[louielace69]

So when I purchased this car for my Son it had a knock upon startup
I've always assumed it could be bearings or the timing chain tensioner most likely
One day it died on my Son & now it's only firing on 3 cylinders, cylinder 4 doesn't fire
I've replaced plugs, coils, injectors cam & crank sensors & intake manifold gasket
I brought a used ecm that did nothing & couldn't even be flashed I was told
I have a new timing chain kit as well as rod & main bearings which I don't think is the issue but the price wasn't too bad so I bit the bullet
I forget the codes that came up bc it's been a few months but they all revolved around the work I did
I'll get her back this weekend to mess with it once again but I really think my chain jumped or so
Any input would be greatly appreciated & if there are any Nissan Tech's in South Jersey please hit me up lol
Car only has 83,000 miles
2004 Nissan Sentra 2.5S
Thanks All

 

[Tritton]

That looks like a 1.8 bruh

 

[louielace69]

It’s a 2.5 Tritton

 

[louielace69]

Ok so I just did the compression test & the numbers were all low but all around the same
110-110-105-110
I did the noid test but only on cylinders 1 & 4
1 lit up & 4 did not
Also plug 4 is clean while the other 3 show carbon so where do I go next lol
I'm glad this was super easy these two jobs

 

[Tritton]

Is it a special edition? Those are rare.

 

[louielace69]

Nah I thought special editions were the 2.0 but you're right
I rarely see a 2.5S mostly 1.8

 

[konkey00]

I’m pretty sure the compression should be about 170 psi according to the service manual. I would try adding about a tablespoon of oil to each cylinder then do the compression test again.
If the pressure increases after you add oil then you may have worn cylinder rings.
If the pressure stays about the same then you may have bad valve seals.
Worn cylinder rings would require a rebuild to fix (sounds like you’re preparing for that?), but valve seals can be replaced in the chassis if you have the right tools for it. JWT has an in-chassis valve compressor that works with QR25’s.

 

[Sus Spec]

If number 4 is not getting power or ground, you have to fix that circuit.

yeah I was gonna say the 2.5S had the 1.8 body but with a qr25. A car of legend for sure.

 

[louielace69]

Sus Spec how can I go about fixing the circuit? Thanks!

 

[louielace69]

I’m pretty sure the compression should be about 170 psi according to the service manual. I would try adding about a tablespoon of oil to each cylinder then do the compression test again.
If the pressure increases after you add oil then you may have worn cylinder rings.
If the pressure stays about the same then you may have bad valve seals.
Worn cylinder rings would require a rebuild to fix (sounds like you’re preparing for that?), but valve seals can be replaced in the chassis if you have the right tools for it. JWT has an in-chassis valve compressor that works with QR25’s.

Thanks konkey00

 

[louielace69]

I found a thread that said if all 4 cylinders read low the timing is off. Can anyone confirm this? Thanks again!