Intake Manifold Cleaning - Liqui Moly

[Blackout]

Hi All,

Just a quick question on this subject which from what I can't find too much on it other than a post about it on a VT V6 going way back.
What is people's best way to clean the intake manifold?

My previous car, VU SS, I would bomb the intake with half a can of liqui moly petrol intake decarb spray & let it sit for 5mins, then let it rip. Then spray the rest of the can in & start up & run/go for a drive.
Within using this product, I have never sprayed into the engine whilst running as per the directions.
Can I ask people's thoughts here or experiences on cleaning the intake?

Thankyou

 

[Fu Manchu]

I can only add that I watched a “Just rolled in” video. Customer had trouble finding “Seafoam” intake cleaner. They used some expanding spray foam instead.

… yeah.

Engine is rooted.

Anyway, I use a vacuum port to spray in on electronic throttle. Idle goes a bit how ya going but gets it done. Just little bursts of the cleaner.

On cable, you can operate the throttle by hand and it’s much easier.

 

[Just Damo]

Would it do it harm if you let it sit in a tub of throttle cleaner or degreaser then hose it out and dry?

 

[Shen Long]

Would it do it harm if you let it sit in a tub of throttle cleaner or degreaser then hose it out and dry?

Just done it to mine since the top 1/2 was out

easier to clean when they’re out/off the engine.

while you’re there, do the PCV Valve correction/mod

P.S.
admittedly, it wasn’t as “dirty” as I thought it would be but I cleaned it any way

 

[Just Damo]

Just done it to mine since the top 1/2 was out

easier to clean when they’re out/off the engine.

while you’re there, do the PCV Valve correction/mod

P.S.
admittedly, it wasn’t as “dirty” as I thought it would be but I cleaned it any way

I did all the PCV mod and added a catch can when I first purchased the car, I read all about the ways to avoid sludging so I did it haha doing the work at work though I didn't have anywhere to soak the manifold or the time really. But I will be stripping the top off the motor in the coming month and freshening it all up.

Want to make it as pristine as I can. From the view of the oil cap though, it should be a pretty clean job already. I just remember looking at the inside of the intake when I removed it and had the goldy brown layer on the inside, always wondered the best way to clean it. But now I know, thank you my man!

 

[vr304]

Hi All,

Just a quick question on this subject which from what I can't find too much on it other than a post about it on a VT V6 going way back.
What is people's best way to clean the intake manifold?

My previous car, VU SS, I would bomb the intake with half a can of liqui moly petrol intake decarb spray & let it sit for 5mins, then let it rip. Then spray the rest of the can in & start up & run/go for a drive.
Within using this product, I have never sprayed into the engine whilst running as per the directions.
Can I ask people's thoughts here or experiences on cleaning the intake?

Thankyou

Definitely no harm in running the engine while you spray it in as you said that’s the way it’s meant to be done as per the instructions, it will be a lot more effective than just spraying into the intake with the engine off

 

[Shen Long]

I did all the PCV mod and added a catch can when I first purchased the car, I read all about the ways to avoid sludging so I did it haha doing the work at work though I didn't have anywhere to soak the manifold or the time really. But I will be stripping the top off the motor in the coming month and freshening it all up.

Want to make it as pristine as I can. From the view of the oil cap though, it should be a pretty clean job already. I just remember looking at the inside of the intake when I removed it and had the goldy brown layer on the inside, always wondered the best way to clean it. But now I know, thank you my man!

i had the same goldy brown colour (lightish not dark)

That being said, thats normal deposit(s) for an inlet manifold.

I turned my manifold upside down (blocked all the ports etc) & pre-soaked it with diesel for 3 days

after that used degreaser or throttle body cleaner (cant remember which)

The finish product wasnt much different from what it was but i was content that i did all that i could

P.S.
ill be doing the catch can upgrade soon enough.....
1 dole cheque at a time

 

[Just Damo]

i had the same goldy brown colour (lightish not dark)

That being said, thats normal deposit(s) for an inlet manifold.

I turned my manifold upside down (blocked all the ports etc) & pre-soaked it with diesel for 3 days

after that used degreaser or throttle body cleaner (cant remember which)

The finish product wasnt much different from what it was but i was content that i did all that i could

Yea its nothing concerning on mine, but more of a may as well job since I will have the car apart for a week (hopefully no longer)

Gives me confidence since I now know it can be done that way. How did you go about cleaning the rockers out?

I am guessing same sort of treatment for the covers, just soak them? Just unsure on how I would clean some of the sludge if there is any.

 

[Shen Long]

Yea its nothing concerning on mine, but more of a may as well job since I will have the car apart for a week (hopefully no longer)

Gives me confidence since I now know it can be done that way. How did you go about cleaning the rockers out?

I am guessing same sort of treatment for the covers, just soak them? Just unsure on how I would clean some of the sludge if there is any.

Didn’t clean the rockers…

do 3 x oil changes (normal or slightly before normal intervals)

use Liqui-Moly engine flush (or diesel if you’re cheap like me 500ml - 1L)
run engine for 3-5 mins then flush engine oil/diesel mixture

by the 3rd oil change the internals should be shiny again.

you can see any progress to engine internals by the colour of the engine oil coming out at service time.

if the engine oil looks like engine oil then you’re on the right track…

if the engine oil still looks blackish, then do a few more rounds.

I prefer to use a cheap mineral based oil (Gulf Western or what ever is on special) until I’m happy with my effort(s)

then swap over to a semi or fully synthetic type oil.

 

[Just Damo]

Didn’t clean the rockers…

do 3 x oil changes (normal or slightly before normal intervals)

use Liqui-Moly engine flush (or diesel if you’re cheap like me 500ml - 1L)
run engine for 3-5 mins then flush engine oil/diesel mixture

by the 3rd oil change the internals should be shiny again.

you can see any progress to engine internals by the colour of the engine oil coming out at service time.

if the engine oil looks like engine oil then you’re on the right track…

if the engine oil still looks blackish, then do a few more rounds.

I prefer to use a cheap mineral based oil until I’m happy with my effort(s)

then swap over to a semi or fully synthetic type oil.

I may already be in the clear then. When I purchased the car I got a full service done just so I had that up my sleeve. Dropped the oil after 8k kms and wasn't much darker than what was going in. That was with using the engine flush too, so must be pretty clean in there as is. only has 90 thou on the odo


I will do the work and see how its all looking inside, if it needs it, I will use your methods to get her shiny.