1998 Volvo V70 AWD - Dipstick still smoking after PCV change

[erikv11]

...
- Cleaning the PTC does not mean it works, check to be sure the PTC valve operates properly. ....

There is no valve in the PTC.

Inside the PTC there is just a metal plate with a narrow hole in it. It's basically just a nipple, that's it, hence the name "PTC nipple."

The little electrical plug provides power to heat the metal moderately. The heat helps to prevent freezing at low temperature (cool air from the intercooler could do that), and maybe helps vaporize gases coming through the small tube.

So indeed, if the PTC is clean on all sides then it works. Well, unless somehow the heater has gone out, that could be an issue in some conditions, but I have never heard of an electrical issue at the PTC.

[kahl]

I just completed PCV in January on a 98 V70. I used brass 90 degree fittings on the hose coming off the oil trap and the bend around the cornor of the block. As Erik and CN pointed out these two bends will kink/collapse. Did you remove the PTC from turbo intake pipe for cleaning? I broke the rubber grommet that the PTC is inserted when I removed it from the intake pipe, I found the grommet under the 2001 XC70 at FCP. To insert the PTC into grommet I boiled the rubber grommet to make it pliable and used an arbor press to drive it home.

[kahl]

That PTC grommet P/N is 3507985

[thedawgfather]

Thanks for the responses.
Ozark Lee - I've not checked the compression, I suppose I should. I'll just have to figure out where to rent/buy/borrow a compression tester. I just figured if the blow by was that bad that it still blew my dipstick out with a modified PCV system with nearly an inch hose that I'd start crying.

erikv11 - Thank you for confirming that this car does not have an EGR valve. I really didn't want to take the intake manifold off again to make extra sure...I couldn't see one or feel one, but just wanted to be sure. Thanks again. No check engine light. And I read extensively on the modification and used 90 degree hose fittings around the bends, i.e. where it comes out of the box and turns around the engine block.

I definitely removed the PTC and cleaned all holes and made sure they were all open and free of junk, and placed the PTC in the grommet securely, and yes it took some time and lots of wiggling.

I just wonder if there is a clogged vacuum line somewhere? Would there be a vacuum line that I should look into that is clogged not vacuuming the extra pressure? Do any hoses that come off of the turbo have anything to do with it? Are there hoses that come off just after the throttle body that could be clogged not providing the correct vacuum? I'm grasping at straws here possibly, but I just can't figure it out.

Next chance I get I'll check the compression (once the temperature gets above 10 and the 9 inches of snow melts a little and if it is bad compression causing enough pressure to blow out my dipstick, I'll re-modify my oil filler snorkel and fashion another snorkel to my dipstick tube!

[wheelsup]

If you replace the PCV system and have confirmed that there is no blockage between it and the block there's only one the reason - too much pressure going from the top of the engine to the bottom of the engine due to worn rings.

Ultimately the solution is to replace the rings however that's time consuming and expensive for very little benefit. The next best solution in my opinion is to route the crankcase pressure from the dipstick to underneath the car via a heater hose.

I've seen some pictures on here recently where guys have used air filters attached to their oil filler cap and dipstick tube and just have to wonder why. Just attach heater hose to the dipstick tube and route it underneath the car, secure with a hose clamp and store the dipstick on the left side of the car near the battery and air filter - it slides in nicely there.

When I replaced my rear main seal approximately two and a half years ago I was concerned about the pressure blowing it out again. I made this modification at that time and have as of yet not experienced any leakage of the rear main seal, crossing my fingers.

[wheelsup]

If you replace the PCV system and have confirmed that there is no blockage between it and the block there's only one the reason - too much pressure going from the top of the engine to the bottom of the engine due to worn rings.

Ultimately the solution is to replace the rings however that's time consuming and expensive for very little benefit. The next best solution in my opinion is to route the crankcase pressure from the dipstick to underneath the car via a heater hose.

I've seen some pictures on here recently where guys have used air filters attached to their oil filler cap and dipstick tube and just have to wonder why. Just attach heater hose to the dipstick tube and route it underneath the car, secure with a hose clamp and store the dipstick on the left side of the car near the battery and air filter - it slides in nicely there.

When I replaced my rear main seal approximately two and a half years ago I was concerned about the pressure blowing it out again. I made this modification at that time and have as of yet not experienced any leakage of the rear main seal, crossing my fingers.

[dwhite66]

I need some help. I've had smoke coming from my dipstick tube and oil filler hole, enough to blow my dipstick out and inflate a rubber glove over the oil filler hole. I'm trying to be pro-active and get my positive crankcase ventilation right so that I don't put too much pressure on other seals. So, of course I started by replacing my PCV system with a PCV Kit from iPD or FCP which didn't improve the ventilation at all judging by the smoking continuing from the dipstick tube and the oil filler hole. I then modified the system based on a post I read and increased the stock hose diameter from 3/8 to 7/8. I though after modifying the hose diameter that there would be no way that the smoke would continue, but it did. Yes I've cleaned the PTC. And when I replaced the oil separator box, I put a hose on the lower hole into the engine block, leading to the oil pan and blew into it and felt no resistance and heard bubbles from the oil pan. I believe I fished a zip tie (flexible plastic) down the hole as well and felt no resistance. I even built a snorkel out of my oil filler cap, by drilling a hole through the oil filler cap and running a tube up to the windshield under the hood, but I even get little sprays of oil out of the snorkel tube (the tube is about 2 feet long). I don't believe that this engine has an EGR valve because I don't see one, but would appreciate a definitive answer on that if anyone knows. I also just had my emissions tested and almost failed because of high NOx GPMs.

I was just really hoping that someone with more knowledge than I would be able to tell me that, "hey, you forgot to check this hose or that hose"

This engine has a turbo and I have no idea if any hoses going to or coming from the turbo might be clogged or if they contribute to the PCV system at all.

I just am looking for any help!

I believe I may have the answer that you are seeking as I had a similar problem that baffled me for days because after thorough and complete replacement of the PCV system I still had crankcase pressure and smoking dipstick. Check this: the vacuum elbow connection to the intake manifold for the PCV system (the one that's hidden under the upper radiator hose and power steering pump) had disconnected from the hard plastic tubing. I replaced it and used a sealer on the plastic tubing to keep it in place. For me, problem solved. I also checked and replaced (if needed) every other vacuum line and connections to the intake. It's easy to assume that all those lines are functioning when reassembled but it is not always the case. I had not thought to check that particular connection again after reinstalling the manifold, but after exhausting all other efforts, I just happened to look down between the radiator and intake manifold and saw the tubing laying there.

My experience with Volvo cars has led me to believe that there is nothing really complicated to figure out about these cars if one takes the most logical approach. I have never resolved any issue with my cars by "over-thinking" the problem or process. At least, that method works for me, even if it takes me a few tries to get there.

[MrGruffles]

Some thoughts:

1) Double-check the vacuum line from the PTC. My 1994 850 Turbo has (I believe) a different PTC hose set-up than your V70, but I had a similar problem: dipstick smoke after PCV replacement until I connected the PTC to a strong vacuum source. My car sucks in a glove until I disconnect the PTC vacuum hose, at which point it inflates it. (Different arrangement than yours, but my original set-up had a vacuum line running from PTC to vacuum tree via a convoluted steel tube running atop the head. I connected a larger diameter vacuum hose directly from the PTC to vacuum tree.) 1) With the engine running, disconnect the vacuum line at the PTC and confirm that you have good vacuum. If you don’t, there’s a clog or disconnect somewhere between it and the vacuum source. 2) Connect a spare hose to the PTC nipple and blow to confirm no obstructions. 3) Given the larger diameter hose, make sure you still have a tight seal on the fittings, otherwise you get weak vacuum.

2) You mentioned specifically blowing through the lower hole into the engine block and hearing oil bubble: did you also blow through all the other holes that the PCV connects to? They can become blocked as well.

3) As others have mentioned, a compression test may be in order.

[thedawgfather]

The weather was finally warm enough for me to do a compression test...here are the numbers:
From passenger side --> drive side(cylinder 1->5): 103-90-95-94-106psi

Do the numbers indicate that the rings are not providing a tight enough seal, allowing for a large blow up of pressure? Essential, do the numbers indicate that even though I've modified the PCV system and improved it greatly, I can never improve it greatly enough because the blow by pressure is too great and the only thing that would improve it would be new rings?

No I didn't pour oil down the cylinders to see if the numbers improved. I figured if they were low and oil improves them, it doesn't matter to me cause I'm not going to replace the piston rings.

Note: After preforming the compression test and posting this message, I just re-read the compression test instructions and have to say, that I think I goofed. The two things that I didn't do are: (1) I didn't take all of the spark plugs out at the same time, i.e. I only removed the spark plug to the cylinder that I was testing and (2) I forgot to depress the throttle fulling/open the throttle plate fully while I cranked the engine while I tested the cylinder compression. My question would be how would these two things affect my results? Do I need to go back and rent the compression gauge again and re-test to get more accurate numbers?

I also had another question: if I put a glove over the oil filler hole and the glove inflates at idle but is sucked down upon reeving the engine, what does that indicate? Same thing with the dipstick tube: smoke comes out at idle but the smoke stops upon reeving the engine?

I think I'm going to go with the snorkel off the oil filler cap and the hose off the dipstick tube to vent the pressure...

[Ozark Lee]

I don't know that I'm believing those numbers. With compression that low the car would barely run if it would run at all. On my '94 I have a cylinder at 90 PSI and even with the others near 200 PSI the car has a real tough time idling. Unplugging the number 1 injector (the low cylinder) makes it run a tad worse but not much. Compression gauges are all over the place and I figured a +/- 20% error when I bought it due to its price - as I recall it was around $35.00 so it obviously didn't come off of the Snap-On truck. The main thing I look at is variance between cylinders if the actual numbers are within reason.

If I were in your situation I think I would be looking for a replacement engine rather trying to re-ring the existing one. The root problem may be as much cylinder wall wear as it is ring wear.

...Lee