2003 Nissan Xterra valve cover leak

2003 NISSAN XTERRA
14,000 MILES • 6 CYL • 4WD • MANUAL
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NJSALAZAR
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Just experinced an oil leak on on the driver side valve cover after driving the car 3 miles after a 3 min warm up in the morning when overnight temps hit 0 degrees.
In the 3 mile drive the RPMs were kept down and speed did not go over 35 mph or rpms above 2300rpm.

Oil has leaked a few times from the driver side valve cover last year and was repaired 3x. each time the the overnight temps were low ( below 10degrees) Am not sure if engine was"warmed up" prior to driving though, more than likely it was.

Last repair to valve cover included a new cover and correct screw from nissan and new gasket. Engine compression was normal.


Oil right now is 5w30castrol synthetic. Oil was changed 800 miles ago with new filter.

Oil leaking from driver side valve cover is reoccuring.,

but why? FYI it has dropped several times to zero and below and there has been no issues.

FYI 6 weeks ago oil was found in engine a minor amount. it seemed teh oil dip stick "popped out" about 2 inches from it seating. That was attributed to the engine nto being allowed to warm up. Rpms at warm up were 1900rpm, oil was changed the day after and intial start up rpm returned to 1500 rpm.
Feb 6, 2010 at 1:19 PM
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2CARPRO JACK
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So it has a recurring valve cover leak? Did they check theoil drainback holes to be sure they are clear when V/C was off? There isnt really any reason for it to continue leaking other than bad gaskets or the washers under the screws are flattened and arent holding it down enough to maintain a seal. Have they tried gluing it down with silicone to see if it will seal it?
Feb 8, 2010 at 8:03 AM
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NJSALAZAR
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they're checking it today.., the mechanic when i dropped it off sat. said there might be blowback from the piston occuring...
I'm going to ask him to check the compression and vacuum test. as well as check the pcv valve.

They ( another mechanic) did place silicone around the seal as well last time.

current mechanic is afraid there might be too much compression occuring int he engine ( blowback) and thus the valve cover leaks and the reason why the dipstick popped out 6 weeks ago.
I'm also curious as to why this occurs inthe bitter cold only ( and when it does occur inthe cold why so infrequent?
Feb 8, 2010 at 8:23 AM
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2CARPRO JACK
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Broken parts can move around an cause problems then not cause them.Heat/cold can make a big differenece due to the expansion rate of dissimilar metals.Have them do a "leak-down" test, this will tell you if i has bad rings
Feb 8, 2010 at 8:26 AM
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NJSALAZAR
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and if it has bad rings.. what would th next step be and the cost?
this is 140k car never any issues other than this oil leak and I plan on keeping it for another 100k /5 more years
so long as the frame holds up

other wear and tear items like shocks and brake pads and oil it has never needed anything
Feb 8, 2010 at 8:29 AM
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2CARPRO JACK
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Rebuilds are risky, I would probably find a low mileage salvage yard engine with a warranty and go that route.Price depends on demand, youmay want to make some calls around if it comes to that and see what they go for.You are probably looking at around 16+ hours of shop labor plus parts
Feb 8, 2010 at 8:32 AM
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NJSALAZAR
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why would a rebuild be risky?

16 hours at 60/hr=960 plus parts for1800$s tota( just throwing a balpark figure out

if they go the piston rings rebuild route.. is there anything else that we should look at and replace?
head gasket? bearings?

the salvage engine is possible.. however the history also come into play with an egine.. ( oil changes, abused( xterras are known to be used as trail trucks/mudding etc)

used engines around here run about 1800
Feb 8, 2010 at 8:57 AM
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NJSALAZAR
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PS. thanks so much for you input so far.

John
Feb 8, 2010 at 8:58 AM
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NJSALAZAR
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PS.. thsi might be elementary with my xterra being 4wd standard .. woud i be able to put in an automatic 2wd engine in there...

I say no as well as to putting a 4wd salvaged automatic.
Feb 8, 2010 at 9:01 AM
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2CARPRO JACK
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If you go with arebuild, machining and assembly will cost as mucha s if not more than a rebuilt engine.You would have to totally disassemble the engine, machine crank,rods, install new pistons, Bore the cylinders, repalce oil pump and a total gasket/seal kit.That isnt even including having theheads checked and any leaking valves fixed (valve job).You can use an automatic 2wd engine in, but you would probably have to swap over the oil pan and oil pump pick-up tube as well as different exhaust manifolds.But that engine would probably be the best as far as wear goes.
Feb 8, 2010 at 11:29 AM