Low Oil Pressure... Ticking... F

Nissan 300ZX technical discussion forum: Maintenance, performance, installations, modifications, how-to's and troubleshooting.
MCNPathfinder
Posts: 46
Joined: Mon Jun 21, 2010 8:29 pm
Car: 2001 Nissan Pathfinder 3.5 LE!

Post

Long story short. I did the 120k service on my ‘91 with 158k. Recently got it, wasn’t sure anything was done. I put new seals on the crank and cams.
Yesterday, I buttoned everything back up and it was running the best it ever has. Just amazing. However, after driving around for like two hours I noticed my oil pressure dropping. No other real issues, so I thought it might be a bad pressure sender (I read that’s pretty common). Nope. I was pretty much home when I started hearing the ticking.
Now that I’m writing this out, I was noticing some dripping. I thought it was PS or AC. Was probably my crank seal.
Another thing to note is that I’m an idiot and mid-aligned the timing marks on the belt. I went off the dot on the crank instead of the dot on the sprocket. When I started it, it definitely had some interference, but a light tap. However, when I aligned everything correctly, it tapped a little, but then cleared itself back up. No issues over the several days that I started it before putting everything back together.

Ultimately it looks like I blew the crank seal thus causing oil starvation to the top of the motor. Definite tapping up top.

How screwed am I? Did I blow this engine? Fixable?


itsa300zx
Posts: 1243
Joined: Sun May 31, 2009 9:39 am
Car: 1990 300zx NA W/TT swap
2011 Nissan Rouge S
2008 Highlander SR5
Location: up North

Post

Do a compression test or cylinder leak down test, this will tell you the health of the piston/rings and valve-train.
As for oil leak, that front crank seal is a b**** sometimes to install perfect since the lip of the oil pump has that sharpe edge on it. I use a thin piece of Mylar sheet around the circ of the seal as a "ramp" to squeeze the seal into the oil pump housing. A piece of pcv pipe (just slightly smaller that the seal OD) is a nice driver to tap in the seal.

MCNPathfinder
Posts: 46
Joined: Mon Jun 21, 2010 8:29 pm
Car: 2001 Nissan Pathfinder 3.5 LE!

Post

A compression test is a good plan. Hard to think straight when I'm so bummed. Yeah I ended up going through two new seals because I wasn't happy with how it was sitting and I didn't feel good about re-using ones that had already been installed. I used the PVC method, but just used assembly lube and not anything else. I'll see about the mylar.

How far in does the seal get installed? It should sit flush against the outer housing of the engine, right? I think I bumped it right up against the ridge that's like a 1/4 inch inside the engine? Seems like that's where my old one was.

itsa300zx
Posts: 1243
Joined: Sun May 31, 2009 9:39 am
Car: 1990 300zx NA W/TT swap
2011 Nissan Rouge S
2008 Highlander SR5
Location: up North

Post

My new oil pump came with the oil seal flush to the housing, that is how I install them.
Next time you have it out take a good look at the Aluminum seat, make sure there are no scratches or grooves.
I have been able to "fix" a small groove with a very small amount of hi temp silicon gasket maker.


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