IS220D Inlet Manifold Cleaning


Removal of Inlet Manifold for Cleaning (Carbon Deposits)

I posted this a while back but I forgot to post in this section. I've added a few photos at the bottom as well. 


First off, I am not a mechanic so my terminology may annoy some of you!

I did this as i was getting a lack of power at about 2500revs mainly in higher gears. It has improved dramatically. Fuel efficiency seems to have improved but only slightly so I can't say for sure. 

For this guide, I refer to right and left as you stand at the front of the vehicle looking into the engine. I know this is not the norm so apologies if confusing. Front refers to the front of the car as standard.

Also, the elec. connectors are the biggest pain in the &%$£. Trying to squeeze the clip and pull at the same time is so difficult as they are usually well stuck in place being nine years old! Don’t give up!


Job time – 10 hours over two days (I didn’t have a guide so hopefully you will do it faster – it would take me about 6 hours if I did it again)


Set up tools, bench, laptop, etc. (1 hour)

Disassembly (5 hours)

Cleaning (2 hours)

Reassembly (2 hours)


Basic tools are required but just having a good socket set is very important. Not necessary to jack up vehicle but would help. I drove the front wheels up on 3inch blocks.


This is the order I did it in, you may want to do it a little differently. I include headings for the most part but in general this order worked well.


Here we go!...




Remove primary engine cover

Remove RH engine cover

Remove LH engine cover

Remove front engine cover

Remove under engine covers (x2)




Disconnect battery terminals

Remove battery horizontal support brace

Disconnect the electrical connection on the LH side of the battery cover

Remove battery cover

Remove battery

Remove base cover of battery

Remove battery vertical support brace

Remove control module under battery (x3 bolts – long one goes on RH side)

Disconnect 3 elec. connectors on control module

Remove bottom battery case (x3 bolts)




Remove EGR pipe and gaskets

Disconnect EGR elec. connector

Remove EGR valve




Open radiator cap and drain ***** (have bucket ready to take ~5 litres)

Drain fluid

Remove air intake duct above radiator

Disconnect inlet and outlet pipes of radiator fluid reservoir tank

Remove reservoir tank




Disconnect fuse box wire harness clips (x2)

Disconnect common rail front end elec. connector

Disconnect common rail fuel supply hose

Disconnect common rail rear end elec. connector

Remove wire harness support bolts (x2)




Disconnect EGR valve rear end elec. connector

Remove five wire harness clips (red arrows)

Remove harness support (green arrow)

Remove sponge adjacent to EGR valve

Lexus 01.png




Remove bolts (x3) on water pipe (blue arrow) below EGR assembly

Remove clip at front end of pipe and slide hose off

Remove vacuum hose (small) from water pipe (underneath)

Remove elec. connector under vacuum hose & remove clip also (hard to see but you’ll know it has to be disconnected)

Push hose assembly out of the way – towards battery area (no need to fully disconnect)

Lexus 02.png


Air Flow (Throttle) Assembly:-


Disconnect three elec. connectors on air flow unit

Remove bolt on air flow unit

Lexus 03.png


Common Rail:-


Remove common rail bolt (x2)

Remove common rail fuel lines

Protect (tissue) the common rail connectors & ports

Remove common rail and keep clean


Inlet Manifold:


Disconnect vacuum hose from inlet manifold

Remove inlet manifold upper stay bolt (it’s a vertical support that can be hard to see)

Remove air flow pipe to inlet manifold (1 clip also) (difficult to remove for me but keep twisting and pulling – there is a lip to overcome)

Loosen inlet manifold lower stay nut (very difficult to access – hard to even see. This was the most awkward part of the whole job. You should really disconnect for easier access but it would be impossible to get it back on – loosening and pushing it aside was fine for me) See diagram below.

Remove bolts (~x9) on intake manifold

Remove intake manifold

Lexus 04.png




Clean inlet manifold – I used a power hose, carburettor cleaner, screwdriver for scraping & kitchen paper.

Clean inlet ports – as above but I used a hoover continuously to prevent as much carbon as possible entering the valves/cylinders


Reinstall in reverse – much easier than disassembly!


Prime the fuel system. 



Photo 1 - Inlet ports exposed after inlet manifold clean. Of the four ports showing, the first has been cleaned mostly, the second is as found, and the third and fourth have some cleaning done. Highly recommend using a hoover if scraping any carbon from here. Otherwise just coat with carburetor cleaner and wipe away with a cloth.


Photo 2 - Inlet manifold removed. Condition hard to see but constriction increases further into the ports. 


Photo 3 - Inlet ports - two untouched and two partially cleared. 


 Report this tutorial


On 6/6/2017 at 5:13 PM, Monocle said:

Looks like a good way to go! But I don't have a blow torch or compressed air handy!:smile:

i cleaned the manifold myself this week i found super effective way to clean it . OVEN CLEANER   cheap one from pound shop 1£ a can  just fill it with the foam,  wait 5-10 mins and just power wash it  comes up like a brand new no scraping with screw driver or anything similar

if its cloged really bad then  repeat just over and over till you are happy with results. i had realy bad one but 3 times left it allmost as new. really saved me allot of time.

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Will try that next time. Don't fancy taking it off again for a good while!

Did you ever take off the exhaust manifold? I presume temperatures are high enough that the carbon build up should be nil and not worth doing???

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