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Black smoke when accelerating + high oil consumption (?)

edusson

New member
Location
Dallas
Hi,

Sorry, this may be just me worrying too much but a basic question... Is >2 qrts of oil in 1k miles normal for this car? It always consumed quite a bit of oil but I think this is excessive.

In detail, not sure if I am into something...
  1. [5/23/2019] Changed the valve cover gasket (at the shop) because of a clear oil leak
  2. [Aug/2019] Mechanic mentioned, during a visit for something unrelated, that they could see some oil leak by the turbo but were not sure.
  3. [11/15/2019] I floored it and the whole car started rattling really bad (it felt below the car all the way to the exhaust). Also saw quite a bit of smoke out of the exhaust. Checked the oil and it was very low so refilled it but scared of flooring it again.
  4. [1/8/2020] Oil change. They told me my oil was 2 qrts low.
  5. [2/4/2020 - 114993 miles] Kept checking oil levels and were going down fast (this car always seems to use a lot of it but this time was going down much faster) so I took it to my shop (different than the oil change folks). They told me that the previous folks had installed the oil filter bad and was leaking there. Did full oil change. Explained them the other concerns but said they didn't see anything. Told me to watch it. After that I step on it and no issues.
  6. [3/7/2020 - sorry didn't write down the miles] Stick was out, so filled it a bit more than the mid level with 1.5 qrts. (Castrol Edge 5W-40, I just changed to this for thickness from 0W-40)
  7. [3/28/2020] I noticed (just looking by the rear view mirror) quite a bit of black smoke coming out from my exhaust when I accelerated. No other issues, except for some small lagging...
  8. [3/29/2020 - 116k miles] Got to check the stick and it is on the min.
  9. [4/1/2020] Didn't drive before coz of Covid... When for a test run before I post here. No smoke... It may lag a bit but maybe it is just my imagination.
Also, I want to say that I saw some small drops on the ground that I am pretty sure they were not there before. It's been raining so it doesn't help...

vwengineer mentioned in a different post that "between max and min there is only 1 quart so that would be a quart for 1k miles which is within VW tolerance. "
So, if my calcs are right, that is about >2 qrts in ~1k miles (between #5 and #8). Is that normal? This car always seems to take too much oil but recently seems worse. Anything that can explain the smoke out (only at acceleration and the bit of lag). I think that if they did wrong #1, it would have shown much earlier, isn't it?

Anyhow, maybe I am paranoia, I know this is super generic, and will take it to the mechanic when Covid allows but thank you in the mean time!

[Golf GTI MkV 2007]
 

vwengineer

Ready to race!
Location
Switzerland
Hey!

Even by VW standard 2 quarts per 1k is too much. They are several points you should check:

If you are burning that much oil, first begin by checking/replacing the PCV which is a common failure point. Then check the valve cover PCV passages if they are still leak proof (where the hoses are connected in the valve cover).

Then if it's not that, then it could be turbo/piston rings/valves seals
 
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GTI's

Go Kart Champion
Location
MD
So its a BPY when they did the VC gasket did they look at the baffles on the underside to make sure they are still intact? As mentioned PCV checked and updated to current version with all the related bits. Perhaps run a leak down test to see what condition engine is at.
 

1131

Passed Driver's Ed
Could be turbo. Could be rings. Do a wet vs dry compression test. Buy a scope. You can try dropping a tablespoon or so of oil down through the spark plug hole. See how quickly it disappears. Leakdown test, as mentioned, is also good.

If it's the turbo, there will likely be oil on the CV axle. Also check the upstream intercooler hose. A small amount of oil (like a quarter cup or less) is normal blowby. A larger amount of oil is not normal.
 
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GIACUser

Master Wallet Mechanic
Location
SoCal
Not that this can be solved online but supply a bit more info and if you can some pics of motor (leaks in particular)
How many miles on the car?
What brand/type/weight of oil are you using?
Black smoke unburned fuel, Blue smoke oil
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Not that this can be solved online but supply a bit more info and if you can some pics of motor (leaks in particular)
How many miles on the car? (He stated 116k miles on 3/29/20)
What brand/type/weight of oil are you using? (Castrol Edge 0W40)
Black smoke unburned fuel, Blue smoke oil
These he stated.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
Can you remove the plugs and post close up pics of them? If they are oily...you may need a rebuild.

VW doesn't consider oil consumption to be excessive until it loses 1L/600 miles. That is when they will consider it a warranty case if still covered.
But really, it shouldn't lose more than 0.5L per 5k miles. Mine never did until it did. I rebuilt mine at 120k miles, once it got to 1L/1k miles. I first found the inner valve cover baffle(secondary oil separator) had just begun to separate but that wasn't all of it as it still smoked on deceleration and acceleration. I then decided to rebuild the head with new valve stem seals and guides. While the head was removed for rebuilding...we noticed excessive oil in the #3 and #4 combustion chambers.
Here's a pic of my head when removed..you can see how oily 3 and 4 are;



So we removed the pistons for new rings and rod bearings. We found one ring had gotten stuck in the piston groove and replaced the #4 piston. Since the rebuild at 35k miles ago...it loses oil at about 0.5L/4500 miles.

I have a vid of when I removed and replaced my rocker cover;
...the thing you hope not to see is oil being able to get inside the two routes for EVAP and PCV recycling where they go through the cover from front to back. If possible, plug one side and "blow/apply pressure" at the other side to see if it is sealed.
 

vwengineer

Ready to race!
Location
Switzerland
0.5l/5000 miles seems like very low no? Mine does 0.1-0.2l/1000km (0W-30), small oil leak at the filter housing (only a few drops here and there) and one spark plug was a little wet (cylinder 3) when I replaced them. But the engine/turbo have also 333'000km so...
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
It's a low loss, yes. But, in comparing 0.5L/5000 miles to your loss....(8)0.15L(your average)/8047Km=1.2L/5000 miles. Yours is looking pretty good for its mileage. Mine was rebuilt 35k miles ago and has 154k miles on it now.
 

edusson

New member
Location
Dallas
Hi,

Sorry took long to update but work, Covid and the rain got on the way...

I think I may have found it. Saw new spots on the floor so took some pics from the bottom and with my limited knowledge, looks like oil in the CV axle, and up on the intercooler hose (what 1131 was saying for the turbo). Also from there seems to drop on the join on the top/right of the pic (don't know what that is 😅) and then onto the floor, where I saw the spots.

IMAG3577.jpg


So, does that mean it is 1/ normal (this looks like a bit of oil from the blow-by getting there) or 2/ this is too much and it could be leaking from the turbo because too much gets in there from a bad PCV or 3/ it could be from above the turbo (I just didn't get to see any further/upper) or 4/ "sorry you are going to need a new turbo" or 5/ none of the above 😆?

Based on your suggestions, I did get to remove the PCV valve (very easy job). Forgot to take pics! Darn. Outside, before removal, didn't see any leaks around that area (forgot to check the back too). Saw that the pipe that goes from the valve to the IM did have oil on the inner walls, all the way to the IM and in the IM. I guess that is normal/expected? Not a whole lot, "just" the inner surface... Also blew into that vent of the PCV, with the PCV removed, but it didn't give (which I think it is the right thing, isn't it?). Other than that, I couldn't tell if anything was wrong with it. Also forgot to check if this is the upgraded PCV or not but I read how to do it so I could do that if you think it's worth.

Finally, these days I don't get to see black smoke on acceleration although I am also careful/not pushing it and drive very little. I do feel a bit of engine power loss (but not 100% sure). Anyhow, no need to explain a whole lot. I have little time/tools/knowledge but if you think that I should try something simple like replacing the PCV, sure I can give it a shot... I trust my mechanic so that is also a good option but just like to learn.

Thank you!!
 

1131

Passed Driver's Ed
Your You still haven't done wet/dry compression tests, leakdown test, or looked INSIDE the upstream IC hose.
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
OK...it is very possible the PCV isn't functioning perfectly. Also, your rocker cover may be coming apart insde. There are two different PCV's and two different rear breather tubes and they need to be paired together properly. I'll add pics for the older; pcv w/check valve goes with rear tube w/no check valve...and then the next pair(newer revision and recommended); pcv w/no check valve(06F 129 101 P ) goes with rear tube w/check valve(06F 103 215 B). It is possible the diaphragm, inside the large disc portion, of the pcv isn't sealing and routing properly under vacuum...allowing vapor to enter the turbo inlet rather than routing it to the intake manifold directly. It could be a combination of issues as well. The forementioned rocker cover come apart inside is one. How you choose to proceed is up to you. Because you have a bunch of oil coming out of the turbo outlet...first; you need a new seal(3C0 145 117 B ) there on the upper turbo outlet hose. Remove the PCV again and determine if you have the older or newer pcv. Replace just the pcv if it is the newer(hopefully it was replaced correctly if replaced previously) and both pcv and rear tube if the older. That's where I would begin.

06F129101N.jpg06f-103-213n_1.jpgpcv.png06f-103-215-b-_1.jpg
 

edusson

New member
Location
Dallas
I am missing a bit the theory behind all this... Do you think that all the oil I am missing is from wrongly routed blow-by? Or could it be that the pressure in crank case blew some seals somewhere else and now the oil is just leaking through those on top of the turbo? Sorry if this is basic question... I didn't check in detail from top (I am thinking about it now) but didn't see leaks.

Along the same lines, I guess that if it is from blow-by the thought is that it gets routed through the turbo, increasing the pressure in the IC hose and blowing through the seal there? Certainly looks more outside the car than getting burnt...

@ROH ECHT Thanks a lot for the detailed description. Took out again the front PCV valve out and got some pics:
IMAG3600.jpg

IMAG3599.jpg

Some strange things:
  1. Hard to find this number: 39 111 32 102 but actually I found it in this forum post you also helped with. In McVee's valve you can see the check valve in his picture. That also matches this website where they link that code to different revisions (N, K, L, F). (No P which makes sense, as that should be no check valve)
  2. Nevertheless, I do not see the check valve on my picture, isn't it? Isn't that weird?
  3. Also, I never changed the PCV valve (front or rear) but another weird thing is the manufacturing date of the valve. Isn't that 2011? My car is from 2007.
  4. I didn't check if it had the rear check valve. I mean, I looked but I don't think I can tell because it is inside the rubber hose and I didn't have spare clamps, so, didn't want to remove the ones there.
Anyhow, I may stop by the shop tomorrow... Got two versions... The TechSmart seems to have the valve inside (looking at the 3rd pic). The URO one I can't tell but I guess I can look it when I see it.

@1131 For the wet/dry, I checked a video (interesting) but one needs the tool/gauge... I don't have... It's ok, if it comes to that, I'll just take it in... May check the inside of the upstream IC hose. That looks more doable :)
 

ROH ECHT

K04 PLAY
Location
PDX OR
Car(s)
2007 MKV GTI
I am missing a bit the theory behind all this... Do you think that all the oil I am missing is from wrongly routed blow-by? Not incorrectly...but perhaps allowed into the pcv due to the plate inside the rocker cover has become unsealed. That plate inside keeps oil from entering the pcv...it is basically a secondary oil separator. The primary oil separator is in the top of the oil filter housing assembly. The rocker cover plate should only be open inside at the rear of the cover at about the back of the engine. Let me know if you haven't seen my vid on my youtube channel. Or could it be that the pressure in crank case blew some seals somewhere else and now the oil is just leaking through those on top of the turbo? This would happen if the PCV diaphragm isn't operating properly or its valves aren't opening for pressure recycling/relief when the crankcase is under pressure. Sorry if this is basic question... I didn't check in detail from top (I am thinking about it now) but didn't see leaks.

Along the same lines, I guess that if it is from blow-by the thought is that it gets routed through the turbo, increasing the pressure in the IC hose and blowing through the seal there? That wouldn't be the case becasue the spot where CC pressure is introduced to the turbo inlet is pre-compression. Certainly looks more outside the car than getting burnt... The problem with oil exiting there at the turbo outlet is simply the o-ring type seal.

@ROH ECHT Thanks a lot for the detailed description. Took out again the front PCV valve out and got some pics:
View attachment 171934
View attachment 171935
Some strange things:
  1. Hard to find this number: 39 111 32 102 (I believe that number is just a makers mark if you will. A code that points to manufacturing info) but actually I found it in this forum post you also helped with. In McVee's valve you can see the check valve in his picture. That also matches this website where they link that code to different revisions (N, K, L, F). (No P which makes sense, as that should be no check valve) Right, the valve there as with McVee's, that is the original design. Most places are getting to where his type are becoming harder and harder to find. The problem with selling just the design you have, or the latter type, means the rear breather tube should contain the check valve that was removed from the "type/design/revision" of PCV McVee has. This is so that when crankcase is under vacuum...intake air for the turbo isn't robbed of air that will enter the crankcase through the rear tube, through the rocker cover, and into the upper engine that then leads to intake manifold. Typically if this is the case, you'll see it in the engine vacuum levels not as great as it should be.
  2. Nevertheless, I do not see the check valve on my picture, isn't it? Isn't that weird? I do not think weird because again...I am pretty sure that number is a makers mark and has nothing to do with revision or design. Revision 'P' had two previous revisions; 'E' and 'G'.
  3. Also, I never changed the PCV valve (front or rear) but another weird thing is the manufacturing date of the valve. Isn't that 2011? My car is from 2007. I believe that is right. Probably means the PCV and rear tube was updated when the open campaign was initiated. Mine was done that way...was in for another service...DSG or timing belt...and they swapped both PCV and tube for free under the campaign. You should confirm your rear tube is valved at some point.
  4. I didn't check if it had the rear check valve. LOL, yeah, I guessed. I mean, I looked but I don't think I can tell because it is inside the rubber hose and I didn't have spare clamps, so, didn't want to remove the ones there. Right, I have reusable clamps on the short hose now.
Anyhow, I may stop by the shop tomorrow... Got two versions... The TechSmart seems to have the valve inside (looking at the 3rd pic). The URO one I can't tell but I guess I can look it when I see it. Right, if we can assume the rear tube is valved, be sure to get the 'P' revision PCV. The other design is looking to be harder and harder to find. I imagine a time will come when all rear tubes will be valvbed and the PCV's will all be like the 'P' revision.

@1131 For the wet/dry, I checked a video (interesting) but one needs the tool/gauge... I don't have... It's ok, if it comes to that, I'll just take it in... May check the inside of the upstream IC hose. That looks more doable :)
You definitely need the turbo outlet seal and to confirm the rear tube is valved. If your PCV is going to be replaced as I believe you mentioned, that's great too, but make sure it resembles the one you are replacing and doesn't have the valve as with the 'P' revision.

Also, whenever you are buying a new PCV, ask if it is OK to blow into it. So to check if it is going to leak boost. You need to blow forcibly where I circled and it should seal 100% or near 100%. I do not buy them if they do not seal 100%. Many do not even seal well when new. I say forcibly because some makers now do not include a spring just inside there on the check valve and the force of air is all that will close off that valve. Typically it is spring loaded and intake vacuum pulls the valve open and it springs back to a closed position. So, mind your eardrums.

pc.png
 
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