1987 240 with a B230F engine.

Got an oil separator box and flame trap kit from Volvo - also got the lower rubber hose that goes into sump.
Is it risky to replace this lower hose or is it recommended to change?

Thanks

I don't have a picture, but that hose is clamped to the side of the oil pump. The hose cannot be replaced without removing the oil pan.
--
john

Right now with a hot engine when I remove oil filler cap air pressure rushes out and revs drop.

I assume changing the oil trap and flame trap will solve this so I get suction.

And should I be able to feel airflow coming out of the tube that goes to filter box?

Getting it done tomorrow.

Thanks for all the help

"when I remove oil filler cap air pressure rushes out and revs drop"

I think your small vacuum hose is blocked. This is the short rubber hose from flame trap (that Y shaped plastic thingy) to intake manifold.

During idle, if this hose is blocked no engine vacuum could suck the blow-by gasses until throttle plate is opened ie. gas pedal pressed. At idle no engine vacuum should pass thru throttle plate. All the built-up pressure is being forced thru the idle valve raising the idle a bit. When you opened the oil filler cap the pressure is released so your revs should drop.

Clean your short vacuum hose. The nipples could be blocked too. Use small wire to unblock the nipples where hose is attached.

Amarin.

mT B230 F RUNS SNMOOTH & REVS REALLY EASY.
i JUST FINISHED A NEW FUEL PUMP & SCREEN!!300,000 MILES,,,
AS FOR ANY CLOGGING IN OIL PASSAGES,DO WHAT MY MECHANIC TOLD ME..
I ADDED A BOTTLE OF KEROSENE & DROVE SLOWLY 25 MPH,,FOR 30 MINUTES THEN i DRAINED IT COMPLETLY OVER NIGHT,,,i DISCONNECTED BEG TERMINAL TO BE SAFE,,NEW MANN OR VOLVO FILTER & 5 QTS OF A FULL SYNTHETIC,,ALL LEAKS STOPPED FOR 6 MOS AT LEAST BEFORE i HAVE TO ADD ANY!!

Hi,

Now this is an interesting observation that you say, "when I remove oil filler cap air pressure rushes out and revs drop."
That must mean less air is going into the engine's intake than before?
The throttle plate didn't move so the air dropped out from going in behind the throttle or was being pushed past the throttle plate.
Definitely surprising!


The crankcase, if it were completely buttoned up, should be operating in a state of "almost equilibrium" with each piston displacing each other's volume as they move up and down opposite direction.
Almost, is being used here to uncover an imperfect world.
As air compresses and it resists movement just like everything else.
So this creates a flutter in the crankcase.
Again, in a perfect engine there would be no blow-by past sealing rings either.
So this is where the air pressure is being made.

If you are totally plugged up, then you really have a Positive Crankcase Ventilation problem or excessive blow-by, of which by the way, is not a great positive for the crankcase.

Do you have engine oil leaks around the front timing belt and/or an engine rear seal?
When the engine drops revolutions that must mean extra air stopped going into the intake, just like a turbo!

If excess air coming from the flame trap route, it must be open! Right?
You should be able to blow air backwards from the throttle plate hose back into the engine and have it come up under the oil cap.
You might plug up the accordion hose/flame trap connection, so you can run the engine without affecting the AMM.
JUST to see what, if anything changes, with the flame trap hose circuit.
The flame trap has another tiny hose, that tees and connects to the intake manifold.
It helps facilitate a pre draw of vacuum. I think it deals with gasoline vapors prevention, in case the crankcase has flooded with injected gasoline. Thus the term "flame trap."


So I'm lost at what symptom(s) you are chasing?
The "bobbling" of the oil cap around on the valve cover while the engine is running can be normal to some extent.


Phil

Let it be.

The lower hose that goes into the sump, don't change it unless you intend to dismantle the oil pan. The hose goes into twisted pathway into the sump its difficult to install without the oil pan off.

Amarin.

And I guess there is always a chance it may break/disintegrate and cause bigger problems ?

Hi,

“And I guess there is always a chance it may break/disintegrate and cause bigger problems ?”

That is one more reason that there is a screen on the oil pump inlet.
It’s purpose is to keep out any chunky clumps of very unusual things! Like silicone sealant, bits of valve cover gasket or a plastic oil bottle cap ring! If it can make it down a drain hole in the engine head.
I knew a person who did that, but has just passed way of lung cancer.
He called me to ask about what to do.
It never caused an issue in his Toyota.
I think he had the valve cover serviced during a normal service.
He did that a lot later and they retrieved it upon request!
So, he knows they actually did the service procedure!
(:) I wouldn’t have remembered the color of it, but he was a little bit OCD and was $300 lighter in his wallet!
Some might even call all that anal? (:-)

Oil sludge or carbon accumulation comes from cold corners, especially, if a faulty routine of oil changes are followed by a high detergent engine flush!
That hose is best left in its little corner above the turbulence.
Carbon particles can often pass into the pump and get crushed up anyways.
The pump is a positive displacement pump, mostly “Meaning” it has voids or gears in mesh to squeeze things.

Here is why the spin-on strainer is for all that stuff above.
What could worry a person though is the full-flow feature that engages just above idle somewhere?
This is done because the pump puts out so much more flow @upper rpms that all of it cannot possibly make it through the spin-on.
I think I read that only up to 15% is getting filtered with each go round.
The go-arounds are quite frequent though, so I imagine, it’s made up for over time!
If you study the specifications on oil filters you have to pay attention to the < > signs and the S.A.E. Test variations of microns “strained.”

I think you should leave it alone too!
Besides, from what others are saying, it must be above the oil and up in vapors only, behind some baffles.

I vote with the others that you should leave it alone too!

Phil




unless some one throws in a special detergent to do an engine flush is one thing

Taking it out might not be the problem. Only when installing it. The lower part of the hose might hit the baffle in the oil pan, preventing it to be fully inserted. I saw how this could happen when I rebuilt my engine last time.

Amarin.