Mystery oil leak from cam cover

broken08 · Post by **broken08** » 29 Jan 2018, 17:04

1998 v70 awd. Did head gasket this year and have been noticing oil on top of the head/ cam cover and out the rear which drips on the turbo. The obvious thought is that I didn't do a good job sealing the cam cover, but the strange part is that the large, 2" circular plug seems to have oil on it always, making me think perhaps oil is leaking out of that and then running back down.
I will do a uv dye test after i clean it all up, but want to know if this is common. What is that plug for? Should I just smear some rtv around that?
thanks all.

Post by **bmdubya1198** » 29 Jan 2018, 17:54

If you're referring to the plug/cap opposite the oil cap (I think that's the only 2" plug on the cam cover) I don't think it's common for that to leak. I've seen them pretty stained and nasty looking, but I don't think I've heard of them leaking.
I think that's there because of the similar casting of the cam cover to the 6 cylinder, which has the oil filler cap on the opposite side.

It could be the top PCV hose that's leaking. When was the PCV last replaced?

Post by **RickHaleParker** » 29 Jan 2018, 18:41

What is that plug for?

The one on top of the cam cover or the Cam seal cover / Crankshaft position sensor on the back of the head?

The one on top is where they mount the Oil filler and cap for Right Hand Drive cars.

Post by **precopster** » 29 Jan 2018, 19:11

RickHaleParker wrote: ↑29 Jan 2018, 18:41 What is that plug for?

The one on top of the cam cover or the Cam seal cover / Crankshaft position sensor on the back of the head?

The one on top is where they mount the Oil filler and cap for Right Hand Drive cars.

Question 1 : Not in use on any Volvo whether LHD or RHD. The only difference in the engine bay b/w LHD and RHD in a 2000 model is the location of braking and clutch systems

You can reseal the plug with a 2 part epoxy rated for high temperature. Autozone, Napa etc will have a variety of brands you can purchase. Worked a treat on my 2001 T5 with the same problem without having to reseal the cam cover all over again after dealing with the head gasket.

Post by **RickHaleParker** » 30 Jan 2018, 00:38

Question 1 : Not in use on any Volvo whether LHD or RHD. The only difference in the engine bay b/w LHD and RHD in a 2000 model is the location of braking and clutch systems.

Oh you got me, I am kind of joking on the LHD/RHD. However the plug is in a second Oil filler port. I cannot come up with any reason they would do two unless it is so the oil filler can be put on the left or right in rear wheel drive cars.

The only reason left or right would make and difference in rear wheel drive cars is, so oil can be added when standing on the curb instead of standing in the street ... LHD vs RHD.

It is a modular engine designed to be flexible and the ability to build multiple versions with the same tooling. It make perfect sense that the engine designers would take front wheel drive and rear wheel drive into consideration when designing a modular engine.

It is a safety feature, the kind of detail Volvo engineers are known for. Production may never of taken advantage of it but the engineers made the option available.

: DualOilFiller.jpg (11.83 KiB) Viewed 3035 times

Post by **bmdubya1198** » 30 Jan 2018, 14:59

RickHaleParker wrote: ↑30 Jan 2018, 00:38 Question 1 : Not in use on any Volvo whether LHD or RHD. The only difference in the engine bay b/w LHD and RHD in a 2000 model is the location of braking and clutch systems.

Oh you got me, I am kind of joking on the LHD/RHD. However the plug is in a second Oil filler port. I cannot come up with any reason they would do two unless it is so the oil filler can be put on the left or right in rear wheel drive cars.

The only reason left or right would make and difference in rear wheel drive cars is, so oil can be added when standing on the curb instead of standing in the street ... LHD vs RHD.

It is a modular engine designed to be flexible and the ability to build multiple versions with the same tooling. It make perfect sense that the engine designers would take front wheel drive and rear wheel drive into consideration when designing a modular engine.

It is a safety feature, the kind of detail Volvo engineers are known for. Production may never of taken advantage of it but the engineers made the option available.

DualOilFiller.jpg

Now that I look at a B6304 (960/S/V90) again, the oil cap is actually mounted in the same fashion as the B52XXX. Now I really don't know why it's there...
Although it's worth mentioning that the N/A S80 has both of those spots plugged. The oil filler cap is mounted in the front right of the cam cover.

Post by **abscate** » 31 Jan 2018, 07:21

Ah but that S80 is a 6 cylinder, unless one of those intake manifolds is a dummy, like the Titanic

Post by **June** » 31 Jan 2018, 08:01

bmdubya1198 wrote: ↑30 Jan 2018, 14:59
RickHaleParker wrote: ↑30 Jan 2018, 00:38 Question 1 : Not in use on any Volvo whether LHD or RHD. The only difference in the engine bay b/w LHD and RHD in a 2000 model is the location of braking and clutch systems.

Oh you got me, I am kind of joking on the LHD/RHD. However the plug is in a second Oil filler port. I cannot come up with any reason they would do two unless it is so the oil filler can be put on the left or right in rear wheel drive cars.

The only reason left or right would make and difference in rear wheel drive cars is, so oil can be added when standing on the curb instead of standing in the street ... LHD vs RHD.

It is a modular engine designed to be flexible and the ability to build multiple versions with the same tooling. It make perfect sense that the engine designers would take front wheel drive and rear wheel drive into consideration when designing a modular engine.

It is a safety feature, the kind of detail Volvo engineers are known for. Production may never of taken advantage of it but the engineers made the option available.

DualOilFiller.jpg
Now that I look at a B6304 (960/S/V90) again, the oil cap is actually mounted in the same fashion as the B52XXX. Now I really don't know why it's there...
Although it's worth mentioning that the N/A S80 has both of those spots plugged. The oil filler cap is mounted in the front right of the cam cover.

The T6 also has both plugged with the cap towards the rear of the engine. Maybe that moved the oil cap because the twin turbochargers have piping covering those plugged holes partially. Here is my T6 which is a 2004. June

Post by **bmdubya1198** » 31 Jan 2018, 08:25

Interesting they did it like that on the T6 too. The reason they placed the cap there on the T6 is pretty obvious though (or is it?), like you said with the intercooler piping.

abscate wrote: ↑31 Jan 2018, 07:21 Ah but that S80 is a 6 cylinder, unless one of those intake manifolds is a dummy, like the Titanic

Yes, that is a 6 cylinder, but it uses a similar cam cover because of the modular design. The reason I bring it up is because it's still a white block.
That is one ugly intake manifold though... I've never liked it.

Post by **abscate** » 31 Jan 2018, 10:18

The back plug is for Aussie models - its the engine drain plug. The oil fill is on the bottom of course.