Spent the last few weeks chasing oil leaks down the exhaust side of the engine and oil pan:
I found leaks from the following four places:
1) Turbo return line - I replaced the oring and seal
2) Rear cam seal - I replaced the cam seal
3) PCV hose under the spark plug cover was leaking, puddling oil on the head and dripping down the back through the weep hole - I put a better clamp on the hose.
4) The oil pan bolt wasn't torqued down all the way - I torqued it.
All four of these areas have stopped leaking, but there is STILL a small leak!
5) The elbow vacuum hose that connects the PCV system to the PTC valve had a tear in it, and it looked like a lot of oil vapor had collected all around that area. I had another elbow that fit and replaced it.
I'll check in a few days, I HOPE #5 was the last leak.
Question - would a tear in that vacuum hose cause oil to leak from it? I assume the oil vapor coming from the PCV system could find it's way out?
8 replies to this topic
#1
Posted Today, 03:45 AM
1997 Volvo 850 GLT wagon - 125K miles
1997 Volvo 850 R sedan - 115K miles
1997 Volvo 850 R sedan - 115K miles
#2
Posted Today, 04:23 AM
BlackBrick, on 25 May 2012 - 03:45 AM, said:
Spent the last few weeks chasing oil leaks down the exhaust side of the engine and oil pan:
I found leaks from the following four places:
1) Turbo return line - I replaced the oring and seal
2) Rear cam seal - I replaced the cam seal
3) PCV hose under the spark plug cover was leaking, puddling oil on the head and dripping down the back through the weep hole - I put a better clamp on the hose.
4) The oil pan bolt wasn't torqued down all the way - I torqued it.
All four of these areas have stopped leaking, but there is STILL a small leak!
5) The elbow vacuum hose that connects the PCV system to the PTC valve had a tear in it, and it looked like a lot of oil vapor had collected all around that area. I had another elbow that fit and replaced it.
I'll check in a few days, I HOPE #5 was the last leak.
Question - would a tear in that vacuum hose cause oil to leak from it? I assume the oil vapor coming from the PCV system could find it's way out?
I found leaks from the following four places:
1) Turbo return line - I replaced the oring and seal
2) Rear cam seal - I replaced the cam seal
3) PCV hose under the spark plug cover was leaking, puddling oil on the head and dripping down the back through the weep hole - I put a better clamp on the hose.
4) The oil pan bolt wasn't torqued down all the way - I torqued it.
All four of these areas have stopped leaking, but there is STILL a small leak!
5) The elbow vacuum hose that connects the PCV system to the PTC valve had a tear in it, and it looked like a lot of oil vapor had collected all around that area. I had another elbow that fit and replaced it.
I'll check in a few days, I HOPE #5 was the last leak.
Question - would a tear in that vacuum hose cause oil to leak from it? I assume the oil vapor coming from the PCV system could find it's way out?
Well, there is no vac line connecting the PCV system to the PTC. There is a vac line on the PTC that goes to a vac source (vac tree or a nipple on the side of the intake manifold). The large hose on the top of the PTC goes to the top of the flame trap. If the vac line on the PTC was torn, it would be possible for blow-by that would otherwise go back into the intake pipe to get escape out of the vac line since it is below the hose from the flame trip to the PTC.

1994 850 Turbo | Rica Stage III | Poke and Stretch
#3
Posted Today, 04:28 AM
Have you serviced your PVC system, make sure it isn't clogged causing all these leaks except the loose oil pan bolt.
95 850 T5-R - Sold : (
'00 V70R-STOCK/ ARD lightened Crank Pulley
'01 C70 Coupe - Stock
'00 V70R-STOCK/ ARD lightened Crank Pulley
'01 C70 Coupe - Stock
#4
Posted Today, 04:39 AM
ok, sorry, i meant the vac line from the intake manifold to the PTC has a tear in it.
Yes, I redid my entire PVC sytstem about 4 years ago. Unfortunately, I bought the URO parts version, back when I didn't know better. Hence the worn out part already.
I'm hoping the blow by is escaping and causing the oil leak, otherwise I'll be chasing down a 6th oil leak soon! If it is the blow by, at least I know the PCV system isn't clogged ;0)
Yes, I redid my entire PVC sytstem about 4 years ago. Unfortunately, I bought the URO parts version, back when I didn't know better. Hence the worn out part already.
I'm hoping the blow by is escaping and causing the oil leak, otherwise I'll be chasing down a 6th oil leak soon! If it is the blow by, at least I know the PCV system isn't clogged ;0)
1997 Volvo 850 GLT wagon - 125K miles
1997 Volvo 850 R sedan - 115K miles
1997 Volvo 850 R sedan - 115K miles
#5
Posted Today, 01:55 PM
The drain could be clogged for the PCV system. back then we (VSers) didn't advice cleaning all the way down the block passage like now. Kinda something that was always overlooked. If the drain is blocked then the PCV will fill out and then you will start to see oil in the PTC area and through the intercooler. More so then normally in those areas.
Just an idea though!
Just an idea though!
#6
Posted Today, 02:25 PM
Hmmm, interesting idea...I remember just cleaning out the entry passage to the block. Wasn't too bad if I remember. How does one clean all the way down? Do you mean with a large pipe cleaner?
I would hate to take the intake manifold off just to check things out. Are there more definitive ways to know if the system is clogged besides smoking dipstick, or assuming the cause of oil leaks?
I am doing the PCV on my other 850 soon, so I will definitely do this, thanks for the tip! And again, do you mean with a pipe cleaner? Or just spray some carb cleaner down the holes?
BTW, i'm suspecting the trace amounts of oil I found under the cam cover were actually leaking in from the above weep hole from the spark plug cover. The cam cover isn't sealed.
And the oil puddling under the spark plug cover was because the hose clamp wasn't the least bit tight. I switched to a worm clamp and it's bone dry there now.
I would hate to take the intake manifold off just to check things out. Are there more definitive ways to know if the system is clogged besides smoking dipstick, or assuming the cause of oil leaks?
I am doing the PCV on my other 850 soon, so I will definitely do this, thanks for the tip! And again, do you mean with a pipe cleaner? Or just spray some carb cleaner down the holes?
BTW, i'm suspecting the trace amounts of oil I found under the cam cover were actually leaking in from the above weep hole from the spark plug cover. The cam cover isn't sealed.
And the oil puddling under the spark plug cover was because the hose clamp wasn't the least bit tight. I switched to a worm clamp and it's bone dry there now.
1997 Volvo 850 GLT wagon - 125K miles
1997 Volvo 850 R sedan - 115K miles
1997 Volvo 850 R sedan - 115K miles
#7
Posted Today, 02:32 PM
Wish a clogged drain the system would still function normally in terms of crankcase pressure. What it would cause is oil to get sucked up into the PTC area since the oil trap would start filling up with oil. If your passage into the block was completely clogged then the passage down to the oil pan has a high chance of being blocked as well. I use a large zip-tie and run it up and down inside the hole with car cleaner. A pipe cleaner would be best but I just have the zip ties that bend well for the 90degree turn.
To test this out, you could take the top head hose and spray some cleaner down through it while you have the drain plug out and see if it flows into the pan and out the drain. If it does drain right away then you know the drain is probably clogged, if it doesn't and it takes a bit to get down to the drain then you probably filled the oil trap and it has started draining on the side port of the block (the larger one).
To test this out, you could take the top head hose and spray some cleaner down through it while you have the drain plug out and see if it flows into the pan and out the drain. If it does drain right away then you know the drain is probably clogged, if it doesn't and it takes a bit to get down to the drain then you probably filled the oil trap and it has started draining on the side port of the block (the larger one).
#8
Posted Today, 02:56 PM
just a quick question not to thread jack but would blowing into the hose and having air come back through the hole under the cover show that it was clear also just without having to pull the oil trap?
1998 s70 267000 miles
Repairs and replacements: strut mounts, spring seat,pcv,timing belt,power steering pump,sas delete,ectx2.
Repairs and replacements: strut mounts, spring seat,pcv,timing belt,power steering pump,sas delete,ectx2.
Tommy., on 14 May 2012 - 11:28 PM, said:
Wait, sandwiches can't help start an engine?!
oh the humanity!
#9
Posted Today, 03:00 PM
haha be more specific! what hoses are you talking about?
If you blow air into any part of the system, you will get air anywhere in the system as it is completely open.
If you blow air into any part of the system, you will get air anywhere in the system as it is completely open.














