94 Volvo 850 Turbo 2.3 with crankcase pressure and oil leak

rippertele · Post by **rippertele** » 12 Nov 2008, 11:31

So I've had an issue recently with the crankcase pressure and my seals (rear main and cam) blowing oil all underneath my car. I managed to find a loose vacuum hose on my turbo and replaced it. that seemed to help a bit but I still go through 1/2 qt of oil in 200 miles. My fuel economy is fare at 28 mpg hwy so I'm assuming I've found the main vacuum leak. I have flow through my oil trap and over to my intake hose so my PVC appears all good. Now, I still have a bit of smoke coming from the dipstick so this morning I decided to run a lg vacuum line from my vacuum tree and stuck it in my dipstick hole to pull the remaining pressure off the crankcase. The car smoked a bit at first but then ran well getting 30 mpg. Is this not a wise thing to do? I also tried the vacuum line off the tree and on the accordion intake hose to run the fumes through the turbo system. Both ways the car seemed to run fine. I've yet to see if the oil leak has stopped but I don't think it has. Now, I'm almost wandering if the oil leak could be somewhere up around or above the turbo because the back of the engine around that area is wet with oil. It has to be coming from somewhere that it is fairly heavy to have the underside of the car oil soaked all the way back to the rear. NOW, to complicate things worse...I recently had the timing belt, water pump, 1 crank seal and 2 cam seals replaced out of town. When I returned home, 500 miles later, I felt like it was leaking on that side. I had my local mechanic look at it and then he said he let it idle for .75 hour and could not see any major leak on that side and felt the seals were all good. Now when I run the car on the street and then park it there is oil all over the bottom of the timing cover and dripping off the frame just underneath that side of the engine. After looking it MAY be coming from just on the back side of the timing cover against the engine up a little higher on the engine but I can't see past that area. When I took the cover off I can see it's pretty wet down near the lower part of the case but no oil on the belt. I'm lost now and feel like I've tried everything but I'm also determined to solve the mystery. Can anyone help?

Post by **Ozark Lee** » 14 Nov 2008, 15:24

I have flow through my oil trap and over to my intake hose so my PVC appears all good.

By what method did you determine that?

Now, I still have a bit of smoke coming from the dipstick so this morning I decided to run a lg vacuum line from my vacuum tree and stuck it in my dipstick hole to pull the remaining pressure off the crankcase. The car smoked a bit at first but then ran well getting 30 mpg. Is this not a wise thing to do?

Any unmetered air is going to trick the O2 sensors into changing the fuel trim and it will likely set a CEL after it gets in a fight with the MAF sensor.

Now, I'm almost wandering if the oil leak could be somewhere up around or above the turbo because the back of the engine around that area is wet with oil. It has to be coming from somewhere that it is fairly heavy to have the underside of the car oil soaked all the way back to the rear.

The oil lines to the turbo can leak, there is a gasket on the inlet line and a couple of copper washers that seal a banjo bolt on the return line.

Now when I run the car on the street and then park it there is oil all over the bottom of the timing cover and dripping off the frame just underneath that side of the engine. After looking it MAY be coming from just on the back side of the timing cover against the engine up a little higher on the engine but I can't see past that area. When I took the cover off I can see it's pretty wet down near the lower part of the case but no oil on the belt.

It may be a leak in the oil cooler line connection. A leak there often migrates to the bottom of the timing belt cover.

What you need to do is throughly degrease the engine - top and bottom and then go after them one at a time. Despite your statement about "flow through the oil trap" I think you are way overdue for PCV service. It makes no sense to change a bunch of seals just to have them get blown again.

...Lee

rippertele · Post by **rippertele** » 19 Nov 2008, 12:51

Well, I blew through each end of the hoses from the top of the engine down through the oil trap and out the hose that connects to the turbo intake. I even blew into the oil filler and had air come threw each of the other attached hoses. Ok, now do you have a pic or something to show me where to find each of these places to check?

Post by **Ozark Lee** » 19 Nov 2008, 15:39

It may be that the oil trap itself is clogged between the "goes-inta" and the "goes-outa". The air would flow around that but it would never relieve the pressure from the crankcase itself. I know of no test other than observing pressure at the dipstick to determine whether or not it is good. You could pull it apart and look for blockage but at that point you might as well just change it all out.

...Lee

SnookWhaler · Post by **SnookWhaler** » 19 Nov 2008, 16:12

Ozark Lee wrote:
It may be a leak in the oil cooler line connection. A leak there often migrates to the bottom of the timing belt cover.

What you need to do is throughly degrease the engine - top and bottom and then go after them one at a time. Despite your statement about "flow through the oil trap" I think you are way overdue for PCV service. It makes no sense to change a bunch of seals just to have them get blown again.

...Lee

+1

You have got to clean things up before you can determine anything.

You can also do a compression check to determine how bad the "blow by" is. IE: Low compression (worn rings/cylinders) = lots of blow by and vice versa. This alone can tell you a lot.

You cannot determine if your PCV (Positive Crankcase Ventilation) is bad by simply blowing through a hose. It is not just the "air", but the "volume of air" that could be the root of the problem.

This system needs to be serviced or at least removed and checked at intervals to determine if it is indeed plugged. The passage where the PCV system plugs into the block could be almost completely blocked as it is a fairly large opening. Air can still flow though... But, not enough and your dipstick will wind up popping out every 20 miles.

Once those seals are blown, that's it. Replacing any of the seals without doing a compression check or at least checking the PCV system is asking for problems again.

When troubleshooting... Always eliminate the "obvious" first.

rippertele · Post by **rippertele** » 19 Nov 2008, 18:50

ok, I was just hoping not to have to get into taking apart the manifold because for me that's gonna be a new venture. Also, I've found that freckling Volvo leaves NOTHING easily accessible and I always strip screws because they're so tight. Nonetheless, I guess I have to get er done and see if that helps. Any pics of the other oil hoses for me to locate? Thanks for your help guys. My local mechanic charged me $45 to look under the caar and tell me the rear main is gone when I asked him to locate the oil return line and other areas of possibilities. THEN he got pissed because I told him I use these sites. This is exactly why I use them because mechanics that do nothing and then send you the bill and a diagnosis that I already knew was possible.

SnookWhaler · Post by **SnookWhaler** » 20 Nov 2008, 14:45

I am new to this site. So, I am not sure where to look. There has got to be a write up with pictures and diagrams somewhere. Probably in the "Repair Database" above.

This is at the top of the 850 page here. Pinned at the top. Shows alot of the routing: http://lakesidedp.com/uploadpics/pcv/

I'm pretty sure VS. has the tutorial as well. I used one when I did mine. I just cannot remember which site.

Or do a search for PCV system (Positive Crankcase Ventilation).

NOT PVC! PVC is PolyVinyl Chloride. That is the stuff for plumbing and plumbers.

double_platinum · Post by **double_platinum** » 21 Nov 2008, 08:28

Well, I blew through each end of the hoses from the top of the engine down through the oil trap and out the hose that connects to the turbo intake. I even blew into the oil filler and had air come threw each of the other attached hoses. Ok, now do you have a pic or something to show me where to find each of these places to check?

LOL Only if you have a picture of your face after you blew into the oil filler

Just kidding, been there and I sympathize

rippertele · Post by **rippertele** » 13 Aug 2009, 22:30

Ok, I have an update but still confused. I pulled the oil trap and it was free and clear of any clogs. I cleaned it thoroughly and then replaced it making sure that every hose had a nice tight clamp on it. Now I noticed the oil leak on the cam side (passenger) seems to have disappeared, for the most part. Although, the leak on the rear main (drivers) side seems to remain steady. NOw, with the car idling I counted 5 sec. between each drip. Here's the catch, I then ran a tube from the vacuum tree to the dip stick and low and behold the drips changed to 20 sec. apart. Is this the crankcase pressure? Where the hell is the clog if the oil trap and lines are clear? I put a larger than normal hose from the PTC nipple on the intake (accordion hose) and boy you can really hear the suction has increased so I feel the PTC is clear. I also plugged this line to the larger nipple left of the vacuum tree which originally had the hose to the EVAP valve, I think, but I placed an adapter on that large hose and placed it on a small vaccum nipple. I was trying to pull the greatest amount of volume off that crankcase through that PTC. Any ideas? Does this still mean the rear main is blown and needing replacement? This oil leak is making me crazy...not to mention it's super messy.

FCPEURO · Post by **FCPEURO** » 14 Aug 2009, 07:45

The RMS does seem like it needs to be replaced because it is still dripping. Did you take the PCV box out and make sure all of the holes in the block are clear?