Hey guys. I finally got around to replacing the rear cam seals, but I'm finding out that both screws are already stripped on the one that's leaking. Looks like the previous owner had tried to either do it themselves or a mechanic had stripped them. The oil leak isn't that bad though. How long can I go without replacing the seal? Will it get worse? How much oil is too much to leak?

Thanks for your time!!

 

Replacing the rear cam seal (only on passengers side) is relatively easy, especially with the Volvo special tool. You simply place the seal on the tool and turn the bolt on the tool which goes into the hole for the little cam sensor plate. I carefully used some very fine sandpaper to polish the cam surface the seal rides on. I liked the OEM seal from a dealer better than the after market seals. The bolts only hold the cam position sensor in place, they have nothing to do with any leak. Therefore, a prior owner / mechanic probably over tightened them attempting to slow / stop a leak.

If the leak is on the drivers side, there is no seal but simply a plastic plate popped into place, that is also available and requires no special tools to replace.

You will need to get the heater coolant lines out of the way at the back of the engine, so I suggest replacing those and possibly getting rid of the coolant blocking valve for max AC operation. The new coolant blocking valves are all plastic (OEM is only partly so) and if they fail the engine will likely overheat without much indication.

 

Thanks for the info, but I can't even start the seal replacement with both bolts (holding the sensor cover on) being totally stripped. I could probably get to the first one with a pair of vice grip pliers, but the second one is a little recessed/flush with the metal.

I'm going to get a local shop to take a look and give me a quote.... unless someone thinks I should just leave it. When should I start to worry about it? I'm cool with a really small leak.

 

I've had the head in pieces, so I know there is no high pressure source of oil behind the seal. We drove the first S90 for a couple of years before I replaced the seal. There only drawback is the hot oil smell after longer drives, we never lost much oil on that leak. The larger oil leak that happened on both our S90s was from the "oil cooler" at the filter mount, both cars had warranty repair that simply smeared RTV everywhere. A careful cleaning and using just lightly oiled new o-rings is an easy fix for that one. I use the word cooler in quotes because I think is actually an oil heater for emissions related to cold start.

 

Yep, I smell the burnt oil often, but that's not bad at all. Thanks for the advice. I'll get the shop to look at it and give me a quote and if it's not crazy probably have it done sometime next year. Between breather boxes, timing belts, misc parts, and shocks/struts my car budget is at the max for 2016.

On a side note I've been driving the S90 to work and back around 2-3 times a week with no problems. I think there's something lose with the front driver's side suspension, but that can wait for another post.

 

Trying to get rid of "clunks" I've been through most of the front suspension. If parts are original, a simple place to start is the roll bar links. The rubber dust boots crack with age and they start to snap with steering, dips, etc. FCP sells heavy duty replacement links, which are much better made than the aftermarket (better than Volvo OEM in my book). Those are two simple nuts each. The other part that frequently goes is the rear lower arm bushing, OEMs seem to be 5 yr +/- and aftermarket can be much shorter. I bought the Volvo tools and a press to do the job, after having the work really screwed up (they stripped a suspension thread) on our original car. I continue to wonder if most current mechanics have ever heard about using a torque wrench. The front lower arm bushing appears to be fairly robust, but if any work is done on the arm the front bolt / nut needs to be tightened ONLY with suspension loaded to normal ride height in order to avoid damage to the front bushing (that is in the maintenance guide). Good luck with the car, my wife loves hers.

 

Another thought, with the roll bar links I found a thin open end wrench useful (which I had for work on my Maserati). I can remember which size I needed for the Volvo, but my wrench is 16 mm on one end and 18 mm on the other. The wrench is used to hold the ball in place while installing each nut.