2019 Altima 2.5 engine swap now long cranks and feels like sort of knocks or heavy singular vibrations?

AARP209

MEMBER
2019 NISSAN ALTIMA
2.5L
4 CYL
2WD
AUTOMATIC
163,000 MILES

My 2019 Nissan Altima the past couple months was having misfires, eventually I replaced the spark plugs and ignition coils and in doing so I had a misfire in the 4th cylinder. I swapped the coil and spark plug from 4 to 3 and when screwing in the spark plug I overtightened and ended up needing to rethread the hole and I dropped fragments not realizing and the pistons got damaged. A mechanic provided the options to have the cylinders machined and would cost $5-7k or get a used engine. I found a 2024 with 30k miles at a reasonable price and went with it. Well, I received the car and the guy told me at first the starter was having issues so he replaced it with an aftermarket. So I said okay and went to start it and it has this now very long cranks. Luckily it starts but it sounds like like before. Guy tells me since I see the Christmas tree on the screen that just to drive till they all turn off. Well, this guy must be from the Stone Age because my Adas codes have nothing to do with this new engine. Sadly this has become the truth because the engine codes I do have all relate back to the crankshaft position sensor aka p0335 and another one p02617 I believe. I have done all the relevant procedures and to no avail. The car is constantly in limp mode, to me it seems like a lot of hesitation, there’s downshifting issues and it’s scary when you don’t know if that shift is going to be good enough to speed ahead of the person behind you. Not to mention I can’t use several functions like cruise control, icc is not working, my auto hold won’t work, etc now I’d go back to the mechanic but I found out they didn’t even put oil in the motor but installed the filter and charged me. So I’m here hoping someone can lead me in the right direction.

Sunday, December 14th, 2025 AT 7:33 AM

4 Replies

LOU P

MECHANIC
122 POSTS

Hello, my name is Lou, I will do what I can to help you.
I am sorry you are dealing with this headache, but in retrospect I think we may have a somewhat easy fix if not an easy diagnosis here. I suspect the P0335 and the other code did not show up until after the engine was replaced. That and the long crank, so that tells me that 1 of two things has happened. 1- wires are damaged or pinched that lead to the crank sensor. Or 2- its a poor connection at the crank sensor or even a bad crank sensor. When you have a code that says "Circuit" we are now looking at the wiring and connections and the sensor itself. So let me know what steps you have already done, but I would focus on checking the wiring to the crank sensor and the routing of the wiring harness, its possible its pinched or damaged depending on where its located in relation to the mounting to the transmission, a lot of times on all sorts of cars we find that wiring gets pinched between the engine and transmission. If you have a scanner that can read live data you will want to read the RPM in the live data of the engine module to see if its reading when you are cranking. If the module doesnt see RPM from the crank sensor it may still start the engine because it does see RPM from the cam sensors. But then you will be in limp mode because it doesnt know the true rpm. Let me know if this helps. Lou

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Sunday, December 14th, 2025 AT 7:50 AM

AARP209

MEMBER
5 POSTS

Hi Lou,

Thanks for taking the time out of your day to assist me in the headache I’ve gotten myself into. The codes actually appeared right before all of this. The car actually had been to 2 prior shops before the 3rd. I actually drove into the 1st shop and it never drove until we did the engine replacement. I never really got a straight answer as to what the first shop did but they began my biggest headache. They actually diagnosed the parts within the cylinder, and they told me then that they don’t do engine work. I then bought a BORESCOPE and I fished out everything I could find but apparently I missed the bottom half of a spark plug thread. Because I succeeded on my own, I told the guy “if I got everything out then why won’t it still crank? He tells me to try and adjust the camshaft? Which I am able to make it move a bit but it does nothing and they don’t shed anymore light onto that. So back to what’s currently going on. I have the two codes but at tha time above a camshaft code appeared and never reappeared. The 2nd shop saw what’s going on and was like to I’m out! So they didn’t touch anything. When you mention about the engine transmission being so close. It sounds like all of these wire harnesses that aren’t tied down anymore, or the very loose ecm, or the harness on top of the starter motor they installed plus all the can possibilities could very well be the culprit? And to be honest, I have had the hardest time locating the crankshaft sensor that I haven’t even been able to test it. I do tho, have a top don rlink j2534 so I do have lots of data but never paid any attention when cranking or even seen if that’s in the live data, tho, rpm’s are for sure. Because the rlink uses oem software or top dons “top guru” app is what’s at my disposal or I believe I have a gst with emissions info

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Sunday, December 14th, 2025 AT 2:12 PM

AARP209

MEMBER
5 POSTS

So I was looking through the live data and I didn’t see anything about the crankshaft under engine but I did record the live data. Let me know if this helps. Tonight I’ll be going under the car for the 3rd time searching somewhere in the front of the engine that meets the tranny/bell housing for this sensor. There’s not much videos online. The most are the ones up to 2018 by trq and they say those are behind the engine

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Sunday, December 14th, 2025 AT 5:49 PM

LOU P

MECHANIC
122 POSTS

Hello and thanks on the replies, so it is in your live data recording. Its called "engine speed" that is the crank sensor reading. It should show rpm as you crank the engine. The sensor is located on the front side of the block, I attached photos and some documents that might help, it is hard finding a good photo of the location. One document says its mounted on the oil pan another shows the front of the block. Alldata doesnt have a replacement procedure that I can find. If I do I will surely repost for you. But you can check the sensor plug for the positive and negative voltages per the document I supplied. That will tell you if you have a wiring issue or not. Let me know if this helps. Lou

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