Hi

 

Dunno if this is normal but each time I come to clean me Zed (weekly) the insides of the exhausts (mongoose quads) are black with soot/carbon - is this normal? Its been de-catted if thats relevant.

 

I'm going to get some proper cleaning stuff for it as scrubbing it was v tiring on the old arms :rolleyes: . What cleaning fluids do people use?

 

Cheers

 

Pete

Sounds like you're running rich (bear in mind I know nothing). My exhausts (stainless too) stay soot-free for much longer than a week... the only time they blacked up like that was when my fuel filter needed a good changing ;)

I've got a Mongoose on my 200Sx, and it gets VERY sooty. Don't know if it's running rich tho' :confused:

Heh, I know nothing, so don't take me seriously. Plus mine's an NA, and I know even less than nothing about turbos :S Perhaps this is something turbos *do*... :confused:

 

My point is that I don't think it should get sooty that quickly, and that it's a sign of non-optimal combustion, too much fuel, or something, surely...? But, Nelson, I know you know more than me ;) so I'm certainly happy to be corrected. I was just sticking my two-pennorth in before anyone else got to the topic, that's all :P hehe

Cheers for the replies, will look at service history to see when fuel filter was last changed, can be that long ago though.

 

What's the best stuff to make it shiny again?

 

Thanks :D

 

Pete

I used anything I could to clean mine. LOL

 

Autogylm metal polish at first before it ran out, and then autoglym paint renovator. :D

 

 

 

The pic is after 2 hours of cleaning. But ones its done, every week, get a cloth and just wipe away the soot. No hard scrubbing needed again.

 

Stuart

Mine certainly get a bit grubby after a couple of weeks. Will always be worse with short journeys, cold weather etc.

 

Autosol, made by Solvol is what I use.

My ones are really sooty after a few days though. Like I never cleaned them.

 

There is no way to find out if your O2 sensors are playing up. The ECU only tells you if they are at total failure.

 

Has any one on here ever changed the O2 sensors? Did they find anything different after?

 

Stuart

Pete,

 

Zedworld mention sooty pipes in their 'Hints & Tips' section, number 5. They say it can sometimes be air filter or O2 sensor. They say go for an ECU check, or failing that an emissions check at a local MOT station.

Yes- AUTOSOL is excellent. And if you have any scatches on your watch-this stuff will make the face like brand new again!!

Originally posted by konrad

Pete,

 

Zedworld mention sooty pipes in their 'Hints & Tips' section, number 5. They say it can sometimes be air filter or O2 sensor. They say go for an ECU check, or failing that an emissions check at a local MOT station.

 

My ECU said all sensors are working fine. But it only detect total failure and not funny readings.

 

I have a new APEX'i induction kit so its starting to sound like the O2 sensors.

 

Never mind!

 

Stuart

Originally posted by SRRAE

Has any one on here ever changed the O2 sensors? Did they find anything different after?

 

I seem to recall that AndyP changed his when his mpg dropped from 20-odd to 17 or so.. And his mpg went back up again after he'd changed them.

 

I changed mine a while back, and I'm fairly sure that my motorway mpg went from about 18-19mpg to 25-28mpg on an easy run (round town it's still terrible, of course :D)..

You're right, the basic ECU test only tells you whether they're completed dead. You need a Techtom/Consult/ConZult to suss it out properly and even that can involve a bit of guess work as

they often tend to get lazy before that actually completey fail.

 

I had to replace one of mine and it immediately made a difference to the fuel consumption and the colour of that exhaust.

 

An emissions check will also help to diagnose the problem, but that doesn't always make the cause obvious.

 

 

Originally posted by SRRAE

My ones are really sooty after a few days though. Like I never cleaned them.

 

There is no way to find out if your O2 sensors are playing up. The ECU only tells you if they are at total failure.

 

Has any one on here ever changed the O2 sensors? Did they find anything different after?

 

Stuart

How much are these O2 sensors? Is it an easy DIY job? It's gotta be worth doing if petrol consumption can go down that much :)

 

Stuart - my pipes looked like that 2 weeks ago, now they are black as the night. Good job mate!

 

I'm spending a week at a Nissan maindealers in a couple of weeks so I'll get some more advise. But they are not touching the car LOL :rolleyes: !

 

Will also check the zedworld site, cheers

 

Pete

You're looking at around £65 ea in the UK. Changing them is a bit of a pig, you really need a special tool, plus arms like a spider monkey. Also helps if the car is an auto (no clutch m/c in the way)

 

Diagnostic info:

http://www.twinturbo.net/ttnetfaq/FAQpages/O2s.html

http://www.aus300zxclub.com/tech/o2.htm

I dont know how much the O2 sensors are. From courtesy they are $8 each I think.

 

They are in a git of a place to get to, but I think snap-on make an O2 sensor tool which makes it easier to take out. They are £30. But it depends on how much a garage would charge to do it.

 

Andy did you replace it yourself?

 

Stuart

Hmmmm might leave it til I get it serviced next :rolleyes: . Sounds more difficult than I'd like to attempt.

 

Pete

$8 they certainly are not - more like $60 I think.

 

I was all set up to do mine, it was even the easy side (passenger), but in the end SE did it at the same time the gearbox was swapped over - dead easy to get to then.

 

 

 

 

Originally posted by SRRAE

I dont know how much the O2 sensors are. From courtesy they are $8 each I think.

 

They are in a git of a place to get to, but I think snap-on make an O2 sensor tool which makes it easier to take out. They are £30. But it depends on how much a garage would charge to do it.

 

Andy did you replace it yourself?

 

Stuart

On more pedestrian cars like Fords or Renaults, the exhaust tail pipe is usually a pale grey colour if the car is in tune. On motorways, it can get quite pale, but town driving makes it go darker. In these cases, if it goes sooty it's either rich or the timing is a few degrees out.Since the Zed engine is covered in sensers, I'd hate to offer an opinion on it. In the perfect world it should not be over sooty. Many years ago, I had a Triumph T.R.5, which was very sooty coupled with poor mpg, and that turned out to be worn injectors.

Regards

 

Stuart S.

Originally posted by AndyP

$8 they certainly are not - more like $60 I think.

 

I was all set up to do mine, it was even the easy side (passenger), but in the end SE did it at the same time the gearbox was swapped over - dead easy to get to then.

 

So they are. I wonder what I was looking at then :S

Are the O2 sensors easier to change than the gear shift bushes ?. Because if they are I'll do it, otherwise I'm going to book mine in for the £30 O2 sensors and the £200 labour LMAO.

Here you go Stuart.

 

£31 for the O2 tool for most Nissans. Most probably work for the 300ZX.

 

I heard they are a git to put in and out if you dont have the right tool. If you do its quite easy.

 

I think 1 side is easy to get to but the other is a little tricky.

 

I may look into it soon, my MPG aint the best and I am deffinatly running rich.

 

Stuart

If the fuel consumption goes down after replacing the oxygen sensors, suggesting that the fuel is being burnt more efficiently (methinks) I guess it should -

 

1. Improve performance

2. Reduse emissions ?

 

Does that sound right ?

Better yet; has anyone noticed it ?

 

cheers !

You can stall an engine by putting too much petrol in it, ever heard of flooding the engine? This is where there is too much petrol in the cylinders and its is too wet for a spark to happen.

 

Same with when driving. If 7% too much petrol is put into the cylinders most probably 5% of that petrol wont burn and will be just blown out the exhaust, so that is a waste. Plus that surplus petrol could hinders the performance of the engine, like how a flooded engine (Petrol flood) wont start.

 

Think of a candle. The wick is like the spark plug and the wax is the fuel. What happens when there is too much hot wax in the top of the candle? The flame get smaller and smaller until the flame goes out.

 

This is just like a engine. Too much petrol can cause the engine not to combust correctly, drowning the spark plug, so that it cant get hot enough, to ignite the whole cylinder.

 

 

I'm crap at explaining things so I am sure some one else will do a better job of it.

 

Stuart

No that makes sense - so changing O2 sensors can reduce fuel consumption and improve performance, and possibly reduce emissions too.

 

Sounds like it's worth me changing them whilst the box is out then !

 

Cheers Stuart !

Originally posted by james300

Yes- AUTOSOL is excellent. And if you have any scatches on your watch-this stuff will make the face like brand new again!!

 

Hear,hear i agree james this stuff is the dogs its bloody MAGIC i swear!!!;)

 

Marc