I tried searching the archive, and didn't find an exact answer, so I'm going to ask another question here.

I have an oil leak somewhere. I bought the PCV kit because I'm over 100k, and it's never been done.

Looking around, I see oil 2 places. Around the spark plug cover all the way on the drivers side of the engine, and on the bottom of the core support.

I'm going to clean both areas well today and see if the oil comes back.

If the oil is under the spark plug cover, where is it coming from? Along with the PCV kit, should I expect to need to replace any cam seals or any other seals? Or should the PCV kit eliminate any pressure, and that will fix the leak?

I need to get an oil cap gasket. I am putting together my 2nd FCP order (this stuff is addictive!) and will order a couple new gaskets. I don't see any oil leaking around the cap, but I've not taken it apart and examined things real close yet, either.

Thanks!

 

Do the cleaning and the PCV and then see if you have any further leaks.

I can guess the oil under the spark plug cover is from the oil fill cap seeping same with the oil on the core support being pushed out the oil dipstick tube. If it looks wet at the top it's likely coming out of there. There is no gasket or seal on that dipstick.

 

That top hose next the oil cap could be disconnected and leaking.

 

Make sure the passage in the block is open for the PCV (black box) to drain.

 

Hi There,

Before I cleaned/installed a new PCV kit, I had leaks and oil in the same places you describe. I cleaned out all of the oil and although I didnt replace the oil cap seal, the "leak" disappeared. I havent seen oil under the spark plug cover since. Also other myterious leaks have since gone away.

 

Kiss- that second shot you submitted, looks like it was taken from underneath with the oil pan dropped, unless I'm just reading that shot wrong. I did the whole pcv service about a year ago and still have a smoky dipstick tube. I replaced everything, but didn't drop the pan and clean out anything from underneath. Canister ports were about 70% blocked. Is there anything to clean out from below to do a proper PCV service?

 

I finally came across a guys post who had cut open the "black box" and had posted pictures of his clogged system.

That isn't my engine. I stole the pictures.

That is with the pan removed but I'm thinking if you just pulled the box and shoved something wood or plastic down there a few inches you could tell if it was open or if you needed to do some chipping to get it open.

That might be a situation where you'd use a strong cleaner and keep working it and adding more as you work you're way down between letting it sit a bit to soften up some.

Even if you ended up pushing it into the pan you'd be good as it would over time break down and get drained out during a LOF and or trapped in the oil filter.

 

The two red arrows in this picture taken of my old engines sump show the oil drain ports in the sump where the PCV oil drains back in to the base of the sump, the end of the "pipe" bends back up on its self so rodding the port out from above is impossible to clear as you hit the bottom of the sump, when it is this blocked you have to take the sump off to dig the carbon out (note picture was taken after I removed the baffle plates in the sump to show the return path to the sump, with the baffles in place you can just about get to the end where it spills in to the sump pan - Mike

 

OPPS !! Like I said, I stole the photos and I haven't been inside a Volvo engine. I thought that was the block upside down.

Being the pan, no way you're going to get that clean without roto-rooter coming out with an auger
I had always thought from other people that it was possible to fish the crap out or what you couldn't get out, push in.

That and now that I've seen the inside of the "black box" I've changed my opinion of people who talk about cleaning them out. I thought they were heavily baffled and likely had some kind of metering orfice in there. The thing looks cheaper than the catch cans you get for ricers on ebay !!

I'm seeing why some guys still have crankcase pressure and dipstick smoke even after doing the PCV black box.

 

There were baffle plates in the sump, I removed them to take the earlier picture so you can see the PCV Oil return path better, when the baffles are in place you can get to the oil drain but only just - This is why connecting a length of 5/8" hose to the lower port on the engine block and blowing through it when changing the PCV is so important, it is the only way you know it isn't blocked - Mike

 

Great idea with the hose blowing. I did that with a hose going to the box the last time I did someone's system without a new box.

I'm not sure how good of an idea it is to poke that crud down into the motor. I was working on an A4 the other day and found that the oil dip stick tube was falling apart. When I asked the dealer service guy about it he said that the pieces fall into the oil pan and clog up the oil pick up then starve the motor of oil (causes low pressure lights and all).

 

If the return port is blocked get 3 or 4 yards of clear plastic tube about 1/4" internal diameter and feed that down in to the sludge and carbon. When it hits the bottom of the sump pull it out and clean off the mess then chop off the bit that is packed with carbon and sludge as the pipe will fill up as it is forced in to the port. Keep repeating this until the pipe comes up clean, this will take around 3 yards of tube! Make sure you are getting all the way to the base of the sump as there is a slight step where the sump meets the engine block which can feel like the pipe has hit the bottom.

At this point connect the 5.8" hose to the lower port in the block and try and blow through it, if you can't it really is time to drop the sump to attack the blockage properly, I tried sending carb cleaner down it, blowing in to it with the thin clear tube to agitate the fluid but all to no avail.

If you don't fancy leaving the carb cleaner down there overnight to soak and it is still blocked use the 1/4" clear pipe to suck up the carb cleaner fluid, watch it come up the pipe with care though as it doesn't taste too good! Obviously after doing all this with carb cleaner if it is successful and clears the blockage change the engine oil with it cold, don't risk running the engine with carb cleaner in the sump.

When the sump came off I had to use a thin screwdriver and drill in to the blockage to get it all out, only the part within the sump where the oil exits was still blocked, the carb cleaner and clear plastic pipe trick had completely cleared out the main downward portion on the oil drain path.

I can't see the point in not replacing the PCV tank at all when doing this job it costs under £20 in the UK so probably around $30 USD unless they are overcharging for parts - Mike

 

So could I clean out those ports from underneath if I dropped the oil pan?

I think maybe you all gave me too many details all at once. dave

 

Dave, I would try clearing it out through the port in the engine, if you can do it this way it will be far quicker and cheaper, the sump is sealed to the bottom of the engine with a liquid gasket/ glue which is applied with a roller and isn't cheap, you also need to get the mating surfaces spotless with no oil dripping down on to them (not easy) - Mike

 

Mike- ok, when I did my PCV service I had the intake manifold off and replaced the oil seperator (and hoses). I cleaned out both of the ports on the lower engine block, (did see a decent amount of buildup) but i didnt run a brush (snake) down into those ports.

Are those the ports you are refering to? That pcv job was pretty involved and I'm not too keen on doing it all over again. I seem to remember that none of that stuff was accesable from underneath, right? Dave

 

I'm pretty sure drain hole No. 1 is the one that mates up to the drain on the side of the oil pan in the other picture.

No. 2 should be open to the crankcase but I'd like someone who knows for sure to jump in and say if it is.


Finally figured out the engineering. They run the drain below the surface of the oil in the pan so the vacuum applied to the box draws in the vapors from hole number 2 as it's easier than sucking up the oil itself.

 

Indeed number 1 is the PCV oil return port
number 2 is the crankcase blow-by port

I have included this next picture from the set when I did the PCV job a few months back, if you take off the sump you will see the baffle plates inside looking like this, the red arrow points at where the oil flows out and most probably where the blockage is:



Once the baffle plates are removed (don't do this other than for a photograph as they are riveted in place and you can get to the port within the sump to clean it without taking the baffles off:



The full guide I wrote for swapping out the PCV contains 29 pictures, I could split this across two posts in the same thread if you think it would be of any use, it is for a phase one V70 built 2000 with Denso engine management and 5 speed autobox - Mike

 

You could post a like if you wanted to but it isn't necessary to repost it as there are plenty of articles with pictures out there already.

Thank you for the info though. It's little crap like that PCV passage in the pan that tend to show how much I don't know.
Every engineer wants to make something new. Some better , , , some just different !!