This is an image of the engine in its current state.
http://imgur.com/nF4J56R,ZoTTzqv,JwEvFY8#2
http://imgur.com/nF4J56R,ZoTTzqv,JwEvFY8#1
http://imgur.com/nF4J56R,ZoTTzqv,JwEvFY8#0

I bought this 1996 Maxima from someone and everything checks out but every now an then my car gives an ever so slight sputter like it spit something out of the exhaust.
(Not transmission related as I know the feel of a gear slip)

At the time I thought it could've been from the weather due to the snow and anything water/liquid might have froze on the outside of it except the engine bay is completely dry everywhere else.

I'd also like to add that the smoke is a little white but not smoking to the point where something seems wrong.
Thing is its about 10-30 degrees in NYC so noticing the color difference and density in smoke would be more apparent.
Compared the smoke to a few running cars and is normal/slightly above along with the smell of it being emission based not with the sweet/antifreeze smell to it.

Temperature gauge in the car reaches halfway at the MOST when driving and when its just started up after a cold night/day or after being parked for a few hours, idling will sit the engine temp a quarter of the temp gauge until I start to drive for about 10 minutes then it reaches halfway.

What could this be and will it be expensive to fix?

I am hoping that it is just the seal resting between the two that might be causing a leak, a crack in the manifold, or maybe it just needs a fluid update but in terms of fixing price on a DIY'er how much do you think it would cost with the smallest issue and the deepest issue it can cause?

And finally, no check engine light.
No idea if it was reset or if it really doesn't have any issues sensor/electrical based.


On a completely other note, I'm thinking to switch to synthetic to help the engine with the cold but after say 140k of the previous owners using only regular oil would a swap be alright for the motor? Or should I go with 50/50 this time and then full synthetic afterwards?

I really would appreciate anyone that can shed some light on this for me.

Thank you for your time,
Jason

 

Welcome to the forum and congrats!

First of all, you got pretty bad oil leaks from valve cover gasket, and they do need to be replaced. I cannot tell from your pictures but it also looks like the lower intake manifold is cracked? Those 2 factors could cause vacuum leaks, resulting engine running lean, rough idle, sputtering, etc..

You engine is in pretty rough shape, my recommendation, you need a major tune up:
1. Clean MAF, TB, IAVC, EGR tube (and all related gaskets)
2. Replace valve cover gaskets
3. Change new spark plugs (NGK)
4. Replace lower intake manifold if it is cracked
5. Replace vacuum hoses if they are cracked
6. Change oil, no problem to go full synthetic oil, I use Mobile 1 5W30
7. Change air filter

There are plenty info in this forum, a lot of DIY threads, do some searching, and reading to understand your car.

Good luck.

 

^ What Walker sez. Your temp gauge is performing normally. You can scan your ECU's with a small flat blade screwdriver and the instructions found on this site or from the Factory Service Manual also available free on this site. Go to a site like Rock Auto or Advanced Auto Parts or one of your choice and run some numbers for parts to DIY what walker suggests above. I would think a couple hundred bucks would cover you. Having done all these myself, its easy for me to say they are not hard, just time consuming.

 

might just need to do a tune up as walkinator suggests. REplace PCV as well.