to say 30 mph, it stays at 1250 -1300 rpm and does growl a bit. Once up to the next gear and a bit higher rpm she runs fine

Again perhaps too early to declare victory yet.....better

Of note.

When i removed the Autolite plugs, there was a bit of oil around the body to the plugs where the ripples are. The plug tops and tips dry as a bone

Swiped the inside of the coil tubes with a q tip and nothing was there

Will drive a few more days and report again

Thanks for all of the help, yet I am not convinced out of the woods just yet

Update late Saturday

After a short drive the shake is back

Worst when placed in reverse

Removed and reinstalled the lower engine mount today to ensure all torque and position of the mount were correct

Also tightened the bolts on the exhaust mounts. These call for 11 lb ft of torque

Runs much better

Will monitor and see what happens

Cold start this am and still vibrating

The vibration is felt coming up from under the seats and the center console area

The rpm dips and the car vibrates at the steering wheel when first started and with the wheel turned to back out of the car port

It's overall better yet not solved

Further torqued the exhaust hanger bolts front and back to OEM spec and a bit more and the vibration is still there yet has been reduced quite a bit

Still no CEL codes and will replace the three remaining coil packs asap

Thanks again