Starting a new post on this new Nissan site, hoping to catch someone’s eye that may be able to suggest what to try next on my daughter’s 2010 Sentra 2.0

What happened?
Three or four months ago she was driving normally, going up a hill and the car lost power. She can down the other side of the hill and stopped at a red light. The car stalled. She was able to start the car and she says it was smoking. She said the smoke smelled sweet.
We drove the car 3 miles to my house and pulled the codes. P0011 and P0300 (days later a P0300 appears after much troubleshooting. At this point I’m not gettgni any codes but the car still runs really rough and the codes might return if I let it run longer or drove it.

Thinks I done:
Replaced coil pack in Cylinder 2 and moved it around when the P0302 appeared. The P0302 remained at cylinder 2 with the new and swapped with other coil packs.
Replaced PVC valve
Replaced Camshaft Position Sensor
Replaced Crank Shaft Position Sensor
Replaced VVT solenoid
Replaced all spark plugs
Replaced fuel rail and all injectors
Checked the wiring to the coil packs
Checked for vacuum leaks.
Replaced valve cover gasket
Thoroughly cleaned throttle body
Autozone tool rental block tester but tested the coolant overflow and did not test from the radiator (fluid stayed blue)

Just looking for someone that may have encountered this problem and fixed it and to share the fix.

After I did all of the above work, it seems that the car runs a little better but still is not drivable due to the lack of power and rough idle. The car does not smoke. Her battery for some reason is corroded to hell. It seems like the positive terminal corrodes just by sitting. I’m hesitant to buy a battery link because I’m tired of throwing money at this car. I ran it last after I replaced the crank sensor. While sitting in the car, I was waiting for the SE light to come on but it did not. The SE light might come on if I try to drive it but I’m just done with this car unless someone can offer something else at no or low cost to try.

Anyone, anywhere have a similar issue to share with the end result?

I’m thinking on grabbing a MAP sensor from the junk yard as a last last effort. Reason: When this problem first started there was a lot of engine oil in her air intake hose leading to the throttle body. Maybe the MAP sensor is saturated.

Thanks
Jeff

Its time to do some real diagnostic testing.

Because you've replaced so many parts already, the water is a bit muddy, so I would start with the basics.

Cold compression check.
Cold leakdown test, done with the radiator cap off.

Those engines do have HG issues. The block test often won't reveal anything unless it's pushing a lot of gas into the radiator. They're not full proof. Use a leakdown tester to pressurise each cylinder while holding the crank pulley on the compression stroke. Wait 20 or so seconds. If coolant pushes slowly out of the rad, the gasket is blown or the head is cracked. Pay special attention to the middle 2 cylinders.

Also, if that engine uses an electronic throttle body, it must be reset by a OEM capable scan tool after any cleaning/service. If you messed with the throttle plate, it needs to be reset.

Thank you

I will get back to this forum and reply once these tests are done probably in a couple weeks

FlatBlackIan,

How can I determine if TDC is the compression or the exhaust? I'm seeing a lot of vids with the valve cover off and I don't want to pull mine. I'm probably best to do a simple compression test with the fuel pump fuse out no? This way I can turn over with batt and get a reading rather than messnig with the valve cover agani. Would hate to buy another gasket should no interesting leak be discovered.

When doing leakdown, you'll know hahaha. The pressure in the cylinder will push the piston down as soon as the valves are shut. So just slowly turn the crank with the longest breaker bar you have access to. When the gauge spikes, lean into it, then take your reading.

Performed compression test today, dry, didn't bother with wet because it doesn't matter anymore:
1=172
2=30 (checked two times making sure of good connection
3=185
4=190

Polish leakdown test: Cylinder 2 TDC - took out air control valve in $29 Autozone compression tester I bought (needed 14 mm and the rental didn't have the fitting) - using lungs, blew into shop air side (fitting not adapting to shop air line) heard air whistling out the oil stick. Put rubber glove (finger) over oil dip tube, blew into compression test hose and the middle finger of this glove started to inflate.

The end

Moral of the story. When you see a P0011 and a P0300, check for compression on all of the cylinders first before wasting money on changing all of these sensors as I did. It's easy and cheap.

I'm going to keep this tread going. I'm not giving up on this. Now that the weather is warming up, I'm pulling the head off to examine for cracks in the head or a bad valve or something obvious. took off most of the top engine except for harmonic balancer, timing chain cover and cam shafts. I plan on spending more time tomorrow on this. The manual says that I need to pull the water pump pulley (don't tell how) and the alternator. I don't think that I need to so I will skip if I can.

I will keep posting on my progress where maybe this might help someone.

Alright,

I've pulled the head and I will attach two pics although I have vids.

From what I can tell, the head gasket is not broken and as a matter of fact looked pretty healthy.
The four valves in this troubled cylinder 2 look okay. Not bent and are completely closed.
One thing that I noticed is some damage on the back side of the top piston and it looks like the rear piston has some gap or a melt spot that is not present on the other three pistons. Piece or ring perhaps was in there.

Next Saturday provided good weather, I'm going to drop the oil pan and pull out that cylinder 2 piston and examine it. I will update at that time with pictures. My plan is if I should find that the rings are stuck or broke, I'm going to replace this piston only (yes I know) with new rings and new bearings on the remaining cylinders. I'm not going to bother to pull the engine and do things the right way. I have other stuff to do so this is just my curiosity getting hold of me. I'm ticked off that I was sold a car with an unreliable engine (MR20DE). Not going to spent too much more cash on this automobile.

Did you inspect the air intake hose? My wife’s 2012 Sentra used to stall at the red lights. Happened two days in a row. It looked fine from a distance but when I took a closer look I saw the rubber was cracked and the air would get in. I replaced it and it solved the problem.

Yes - I replaced this hose when my daughter first bought this car. Ran great after changing that. This issue is only 30# of compression in cyl2. All of the rest as 170-190. Leakdown test I noticed air coming out of the oil cap and dip stick denoting something really bad ;-)

Head gasket would not cause this but a cracked head or a broken or stuck ring will. It's a shame, not too many miles on this engine.

Thanks!
Jeff