94 Q45 white smoke coming out from exhaust manifold, what is the cause? Thanks

[94 Q45]

Hi, I noticed after driving today, there are white smoke coming out from around the exhaust manifold area of the cylinders near the air filter and it smell like burning and like the burning of coolant, I check the temp gauge and the temperature is in the normal range, so I want to know if anybody has experienced this and how could I tell what is wrong. Thank you for your input.

[maxnix]

Blown head gasket? I'd seriously consider a compression test before driving it again. Damage could be severe if it is a head gasket leaking.

Sure it isn't just steam from an coolant underhose? Mileage? Maintenance history?

[superuber]

Sure it isn't just steam from an coolant underhose? Mileage? Maintenance history?

He's right. Without any mileage or repair history it is hard for someone to make any kind of diagnosis.Please post more info. I know my valve covers leakedand caused much smoke and odor. Could be that too...



http://community.webshots.com/user/neheadsuperuber
Modified by superuber at 7:53 AM 8/22/2006

[94 Q45]

Hi, Thank you for the information, the milage on the car is 150K and I don't know any mantainence history becasue I bought the car used, but I am sure it has not been maintain well becasue the air filter is cover with oil and dirt the car idle at 500 RPM. I think blown head gasket might be the cause and is it hard to replace the head gasket for a not well experienced DIYer? Thank you.

[maxnix]

Head gasket is a challenge (DOHC), valve cover gasket not so bad.

You can obtain the Infiniti dealer performed service history by submitting your VIN to your local friendly service writer or by registering with Infiniti Customer Service as the new owner.

You don't quite specify if it is off the manifolds (like from a leak) or around the exhaust manifold. If it smells like burnt oil, bet on the valve gasket. Take a good look and report back, please.

[5seryan]

Are you seeing big brown spots after you park your car? How are your fluid levels? Oil and coolant. If you oil is low and youre seeing spots after the car is parked for a while then most likely you have a valve cover gasket leak. For your sake hope that is the case rather then head gasket. Joe from infinti of scottsdale sells the gaskets i think for about $20. Also if im not mistaken, Jeff Williams did a write-up on changing the VC gasket. If you do a search it should come up.

[94 Q45]

Hi, the smoke come out from the exhaust manifold area on the right hand side cylinder by looking and I see black oil burn spot on the 2 exhaust manifold pipe under the right hand side cylinders by looking from the top. I can't see very deep because of the limited space in the engine compartment. Also I see coolant leak from the left hand side radiator cap(one that is connected to a host to the radiator from the engine. May be that is the cause, I will try to replace the left side radiator cap. Thanks for your input.

[maxnix]

L = Driver's Side

R = Passenger's Side

No. 2 would be the front cylinder on the passenger's side.

[94 Q45]

Hi, lefe side is the passenger side and right side is the driver side, I was trying to say there are couple of black exhaust manifold pipe on the driver's side and passenger's side but I am not sure which cylinder they are attached to.

[maxnix]

Hi, lefe side is the passenger side and right side is the driver side

No, you have it reversed. Cylinders are numbered alternatively front to back, starting on driver's side.

Suggest you study the FSM, at least the General Section.

[elwesso]

I would DOUBT that the head gasket is bad (which as we've discovered the gasket itself doent blow, the head just gets warped a little so it doesnt seal as well)..... i would lean more toward the valve cover gaskets

Next time the car is cool, run your hand under the valve cover (near the exhaust manifolds)... if you pick up a lot of oil on your hand, then theres your problem!

[slinger5150]

In my experience, white smoke was usually coolant leaking and burning. Blue smoke was usually oil leaking and burning. If the valve cover gaskets are leaking, I'd expect blue smoke burning off the exhaust manifolds. I'm not a professional mechanic though, so I could be wrong.