PCV service didn't release pressure.. Now what?

Post by **luketrash** » 09 Nov 2006, 21:37

Well, I got my new oil trap from FCP along with the misc parts I needed to finish the job.

I got everything back together and only lost one part in the process (the circular rubber ring mount for the IAC motor...)

I made sure 100 times that I had the ports to the crankcase cleaned out. The only one that was really 'plugged up' in any sense was the bottom most hole, which is the oil return port.

All of that was cleaned with a brush to the point it looked like the day it rolled off of the assembly line. I took my time (ha, four hours) to put everything back together.

Anyway, the dipstick still billows oil vapor when the vehicle is running!@ The only thing I can think of is that my piston rings must be shot and I'm getting a lot of blowby? I'll be digging around my garage for my pressure tester tomorrow.

Do any of you know the psi rating on the 850 NA from 1994?

- - -

Also, I started the car with my fingers crossed (cycled the fuel pump a few times before cranking it) and it started up. Exhaust smelled a bit rich, but I tried taking it out on the open road. As soon as the car shifted from first to second, the orange up arrow light started flashing on the dash and the car nearly died. It must have went into limp mode or something. The LED on the transmission economy/sport switch was flashing too. So I turned around and pulled back into my driveway and let it idle, looking under the hood for anything out of the ordinary.

FInally I just turned the key off/on 4 times and the orange arrow light quit flashing. At that point, the car has been running just like it did before I tore everything apart. The exhaust smells like it did before I undertook the project.

I'm pretty bummed out that I still have positive pressure at the dipstick. For only having 108k miles, I figured the piston rings wouldn't be in trouble, based on the other Volvos I've owned (some with over 300k miles..)

bobsnow100 · Post by **bobsnow100** » 10 Nov 2006, 07:34

I am thinking engine blow by also, but there are not a lot of miles on your car. Maybe if the oil was never changed and the rings prematurely wore out. Besides doing a compression test I think more importantly you need to do a leak down test also. That's where you put your piston up to TDC with the valves closed and put pressure into your cylinder and see if it holds air,
I believe when you do your compression test it should be about 180 psi + or -. All the cylinders should be within range of each other.

CarVolvo · Post by **CarVolvo** » 10 Nov 2006, 08:33

The 94 with 180,000 miles did the same thing. Kept blowing oil not only though the dipstick but had an unbelievable build up in the engine.. every time you opened up the oil filler cap it would shoot out tons of oil vapour.

It was not good news... thats why the engine was replaced.

Hopefully yours is not the same.

Post by **pfeener** » 10 Nov 2006, 10:32

My 98 S70 runs in the high 180s on all cylinders on a compression check. I believe the NA engines are normaly slightly less.

As far as the engine puffing out smoke. It's always a race between the amount of blowby the PCV system can clear out and the amount of blowby going past the rings. When the car is new there's little blowby and the PCV system is running at full potential. As the engine gets older the PCV system gets less efficient and the blowby from the cylinders increase. At some point the two lines will cross and the blowby can no longer be handled by the PCV system. You may or may not be at that point.

I only know about my 98 S70 turbo, so what I'm telling you may or may not apply, but there should be two hoses (a small and a larger one) coming from the oil trap that feeds into a block that's mounted on the intake pipe. That block is know for getting clogged up and needs to be reamed out every once in awhile. If it's plugged up the PCV system won't operate at all.

Post by **luketrash** » 10 Nov 2006, 11:55

The numbers should be higher on the NA since it's a higher compression ratio. 185-213psi are the specs I found online for the NA engine.

I changed out the plugs this morning.. I replaced the Volvo ones with 4 tips that were in there?? (must be bosch platinum knockoffs)

And put in the el cheapo bosch OEM plugs.. It runs smoother now.

The bad news:

Compression test results (with my admittedly cheap compression tester)

1: 150psi
2: 150psi
3: 150psi
4: 150psi
5: 135psi

The cylinders all hold pressure. I left the tester on each cylinder for about a minute and pressure didn't fall off. But after about 6 cranks, they all maxxed out at the above figures.. Everything was at least looking consistent until I hit #5.

So, when your car runs below spec by this much (-20%) what can you do to make it operate better? I'm on my way out to change the oil. Who knows what the dealership had in it. I'm putting in some Castrol GTX 10w30. I bought Mobil 1, but I want to get more familiar with the car before pouring 30.00 of oil down its gullet.

Post by **kelvin6** » 10 Nov 2006, 12:49

The Mobil 1 may cause seals to leak, because if not the mileage, it could be the age of the seals. Good conventional oil will do fine.

Have you heard or considered AutoRX? I've only seen and heard of good stuff from this oil 'additive'. I've used it myself it it only gave good results. Its main job is to clean the engine piston rings, so it might be worth (you'll need two bottles) it. www.auto-rx.com be sure to read the FAQ, because there is a coupon code in there for a discount.

This stuff did really clean out my engine, literally for the first time I actually found stuff on my magnetic drain plug, the filter was full of crud for once, it was nuts, but now whenever open my oil filler cap, the cam lobes are so shiny, looks like brand new!

If you head back over to Volvospeed.com, I think RussB had a good sucess story of Auto-Rx fixing one his cylinders which had much lower compression than the others... must've fixed the piston ring I say.

bobsnow100 · Post by **bobsnow100** » 10 Nov 2006, 14:27

Did you do the compression test with the engine warm . If you didn't you will have lower readings, It's a good sign if the cylinders held air.
I think if your compression was 150 that you wouldn't get that much blow by ,you may have a little less engine performance though

Post by **luketrash** » 10 Nov 2006, 15:44

The engine was warm, but it had been sitting for about a half hour in my garage. The fact that every cylinder but 5 was pretty much the same is a good sign I guess. I might try that auto RX stuff and see it if does everything it says (mainly rejuvinating the rear main seal and cleaning the piston rings and valve seals)

However, seeing metal shavings for the first time, after using it sounds suspicious

I did install my FCP magnetic drainplug when I changed the oil. They must have had thinner oil in it, because when I started it with the 10w30 when I went to go eat, I heard valve ticking for the first time. It went away once I had revved up the engine and warmed it up.. But I'm betting they had 5w20 or something in it.

Looking into the intake when I did the PCV, there was black gunk thinly coating the inside of the intake manifold, and along the head on the sides. The centers were clean.. There was oil on valvestems, suggesting maybe they don't seal up as good as they should.

bobsnow100 · Post by **bobsnow100** » 11 Nov 2006, 18:21

It looks like your valves or guides maybe worn. The valve guide seals are probably shot and thats why you have oil coming down the valve stems. They seals do get hard and lose there elasticity from the hot temperature and the oil itself.

Post by **luketrash** » 11 Nov 2006, 19:25

I'm going to be reading up on the Auto RX. I'm still not sold on the idea of putting something thinner than oil in the oil to free up sludge.. It just seems like Friction City to me.. But people seem to swear by it.