PDA

View Full Version : Clogged PCV burns oil?



Fantastic
09-20-2017, 04:58 PM
I took my car in to the Chrysler dealership, I know not as good as a studio but I ain't got one of those less than 4 hours away, to have them check the turbo one last time before I bought the parts. They said it was within factory specs and asked what problems I was having. I told them I was burning oil and the higher in the rpm range/higher boost range I got to the more I burned and sometimes when in 3rd or higher gear(where it goes to 22-24psi or more boost) I actually get backfiring. They suggested it was actually the PCV system being clogged causing too much crankcase pressure and that pressure preventing the oil in the turbo from returning so it would force its way passed the seals and burn there. Does this make sense to the Fiat gurus?

streetsurfer
09-20-2017, 05:29 PM
Yes.

You can, and maybe should, remove the oil separator occassionally and flush it out, and check and clean or just replace the pcv valve. There are also many other reasons for excess oil consumption.

Here is a very thorough article on the various causes.
https://www.amsoil.com/techservicesbulletin/MotorOil/TSB%20MO-2004-04-03%20Oil%20Consumption.pdf

Fantastic
09-20-2017, 06:08 PM
maybe should, remove the oil separator occassionally and flush it out

Where is the separator? I will place the order for a new PCV asap.

streetsurfer
09-20-2017, 06:34 PM
Driver's side on top of the engine, tucked under that end of air filter assembly cover. Black box that has the hoses going to it. It is known for developing a leak from a bad o-ring seal, also. My reference is from the Abarth. I dont know how other models may differ.

Just from recall, reading of others dealing with it, the box is around Fifty beans, the valve around ten. The o-ring may have been updated. Seems I read that.

I hope this is your only cause for excess oil consumption and that it is rectified with with a good cleaning.

Fabio13
09-20-2017, 10:15 PM
yes the o-ring has been updated

Fantastic
09-20-2017, 10:49 PM
Driver's side on top of the engine, tucked under that end of air filter assembly cover. Black box that has the hoses going to it. It is known for developing a leak from a bad o-ring seal

That is what was ordered so once I replace it if the oil burning remains we know it's much more expensive and internal.

Fiat500USA
09-20-2017, 10:57 PM
I took my car in to the Chrysler dealership, I know not as good as a studio but I ain't got one of those less than 4 hours away, to have them check the turbo one last time before I bought the parts. They said it was within factory specs and asked what problems I was having. I told them I was burning oil and the higher in the rpm range/higher boost range I got to the more I burned and sometimes when in 3rd or higher gear(where it goes to 22-24psi or more boost) I actually get backfiring. They suggested it was actually the PCV system being clogged causing too much crankcase pressure and that pressure preventing the oil in the turbo from returning so it would force its way passed the seals and burn there. Does this make sense to the Fiat gurus?


How much oil do you burn - quarts per mile?

Fantastic
09-20-2017, 11:03 PM
How much oil do you burn - quarts per mile?

The fact it burns oil is not such a concern but it is a concern that it burns oil high in the RPM range and it can do it quite explosively sometimes.

Fiat500USA
09-21-2017, 02:05 AM
The fact it burns oil is not such a concern but it is a concern that it burns oil high in the RPM range and it can do it quite explosively sometimes.

Do you get oil smoke out the back? If it does smoke when do you get it? On deceleration or while accelerating? When you say backfire, you aren't talking about the occasional and normal backfire you'll get when shifting?

Do you have an aftermarket boost gauge? 24 psi is unusually high for a stock car. Is your car modified?

Fantastic
09-21-2017, 10:07 AM
When you say backfire, you aren't talking about the occasional and normal backfire you'll get when shifting?

Do you have an aftermarket boost gauge? 24 psi is unusually high for a stock car. Is your car modified?

I am talking about on the power 4500rpm+ it will sometimes turn into a machine gun and there is a loss of power.
Depo racing boost gauge. It is not stock at all and I bought it used from a dealer so there is no list of what all has been done but given that absolutely every part of this car is modified from the suspension to the brakes to the engine I think the only thing not changed was the turbo for a GT1752 at this point.

streetsurfer
09-21-2017, 11:56 AM
Others suggest you also clean the lines to and from. They have been found loaded with gunk too, in one of the cases I mentioned.

Fantastic
09-22-2017, 12:26 AM
I ordered both lines just in case as well.

Fiat500USA
09-22-2017, 01:12 AM
I am talking about on the power 4500rpm+ it will sometimes turn into a machine gun and there is a loss of power.
Depo racing boost gauge. It is not stock at all and I bought it used from a dealer so there is no list of what all has been done but given that absolutely every part of this car is modified from the suspension to the brakes to the engine I think the only thing not changed was the turbo for a GT1752 at this point.

I am curious to how do you know it is oil? Is there smoke? Are the plugs getting oil fouled? I can't check your post history right now, but I assume you have proper plugs and they've been gapped to the correct specs and changed at the proper interval. Do you have a piggy back or an ECU reflash?

If it is oil that is not a good thing. I guess before you go too far troubleshooting it is a good idea to go over the basics like the PCV system, etc. Maybe it is something that simple.

ice445
09-23-2017, 02:11 AM
I have some experience with this. My air oil separator box was clogged. Very clogged to where the PCV valve was barely functioning. When I removed it from the car and shook it, the ball valve had very restricted movement compared to the new box where it was very free and clicks easily. I cleaned out my box with brake cleaner and so much nasty oil and garbage came out that it was shocking. After some serious efforts with cleaning, the PCV ball valve started to move freely again. Put it back on the car (since the new box was apparently slightly different and didn't fit), and it made a large change in how the car feels on the road. The car pulls easier and doesn't choke as hard on decel or quick throttle snaps.

I still need to replace the box, since I think having the box clogged for as long as I did caused a crankcase pressure restriction that was significant enough to split one of the seams on the box (there are many) and let oil vapor out, since I tend to smell it whenever I get on the car hard. I also found some oil around the #4 coil that supports this theory. The o-ring that seals the unit to the valve cover had also failed and was letting oil and vapor past. There is a new updated o-ring that I replaced it with.

streetsurfer
09-23-2017, 02:02 PM
I suggest studying the article I linked to thoroughly. Particularly 9 and 34, and any and all on rings and lands, the points on increased engine vacuum, spark knock, and fuel dilution, and oil and cooling system contamination. These can all help in your diagnosing of engine troubles. If your car had faulty pcv, there may be other things to address because of it. At the very least, an oil change and continuing on in that and air filter maintenance in order to clean up the engine. You also want to verify you dont have such as a broken ring land or loaded up or stuck rings, excess carbon deposits, etc.

ice445
09-23-2017, 04:44 PM
I suggest studying the article I linked to thoroughly. Particularly 9 and 34, and any and all on rings and lands, the points on increased engine vacuum, spark knock, and fuel dilution, and oil and cooling system contamination. These can all help in your diagnosing of engine troubles. If your car had faulty pcv, there may be other things to address because of it. At the very least, an oil change and continuing on in that and air filter maintenance in order to clean up the engine. You also want to verify you dont have such as a broken ring land or loaded up or stuck rings, excess carbon deposits, etc.

Dunno, never had any problems with the car beforehand. It doesn't consume a ton of oil or anything. It also wasn't running horrible, cleaning it just made it run even nicer. I think the design of the canister is just subpar, after 4 years and 40,000+ miles, the oil inside tends to decay and varnish and clog the tiny passages.

streetsurfer
09-23-2017, 06:38 PM
Dunno, never had any problems with the car beforehand. It doesn't consume a ton of oil or anything. It also wasn't running horrible, cleaning it just made it run even nicer. I think the design of the canister is just subpar, after 4 years and 40,000+ miles, the oil inside tends to decay and varnish and clog the tiny passages.

Sorry, that was meant for Fantastic, and due to the mention of high boost oil loss and high speed break up or misfore. Not to give him things to worry about, but if it's pcv related and has been going on for long before he bought it, there might be some crud build up that can take a while to clear, or other things needing checked or attention.

Fantastic
09-26-2017, 10:54 PM
For those of you who have been following my story I have a possible conclusion:
Took my car to my local Pasta Burner specialist, he normally deals with Ferrari and the occasional Porsche. He test drove it and did a ride along so I could point out the issues I felt and he was quick to say it's not burning oil it is just running very rich and being unable to fire if I give a bunch throttle at low rpm.


I know that with an improper tune the fuel system will probably overload the spark system and be unable to ignite until the boost catches up with the fuel so are there any tunes or piggybacks that fix the car running so rich?

KellyfromVA
09-27-2017, 05:54 AM
The only thing that I could think of that would tie fuel fixture to oil consumption would be due to excessive or non-atomized fuel washing past the piston rings and diluting the oil, which would cause the crankcase to be over-filled and either leak, or be burned in the combustion process. The reason I don't buy that theory, is because modern gasoline injected internal combustion engines are pretty much incapable of allowing that much fuel to come out of the injectors. Diesel engines have this happen, because the fuel injectors can become stuck open. If your car was running that rich, you'd be seeing a lot of un-burned fuel coming out the exhaust and your catalytic converter would be glowing red hot, or completely toast by now. But considering all that; you haven't been fooling with the ECU settings, or done some "performance tune" have you?

If not, then I'd recommend getting a second opinion, starting with a compression test on all four cylinders.

Fiat500USA
09-27-2017, 09:34 AM
I moved this post into the original thread for continuity. Glad to hear you figured it out. As was mentioned, if there was so much oil in the combustion chamber to cause a misfire you would spew a lot of blue smoke out the exhaust.

I was under the impression you already had a tune/piggyback?

If you are getting misfires, start at the basics - maintenance like plugs, filters and don't forget oil if this hasn't been done within a reasonable time frame. Dirty oil in the MultiAir engine can cause misfires. If your plugs were changed, make sure they were the proper ones and were gapped correctly. If your engine is tuned it may push the stock ignition system to the max, so you may have to go to a different spark plug gap or try another spark plug. They sell upgraded coils, too. If there is a piggy back, let us know which one. It may have an adjustment where you can dial it back.

As you have a bunch of mods done to your car, a suggestion is to inventory them and then put them in your forum signature as that will make it easier for folks to jump in with suggestions.

If you are having trouble figuring out what is modded, post a picture of anything you think is not stock and we can try to ID the mod for you. Start a seperate thread for that.

Fantastic
09-27-2017, 09:29 PM
I was under the impression you already had a tune/piggyback?

If you are getting misfires, start at the basics - maintenance like plugs, filters and don't forget oil if this hasn't been done within a reasonable time frame. Dirty oil in the MultiAir engine can cause misfires. If your plugs were changed, make sure they were the proper ones and were gapped correctly. If your engine is tuned it may push the stock ignition system to the max, so you may have to go to a different spark plug gap or try another spark plug. They sell upgraded coils, too. If there is a piggy back, let us know which one. It may have an adjustment where you can dial it back.

As you have a bunch of mods done to your car, a suggestion is to inventory them and then put them in your forum signature as that will make it easier for folks to jump in with suggestions.

If you are having trouble figuring out what is modded, post a picture of anything you think is not stock and we can try to ID the mod for you. Start a seperate thread for that.

Put all the mods I have found in my signature for you!
Oil was done about 3k ago with Motul 300v Power 5w40 and is being changed when the PCV replacement part gets to my shop. The oil change didn't have any effect on the issues I have had.

Pretty sure the while under power backfiring is actually a loose connection somewhere that is killing the ignition system for a split second. Will have to remove the piggyback to see if that fixes it, if it does I will change to an ECU flash from TORK.

Fantastic
10-02-2017, 09:12 PM
The new PCV black box thingie and hoses were a dramatic improvement in engine smoothness under power and at idle.