Volvo oil leak? PCV issues that could be the cause

It’s a little after lunch time and I wanted to give you guys a quick rundown of my morning. A 99 Volvo V70 came in, this car happens to be my brothers. He had called me a few nights before saying his oil light came on right before he got to work, when he got there he saw a good sized puddle under the car. I told him to check the oil, none on the stick….crap.

I had him top it up and start it, sure enough he saw some oil slowly dripping. So that’s where we start, I had him tow it in. The first thing to do was put it up and find the leak…. oil everywhere, especially at the crank pulley area. I pulled the timing cover and found the intake cam seal had blown out and the exhaust cam seal was very close to blowing out as well.

Timing belt, water pump, job sweet!

Hang on, what I really want to talk about is why this happened. You can just do the oil covered belt and pop some new cam seals in and call it done right? No way, and if you did think this was a good idea you will have comebacks.

Anytime a seal blows out you need to confirm why, and the way to do this is by checking crankcase pressure. If we have a breather system that is not functioning properly the engine can develop positive pressure, thus blowing out the weakest link, in this case our cam seal.

I cleaned it all off and replaced the timing belt, seals etc. make sure you do all rollers and tensioner. I also replaced the water pump. After this I started the car with the dipstick pulled out a bit to release pressure, if it is that bad you don’t want to blow out the new seals.

I hooked up the cem meter and this is what it read, this is a millibar reading. It indicates – 1.4 millibar. One quick note, our cem meter has been around for a while and -1.4 is the zero point of our meter. All of this indicates zero vacuum.

Remember this is with the dipstick out a little, next I pushed it in and watched my reading.

You can clearly see here that the breather system is not functioning, without the dipstick venting the pressure we are already developing positive pressure. Now we know why those seals blew out. This is the reason you need to check this stuff, if we just replaced the seal we would have a comeback for sure.

Off with the intake!

So here you can see the black breather box and hoses. All of this gets replaced, the rubber gets soft after a while and tears. Let’s remove it.

Now we can see the ports that the breather hooks into. One other thing is the importance of oil changes, below is a picture of the breather port on the engine block, you can clearly see how restricted it is with sludge.

Nasty stuff!

Next I match up all of the hoses and make sure everything will line up correctly before clamping anything. Make sure not to over tighten these hoses, it can cause slices over time. Remember we need to do this right, all of this is buried under the intake.

Here it is with the breather components, now we reinstall the intake with new gaskets and injector seals.

Ok , the intake back on and torqued properly. I’ve hooked up all the vacuum hoses and done some small odds and ends. Sometimes after a job like this I’ll hook up the smoke machine just to make sure I didn’t leave a line off or something along those lines.

Everything looks good, fire it up.

After running for a bit we hook the CEM meter back up, we can now see that we have fixed the issue. I love this, – 4.2 indicates proper vacuum in the breather system. Those new seals will stay where they belong now.

You can 100% see that we have corrected the issue. we can hand the keys to the customer with confidence, this one is done.

Thanks for reading.

%d bloggers like this: