Really gummed up intake, under the intake manifold. Advice?

[mtbtim]

If you read my reply, you will see its from oil vapors traveling from the valve covers into the intake. It's the nature of the beast and is very common on here and Tacoma forums. Actually, if you don't have some oil in the intake, the system may not be working correctly.

Someone with more knowledge maybe able to respond, but I believe Toyota installed something on 01 & 02 4runners to prevent oil buildup on the intake. I want to say it was on here or TTORA.

I only know what I've now seen on two 3.4 liter engines. My 2000 with 138,000 miles and @infamous 2002 with 150,000 miles. Neither of our engines had anything close to that buildup in the intake.

Maybe it's a mileage thing and the OP's engine has a ton more miles and my engine intake will eventually look like that as well.

I'm not an expert by any means on these engines. However, It's still my belief that amount of buildup is not normal for a well-maintained engine.

It would be great for someone with a lot more knowledge chime in on this.

 

[ShooterMcGavin]

My engine has 269,000 miles on it. I agree that a poorly maintained engine can have an intake like what I am seeing, but it could also be a well maintained engine with a very poorly maintained PCV valve. That's all it could take. I'm hoping it's the latter

Looking at the whole of my 4Runner and having not looked into the engine yet, (being honest with myself) I would say that the maintenance on my vehicle has only been "fair" before I took ownership. Yeah, I wouldn't call it even "good" on my initial inspection, based on some of the things I have seen (worn accessory belts, long over-due TB, rust, dirty interior, clutch badly in need of bleeding), but I'm hoping that regular oil changes will at least reveal that I have very little sludge under the valve cover. I did get a pretty good deal, for my area.

I have to say... I went into this valve cover gasket repair not expecting to need to dig deeper into the engine. However, if you guys recommend doing this extra work while I am so far into it already, I will do it. I just need to figure out which gaskets to buy now. Shouldn't be too big of a problem, I'm really hoping.

Another thing. Pulling the plenum means that I will need to drain the coolant. I was really trying to avoid doing that for this project, or any project, until I can get my floor jack working again.
[MENTION=92510]Ol'Blue[/MENTION], can you suggest again what I should remove and clean? I have the upper and lower intake manifold off now. The filthy piece I'm looking at is the Lower Plenum? Is there another piece I should remove and clean below that? Besides the gaskets for the upper/lower intake manifolds, is there only 1 more gasket I will need to buy for the lower plenum?

*ETA: For the lower plenum contact to the heads, will I need just 1 gasket or 2?

*ETA2: I am getting a little confused on some part names... On the very top of the engine (fully assembled), the piece that the throttle body bolts onto... I thought people were calling that the upper intake manifold (on my G35, that would have been part of the plenum), and the piece below it was being called the lower intake manifold? Those are the 2 main pieces that need to be removed for removal of the valve covers. Is that correct? The piece with 6 vertical tubes in it, the piece that I show in my initial posting, which is really filthy inside... So, is that the lower plenum?

 

[mtbtim]

My engine has 269,000 miles on it. I agree that a poorly maintained engine can have an intake like what I am seeing, but it could also be a well maintained engine with a very poorly maintained PCV valve. That's all it could take. I'm hoping it's the latter

Looking at the whole of my 4Runner and having not looked into the engine yet, (being honest with myself) I would say that the maintenance on my vehicle has only been "fair" before I took ownership. Yeah, I wouldn't call it even "good" on my initial inspection, based on some of the things I have seen (worn accessory belts, long over-due TB, rust, dirty interior, clutch badly in need of bleeding), but I'm hoping that regular oil changes will at least reveal that I have very little sludge under the valve cover. I did get a pretty good deal, for my area.

I have to say... I went into this valve cover gasket repair not expecting to need to dig deeper into the engine. However, if you guys recommend doing this extra work while I am so far into it already, I will do it. I just need to figure out which gaskets to buy now. Shouldn't be too big of a problem, I'm really hoping.

Another thing. Pulling the plenum means that I will need to drain the coolant. I was really trying to avoid doing that for this project, or any project, until I can get my floor jack working again.
[MENTION=92510]Ol'Blue[/MENTION], can you suggest again what I should remove and clean? I have the upper and lower intake manifold off now. The filthy piece I'm looking at is the Lower Plenum? Is there another piece I should remove and clean below that? Besides the gaskets for the upper/lower intake manifolds, is there only 1 more gasket I will need to buy for the lower plenum?

*ETA: For the lower plenum contact to the heads, will I need just 1 gasket or 2?

*ETA2: I am getting a little confused on some part names... On the very top of the engine (fully assembled), the piece that the throttle body bolts onto... I thought people were calling that the upper intake manifold (on my G35, that would have been part of the plenum), and the piece below it was being called the lower intake manifold? Those are the 2 main pieces that need to be removed for removal of the valve covers. Is that correct? The piece with 6 vertical tubes in it, the piece that I show in my initial posting, which is really filthy inside... So, is that the lower plenum?

The two pieces you take off to access the valve covers is the Upper and Lower Plenums. The throttle body bolts to the upper plenum. The piece you show in the picture is the Intake Manifold. The plenum gaskets are a two-piece gasket. One between the upper and lower plenum and one between the lower plenum and the intake manifold. I don't know what the intake manifold gasket looks like because I've never had my intake manifold off.

 

[ShooterMcGavin]

Thanks Tim. That is exactly what I would have expected. I guess I had heard, or thought I understood, other people to mean that the plenums were the manifold. Thanks.

I will need to look into getting the intake manifold gasket. I have all of the other parts.

 

[mtbtim]

Thanks Tim. That is exactly what I would have expected. I guess I had heard, or thought I understood, other people to mean that the plenums were the manifold. Thanks.

I will need to look into getting the intake manifold gasket. I have all of the other parts.

Good luck with repair. Please report back with some pictures of the process. I'd like to see what it looks like with the intake manifold off.

 

[solsnowbarger]

If I'm reading this all correctly, and my earlier inebriation may still be in effect, let's count everything you need to get gasket wise:
-new coolant after drain
-Gasket between upper and lower plenums
-Gasket between lower plenum and intake manifold
-Gasket between intake manifold and the two heads. You'll need two of these, and they are identical, they connect the intake manifold to the right and left heads.

P.S. those plenum gaskets may be the same part number, I don't remember.
P.P.S. A new throttle body gasket, cheap, wouldn't hurt either.

Haha I'm going to sleep now.

 

[ShooterMcGavin]

If I'm reading this all correctly, and my earlier inebriation may still be in effect, let's count everything you need to get gasket wise:
-new coolant after drain
-Gasket between upper and lower plenums
-Gasket between lower plenum and intake manifold
-Gasket between intake manifold and the two heads. You'll need two of these, and they are identical, they connect the intake manifold to the right and left heads.

P.S. those plenum gaskets may be the same part number, I don't remember.
P.P.S. A new throttle body gasket, cheap, wouldn't hurt either.

Haha I'm going to sleep now.

Yes, those are the gaskets I need. The plenum gaskets are already here and, yes, they are the same.

Since I'll be thoroughly cleaning the upper plenum, I'll get a new throttle body gasket too. I already have the IAC gasket.

 

[Ol'Blue]

Looms like you have it under control. When you get the lower intake gaskets it is a set. There are two gaskets for the lower. The upper has two as well if I remember right. I'm pretty sure. Then you need the throttle body gasket. That's pretty much it. Sounds like you are doing fine. The 3.4 is actually pretty easy to work on. The parts are big and you can do almost everything with a 10mm 12mm in this truck.

I'll check back tomarrow and see how it's coming along.

Blue

 

[ShooterMcGavin]

I bought the new gaskets that I'll need from Camelback. $85 for both intake manifold gaskets and a throttle body gasket. I will continue on with the valve cover gasket work while I wait for the parts to arrive.

 

[ShooterMcGavin]

The heavily anticipated valve-train pictures...
I'm pretty happy with the way it looks. I think the previous owner(s) at least kept up with regular oil changes. 269,000 miles

Driver's side


Passenger's side


Thoughts?

I have the plugs and half-moons removed. Take a look at this half-moon. I did not pull it sideways, I'm pretty sure, but the flange on one side is chipped. Should I just reuse it or buy a new one? Since it's on one flange, I'm thinking it can still be used again.

 

[mtbtim]

Right on. I'm glad I was wrong. Looks great under the valve covers. If it were me, I wouldn't reuse that chipped half-moon. I think they are pretty affordable to replace.

 

[Rock_Rat]

Your video was really thorough and helpful! Thank you for all that work.

I will take some of the ideas and figure out what might work best when I'm back home. Can the lower plenum be separated from the head? I will look into it. the truck ran fine before this work, not perfect, but good. maybe down on power slightly.

I have many cleaners... brake, throttle body MAF, Simple Green, etc. I also have a new PCV and grommet, which really needs replacing from what I have seen so far.

I will post pictures when I get the valve covers off.

First of all that is your intake manifold and not your plenum. You've already removed your upper and lower plenum. Intake manifolds are designed to be rough to allow for atomization of your air/fuel mixture for a clean combustion when it gets to your pistons/cylinders. That's why it "collects" unused fuel air mixtures

I've attached a photo of my manifold from about a little more than a year ago and it doesn't look at all gummed up like yours. Neither did the intake ports on my heads.

A few recommended it already, use brake clean (evaporates rapidly) in a well ventilated area with a tooth brush or small wire brush. Nice thick Nitrile gloves because it's awful stuff. Cheap white respirator mask.

It would seem to me that you would be taking a big hit on your gas mileage and possibly a rougher idle than normal with the looks of it. Surprised you haven't kicked off a 0420 for HC or for your A/F.

No reason to remove your intake manifold unless you want to clean it and the ports on the heads. I needed to remove mine to replace my knock sensors. Pics are at 309K

Honestly, gaskets are gaskets. The only difference you'll see is in your wallet. I use Felpro.

Once back together, begin with cleaning all of your Air/Fuel components, Filter, MAF, IAC, Vacuum lines, Etc....

Just my own .02

EDIT: Disregard the white arrows in the second photo. It was for another project. I'm just showing you the intake ports on the heads.

 

[Rock_Rat]

Not 100% necessary but the OEM plenum gaskets are reasonably priced so while you have them off....:hatsoff:

Disagree with you here. I think... (Not sure if you're saying it's not necessary to replace the gaskets or not necessary to use OEM :shrug

ANY time you "crush" a gasket you should replace it. The last thing you want to do is chase vacuum leaks.

 

[ThorInc]

Disagree with you here. I think... (Not sure if you're saying it's not necessary to replace the gaskets or not necessary to use OEM :shrug

ANY time you "crush" a gasket you should replace it. The last thing you want to do is chase vacuum leaks.

Saying use OEM for the cost of the OEM plenum gaskets, replace them but it is not 100% necessary. Basically, if I had to pinch say $30.00, I would pinch it on the gasket.

 

[NHRunner]

Preferably, you should get a new half moon. But you could probably get away with using a little extra rtv and placing it chipped side out. Acetone works great to remove the carbon buildup and soften the old rtv.

 

[Rock_Rat]

Saying use OEM for the cost of the OEM plenum gaskets, replace them but it is not 100% necessary. Basically, if I had to pinch say $30.00, I would pinch it on the gasket.

Thanks for the clarification, but I would sell something on Craigslist for $30 before re-using a gasket. I would hate to go back in and have to tear everything apart chasing a vacuum leak. My time is well worth the $30. But hey, that's me.

 

[ileinujhekar]

critically wounded on Saturday

Oscars 2016 Live Streaming

 

[ShooterMcGavin]

First of all that is your intake manifold and not your plenum. You've already removed your upper and lower plenum. Intake manifolds are designed to be rough to allow for atomization of your air/fuel mixture for a clean combustion when it gets to your pistons. That's why it "collects" unused fuel air mixtures

I've attached a photo of my manifold from about a little more than a year ago and it doesn't look at all gummed up like yours. Neither did the intake ports on my heads.

A few recommended it already, use brake clean (evaporizes rapidly) in a well ventilated area with a tooth brush. Nice thick Nitrile gloves because it's awful stuff. Cheap white respirator mask.

It would seem to me that you would be taking a big hit on your gas mileage and possibly a rougher idle than normal with the looks of it. Surprised you haven't kicked off a 0420 for HC or for your A/F.

No reason to remove your intake manifold unless you want to clean it and the ports on the heads. I needed to remove mine to replace my knock sensors. Pics are at 309K

Honestly, gaskets are gaskets. The only difference you'll see is in your wallet. I use Felpro.

Once back together, begin with cleaning all of your Air/Fuel components, Filter, MAF, IAC, Vacuum lines, Etc....

Just my own .02

EDIT: Disregard the white arrows in the second photo. It was for another project. I'm just showing you the intake ports on the heads.

Thanks for all that advice. Regarding the bolded part, would you personally remove it to clean out that level of residue? Should I also spend time cleaning the plenums? They have more residue than your intake manifold picture shows. I can post a picture if you need to see it.

BTW, I agree with you, replace gaskets, ESPECIALLY crush gaskets! I usually use Felpro. I think that level of crud is hurting my mileage and my power. I have a 5-speed but it still feels pretty sluggish. Idle is actually really smooth, for a vehicle with 269,000 miles. I do get a CEL about 10-20% of the time. I haven't look at the code yet; I kinda thought it would be O2 sensors.

I have a new gasket to clean the IAC while I'm in there and I have cleaned all the other components. I'll be cleaning the throttle body again, because it already has new residue. How would you recommend cleaning the vacuum lines?

SPAM

Get the F out of my thread.

 

[Rock_Rat]

Thanks for all that advice. Regarding the bolded part, would you personally remove it to clean out that level of residue? Should I also spend time cleaning the plenums? They have more residue than your intake manifold picture shows. I can post a picture if you need to see it.

BTW, I agree with you, replace gaskets, ESPECIALLY crush gaskets! I usually use Felpro. I think that level of crud is hurting my mileage and my power. I have a 5-speed but it still feels pretty sluggish. Idle is actually really smooth, for a vehicle with 269,000 miles. I do get a CEL about 10-20% of the time. I haven't look at the code yet; I kinda thought it would be O2 sensors.

I have a new gasket to clean the IAC while I'm in there and I have cleaned all the other components. I'll be cleaning the throttle body again, because it already has new residue. How would you recommend cleaning the vacuum lines?



Get the F out of my thread.

If it were mine and I was this deep into the engine, I would pull the manifold and clean as much as I could. I'm lazy like that. I hate to do a job twice. Plus you can get a look at your intake valves and see what they look like. Just be careful. Get yourself 2" masking tape and cover all the holes. As we speak, go and cover up the holes in your manifold. The last thing you want to do is drop a non-magnetic washer in there. I've seen a thread on here about that before.

As for vacuum lines, just replace the ones that look old and dried out. Once together you can always check for leaks. Invest in a scangauge or at least an OBDII reader. I watch my A/F, trans temp and coolant temp all the time. 14.53 is what I average on A/F.

If you get a CEL and its a 0420 code (O2 sensor or "catalytic efficiency" I think is how its worded) you'll know. Your rig goes into failsafe mode and your gas gauge moves faster than your speedometer. The computer is trying to protect your engine.

 

[ShooterMcGavin]

Thanks.

How should I clean the valve covers? A bucket with soap and water? They are covered in grime on the outside, but I want the gasket channel to be clean as well.

New problem; it's always something. I scored the side of the PCV grommet hole, as I was removing the PCV grommet. Yeah, I'm an idiot. Anyways. What should I do about it? Can I put some FIPG in there as I install the new grommet? JP Weld - probably a bad idea.