ZCar Forum banner

Status
Not open for further replies.
1 - 8 of 8 Posts

·
Registered
Joined
·
248 Posts
Discussion Starter #1
1977 280Z with fuel injection with new 3 into 2 headers from MotorSport blows black wet soot out tailpipe upon star up. When the engine is warmed up nothing unusual at the tailpipe.
Coolant levels have been constant for two years.
The wet black mixture does not smell like raw fuel. Is this a sign of something very wrong or is it simply something unique to these Z engines that is not really a problem but more of an annoyance. The Black soot drys and gets on shoes finally finding it's way from the garage floor to the carpet.
Anyone else experience this?
Thanks for your input.
Larry in Nappanee
 

·
Registered
Joined
·
100 Posts
> 1977 280Z with fuel injection with new 3
> into 2 headers from MotorSport blows black
> wet soot out tailpipe upon star up. When the
> engine is warmed up nothing unusual at the
> tailpipe.
> Coolant levels have been constant for two
> years.
> The wet black mixture does not smell like
> raw fuel. Is this a sign of something very
> wrong or is it simply something unique to
> these Z engines that is not really a problem
> but more of an annoyance. The Black soot
> drys and gets on shoes finally finding it's
> way from the garage floor to the carpet.
> Anyone else experience this?
> Thanks for your input.
> Larry in Nappanee

I have the same problem not with my 75 Z but with my 77 camero. Some of it is moist and some dry correct? What I have found out about this problem is that the seals inside the motor are bad. That it is a very expensive operation and is cheaper to just up and replace the motor. How much oil do you go thorough compared to miles driven? Using some is ok but too much means most likely in my expirence is that it is going out your tail pipe ie the black sludge
 

·
Registered
Joined
·
248 Posts
Discussion Starter #3
> I have the same problem not with my 75 Z but
> with my 77 camero. Some of it is moist and
> some dry correct? What I have found out
> about this problem is that the seals inside
> the motor are bad. That it is a very
> expensive operation and is cheaper to just
> up and replace the motor. How much oil do
> you go thorough compared to miles driven?
> Using some is ok but too much means most
> likely in my expirence is that it is going
> out your tail pipe ie the black sludge

No sludge and the car doesn't burn oil. Have changed oil several times in the past two years but have only driven less than 5,000 miles. At each oil change the oil is very clean. Difficult to tell the difference between new and old oil.
Don't know what seals you are refering to, plugs look great.
Thanks for your thoughts.
Lary
 

·
Registered
Joined
·
107,695 Posts
> I have the same problem not with my 75 Z but
> with my 77 camero. Some of it is moist and
> some dry correct? What I have found out
> about this problem is that the seals inside
> the motor are bad. That it is a very
> expensive operation and is cheaper to just
> up and replace the motor. How much oil do
> you go thorough compared to miles driven?
> Using some is ok but too much means most
> likely in my expirence is that it is going
> out your tail pipe ie the black sludge

It is normal to get moisture out of the exhaust, in cold wheather, you can see it condense, looks like steam. I get this too in all of the cars I've owned. Same with the black soot. If you don't burn a lot of oil and the coolant level is ok, then it's not a problem. How much soot do you get. Can someone explain where this moisture comes from? I've always wondered this. In the winter you see the white exhaust coming from every car. Does it have something to do with the catalytic converter? That is my guess.
 

·
Registered
Joined
·
248 Posts
Discussion Starter #5
> It is normal to get moisture out of the
> exhaust, in cold wheather, you can see it
> condense, looks like steam. I get this too
> in all of the cars I've owned. Same with the
> black soot. If you don't burn a lot of oil
> and the coolant level is ok, then it's not a
> problem. How much soot do you get. Can
> someone explain where this moisture comes
> from? I've always wondered this. In the
> winter you see the white exhaust coming from
> every car. Does it have something to do with
> the catalytic converter? That is my guess.

Thanks for your thoughts. Can't be the cata;ytic converter. I pulled all the original exhaust system off when I changed to the headers and twice pipes. Whatx next?
 

·
Registered
Joined
·
863 Posts
> Thanks for your thoughts. Can't be the
> cata;ytic converter. I pulled all the
> original exhaust system off when I changed
> to the headers and twice pipes. Whatx next?
you didn't say if it did this before the swap on the exhaust system,but I have a big block Trans Am and a '79 280zx that both do this, both have headders, high flow mufflers and over size mandrel bemt pipes. once they are warm it goes away, with the better breathing capacity, more heat is pushed back out the tail pipe instead of stuck in the cast iron manifolds, it all cools down faster and allows more condensation of moisture to take place inside the whole system, I know that putting a sock over the tail pipe helps keep the cold moist air from creeping in when you park it. just dont forget to pullit off before you start your next day of driving.
 

·
Registered
Joined
·
107,695 Posts
Nothing to worry about, I've had the motorsport header and turbo exhaust for years attached to a total rebuild 2.8l/E-31 and it's always done it. I think it's slow oxidation of the steel header vs the cast original. Plus the flow thru muffler allows more to escape the system than the stock system
 

·
Registered
Joined
·
107,695 Posts
The moisture in the exhaust is more to do with condensation than anything else. I was told the following:

- If you just make a lot of short trips, the moisture doesn't dry up when the car is shut off as the exhaust hasn't heated up enough to burn it off.

- You can make your exhaust muffler last a lot longer by drilling a small hole (NOT on the underside) but at the base at the tailpipe end. This allows the water/moisture to drain away better and allows the exhaust to dry out faster when the car is shut off.

I have seen water come out the hole before so what else can I say except that it would seem to work...

> you didn't say if it did this before the
> swap on the exhaust system,but I have a big
> block Trans Am and a '79 280zx that both do
> this, both have headders, high flow mufflers
> and over size mandrel bemt pipes. once they
> are warm it goes away, with the better
> breathing capacity, more heat is pushed back
> out the tail pipe instead of stuck in the
> cast iron manifolds, it all cools down
> faster and allows more condensation of
> moisture to take place inside the whole
> system, I know that putting a sock over the
> tail pipe helps keep the cold moist air from
> creeping in when you park it. just dont
> forget to pullit off before you start your
> next day of driving.
 
1 - 8 of 8 Posts
Status
Not open for further replies.
Top