The Stupid Engine Questions Thread

[kamokevin]

What line is this?
It was severed in half a while ago

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Zoomed out for location reference

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From what I recall from when I "fixed" it was that it was a vacuum line. It runs across the intake to something near the passenger firewall

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I replaced the missing section with some clear tubing and secured it to the OE tubing using some heat shrink tubing.
I guarantee this isn't an airtight method, but since I don't know what this line actually is/does I have no idea how important having an airtight seal would be.

 

[SAATR]

The pod in pic#1 is a vacuum distribution point, or "tree", if you will, that supplies vacuum to the PCV valve and the line pictured. The line you spliced runs from the tree, across the intake, to the fitting that feeds said vacuum to the control head on the dash, thus operating the blend door and airflow direction pots (what makes your air hot/cold and what points the air to the defrosters/panel/floor vents). It's a vacuum line so a good seal is very important, because vacuum leaks will cause loss of fuel mileage, rough running, or just an occasional miss that's hard to pinpoint. I would go to your local parts store (Autozone, Advance, NAPA) and they should sell the tubing in rolls three or four feet long. Apply a little heat (like from a hairdryer or heatgun) and the stuff will bend and twist to your hearts content, and then stay there once it cools. Otherwise, some tiny, tiny rubber vacuum hose will also do the trick.

 

[DRAGGIN95]

Yeah on Hoe's, burb's and yukon's that control's that's the vacume controlled rear heater hose shutoff valve.

 

[kamokevin]

The pod in pic#1 is a vacuum distribution point, or "tree", if you will, that supplies vacuum to the PCV valve and the line pictured. The line you spliced runs from the tree, across the intake, to the fitting that feeds said vacuum to the control head on the dash, thus operating the blend door and airflow direction pots (what makes your air hot/cold and what points the air to the defrosters/panel/floor vents). It's a vacuum line so a good seal is very important, because vacuum leaks will cause loss of fuel mileage, rough running, or just an occasional miss that's hard to pinpoint. I would go to your local parts store (Autozone, Advance, NAPA) and they should sell the tubing in rolls three or four feet long. Apply a little heat (like from a hairdryer or heatgun) and the stuff will bend and twist to your hearts content, and then stay there once it cools. Otherwise, some tiny, tiny rubber vacuum hose will also do the trick.

Yeah on Hoe's, burb's and yukon's that control's that's the vacume controlled rear heater hose shutoff valve.

Thanks guys! I'll have some time off from school in a few weeks so I'll be making a trip to the parts store to pick up a few things including some new tubing.

Next issue: I'm slowly losing coolant (never a fun issue). It seems to be coming from somewhere towards the front of the truck, working its way down the oil pan to the front edge of the tranny where it drips off.

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I'm really hoping it not a faulty intake gasket (no white smoke, oil doesn't seem cloudy), but on a vortec with 145,000 miles, I can't exactly dismiss that possibility. However, it seems like its leaking from somewhere I'd actually be able to see.
I believe the truck still has the stock water pump but I haven't checked the weep hole.
Truck will get up to about 160 degrees and stay there.
Also the radiator is only about 2 years old, but I'll check the lower fan shroud for coolant tomorrow anyways.

Suggestions?

 

[DRAGGIN95]

The first thing I would check is the heater hose quick disconnect on the passenger of the intake, they are pieces of junk and leak all the time. There is a very good possibility that your intake is leaking though.

 

[kamokevin]

The first thing I would check is the heater hose quick disconnect on the passenger of the intake, they are pieces of junk and leak all the time. There is a very good possibility that your intake is leaking though.

That is what I was afraid of I'll have to check the quick disconnect tomorrow as well. Do you think it would be leaking into the intake if I can see the coolant actually dripping off the underside of the engine?

 

[DRAGGIN95]

It's possible, I have seen it before, but it could be something else, you will just have to really check it out good!

 

[kamokevin]

Well today has proven to be rather unsuccessful, I have only been able to narrow it down to a guaranteed front end leak. Probably somewhere between water pump and radiator. Seems to be near where the plastic tanks meet the aluminum. From what I remember about replacing the radiator it requires disassembling most of the front end, but if it does turn out to be the radiator (which would be so much more convenient than intake gaskets) it will give me an excuse to get an alumarad like this http://alumarad.com/chevy-tahoe-new-all-aluminum-radiator-95-96-05.html or some other full aluminum radiator.

 

[Silverado9798]

My '97 350 vortec has begun to have a loud knock that speeds up as you accelerate and slows down at idle. Any ideas on what's gone out? I've got to get this fixed asap.

 

[DRAGGIN95]

Well today has proven to be rather unsuccessful, I have only been able to narrow it down to a guaranteed front end leak. Probably somewhere between water pump and radiator. Seems to be near where the plastic tanks meet the aluminum. From what I remember about replacing the radiator it requires disassembling most of the front end, but if it does turn out to be the radiator (which would be so much more convenient than intake gaskets) it will give me an excuse to get an alumarad like this http://alumarad.com/chevy-tahoe-new-all-aluminum-radiator-95-96-05.html or some other full aluminum radiator.

That's a nice radiator!