# 01 Sentra 1.8L Rod Bearing...or is it??



## Diceman (Jun 8, 2010)

Well....Long Story Short:

Low Oil Pressure....Fixed that (Oil Pickup Screen Clogged) 
----Put the oil pan back in, oil change------
Slapping sound, definitely coming from the timing belt area
----figured guides were worn, or chain stretched due to low oil pressure---
Bouhgt new Timing Kit (Chain, tensioner, guides, cam sprocket, exhaust cam sprocket)
-------Replaced all the above-------
Just tried to start it again.....exact same sound as before

Note: When I pull each coil pack connector the noise decreases, when I unplug Cylinder One coilpack, the noise is still there (although it does lessen somewhat)

If it was a rod bearing (or what else could it be?) how hard are those to replace...any harder than doing the timing chain?

Any help would be GREATLY appreciated......I am kinda at a loss here...


----------



## jdg (Aug 27, 2009)

Sounds like a main bearing...



> If it was a rod bearing (or what else could it be?) how hard are those to replace...any harder than doing the timing chain?


Ya think?
Get a book, an engine manual, of any type, for any car.:balls:


----------



## Diceman (Jun 8, 2010)

Main bearing...stupid question, I know, but can that be changed? How hard would that one be?


----------



## smj999smj (Jan 1, 2006)

You would have to drop the oil pan and remove the bearing caps (main or rod) and inspect for wear and scoring. Bearings are easy enough to replace, but if the crank journals are scored, it will need to be replaced or have the journals cut and undersized bearings installed (the machine shop will usually provide the bearings with the crank after they cut it, but you should still check the clearances with plastigauge during the installation). Of course, servicing the crank means you will have to remove the engine and teardown the front cover, as well. Even when just replacing the bearings, it should also be checked with plastigauge to ensure the clearances are within spec.


----------



## rogoman (Dec 16, 2004)

Diceman;1353985Note: When I pull each coil pack connector the noise decreases said:


> It was recommended on your previous thread to measure the oil pressure first. The oil pump may be producing very low oil pressure and causing the noise. Before you go and end up with a lot of dead ends and spend a lot of $$$$s, checking the oil pressure is a very cheap and positive thing to do. On your previous thread, I posted info about a temporary oil pressure gauge kit.
> 
> A bad rod bearing generally produces a loud metallic knocking sound, while a bad main bearing generally produces a more subdued metallic knocking sound. The slapping sound that you described as coming from the front of the engine may be due to a loose chain not getting enough tension from the tensioner; again possible low oil pressure.


----------



## Diceman (Jun 8, 2010)

Ok, so finally got the manual oil pressure gauge, hooked it up to where the Oil Sending unit goes and started the car. (Dead cold start) and I was getting about 2 to 4 psi in oil pressure. The Service manual said at 600 RPM, should be at 14. My car idles just at about 1000 after it warms up...

So looking at the manual, I have to take the front cover of the motor off again? Is there anything else to try before that?


----------



## smj999smj (Jan 1, 2006)

Answer at your other post.


----------



## Diceman (Jun 8, 2010)

So I am in the process of taking the front cover back off to replace the Oil Pump i got from rockauto. I noticed the timing chain has slipped. I had it lined up when I installed it. Tensioner is on etc. Any reason it would have slipped?


----------

