weird... Let us know how it goes man...

 

if he shorted out an injector or coil pack with water it may. To me his smoke sounds like unburnt fuel from one cylinder...The syptom started after he washed the car, then stopped once the dealer got it,perhaps it had time to dry out.

 

I understand what you are saying, but the OP’s description unfortunately sounds much worse with the symptoms he describes.

He said: “A week later, started it up and lots of knocking in engine area. Laots of white smoke coming from exhaust.” He also said he washed the car’s exterior, and not the engine bay.

What he describes (white smoke from the exhaust and knocking) it sounds as though there is coolant leaking to the engine. If that is the case, his valves and camshaft are ruined. This is bad… really bad.

--Spike

 

Ever sit back and think of something simple like a bad O2 sensor, causing the car to dump fuel and misfire, which would cause White smoke and knocking..

Just curious as to why you say his cams and valves are ruined..

 

…Because that is probably what is going on here.

At this point… all is guessing. Let’s wait for the OP to tell us what finally happens.

--Spike

 

But how would a leaking headgasket ruin his cams and valves? Im curious..
if he has "Knock" as in "rod knock" its not going to simply go away...A cylinder with a misfire at idle, may duplicate a knocking sound.
an excess of fuel would also cause white smoke..
So if an 02 sensor went bad it would do the same or if an injector shorted open it would also do the same..

 

Julian,

I don't see you mentioning a blown head gasket.... Why?

 

Cause people jump to conclusions on this forum with very little knowledge and experience. We like to eliminate the smaller obvious things first, which 80% of the time are overlooked..
I find it hard to believe a stock N/A low mileage Z would blow a Multi Layer Steel headgasket that has upheld up to 10-12 psi of boost pressures. Plus once a headgasket is blown, its blown, it does not go away..
Im just sceptical on the headgasket issue, unless he was running a turbo, or overheated the car very bad..

 

I have this problem now that I think about it. I'm leaning to think it could have something to do with what Julian said but I need to swap out coil packs to see (I'm thinking an oil leak may have shorted one out). My temperature is always normal and my coolant level is fine. When it idles it smells like a decent amount of fuel

 

I don't think it is either but that's just me. I'll say this... my symptoms are similar and if it was a head gasket, I'm almost sure my motor would be blown already with the way I drive it

 

995 of the time, Im correct..the 1% when Im wrong, I admit it..We has similar issues as well.

 

That's 100.5%!

 

Of course we are all guessing because there isn’t enough information to make a diagnosis. If the head gasket is leaking and coolant is going into the engine, he should also be experiencing engine overheating (and, there would be a great amount of friction, and thus heat, and subsequent damage to the valves and camshaft).

He said…
…and I can’t tell if he is saying it is overheating or not. If soccertoad is not experiencing engine overheating, your answer is more likely than what I present.

I am not challenging your diagnosis, but simply offering the worst case scenario.

This is sort of like listening to the “Car Guys” on Public Radio where the two bothers from New Jersey attempt to diagnose problems presented by callers. It’s fun, but often not accurate.

--Spike

 

All Nissan technicians graduated from Cannot Replicate School.

 

^^ I really believe that the dealership is often caught between a “rock and a hard place.” By this I mean they cannot get reimbursement from the manufacturer unless they present a repair as clearly covered by warranty; and even when they do this, they only get a partial reimbursement when comparing to a non-warranty repair.

For problems as these, I think the blame should be placed on Nissan rather than its dealerships.

--Spike

 

I went to a dealership regarding this very same problem. They said that due to my lack of cats (due to test pipes) my pcv valve is not functioning and that i am blowing oil out of the exhaust. That is what the smoke is on my car. I believe them mostly because i go through 1qt of oil every month.

 

^^ Wouldn't that be a blue-colored smoke instead of white?

--Spike

 

Why would that cause the PCV valve to not function properly

 

Sludge (burnt or old oil). Sounds like overheated oil in this case.

--Spike

 

So what the hell happened with all the smoke? Did it just go away on its own?