I Dunno What It Is

[atkinson40]

Can anybody tell me what this tube is coming out of the Block?

 

The hose is kinda frayed and its drooling muck on the exhaust manifold.

 

I also have a carb leak from the bowl or gasket.

 

Thanks Kevin

 

[MikeRL411]

So! Which vehicle is this?

[MicroMachinery]

That is your PCV pipe that should loop around into your PCV valve(located on your intake manifold)

[wayno]

The lower arrow is the L16/18 crank case vent going to the pcv valve.

[ggzilla]

The fuel stain is very common. Probably a very slow leak.

[datzenmike]

Solid steering column. Brake master outlets to the right (won't work on vehicle with strut towers) Block vent hose straight out to side makes this an L16/18. Brake booster makes this an early 620 up to '74

 

 

 

The bottom "WHAT IS THIS" with bent arrow is pointing at the block vent tube that goes to the PCV valve on the intake. Leave alone. The smaller rubber tube above it that goes over to and under the master is coming from the flow guide that takes gas fumes from the tank and sends to the PCV system. Leave alone

[Tristin]

Solid steering column. Brake master outlets to the right (won't work on vehicle with strut towers) Block vent hose straight out to side makes this an L16/18. Brake booster makes this an early 620 up to '74

 

Fucking Sherlock Holmes Mike... Jesus.

[atkinson40]

Thanks Everyone.

 

How do I know the PVC valve is OK?

 

I wanted to replace the hose, but one end is big. The other small. It's leaking.

 

Wouldn't know where to start my search for a replacement.

 

Thanks kevin

 

PS:

 

'72 620.

 

Someone replaced the L1600 with an L1800.

 

Otherwise all stock except for replacing that big honkin blue air cleaner that was driving me nuts with a 65MPH rattle.

[atkinson40]

How do I know the PVC valve is OK?

 

 

OK Forum. Sorry for being lazy and asking to be spoon fed. :blush:

 

A little research shows it to be a check valve that I can blow/suck on to check.

 

Thanks kevin

 

EDIT: @#$%$# Just went out and started it up and pulled the oil filler cap.

 

I got a bunch of blowby. Doesn't go away as its reved either.

 

I hope its the PVC valve. Thanks kevin

[datzenmike]

The PCV valve is tightened into the manifold end of that hose. The engine will run weather it is working or not. Start up with hose off and you should hear a loud hissss sound coming from it. This is a from a metered hole, very small, that uses intake vacuum to draw fuel and water vapors (and any combustion vapors) out of the crank case and burn them. This small vacuum 'leak' is designed into the engine and is normal.

 

You can remove the PCV valve and shake it. It should rattle. Inside is a round ball and a spring to make up a one way valve. Engine vacuum pulls it open but it's normally closed. It's function it to close if there is a backfire in the manifold and prevent fumes traveling back down the hose into the motor.

 

If you can find another hose, fine. If not, remove and clean it thoroughly and seal up the crack or hole with anything that will work. RTV, duct tape, hose clamp whatever until you can replace..

 

 

Fucking Sherlock Holmes Mike... Jesus.

 

PS:

 

'72 620.

 

Someone replaced the L1600 with an L1800.

 

 

Hmmm pretty close.

[atkinson40]

 

You can remove the PCV valve and shake it. It should rattle. Inside is a round ball and a spring to make up a one way valve. Engine vacuum pulls it open but it's normally closed. It's function it to close if there is a backfire in the manifold and prevent fumes traveling back down the hose into the motor.

 

If you can find another hose, fine. If not, remove and clean it thoroughly and seal up the crack or hole with anything that will work. RTV, duct tape, hose clamp whatever until you can replace..

 

 

Thanks DM.

 

The hose is cracked and leaking at the tube coming out of the block.

 

Could this or a bad PVC valve cause the massive amount of blowby I have?

 

I did pistons, rings and head rebuild.

 

I did dry comp test and got staright 100PSI across the board. <2PSI variance.

 

Was hoping this was operator error when I did the test.

 

Thank Kevin

[datzenmike]

The PCV system does not cause blow by. What it does do is collect blow by and run it back through the motor to burn it up. At some point a worn out motor makes way more blow by than can be handled by the PCV and it backs up and flows out the valve cover vent.

 

100 PSI indicates a well worn motor. If all the cylinders read very close to the same it will still start and run pretty good. May lack power and burn oil though.

[banzai510(hainz)]

I wanted to replace the hose, but one end is big. The other small. It's leaking.

 

That will be a L16 PCV hose set up. I have part number at work. They all leak eventually

 

PCV valve are ez to get . You can just wiggel them side to side and thats about it. clean it out with gas or what ever you want to use.

 

Everythin look hook up correclty by your photo.

 

Only thing is L16s(come straight out) the mettall crank tube is different on the L18s I have seen(those come out from block at a 90deg bend). I modded mine using the L16 PCV hose But cutting a extra L16 tube and mated it to the L18 tube.

But I have my old L16 back in and use the L16 crank case hose to PCV valve.

 

 

Whats photoed you have look fine Im thinking

[atkinson40]

Thanks DM

 

I did the smoke test. Had my kid watch the exhaust. I floored it 3 times.

 

No smoke he says. Nada

 

Had kid floor it while I watched.

 

I'd have to use my imagination to see any smoke. If there is any, its elusive. Nada

 

If I really had 100PSI across the cylinders, wouldn't I see some smoke??

 

Pulled the hose coming off the tube coming out of the block and I feel puffs of air coming out of tube.

 

Pulled the oil filler cap while the hose was disconnected and air is still blowing out.

 

How does the blowby get up to the valve cover?

 

Anything else that could cause air to come out the oil filler cap?

 

Thanks Kevin

 

Gonna try the dry/wet comp test again during the week

[banzai510(hainz)]

Pulled the hose coming off the tube coming out of the block and I feel puffs of air coming out.

 

Pulled the oil filler cap while the hose was disconnected and air is still blowing out.

 

How does the blowby get up to the valve cover?

 

Anything else that could cause air to come out the oil filler cap?

 

STOP

I think yout over thinking this. all sounds correct

[atkinson40]

STOP

I think yout over thinking this. all sounds correct

 

Thanks banzai

 

I just thought I remember reading that there should not be air coming out the oil filler cap.

 

I got a bunch coming out. If this is OK, sweet. Thanks kevin

[atkinson40]

Is there a difference between air and blowby coming out of the oild filler cap.

 

I have air coming out mine and just assumed it was blowby.

 

It doesn't have any smoke in it. Just a mist of oil being churned up.

 

It got me to thinking when I pulled of the PVC hose and it didn't diminish the air coming out of the oil filler cap.

 

Thanks kevin

[datzenmike]

Any 'air' coming out of the oil fill cap or the valve cover vent hose IS blow by. How could it be anything else? It's just gasses pushing past worn rings. It get's to the valve cover from the crank case up beside the timing chain and oil drain back holes in the head. Just because there is blow by does not mean the the oil control rings aren't working... it may still not smoke much. There is always a fog of oil droplets and spray under the valve cover, he problem with large amounts of blow by is that it will drag some of this fog of fine particles out the vent on the valve cover. There are baffles to slow and catch these droplets and allow them to collect and drain back, but that's on a normal engine.

 

 

You could run this hose to a catch can and once a week pour back in. It's just oil.

[atkinson40]

You could run this hose to a catch can and once a week pour back in. It's just oil.

 

Thanks Mike.

 

I'm not seeing any oil come out the hose from the VC vent. Just a mist with the air when I pull the filler cap.

 

I also don't have any noticable oil leaks anywhere. If I understand everything right this BB could cause that.

 

I pulled, checked and cleaned the PVC valve. Its OK.

 

I'm going to redo the compression check. Wet and dry. And just run it.

 

It has power. It seems to be reliable. It only gets maybe 20-30 miles a week.

 

I think I'll beat down my OCD and let it be. Move on to the other two cars for awhile.

 

They need timing belt, CVC joints, motor mounts and a water pump.

 

I wish they were as easy to work as the 620. Thanks kevin

[atkinson40]

Drove the beast to and from the VA today. About a 70 mile round trip.

 

When I got home I parked it and lifted the hood to hear the engine.

 

Looked down at the VC breather hose and seen it was exiting against a dry brake line junction.

 

I realized if it was spewing out oil it would show up.

 

Put my finger on the exit and there is a tiny bit of vaccumm. No blowing out. I guess the PVC valve is keeping up.

 

Gotta redo the comp test.

[banzai510(hainz)]

I wouldnt even worry about it the comp test. I never have don one myself.

 

There is always a certain amount of air in the crank case and when the pistons move up and down it will cause tubulance and movement of air underneath the piston. Think more into it of like a 2 stroke motor. when the piston goes up the carb is on the crank case. Piston moving up it creates a neg pressure in crank case and suck air in to the crank case via the carb. then the piston goes down the air in crank case goes to a reed valve to the top side of the piston(combustion chamber).

4 strokes still have soemwhat if this. The PCV helps. In a stock motor the stock aircleaner has another valve to let this get suck in to the carb ect.......

 

As for oil comming out he oil cap when running. Well you have a cam lobe there and there is a hole in it and it will spray oil out. NORMAL