Diagnosing 3.3L VG33E issues - running out of ideas & $$ fast - SOS!

Alexanderkays

Test Drive
Location
Los Angeles
[shamelessly copy/pasted from another forum where I was getting no responses]

Hello all! Very excited about my first Xterra, however I am having a very difficult time with it so far. I know this is a strong car so I'm very much hoping to get this baby back to optimal again. Sorry for the novel, but a lot has happened....

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2003 Nissan Xterra 3.3L VG33E 2wd 5-Speed Manual, 125,XXX miles.

Bought 1 month ago. Single owner until mechanic purchased from them to rebuild engine and sell. Repairs are documented as follows:

- Timing Belt - remove & replace
- Timing Belt tensioner - remove & replace
- Water pump replacement
- Cylinder Head Gasket (includes: remove carbon and check surfaces for warpage, asjust idle speed, ignition timing, valves and clean and adjust spark plugs)
- Cylinder machines and repair, valve repair, replace valve seats
- Thermostat Housing
- Knock Sensor

Ran well for about 3 weeks, no codes. Noticed poor MPG, possible lack of power but no hesitation or misfiring.

Broke down while driving, severe misfire, started then stalled immediately, then wouldn’t turn over anymore at all.
Shop diagnosed and replaced fuel pump
Car would start then, but still severe severe misfire
Throwing crankshaft sensor code & MAF code

Dealership replaced crankshaft sensor
After repair, car then started throwing camshaft sensor code (no more MAF code) is
Dealership replaced distributor

Car returned to me still with slight misfire and rich air/fuel mix
Now throwing 02 sensor code
I couldn’t afford anymore dealer repairs so I started myself
Dealer suggested next repairs to be new plugs and wires, and if necessary new 02 sensor.

Replaced plugs and wires on all 6 cylinders
spark plugs were all very black

Started and ran very strong, but seemed like occasional misfiring and white smoke started coming from exhaust intermittently. Still smelled very rich. Also at this point it started sounding like a diesel truck with clicking coming from engine.

Replaced Bank 1 Sensor 1 with OEM 02 Sensor.

Noticed white smoke coming from valve cover when checking oil.
Replaced oil & filter with high mileage synthetic & Lucas high mileage additive

Car started throwing Cylinder 5 misfire shortly after.
Replaced fuel injector on cylinder 5.

Cleared all codes.

Suspecting that cylinder 5 fuel injector may have been dumping extra gas past the piston rings into oil, I again Replaced oil & filter with new high mileage synthetic & Lucas high mileage additive. Upon starting the diesel clicking went away after about ten seconds and idle was strong.

Car seems to be running very strong at times with steady idle, no shaking, and no smoke. However, at other times it seems like it is slightly misfiring again, with diesel sound coming back, and white smoke coming back intermittently. (Clue: Seemed to be no white smoke during highway driving, even when downshifting/passing

Added fresh tank of Valero gas with Royal Purple Max-Clean gas treatment

I’m suspecting I will throw another code soon, but nothing is showing up so far.
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Please help me diagnose, I’ve almost purchased the car twice at this point and I’m getting a little hopeless here. I can wrench a lot of things myself as long as I don’t need some very specialized equipment. This car is in amazing condition otherwise and I’m doing everything I can to get it running well as I think it’s a good investment that I don’t want to give up on!
 

kirk

I'm Shady AF. Ask Anyone.
Moderator
Supporting Member
Location
Allen, Texas
So the shaking, smoke and diesel sound are intermittent? Are you comfortable the timing job and head gasket were done well?
 

Alexanderkays

Test Drive
Location
Los Angeles
It seems so, the mechanic that did the repair did thorough itemized paperwork detailing every bit of it that I have. Seems reputable. At least I have no reason to suspect otherwise. Today I am disassembling and cleaning fuel rail and injectors, plus replacing fuel pressure regulator. At this point trying to play process of elimination and crossing fingers it’s not piston rings or valve problems.
 

Alexanderkays

Test Drive
Location
Los Angeles
So the shaking, smoke and diesel sound are intermittent? Are you comfortable the timing job and head gasket were done well?

oh and yes, those problems seems intermittent. I’ve been driving it around and testing it. Some drives have a little smoke almost the whole time. Some have none. Some have big bursts of smoke here and there, and otherwise none.
 

2002XterraSC

Test Drive
Is it using oil as well? On my 2002 the catalytic converter disintegrated and got sucked into the motor. The same symptoms followed for me, poor running, massive oil consumption, blow by smoke coming from the dip stick tube and oil filler cap when removed. Plus the top end making an awful racket.
 

Alexanderkays

Test Drive
Location
Los Angeles
The
Is it using oil as well? On my 2002 the catalytic converter disintegrated and got sucked into the motor. The same symptoms followed for me, poor running, massive oil consumption, blow by smoke coming from the dip stick tube and oil filler cap when removed. Plus the top end making an awful racket.

Ah, very interesting, yes it seems to be drinking a lot of oil too. And it is very very tappety sounding. Also, I’m now throwing P0430 and P0420 which are both cat codes to my knowledge. What was your solution to your problem? Right now I feel like im trying to start swallowing the very bitter pill of getting a full engine rebuild and new CA cats because I just don’t know what else to do. Those things will likely cost me over 5k more in repairs....
 

TheCrabby1

Lockers Installed
Supporting Member
Location
Burtonsville, Md
The


Ah, very interesting, yes it seems to be drinking a lot of oil too. And it is very very tappety sounding. Also, I’m now throwing P0430 and P0420 which are both cat codes to my knowledge. What was your solution to your problem? Right now I feel like im trying to start swallowing the very bitter pill of getting a full engine rebuild and new CA cats because I just don’t know what else to do. Those things will likely cost me over 5k more in repairs....
After sucking cat dust back into the motor and losing oil and oil pressure it made more sense to me to find a low mileage motor from a auto recycler [ some offer a warranty, mine had 6 month's ] then go through a rebuild and hope they didn't miss something. Do the cat's at the same time . Just my 2cent's of experience.
 

kirk

I'm Shady AF. Ask Anyone.
Moderator
Supporting Member
Location
Allen, Texas
Would be nice to know if you could take the cats off and see before diving into the rest of that. I have had good luck with auto recycled motors as well.
 

TheCrabby1

Lockers Installed
Supporting Member
Location
Burtonsville, Md
Would be nice to know if you could take the cats off and see before diving into the rest of that. I have had good luck with auto recycled motors as well.
I'm already growing tired of the flowmaster 40 so I might replace the y pipe also, in which case I would drill out the back cat's since there not monitored and it would let more of the dust/particulates flow downward [ in case of failure , again ! ] and out verses' clogging up the rear's and restricting air flow causing more crap to be sucked back in the motor . You don't have a spare motor sitting around with all those vehicles ??
 
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