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S80 T6 Cam Seal Replacement — Oil Leak Repair, Timing, PCV

MVS Forums guru zacharyzoosh shows us how to do an S80 T6 cam seal replacement, timing belt and PCV:

“Hello. I’m here to share a recent repair I’ve finished on a 1999 Volvo S80 T6 (2.8 liter turbo automatic dual over head cam VR6) This is applicable to all P2 Volvos generally, as the repair here is the CAM SEAL Replacement, with an overview on checking the PCV Air System (Positive Crank Ventilation). Subsequent years of other Volvos should be relatively similar.

If you have one of those bad Volvo oil leaks where oil is smattered all over the top of the engine in puddlse around the coil packs, and all in and around the timing belt and accessories, then most likely you need to replace the Camshaft seals, and also you most likely have a PCV problem. Cam Seals usually blow because of positive pressure in the upper crank case. This only happens if the PCV air system isn’t working properly. I recommend also checking/replacing your timing belt, crank seal, rear cam seals/covers as well as: Waterpump, pulleys, accessories and serpentine belt as these parts will all be accessed throughout this process.”

S80 T6 Cam Seal Replacement

S80 T6 Cam Seal Replacement/Oil Leak Repair, Timing, PCV

If you’re going to be inspecting/replacing your Cam Seals/Timing Belt etc, you’ll want to prepare the proper set of tools and at least a minimum of a couple days for the project (unless you’re a speedy pro and have helping hands) because you’re going to want to clean and inspect each part as you go through it, especially if the parts are saturated in oil. I took about two weeks on this job because I had to eek through the process for the first time, and I had to order the special cam stabilizing tool, as well as all the various parts I decoded to replace as the process unfolded. On my last day of re-assembly where I had everything apart, and all parts in hand, it took me a full 8 hours to put it all back together thoroughly. That’s just an estimate so you book yourself enough time to do the job with realistic patience.

Tools: You will need a special cam stabilizing tool (see picture) to hold the camshafts from the rear in order to remove the timing belt and be sure to not loose position.

Excerpt — S80 T6 Cam Seal Replacement

I installed a whole new PCV system, so I’ll take you through that process here.

The bolt that holds the PCV hose assembly to the Manifold underbelly is 17mm, and is a hollowed bolt with a passageway. The passageway hole should line up with the air line pathway on re-installation, so pay attention to how this bolt is when you start to remove it. This may be where a problem exists. I found a bunch of oil backed up at this section, because the previous mechanic installed it wrong. Be sure there is a washer on each side of the bolt and not two on one side.


Once you remove the one side of the PCV assembly hoses, follow the lines around to the other side of the engine. One of the three lines went to the turbo assembly up top and will already be floating free. But the other two are connected. One is connected to the driver’s side of engine below and between the rear cam covers. My lines were switched (I don’t know what fool did that last assembly) but if you buy a new kit, you’ll see that one line has a rounded head, where another hollowed bolt and washers is to go. The other hose attaches to a metal welded line that pops off another line that goes around the back of the engine and up to feed the turbo system I believe. That line just attached like a regular air hose with a metal ring clamp.

After removing all lines on the PCV Hose assembly, you can pull that out from under the Intake Manifold and out of the way.

Next to remove the oil trap/breather box, you must actually remove the alternator and the AC clutch from its housing bracket. You must also remove all bolts from the accessory housing bracket in order to get to the oil trap box’s left bolt. Its ridiculous I know. I was cussing a lot when I realized I had to remove all these things just to get to one bolt, but its true, you’ll see for yourself.


You don’t’ need to disassemble any of the power steering. Only one of the alternator bolts attaches to the power steering metal frame. But the lower Alternator bolts are designed into the AC bolts, The same bolts hold both in, and are framed by the metal supporting plate behind them.
So you have to remove all the bolts of the metal housing plate which the AC and ALT attach to.

Start by removing the upper AC bolts (which are also the Alternator bolts, he he), then remove the upper alternator bolt. Detach Alternator Electronics, pull away from assembly, and set Alternator aside.
Remove all AC Clutch/pump assembly bolts, but leave all lines and electronics intact; and let lay against whatever.

Working around the loose AC assembly, remove all bolts from the metal housing bracket that theAC and ALT were attached to, and which hides the one Oil Trap Box bolt that you need to get to. I removed all bolts but the lower right bolt, which I just loosened. That way I could just twist and lean the bracket out of the way and leave it in place (see photo)
Removing Air breather Box/Oil Trap:

As you can see, the oil trap box has a couple bolts, 10mm, easy to access NOW, and one hose moving down to the right side of the engine block. Loosen any remaing clamps, and the bolts and pop the box right off. Clean the port holes of the engine block as good as possible, and inspect breather box for build up.

This completes the PCV system inspection. I recommend installing a new PCV system if you’re unsure about any portion of this system. My system was good, but I had to replace the whole kit because I broke pieces taking it out. My problem was that it had been installed wrong. So take note of that if you bring your car home from a shop and all of a sudden you have a major oil leak! Hmmm. The important things to note are condition of breather box buildup/air flow, the hollow bolts and proper washer placement, and correct installation of each hose to its proper location.

Re-assemble in reverse order, and be very careful not to drop any manifold bolts on the install! Use something stick on the bolt head so you don’t drop it back down behind the oil trap.

S80 T6 Cam Seal Replacement/Oil Leak Repair, Timing, PCV

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