31 replies to this topic

[NateB]

and out of top of engine with the oil cap removed.

Noticed this for the first time yesterday while I was checking the oil while at the gas station.

Perhaps I have not been observant over the years- but I nevr noticed this before.

I don't thing the 850 turbo engine hse a PCV valve (right?).

Is this normal ??

If not, what do you suggest I look for to fix ?

[Bay13]

The turbo does have a PCV system. If you are getting smoke out the dip stick tube and the oil cap then the chances are very good that something in the system is not working correctly. THose crank case fumes are suppose to be sucked into the PCV box thats under your intake maniflod, then the large tube makes it's way over to the induction pipe. The induction pipe hooks up to the turbo intake, it's the black plastic one that leaves the air box and goes down. The large hose connection down there has the crank case fumes and the smaller line is vacuum to help suck the fumes into the connection there. You will also find an electricial connection down in that mess, that is for the heater circuit that is part of connection mess. Where to start. A new induction hose with a good clean up of all the connections. IF that doesn't work you might have to replace the PCV box under the intake manifold. A note on the new induction hose, when you get one you will find extra nipples on it that you don't use, you can cap them or melt them closed like I did. Below is a lay out of the different set ups for the turbo PCV.

[NateB]

Thanks Rich- WOW that is a spagetti mess of hoses !

I can't tell from your schematic which is the induction hose you recommended replacing.

Any chance you could post the part number for a 1995 Volvo Turbo 850 ?

Do you think the vacuum hose that provides the suction to the PCV system may be the culprit instead of the induction hose ?



Also, is it OK to drive the car until the problem is fixed ?

PS- Just took a look under the hood. Where is the PCV box and the other plumbing ? I cannot figure out how to relate the the diagram to what's under the hood. Perhaps you could provide some point of reference so that I can "triangulate" the position better ?

Edited by NateB, 30 October 2004 - 02:40 PM.

[Bay13]

GIve me a few and I'll color code the set up thats on the 1994 and 1995s.

[Bay13]

The green is the PCV under the manifold. The red are the elbow that you have, don't be confused by the piping from the PCV to the input to the down pipe in blue.

[lax01]

now, I've modified my PCV system to include a catch can, but its the same idea....



This shot is taken from behind the motor, near the turbo (under the torque rod)...you see the two hoses clamps? thats the top of the PCV valve....the vacumn nipple is hidden but its on the heat shield side of the intake hose....the swap is pretty easy (as long as you aren't swaping out the hoses that run to the front of the intake manifold and to the PCV box, which I would fear would be a total PITA.

Rich correct me if I'm wrong on anything....also, wouldn't it matter whether the car is running when he took the oil cap off? Say he was running it hard....and turned the engine off to check the oil....wouldn't the smoke come up from the oil filler cap? and same thing from the dipstick? Just thinking since there would be no vacumn to pull the vapors towards the PCV...

[Bay13]

You should never have smokie fumes(blowby gases) coming out of the dipstick or the oil cap if you take it off, running or not.

[NateB]

You should never have smokie fumes(blowby gases) coming out of the dipstick or the oil cap if you take it off, running or not.

What damage do I risk to the engine until I can get it repaired properly ?


Call me blind- but even with the color enhanced diagram I cannot figure out where the PCV box or the induction hose is located.

I looked under the intake manifold- cannot see it- help!

Edited by NateB, 30 October 2004 - 05:39 PM.

[theunderlord]

lax, is that filter sposta be oiled? looks very K&N ish...

Edited by '98S70R, 30 October 2004 - 06:34 PM.

[beachnut]

Do you think the vacuum hose that provides the suction to the PCV system may be the culprit instead of the induction hose ?

If that particlar vac line is broken you should get a code thrown, P0171 iirc, but it will probably be one of the elbows that are broken not the hardline. I you look at Rich's pic on the left side there is a red elbow that hooks onto the left of the intake just behind the power steering pump - that's right, the infamous elbow that everybody has a bitch of a time replacing. The elbow attaches to a run of white hardline which disappears into a larger rubber sheath that runs under the manifold to the driver's side of the motor. This sheath also contains a larger hose (the induction hose) which is the one that connects into the PCV under the manifold (in green). Both of these hoses, the white hard vac line and the larger PCV hose (both inside the sheath) exit out the other side of the motor just under the distributor, then they run down to the fresh air intake pipe and come out of the sheath.

The larger PCV hose hooks into a small plastic "junction" (for lack of a better term) that has an electrical connection. There's also a nipple on this "junction" where the white hard vac line connects with another elbow that notoriously goes bad. Again in Rich's pic, this is the red elbow in the middle. Notice in the pic that the elbow looks like it connects to a short piece of hose, then to the smaller hard vac line, then into the sheath. This is kind of deceiving because that short piece of hose is actually a black rubber hose that goes over the white hard vac line as it exits the sheath to protect it from the heat. When you're looking at that area and expecting to see a white line you won't, but trust me if you pull that elbow off and slide the black hose back you'll see the white line.

This is my question to Rich - can you purchase from the dealer that entire run of hoses already assembled? In other words, the white vac line plus the large PVC hose together already inside the large rubber sheath? If that is what is causing Nate's problem I'd try to go that route ....

Edited by beachnut, 30 October 2004 - 07:16 PM.

[lax01]

lax, is that filter sposta be oiled?  looks very K&N ish...

no idea...its what came on the catch can

[NateB]

Do you think the vacuum hose that provides the suction to the PCV system may be the culprit instead of the induction hose ?

If that particlar vac line is broken you should get a code thrown, P0171 iirc, but it will probably be one of the elbows that are broken not the hardline. I you look at Rich's pic on the left side there is a red elbow that hooks onto the left of the intake just behind the power steering pump - that's right, the infamous elbow that everybody has a oh yeah! of a time replacing. The elbow attaches to a run of white hardline which disappears into a larger rubber sheath that runs under the manifold to the driver's side of the motor. This sheath also contains a larger hose (the induction hose) which is the one that connects into the PCV under the manifold (in green). Both of these hoses, the white hard vac line and the larger PCV hose (both inside the sheath) exit out the other side of the motor just under the distributor, then they run down to the fresh air intake pipe and come out of the sheath.

The larger PCV hose hooks into a small plastic "junction" (for lack of a better term) that has an electrical connection. There's also a nipple on this "junction" where the white hard vac line connects with another elbow that notoriously goes bad. Again in Rich's pic, this is the red elbow in the middle. Notice in the pic that the elbow looks like it connects to a short piece of hose, then to the smaller hard vac line, then into the sheath. This is kind of deceiving because that short piece of hose is actually a black rubber hose that goes over the white hard vac line as it exits the sheath to protect it from the heat. When you're looking at that area and expecting to see a white line you won't, but trust me if you pull that elbow off and slide the black hose back you'll see the white line.

This is my question to Rich - can you purchase from the dealer that entire run of hoses already assembled? In other words, the white vac line plus the large PVC hose together already inside the large rubber sheath? If that is what is causing Nate's problem I'd try to go that route ....

Thank you for the detailed response !!

Yes- I know about those hard to get to elbows. I'll give them a check.

Where the heck is the PCV Box ( colored in green in Rich's picture) ? I do not see it under the intake manifold. Is it somewhere under the throttle body ??

I am really having a hard time orienting myself to the diagram.

[Bay13]

OK the PCV box (green is located under the intake manifold, bolted to the block inbetween cylinder 1 and 2. The blue induction is the black large plastic piping that comes out of the air box, the Mass Air Flow is connected to it, then it heads down and connects to the turbo intake.

The danger with running without a PCV thats working is that you have excessive pressure and that pressure will work on your seals and cause leaks.

This is my question to Rich - can you purchase from the dealer that entire run of hoses already assembled? In other words, the white vac line plus the large PVC hose together already inside the large rubber sheath?

Yes when you buy the hose/hoses they come all made up as one unit. Problem is that to get the hose on the PCV box you are going to need to pull the intake manifold.

[NateB]

OK the PCV box (green is located under the intake manifold, bolted to the block inbetween cylinder 1 and 2.  The blue induction is the black large plastic piping that comes out of the air box, the Mass Air Flow is connected to it, then it heads down and connects to the turbo intake.

The danger with running without a PCV thats working is that you have excessive pressure and that pressure will work on your seals and cause leaks.

This is my question to Rich - can you purchase from the dealer that entire run of hoses already assembled? In other words, the white vac line plus the large PVC hose together already inside the large rubber sheath?

Yes when you buy the hose/hoses they come all made up as one unit. Problem is that to get the hose on the PCV box you are going to need to pull the intake manifold.

Thanks Rich !

Sounds like a job for my indy Volvo specialist - rather than a DIY. I looked under the hood, and it looks like a PITA to DIY.

Guess I am getting old- cause I think I'd rather pay someone else to do it.

Is it as big a PITA as the job looks ??

[Bay13]

Lot more than an Oil change.

It's time consuming, and lots is being taken off and moved, if you are not familiar with whats going on it could be a PITA. It all depends on what you want to do.

[pfeener]

Rich, could you give us a paragraph on the theory of how the crankcase ventalation system works in the Volvo system. In a car with just a regular PCV valve, it just sucks air out of the cranckcase as long as there's maniford vacuum. If the manifold pressure drops, when the accelorator is haevily depressed, the PCV check valve closes and keeps the crankcase from being pressurized.

I assume the Volvo system accomplishes the same basic thing, but it isn't intuitive in how it functions.

[Bay13]

The PCV system on the Volvo doesn't have the PCV valve that opens with vacuum and closes with loss of vacuum.

There are no check valves in the 850 PCV system. Lets start with the PCV box, it can be set up with various connections from the block as well as the head. the fumes will be directed to the PCV box, mainly the top portion of the box via connections, there is a bottom connection at the block that allows condensed oil and such to go back into the block. Once the fumes are in the box, there is always a large hose leaving and going to hook up some where on the intake. The large hose going to the intake needs a little help to have it drawn out and thats where the small little vacuum line comes into play. Usually the large and small line are wrapped to gether for much of the run to the intake. This mixture of gases is kept as warm as it can be to help to keep it from condensing. The ones with turbos can see the oil that lines the discharge pipes going to the intercooler, that is oil that has condensed.

[pfeener]

Thanks, Rich. That's makes a lot more sense. Basically what it sounds like you're saying, is that there are no moving parts to the system and as long as the piping doesn't get clogged or spring a leak the system should work fine.

[Bay13]

as the piping doesn't get clogged or spring a leak the system should work fine.

Exactly

The oil mixture in the vapor is hard on the rubber, good thing to keep an eye on. Every two or three years.

[ziddey]

hmm

i believe that my volvo has been smoking out the oil cap and dipstick ever since i got it about three years ago. i went to the dealership to get a new oil dipstick because it was broken when i got the car and i thought that was what was causing my check engine codes. thats what the dealership said when they jacked me $75 too and said it would be good.

then they sold me the wrong dipstick and refused to take the old one back

then the check engine came back

and they said i needed a new o2 sensor

i explained that it was changed two times in the past three years already and so they reexamined it and said it was just a fluke.

then it happened again and again and they told me to ignore it. they said it was probably just the computer not able to read the sensors correctly.

then i started posting here and found that it was indeed bad.

all the meanwhile, the car has been smoking out the dipstick and oil cap. and all the meanwhile, there has been this air noise when the car was on, which the dealerships i went to said was normal. and my boost gauge never exceeded more than a few degrees past pi/2 in either direction, and i mentioend it and they didnt say it was a big deal.

it wasnt until later that a friend and i finally pulled off the tb cover and found a melted vacuum elbow. i got that replaced and my turbo gauge went crazy on me. i had never seen a turbo gauge work like that before and it was wild. im so silly

im hopign that was the only vacuum leak that i had... i dont hear air anymore. im going to do a fairly complete stage0 this summer, and will without a doubt be asking for more help in the future.

but anyway, if that was my only issue, that ONE TINY elbow leaking that little bit, could that in and of itself cause my front o2 to go bad so bloody quickly?? or is there most likely something else? im willing to bet that if i caved into the dealership that i would have already replaced that twice by now.

ive even seen a cat low efficiency one night when i was in a rush to go home and probably had the turbo constantly spooling up and down

but since then, after the elbow fixing, its still showing front o2, so i know that thats already gone. do you think my cat can still survive? i have a front o2 waiting in my garage for when i go back home to my car in a few weeks

and so youre saying that the only problem the smoke out the dipstick could cause is leaky seals? ill still get that addressed, but i was a little surprised when the dealership explicitly said that it was normal and i just needed a new dipstick so that it doesnt escape and cause my checkengine codes


also, when i first got the car, and before i got the new dipstick, when the old one wasnt totally sealing the dipstick hole, there developed a white sludge of something when i was reading the dipstick. when i took it to a third party garage to get an oil change done, the mechanic strongly advised me to do a engine cleanup which i did. but what a mess i guess

anyone able to comment on any or all of what happened?

thanks!