What is this hose? Chevy Lumina APV, 3400 Engine, 1996

[Nehmo]

The front of the engine is at the bottom of the photo. The driver's side is on the right. The big fat hose going from right to left with hose clamps is the air intake. I'm interested in the small hose going up from the center of the picture. You can see a break in it that was previously repaired by surrounding the break in a larger hose, which is now removed.
What does this small hose do? Where does the upper end go? I can't see well where it goes because it seems to go behind the engine on the firewall side.

[aleekat]

No photo.

[Nehmo]

Originally Posted by aleekat

No photo.

I can't seem to use a link to a picture in Google Photos. I've added it as an attachment.

[aleekat]

You have to use a website to show the pic.

[Nehmo]

Originally Posted by aleekat

You have to use a website to show the pic.

Can you see it as an attachment?

[Blue Bowtie]

The composition of the photos doesn't show a lot of background or surrounding references.



From what is pictured, I would guess that tube is the makeup air tube for the PCV system. It should connect to the rear valve cover, or in some cases, the lower intake manifold hole into the lifter valley area.

With a crack like that, the MAF can get a skewed reading, provide incorrect air flow data, and cause several problems like lean running, error codes, etc.

[Blue Bowtie]

And since you show the condition, it appears that the PCV valve may need some attention since there is LOT of moisture-laden oil film in there which should not be present.

[Nehmo]

Originally Posted by Blue Bowtie

The composition of the photos doesn't show a lot of background or surrounding references.



From what is pictured, I would guess that tube is the makeup air tube for the PCV system. It should connect to the rear valve cover, or in some cases, the lower intake manifold hole into the lifter valley area.

With a crack like that, the MAF can get a skewed reading, provide incorrect air flow data, and cause several problems like lean running, error codes, etc.

I don't know how you posted the image. It seems like you just used the image button. Anyway, returning to the minivan.
There is a coolant leak somewhere. I'm not sure where it is, but it is coming from the general area of the center of the picture. I can't get a good look at anything because everything is jammed in there and the wiper cowl (or windshield) goes over the engine.
That tube had previously been repaired with another tube surrounding it. I think coolant was coming from it.
There is definitely a coolant problem. I overheated but managed to get the minivan home.
I'm not sure what my next step is, but I have to find the leak. Somewhere in the back of the engine by the firewall coolant is coming out. How do people look back there?

[Blue Bowtie]

It's not an easily accessible area. I know them well.




Ford Windstars are worse, as least a little bit.

An internal coolant leak would explain the excess moisture in the PCV and vent system. It would be good to monitor the condition of the crankcase oil so that the crank, cam, and all the bearings don't get wiped out due to coolant contamination.

[Nehmo]

Originally Posted by Blue Bowtie

It's not an easily accessible area. I know them well.




Ford Windstars are worse, as least a little bit.

An internal coolant leak would explain the excess moisture in the PCV and vent system. It would be good to monitor the condition of the crankcase oil so that the crank, cam, and all the bearings don't get wiped out due to coolant contamination.

The oil on the end of the dipstick is dirty but doesn't appear to be contaminated with coolant. I suspect the leak is outside of the engine because the firewall is wet in a spot. I need to remove the windshield wiper cowl to see back there. I already tried a mirror.

[Nehmo]

The engine will start, but it bangs around in noise. Something is broken inside. I don't know what. I'll try to record it.
A more thorough description: When I finally got the courage to work on the van, I decided to make it leak again so that the source of the leak would be easier to find. I added water and started the engine. It's hard to describe the noise. It banged around seemingly from the inside of the engine, but the engine continued to run. The noise wasn't regular enough to be something like a rod. I turned it off so as not to damage anything further.
Also, this wasn't the engine's condition when I first drove the van here. I didn't hear this erratic noise then; it is loud enough to hear from inside the van.