Someone slap me please...oh nvm, I'll slap myself again.
Got back from a week away this past Tuesday. Drove my car locally for work and started noticing a knocking sound Thursday night...sounded like it was the right front wheel so pulled into a parking lot to check, and opened the hood when I saw it wasn't the wheel. Surprise surprise...oil all over the valve cover...and the bloody oil cap was sitting on top of the IM (((.
I remember checking and topping up my oil the day before I left for vacation...my mind on all the crap I had to get done that day...looks like I didn't put the cap back on.
I don't think the oil warning light was on when I pulled over, as if that matters since the damage is usually done by then... I figure I was down about 2 liters of oil, but I ended up adding 3 since it was dark and I misread the level. Got home no problem, but could hear some knocking. Changed the oil/filter yesterday and drove no problem...yes, I know I probably shouldn't have driven it until diagnosing the damage, but the knocking was quite faint.
Here's my question, for anyone who's had experience with a VQ35 that had oil starvation...what engine components are typically the first to be affected?
I'll take a stethoscope to it later and source the noise, but was hoping for some feedback from the been there done that crowd.
Thanks

 

Just drive it and see what happens. If there is damage from oil starvation, it's not worth fixing. You'd be better off getting a used engine.

 

My buddy starved his vq30. Had less than a quart in it when we pulled the engine. He snapped the end cap on cyl 2, snapped the rod and bent a couple others. If it's been starved and it's knocking it likely has a bent rod.

You can keep diving it but it will definitely go eventually. Pick up a used engine and swap it out.

 

Time to find a 6th gen motor.

 

If you have a spare car, send an oil sample for analysis to Blackstone. They will be able to tell you what kind of trouble you are in.

 

I drove without an oil cap for like a week, no problems lol...

 

And I thought the VQ35 operates using positive crankcase ventilation so if the oil cap is off, you'll get a DTC. Also the engine sounds a little off if the oil cap is off.

 

Thx guys. RR5...I can't remember when I haven't had a DTC on this car for one reason or another. Makes me wish I'd gotten around to changing the purge valve on the gas recirculation canister...your suggestion of an oil analysis is a good idea. I agree with the consensus- a new engine is probably the best option.Spent a few hours researching yesterday ChrisMan, and an 04-06 6th gen engine is a direct swap if the engine was mated to a manual tranny, in which case the sensors will be identical, if auto I'll need to swap the upper/lower oil pans, swap over one or more sensors(CPS?), the upper IM or al least cap the EGR...is that about right? Wasn't there also some issue with 6th gen engines..I seem to recall timing chain tensioner or something..

 

I've done that before, but luckily the oil cap ended up falling on the accessory belt and making a loud rattling sound... I drove only about 10/15 miles with the oil cap off... I felt really stupid, but lucky it didn't end up like yours...

 

When it starves, the very first thing that fails are the bearings (rod or main). From there, you can break a rod, bend, etc... if you still hear tapping, its probably the bearing wore out, so now there's a bigger gap than spec. You should not drive it, you can remove the ypipe, cross member, upper oil pan, and have access to the rod bearings. Can the rod ends with your hand and see if you feel a play. Or take out one end cap and look at the bearing, etc...

 

Gizmo
So you can imagine how stupid and frustrated I feel

streetzlegend
Thanks, that's about what I figured. Can the main/rod bearings be replaced from beneath, or do the heads need to be pulled and pistons removed? I'm assuming the latter, and it's probably asking for trouble to assume the cylinder bores/pistons/pins are ok anyway. At that point I might as well replace the rings. What are the chances the camshaft journals are buggered up too?
Time to slap myself again-thanks

 

One of our local members just went through this today on his 4th gen.

 

Done this twice.

First time I drove about 70 miles, lost the damn lid. Ordered another.

Second time about 80 miles.

Second time was funny. Was headed to the dyno, popped the hood to connect the coil, and where in Christ did this oil come from!

Found the cap in there somewhere, asked the dyno shop to "lend" 0.75 quarts, put some in, and hit the rollers.

 

Yeah, if you go with pretty much ANY '04-'06 VQ35 make sure that you change the secondary timing tensioners while you got the engine out of the car. While out of the car, its a 3 hour job. With the engine in, its about a 7-8 hour job. And you WILL wind up doing it (unless its already done on the engine). Good luck!

 

This is what happened to mine about a year later after running it low on oil and it started ticking did a 6th gen swap.

Came out of the oil pan.... WTH


Piston # 2 I think

 

From reading the 6th gen forum on the problem, this, IMO, is imperative.

 

bgsl1ck..that's a lovely batch of souvenirs you have there
I haven't driven the car since Friday, and been too bummed out to take the stethoscope to it. I have been searching for a replacement motor though-finding some 04-06, but all automatics. Thx for the heads up about the secondary chain tensioner 02 Style.
I did come across an 07 engine also. Anybody have the poop on how complicated that swap would be? Looks like 07-08 were all CVT, so I'm guessing I need to change the oil pans, but if there are no chain tensioner (or other) issues then it sounds like a better base...time for me to start researching-thanks again!

 

The trans shouldn't matter the upper oil pan should be all you have to change...

 

Ended up going with an 06 from an Altima with 80k kms... about 50K miles. So this is what a VQ35 looks like when it's clean? Swapping an engine in rented garage space sucks- you have to get your *** to the garage every day regardless- I miss having a garage at home. Started working on the car Tuesday afternoon and dropped the motor this afternoon. I was planning to pull it but an Infiniti mechanic who moonlights at this garage suggested dropping it (car is on a lift) as the recommended method, and it came out without much trouble... but damn there's not much room around the power steering pump. I'll be swapping the oil pans tomorrow and will satisfy my curiosity re what went south on my engine. Hopefully by Saturday I'll be up an running again.