NS Paj - best method to clean intake?

[Aspiro]

Pretty sure that my vehicle is overdue for an intake clean and am looking for advice on which way to go.

I doubt that my vehicle - with just over 200,000 km on it - has ever had an intake clean, but guessing that it hasn't. Its performance has dropped off as I now need to take some hills in 3rd gear rather than 4th. My mechanic noticed that the intake had a lot of gunk in it and recommended that it be dismantled and cleaned properly.

I'm aware of companies that do a in-situ clean by spraying chemical into the intake with the engine running. They claim that this method also cleans further into the engine than a mechanical clean.

What are the pros and cons of each method and would a chemical clean be successful if (after 200,000 km) the intake is severely clogged?

Cheers

[crispus]

You have here a good experiment: https://www.youtube.com/watch?v=gcP5...F9aW9f&index=2
That shows that decarb sprays aren't good when you have a clogged intake.

A pretty good how to is this (there are multiple episodes):

[DibbyDibbyDJ]

Removal and cleaning is the only way to go. You dont want all that carbon going into your cylinders and possibly getting stuck on a valve seat, gumming up a ring, blocking your cat or DPF.

[Jasonmc73]

The "best method", when you have your valves done, do it then, if you have someone do your valves & not yourself?

The injector pipes & top section will be off.

Remove lower section & mechanical clean.

I think that would be the "best time" to do it/ have it done.

[erad]

Those videos 3 posts above are really useful. Well done to the guys who made them.

[Aspiro]

You have here a good experiment: https://www.youtube.com/watch?v=gcP5...F9aW9f&index=2
That shows that decarb sprays aren't good when you have a clogged intake.

A pretty good how to is this (there are multiple episodes):

Thanks very much Crispus - great videos all round, and I'm now convinced that this is the best way to do a clean.

[Aspiro]

The "best method", when you have your valves done, do it then, if you have someone do your valves & not yourself?

The injector pipes & top section will be off.

Remove lower section & mechanical clean.

I think that would be the "best time" to do it/ have it done.

Thanks Jason. When you refer to having the valves 'done', do you mean valve clearances adjusted, or valves cleaned or re-seated or something else?

[Aspiro]

Removal and cleaning is the only way to go. You dont want all that carbon going into your cylinders and possibly getting stuck on a valve seat, gumming up a ring, blocking your cat or DPF.

Thanks DibbyDibbyDJ - appreciate the feedback.

[Jasonmc73]

Thanks Jason. When you refer to having the valves 'done', do you mean valve clearances adjusted, or valves cleaned or re-seated or something else?

Yes mate clearances, they are an "extended" routine maintenance.

No valve cleans required.

I think some people get a bit carried away about intake blockages my self.
Is it actually hurting the engine
Looks terrible i know that.

Early years i'm not sure but i wonder if the turbo will boost enough pressure to feed the combustion enough oxygen to make a fine fire & you wouldn't even know?

Don't get me wrong i drove A Nissan Navara & she use to belch black smoke big time up hills under load like a mozzie fogger . I'm not exagerating.
Worse older it got.
I suspect over the years the inter cooler & intake were possibly quite blocked, which became evident more so under load as the years passed.
Tailgate of the ute use to become greasy like black from the exhaust.
Cut & polish to remove it, horrible black film on paint.

Pro longing requirements to clean manifold or maybe never have to says fit catch can & or get rid of/ switch it off that other little fella EGR.

[Aspiro]

Yes mate clearances, they are an "extended" routine maintenance.

No valve cleans required.

I think some people get a bit carried away about intake blockages my self.
Is it actually hurting the engine
Looks terrible i know that.

Early years i'm not sure but i wonder if the turbo will boost enough pressure to feed the combustion enough oxygen to make a fine fire & you wouldn't even know?

Don't get me wrong i drove A Nissan Navara & she use to belch black smoke big time up hills under load like a mozzie fogger . I'm not exagerating.
Worse older it got.
I suspect over the years the inter cooler & intake were possibly quite blocked, which became evident more so under load as the years passed.
Tailgate of the ute use to become greasy like black from the exhaust.
Cut & polish to remove it, horrible black film on paint.

Pro longing requirements to clean manifold or maybe never have to says fit catch can & or get rid of/ switch it off that other little fella EGR.

Thanks for clarifying that Jason.

[Scooby]

Yes mate clearances, they are an "extended" routine maintenance.

No valve cleans required.

I think some people get a bit carried away about intake blockages my self.
Is it actually hurting the engine
Looks terrible i know that.

Early years i'm not sure but i wonder if the turbo will boost enough pressure to feed the combustion enough oxygen to make a fine fire & you wouldn't even know?

Don't get me wrong i drove A Nissan Navara & she use to belch black smoke big time up hills under load like a mozzie fogger . I'm not exagerating.
Worse older it got.
I suspect over the years the inter cooler & intake were possibly quite blocked, which became evident more so under load as the years passed.
Tailgate of the ute use to become greasy like black from the exhaust.
Cut & polish to remove it, horrible black film on paint.

Pro longing requirements to clean manifold or maybe never have to says fit catch can & or get rid of/ switch it off that other little fella EGR.

In general inlet restrictions will effect engine performance and fuel consumption.
A turbo will only help if it is on boost, but pressure is a result of restriction to flow so if the inlet ports/ manifold are blocked and the MAP sensor is located well before this (as on the Pajero) it will see a higher reading than what is actually getting into the combustion chamber and the engine will get more fuel according to the ECU programming which would be a rich mixture so more fuel being burnt, which could give the same power, so you don’t notice a performance drop just increased fuel consumption.
At low engine loads restriction will cause lag and increase fuel consumption as you have to add more throttle.

Depending on the restriction and time taken to form the restriction, you may not notice an increase in fuel use and throttle input increase required to maintain the same performance from the vehicle.

I suspect that the 3.2 has a fair amount of extra capacity. When I cleaned the manifold on my NW it had about 3mm build up of gunk in the manifold and in the head inlet ports, so that equates to 6mm diameter restriction. I am not sure if I could feel any difference between before and after cleaning, but am happy I cleaned it as large sections of the crud had looked like it was falling off the walls of the intake manifold and could have only gone through the engine.

I had been trialling a EGR resistor for 20000kms with no catch can so the gunk was very oily and soft. This made cleaning the manifold and head ports easy, basically water pressure cleaned the manifold clean and blew the intake ports out with compressed air and brake clean. I only had to scrap a couple of spots. I am now fitting a catch can.

[Jasonmc73]

In general inlet restrictions will effect engine performance and fuel consumption.
A turbo will only help if it is on boost, but pressure is a result of restriction to flow so if the inlet ports/ manifold are blocked and the MAP sensor is located well before this (as on the Pajero) it will see a higher reading than what is actually getting into the combustion chamber and the engine will get more fuel according to the ECU programming which would be a rich mixture so more fuel being burnt, which could give the same power, so you don’t notice a performance drop just increased fuel consumption.
At low engine loads restriction will cause lag and increase fuel consumption as you have to add more throttle.

Depending on the restriction and time taken to form the restriction, you may not notice an increase in fuel use and throttle input increase required to maintain the same performance from the vehicle.

I suspect that the 3.2 has a fair amount of extra capacity. When I cleaned the manifold on my NW it had about 3mm build up of gunk in the manifold and in the head inlet ports, so that equates to 6mm diameter restriction. I am not sure if I could feel any difference between before and after cleaning, but am happy I cleaned it as large sections of the crud had looked like it was falling off the walls of the intake manifold and could have only gone through the engine.

I had been trialling a EGR resistor for 20000kms with no catch can so the gunk was very oily and soft. This made cleaning the manifold and head ports easy, basically water pressure cleaned the manifold clean and blew the intake ports out with compressed air and brake clean. I only had to scrap a couple of spots. I am now fitting a catch can.

Your a legend writing that & thanks, i am now more educated.
Was giving me a headache so thanks
It makes total sense, sensor would see more pressure if manifold is actually restricted, more unburnt fuel, belch black smoke under load if real restricted i think?
More pressure inlet side of manifold & less on outlet side, ecu feeding fuel on inlet readings & throttle position.
Light bulb moment for me

[redbruce]

Check out Mr Pajero's (Runs Pajero specialist workshop in Perth) youtube videos on intake clean.
https://www.youtube.com/channel/UCEk...zREQjefnaCQ8Ew

[Aspiro]

Check out Mr Pajero's (Runs Pajero specialist workshop in Perth) youtube videos on intake clean.
https://www.youtube.com/channel/UCEk...zREQjefnaCQ8Ew

Thanks redbruce - that's the same series as was linked in post #2 - I watched all six episodes and learned quite a bit - they are very descriptive and show a lot of detail.
Cheers

[NSGaz]

Does anyone know if Mr Pajero provides this service to the general public? and if so any ideas on what he would charge to do the clean?