[BluStang6]

Ok i have been to three different shops and nobody can fix my car. I have a 00 auto v6 with straight back duals and the denscharger ful length intake. After the car is warmed up it makes this knocking sound when I accelerate. It is not detonation but has suomthig to do with carbon build up. One place replaced the EGR valve (whatever that is) and it was fixed for about 3 days but then came back. Also when I start the car smoke comes out the left tailpipe and it stinks. If anybody knows what the hell is wrong with my car any help would be appreciated. Thanks!

 

[Brent]

is it white smoke or dark smoke? White smoke you might be leaking oil into somewhere your not suppose to be.... somewhere in the left side of the block maybe?

Not an engine tech but just my .02

 

[Danger Dude]

Ok you have to look at the problem Knocking under acceleration. Fuel/ Air and timing would be the culprit if the EGR was replaced. if your right cats are plugged you will have no flow in that side of the motor over rich condition causing a fuel burn problem but not usually a knock unless the fuel is is puddling in the cylinder and igniting. Possible fuel starvation from clogged fuel filter or fuel pump dying causing lean condition and detonation. very dangerous if this is happening. Could have a faulty ignition system and is causing the detonation cause the timing is off.

you need to get it to a qualified service center that has state of the art diagnostic equipment.

What is the closest big city to where you libve in TX someone on the forum might direct you to a good place to go

 

[Dom]

is it white smoke or dark smoke? White smoke you might be leaking oil into somewhere your not suppose to be.... somewhere in the left side of the block maybe?

Not an engine tech but just my .02

Blue Smoke - Burning Oil
Black Smoke - Rich Condition (Good Kind )

 

[Rick0636]

No, what you want is stochiometric, neither rich or lean, but correct air fuel mixture, either too rich or too lean is bad.

 

[stangin99]

well your both, kinda, wrong.

Stoich A/F ratio is like 14.7 isnt it? Most tuners will tune a car for high 12s into the mid 13s for optimal performance A/F ratio.

So techinically, you want to be slightly rich, but not so much that you make black smoke. Grey smoke is good, white is very bad and black is a sign of being rich(can be bad sometimes)

 

[BluStang6]

It is White smoke and I live in FLower MOund. It is in Denton and near Dallas. Thanks

 

[Brent]

yikes

that sounds like a head gasket problem

 

[Dom]

well your both, kinda, wrong.

Stoich A/F ratio is like 14.7 isnt it? Most tuners will tune a car for high 12s into the mid 13s for optimal performance A/F ratio.

So techinically, you want to be slightly rich, but not so much that you make black smoke. Grey smoke is good, white is very bad and black is a sign of being rich(can be bad sometimes)

Did you see Trucks on Spike when he tuned that disel and when he launched it, it blew back smoke out like you wouldn't believe.

 

[stangin99]

deisel smoke is different from gasoline smoke

 

[Dom]

I know that. My dad works around them. I've even been in the yard when a tractor came in and the supercharger blew up.

I brougt up another topic.

 

[Brent]

yikes

that sounds like a head gasket problem

So am I in the ballpark stangin99?

 

[Danger Dude]

It could be a head problem but the knock is troublesome. Typically in a head gasket problem the car acts up more at idle and runs better under acceleration. This car is doing the opposite. Something more is going on !!!!!!

 

[232SCstang]

Did you buy the car new? If you did see what the dealership has to say about it if the car is still under warrenty. Otherwise maybe you spun a bearing. But that wouldn't explain the smoke. My friends dad has a 1994 Thunderbird with the 3.8 and when you start the car in the morning and it idles up as normal, it gives this god awful knocking/rattling sound. When ur driving around and under acceleration, sometimes it does it, and sometimes it doesnt. I dont get it. Maybe you have the same problem.

 

[ASSEMbler]

I'd yank off any modded parts on the intake and see if that fixes it.

 

[stangin99]

I know that. My dad works around them. I've even been in the yard when a tractor came in and the supercharger blew up.

I brougt up another topic.

they use superchargers? I always thought they used huge ass turbos...hmm


Brent, could be. I haven't had the luxury of having a head gasket problem yet (I just destroy my heads ) so Im not 100% sure how white the exhaust smoke has to be to indicate a head gasket problem.

Your best bet is to start testing the engine. Look for anything metal that might be bouncing on the engine bay walls, my CAI bounces on my strut tower and makes a thump.

Do a compression test, look at your oil/coolant for starters.

 

[Danger Dude]

People often confuse white smoke with steam when you blow a head gasket water vapor comes out most of the time

 

[Rellik]

People often confuse white smoke with steam when you blow a head gasket water vapor comes out most of the time

The last time I blew a head gasket... the Gasket blew between cly 4 and 5, then out the side of the gasket to the outside (BTW, this was on my 66 I6 Stang). But I didnt have ANY abnormal exhaust colors.

 

[Danger Dude]

You are right a small blow between just 2 cylinders will put out minimal vapor. I had a nissan Stanza that when the headgasket blew it look like a steam engine letting off presure. It happened in traffic and as I looked behind in the rear view all the cars behind me dissappeared in a misty cloud. It took a while to get home The car was using about 2 gals of water a mile hehehhehhehe

 

[Ponycarman]

Maximum power occurs with a slightly lean mixture. Tuners tune for a bit richer than optimal to prevent failure of the engine. If you go too lean the engine starts to burn itself, essentially, causeing the engine to failure, usually a piston. Keeping it richer than optimal ensures enough fuel to prevent this failure.

Steve