Throttle Body Clean

[Commodus]

Have to admit it’s been over 20 years since I worked at a dealership and electronic throttles wre not part of the system. Has anyone performed a throttle body clean on their JT? I did clean the best I could with the engine off but not sure how to perform while running and not create a check engine light, even not running I got a service stop/start system I figured due to extended cranking but it cleared on second start up. Any tips would be appreciated

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[Maximus Gladius]

I did a throttle body clean on the first and second engine. I did mine with the engine off and took the body right off. 4 simple bolts to undue on the corners of the unit, take off the intake tube and it comes right off. It’s the easiest job ever and it doesn’t trigger any engine lights.

 

[ShadowsPapa]

The 4.0 had a throttle body - albeit it was a cable operated throttle with a sensor and not driven by a motor.
Of all of the 4.0s I've owned- I've never cleaned the throttle body as - well, I never saw a need.
Carburetor throttles get far dirtier and gunked up with gasoline gum and I've cleaned carb butterflies, but never bothered to clean a throttle body.

What's the purpose of keeping a round metal disk spotless?
Maybe I should pull the intake and clear and clean all the runners since that's exposed to the intake valves and any push-back from valve overlap.

I suppose if the shaft gets sticky it won't move freely, but that would be noticed.

 

[ChrisNLA]

The 4.0 had a throttle body - albeit it was a cable operated throttle with a sensor and not driven by a motor.
Of all of the 4.0s I've owned- I've never cleaned the throttle body as - well, I never saw a need.
Carburetor throttles get far dirtier and gunked up with gasoline gum and I've cleaned carb butterflies, but never bothered to clean a throttle body.

What's the purpose of keeping a round metal disk spotless?
Maybe I should pull the intake and clear and clean all the runners since that's exposed to the intake valves and any push-back from valve overlap.

I suppose if the shaft gets sticky it won't move freely, but that would be noticed.

So - I've never cleaned a throttle body until my mothers 2006 Chevy Equinox - and boy did it make a hell of a difference.

At some point several years ago it started becoming hard to start. You'd have to turn the key then give the gas pedal a tap to make it start. Otherwise it would start, stumble, and immediately die - or take several attempts. We never messed with it because otherwise it ran fine and we knew the trick to start it right up (also - call it laziness or whatever).

A month ago I said the heck with it - everything else is fixed on it right now so lets go after that pesky starting issue. A quick Google search said it was a semi-common issues on a 3.4L Equinox and cleaning the TB would fix it.

Ain't no way. Pulled off the TB - it was CAKED with gunk behind the blade. Spent twenty minutes scrubbing it with a brush and put it back in.

It starts like brand new now, no lie

The reason I theorized it was such an impact on the Equinox is that like all vehicles, the PCV system grabs oil and throws it back into the intake tract. This does cause oil residue to build up. My 5.3L LS intake was full of oil when I did the knock sensors, and the TB on it had residue. But this was different.

The 2006 Equinox has an EGR valve and it pulls hot exhaust gases into the intake directly behind the throttle body. Like an inch away. So now hot exhaust soot is coming in, along with the existing oil from the PCV system and is now BAKING all of this mess into the back of the throttle body. This hard baked on mess from this perfect storm built up to the point that an appropriate amount of 'idle air' couldn't freely flow past the blade and this mountain of crap inside the TB.

My best guess, anyway.

 

[ShadowsPapa]

So - I've never cleaned a throttle body until my mothers 2006 Chevy Equinox - and boy did it make a hell of a difference.

At some point several years ago it started becoming hard to start. You'd have to turn the key then give the gas pedal a tap to make it start. Otherwise it would start, stumble, and immediately die - or take several attempts. We never messed with it because otherwise it ran fine and we knew the trick to start it right up (also - call it laziness or whatever).

A month ago I said the heck with it - everything else is fixed on it right now so lets go after that pesky starting issue. A quick Google search said it was a semi-common issues on a 3.4L Equinox and cleaning the TB would fix it.

Ain't no way. Pulled off the TB - it was CAKED with gunk behind the blade. Spent twenty minutes scrubbing it with a brush and put it back in.

It starts like brand new now, no lie

The reason I theorized it was such an impact on the Equinox is that like all vehicles, the PCV system grabs oil and throws it back into the intake tract. This does cause oil residue to build up. My 5.3L LS intake was full of oil when I did the knock sensors, and the TB on it had residue. But this was different.

The 2006 Equinox has an EGR valve and it pulls hot exhaust gases into the intake directly behind the throttle body. Like an inch away. So now hot exhaust soot is coming in, along with the existing oil from the PCV system and is now BAKING all of this mess into the back of the throttle body. This hard baked on mess from this perfect storm built up to the point that an appropriate amount of 'idle air' couldn't freely flow past the blade and this mountain of crap inside the TB.

My best guess, anyway.

A lot depends on where things go into the intake - EGR and PCV for example.
I've never seen oil in mine that is any concern. In fact, when I check the oil, it's never down.
My 3.6s haven't seemed to have any PCV issues. I don't see excess oil and mine looks pretty decent when I pull the tube off for cleaning up the engine or doing wiring, etc.
If something enters right behind the throttle plate and cakes it up or makes it stick, I can see that - but mine have always looked pretty normal, and never any starting or running issues.
My 4.0 starts and runs like a champ - I cleaned the throttle body on it when I rebuilt the engine at 100,000 miles but it was only a dark carbon on it, not sticky or gummy.
It's still very clean at about 35,000 miles since the rebuild.
I'm not concerned about a little bit of black.

This, for example, I won't clean for that - not a concern to me. It's not sticky, not making the throttle movement uneven and no impact on flow.

I can see cleaning sensors or if there's a problem with smooth movement, but otherwise, I wonder - why?
What am I missing?

 

[Commodus]

So - I've never cleaned a throttle body until my mothers 2006 Chevy Equinox - and boy did it make a hell of a difference.

At some point several years ago it started becoming hard to start. You'd have to turn the key then give the gas pedal a tap to make it start. Otherwise it would start, stumble, and immediately die - or take several attempts. We never messed with it because otherwise it ran fine and we knew the trick to start it right up (also - call it laziness or whatever).

A month ago I said the heck with it - everything else is fixed on it right now so lets go after that pesky starting issue. A quick Google search said it was a semi-common issues on a 3.4L Equinox and cleaning the TB would fix it.

Ain't no way. Pulled off the TB - it was CAKED with gunk behind the blade. Spent twenty minutes scrubbing it with a brush and put it back in.

It starts like brand new now, no lie

The reason I theorized it was such an impact on the Equinox is that like all vehicles, the PCV system grabs oil and throws it back into the intake tract. This does cause oil residue to build up. My 5.3L LS intake was full of oil when I did the knock sensors, and the TB on it had residue. But this was different.

The 2006 Equinox has an EGR valve and it pulls hot exhaust gases into the intake directly behind the throttle body. Like an inch away. So now hot exhaust soot is coming in, along with the existing oil from the PCV system and is now BAKING all of this mess into the back of the throttle body. This hard baked on mess from this perfect storm built up to the point that an appropriate amount of 'idle air' couldn't freely flow past the blade and this mountain of crap inside the TB.

My best guess, anyway.

The 4.0 had a throttle body - albeit it was a cable operated throttle with a sensor and not driven by a motor.
Of all of the 4.0s I've owned- I've never cleaned the throttle body as - well, I never saw a need.
Carburetor throttles get far dirtier and gunked up with gasoline gum and I've cleaned carb butterflies, but never bothered to clean a throttle body.

What's the purpose of keeping a round metal disk spotless?
Maybe I should pull the intake and clear and clean all the runners since that's exposed to the intake valves and any push-back from valve overlap.

I suppose if the shaft gets sticky it won't move freely, but that would be noticed.

if you had any 4 liter with any miles and never cleaned and never had a idle problem your vehicles were very rare indeed. If the throttle bore behind the throttle plate and cold air intake above the throttle plate weren’t kept cold start up and idle was a real problem

 

[ShadowsPapa]

if you had any 4 liter with any miles and never cleaned and never had a idle problem your vehicles were very rare indeed. If the throttle bore behind the throttle plate and cold air intake above the throttle plate weren’t kept cold start up and idle was a real problem

My last Jeep with a 4.0 had 127,000 miles on it. I know my father never had anything like that done, and it was doubtful anyone did that as regular maintenance.
Can't recall what my first 4.0 had on it but then it was a RENIX system back then.
I've had several others in between.

Idle would only be a problem if there were air flow restrictions. It's a very simple device.
Not sure why cold starting would be a problem, or idle, unless it was actually building up to the point of disrupting air flow.

I've never had an idle problem, never cleaned a throttle body other than like I said - 100,000 miles when I rebuilt the engine for my SX4 - it's now got about 35,000 miles on it (and I didn't really make the throttle body spotless - just used carburetor cleaner on it)
It idles perfectly and starts any time I want.
We're talking air flowing past a disk so unless there's something causing the air flow to not match what the PCM is expecting..........

 

[ChrisNLA]

A lot depends on where things go into the intake - EGR and PCV for example.
I've never seen oil in mine that is any concern. In fact, when I check the oil, it's never down.
My 3.6s haven't seemed to have any PCV issues. I don't see excess oil and mine looks pretty decent when I pull the tube off for cleaning up the engine or doing wiring, etc.
If something enters right behind the throttle plate and cakes it up or makes it stick, I can see that - but mine have always looked pretty normal, and never any starting or running issues.
My 4.0 starts and runs like a champ - I cleaned the throttle body on it when I rebuilt the engine at 100,000 miles but it was only a dark carbon on it, not sticky or gummy.
It's still very clean at about 35,000 miles since the rebuild.
I'm not concerned about a little bit of black.

This, for example, I won't clean for that - not a concern to me. It's not sticky, not making the throttle movement uneven and no impact on flow.

I can see cleaning sensors or if there's a problem with smooth movement, but otherwise, I wonder - why?
What am I missing?

For sure. I've never had any cause for cleaning a TB outside of this one car. That's why I thought it was so wild that it made a dramatic difference.

 

[ShadowsPapa]

For sure. I've never had any cause for cleaning a TB outside of this one car. That's why I thought it was so wild that it made a dramatic difference.

I have seen people have issues with Chevy engines and oil through the PCV........ but that's their current V8 line-up and likely due to the DI design.
Not sure where EGR, PCV and other things line up in the Equinox - or if there are sensors there or whatever.
I suspect a lot depends on the design.

 

[Minty JL]

Simple process as explained above.....a clean TB is a happy TB.

I know on the GM side of the house having a clean MAF is also key

 

[ShadowsPapa]

Simple process as explained above.....a clean TB is a happy TB.

I know on the GM side of the house having a clean MAF is also key

I suspect the key is that in the process, it's not that throttle butterfly that's making a difference, it's the other cleaning being done. That butterfly won't have any impact one way or another if there's traces of carbon on it. All it does is throttle the air going in. Other sensors decide how much air should be coming in based on the position of that butterfly/disk, MAP/MAF and so on.
The butterfly plate itself is of little consequence until or unless there's enough buildup to disrupt air flow.

Here are examples from my current vehicles. I didn't take pics of another 4.0 I have next to my shop I'm salvaging for other uses - it's got probably 100,000 miles on it and the thing looks similar to the one in my own car.
First, the 4.0 in my SX4 - an engine with about 135,000 miles on it - 35,000 since I did a rebuild and I didn't do a really thorough cleaning of the throttle body because history has shown me some staining and carbon makes no differences. So it wasn't spotless when I put it together other than the outside because that was grungy as @#$%.
It starts and runs like a dream. Idle is perfectly smooth. Extremely responsive to the throttle and low end torque is wow. I can be doing 20-25 mph up a 3% hill near our home in 3rd and push the throttle and it climbs right up.

Until there is carbon build-up on the edge of the throttle plate, I'm not going to worry about it. At that point it would possibly disrupt smooth air flow past the throttle plate. Note that when you clean things up you are cleaning more than just that plate - and that's likely where the "clean the throttle body" bit comes in.
PCV tube entry is close to #4 runner, between there and the throttle body. So in this version of the 4.0, the rear 3 cylinders, mostly #4, take the PCV fumes.

And now my JT's throttle body -

Just the above pic and this snip giving a closer view as frankly, one of my favorite phrases "nothing to see here, folks". And honestly, that's how my 2020 looked at 27,000 miles. So why would I worry? There's no carbon, no oil. And there should be no oil because the PCV entry is a ways downstream of the throttle body.
There may be a bit of dark staining back of the plate - I did take a bright light and look into the gap close-up, but didn't see any carbon or black and nothing is oily.

 

[Nexstar7]

Piece of cake. Don't over tighten the throttle screws. Make sure rhe gasket looks good. And be careful with the wire Harness.

 

[ShadowsPapa]

Piece of cake. Don't over tighten the throttle screws. Make sure rhe gasket looks good. And be careful with the wire Harness.

Disengaging the wiring clips and connectors is the most time consuming part of the whole thing. The rest is a piece of cake. 2 bolts, 2 screw clamps, press to disengage a hose, pull wire clips out of the intake tube and that's out of the way.......... then just wiring connector and 4 bolts. No need to gorilla things back in place. Can be done on your lunch break with time to spare.

 

[ShrimpHappens]

if you had any 4 liter with any miles and never cleaned and never had a idle problem your vehicles were very rare indeed. If the throttle bore behind the throttle plate and cold air intake above the throttle plate weren’t kept cold start up and idle was a real problem

My XJ had over 220k miles when I sold it. I never cleaned the throttle body. IAC valve died once, but never had any problems from the throttle body itself.

 

[Lunentucker]

If they don't need cleaning then explain this!!
Also, YouTube stars say clean your throttle body once a month.

https://www.crcindustries.com/throttle-body-air-intake-cleaner-12-wt-oz/

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