'99 S70 T5 Rear Camshaft Plug Blowout

Post by **bmdubya1198** » 17 Dec 2016, 20:21

Well, another problem with my cousin's T5...
He's had an oil leak from that rear cam "plug" or cap (on the intake cam) since I stabbed it with a screwdriver when we were fixing the timing. He ordered a replacement (ProParts from FCP) cap a while back, and since we couldn't get it seated right, it was still leaking. Finally got it seated a couple weeks ago, and it blew itself back out after a drive. Led us to the PCV, assuming that excessive crankcase pressure was the cause.
Now here we are two or three weeks later, just did the PCV last Sunday, and the car is leaking oil worse now. Just noticed today the cam plug blew out again, which seems strange to me since the PCV is brand new, and any excess crankcase pressure should be gone. Almost looks like it's coming from the RMS, but I highly doubt it is. It looks like it's trailing down from higher up and coating the engine/transmission mating seam, like I've seen many times before with these cars. After a quick peak today, the rear cam seal on the exhaust side appears to be leaking. The wastegate TCV hose is wet, and it looks like oil is dripping from the cam position sensor. So that makes for two oil leaks...
Anyway, how it it that the plug keeps blowing out, even with a new PCV? Is it the wrong size maybe since it's ProParts Sweden rather than OE Volvo? Others seem to have had good luck with this part, so I don't see that being a real issue. Could it be because I put a cam seal on that side when it wasn't supposed to have one? I didn't realize until after I put the cam seal in there that the intake cam on coil-on-plug cars didn't have one due to that plug/cap. Seal is Duralast, so it isn't quite the right size and isn't seated (imagine that...). Anyone got any ideas why this keeps blowing out?

Post by **Ozark Lee** » 17 Dec 2016, 21:23

You can add a seal to the intake cam, I did that on the last '99 I had apart. That said, it shouldn't build up enough pressure to blow out the plug unless the plug doesn't fit correctly. I used OEM for the plug and it fits really tight.

...Lee

Post by **rspi** » 18 Dec 2016, 02:18

Have you tested the system at warm idle? The glove test?

Post by **bmdubya1198** » 18 Dec 2016, 08:54

I did a glove test a while back (before the PCV) and it was sucking in, so that's why I didn't think much of the PCV being blocked up. I might tell him to buy a new Volvo plug. This one seems to fit nice and tight, but the only thing I can think is that it isn't quite the correct diameter.