# Effect of overfilling oil?



## Cypher2k (Nov 23, 2000)

http://forums.vwvortex.com/zerothread?id=781078
This thread brings this to question, but the title doesnt really address this.
In short, my oil got overfilled by about 500 mil, (half a quart)
A day or so later i noticed that a lot of oil had started bleeding out of the pipes and hoses of the PCV valve system under the intake manifold.
Simple cause and effect analysis would indicate that overfilling the oil caused this, as it was clean clean clean, both before and after the oil change. (You could clearly see where the oil was coming out of the fittings)
If I examine the dipstick, the oil level is just over the crosshatch markings indicating over filled.
Could this alone cause this problem, or, combined with a slightly leaking PCV valve (under boost) exacerbate it?

Incidently both times I have seen this have been after a dealer oil change and a shop oil change where they put in a full 5 litres. Any time i have done my own oil, its been 4.5 litres on the nose. Also, this is not oil from the oil change, the oil is clearly dripping down from above the filter housing and from the PCV system.(appears to be bleeding out from the various clamped fittings)



[Modified by Cypher2k, 8:55 AM 4-3-2003]


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## Cypher2k (Nov 23, 2000)

*Re: Effect of overfilling oil? (Cypher2k)*

bump.


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## Cypher2k (Nov 23, 2000)

*Re: Effect of overfilling oil? (Cypher2k)*

Well, I was a couple of fingernail widths above the full line on the dipstick so we backed it off to about 3/4s of the way up the marker..
Time will tell, but it doesnt look like its leaked again since I modded the PCV valve.


[Modified by Cypher2k, 10:39 AM 4-4-2003]


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## 02uphillracer (Feb 14, 2002)

*Re: Effect of overfilling oil? (Cypher2k)*

the theory in the old school days was that you can blow an oil seal when overfilled. dont know about the 18t though.


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## Cooper (Sep 11, 2000)

*Re: Effect of overfilling oil? (Cypher2k)*

I'd me surprised if a 1/2qt. overfill would be a problem. I'd like to think that there is more of an error margin built in.
I always thought that the problem with overfilling was that it could cause the oil could foam, which would then mean that a foamy oil/air mixture was them pumped through the engine, greatly decreasing lubrication properties.
Edit - Yup (hatethe reference to VW 4-cyl. engines, though) 
http://cartalk.cars.com/Columns/Archive/2001/August/03.html

Dear Tom and Ray:
Each time I had my car's oil changed at the dealership, the dipstick showed that the oil level was a quarter of an inch to almost an inch above the "full" level. According to the owner's manual, over-filling could damage the engine. I called this to the mechanic's attention several times, and each time he insisted that the amount he put in was correct. He also claimed the extra oil would cause no damage. Finally, he checked his oil-dispensing gauge and found that -- guess what? -- it was not accurate, after all. He then proceeded to correct it. I still want to know if that previous overfilling could have caused any damage. -- Will 
Tom: It's unlikely, Will. It's true that overfilling the crankcase with oil can damage the engine. But in the vast majority of cars, you won't do any damage in the quantities we're talking about here. 
Ray: A quarter of an inch on most dipsticks equals a quarter of a quart. And adding an extra quarter of a quart, or even half a quart, won't hurt anything. 
Tom: When you overfill the crankcase by a quart or more, then you risk "foaming" the oil. If the oil level gets high enough, the spinning crankshaft can whip the oil up into a froth, like the stuff that sits on top of your cappuccino. And the problem with that is that the oil pump can't pump froth. 
Ray: It's like trying to drink from a straw when there's not much left in the glass -- what you get is mostly air. And air can't lubricate your engine. 
Tom: Now, there are some cars that are more sensitive to overfilling than others. Volkswagens with four-cylinder engines come to mind. And if you had one of those, and the mechanic overfilled it by half a quart, I'd tell you to have him drain the oil and refill it more precisely. But unless your owner's manual specifically warns you -- in dire language -- not to overfill the oil, I wouldn't worry about it unless it's approaching a quart over. 


[Modified by Cooper, 6:55 PM 4-4-2003]


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## okanagan45 (Feb 19, 2003)

*Re: Effect of overfilling oil? (Cypher2k)*

I agree with everyone here, 1/2 a litre of oil should not be a problem.


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## kwokA3T (Sep 3, 2002)

*Re: Effect of overfilling oil? (okanagan45)*

Do Not overfill any vag/audi engine ... excess oil will eventually accumulate in exhaust manifold (as result of incomplete combustion) & contaminate catalytic core ... an "oily" cat core will not be replaced under warranty ... some vag/audi models have oil level warning light (too low & too high) ...
remember synthetic engine oils resist combustion process far better then fossil oils ...


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## AZGolf (Jun 6, 2000)

*Re: Effect of overfilling oil? (kwokA3T)*

quote:[HR][/HR]Do Not overfill any vag/audi engine ... excess oil will eventually accumulate in exhaust manifold (as result of incomplete combustion) & contaminate catalytic core ... an "oily" cat core will not be replaced under warranty ... some vag/audi models have oil level warning light (too low & too high) ...
remember synthetic engine oils resist combustion process far better then fossil oils ...[HR][/HR]​Would you care to explain how oil would magically end up in the exhaust? This ought to be good.


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## FreeStage3 (Mar 18, 2002)

*Re: Effect of overfilling oil? (AZGolf)*

quote:[HR][/HR]Would you care to explain how oil would magically end up in the exhaust? This ought to be good.[HR][/HR]​its called "blow by" and it happens when there is too much oil pressure caused from over-filling and or worn parts. oil can and will "blow by" the piston rings and valve seals. 
matt


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## okanagan45 (Feb 19, 2003)

*Re: Effect of overfilling oil? (FreeStage3)*

I think he means the oil will get sucked up by the EGR tube or similar pollution device, thingy.


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## FreeStage3 (Mar 18, 2002)

*Re: Effect of overfilling oil? (okanagan45)*

quote:[HR][/HR]I think he means the oil will get sucked up by the EGR tube or similar pollution device, thingy.[HR][/HR]​also true....







but that oil will typically remain on the intake side or end up in the bottom of our intercoolers. if the oil makes it past our intercoolers then most of it should burn up during the combustion process. 
matt


[Modified by FreeStage3, 5:24 AM 4-5-2003]


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## kwokA3T (Sep 3, 2002)

*Re: Effect of overfilling oil? (FreeStage3)*

1. crankcase overfill will result in air entrainment/frothing/excessive lower cylinder bore wetting & ring blow-by/resulting in combustion chamber wetting ...
2. engine oil in i.c./charge cooler results exclusively from ko3/ko3s/ko4 floating center bearing thrust washer clearance; i.e. it is essential to permit lubrication oil seepage to face of thrust washer to a. control centering of turbo wheel shaft, b. to control oil temp rise in bearing cartridge - prevent superheating of oil during turbo operation ... yeas there is small oil seepage on hot wheel side - but this will be smaller oil volume, then compressor wheel side - hot side positive pressure / cold side pressure varies significantly during operation (the gas pressure inside hot & cold wheel chambers ... 
if turbo in good condition, hot chamber oil seepage always less then ring blow-by resulting from over filling ... cat core will not be damaged during normal service life of core - overfilling crankcase will alter this ...
egr valve/circuit may also contribute - ring blow-by is 1st factor - due to oil wetting & film strength, on piston downstroke hydraulic pressure will occur within lower cylinder wall excessive oil film, & drive oil upward (as piston moves downward) above oil control ring land - small amounts of unburned oil will accumulate in exhaust manifold ... this reverse hydraulic pumping will occur in an engine with "good" rings, if there is excessive oil film on lower cylinder surface ...


[Modified by kwokA3T, 12:38 PM 4-5-2003]


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## okanagan45 (Feb 19, 2003)

*Re: Effect of overfilling oil? (kwokA3T)*

SO, is 1/2 litre (quart) extra oil in the crank case too much for our 1.8 engines?
Now you got me wondering.


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## Jay24 (Jul 13, 2001)

*Re: Effect of overfilling oil? (okanagan45)*

Anyone else think kwokA3T and john s are the same person?








Just kidding.


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## jabbajaw (Mar 22, 2002)

*Re: Effect of overfilling oil? (Cypher2k)*

I changed my oil and put in 5 quarts instead of the usual 4.5. I had spilled a bit of the oil and the dip stick showed a normal amount so I didn't think much of it.








Today the engine check light came on and when i checked the dip stick it was overfilled. I suppose i'm getting oil in my cat. I'm gonna go drain of a bit of the oil and hope that I didn't damage anything permnently.


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## enginerd (Dec 15, 2001)

*Re: Effect of overfilling oil? (Jay24)*


_Quote, originally posted by *Jay24* »_Anyone else think kwokA3T and john s are the same person?








Just kidding.









they both know their sheit. John S will be missed. Dont overfill. A buddy of mine had ~6 quarts added to his VR6 and it blew smoke and killed hit cat. Otherwise the engine was fine. 

_Modified by enginerd at 6:53 PM 11-15-2004_


_Modified by enginerd at 7:04 PM 11-15-2004_


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## Blue.Jester.02Gti (Jul 31, 2002)

*Re: Effect of overfilling oil? (jabbajaw)*


_Quote, originally posted by *jabbajaw* »_I changed my oil and put in 5 quarts instead of the usual 4.5. I had spilled a bit of the oil and the dip stick showed a normal amount so I didn't think much of it.








Today the engine check light came on and when i checked the dip stick it was overfilled. I suppose i'm getting oil in my cat. I'm gonna go drain of a bit of the oil and hope that I didn't damage anything permnently.









youre okay with 5 quarts.. wow talk about back from the dead


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## slickfisher (Oct 16, 2004)

*Re: Effect of overfilling oil? (Cypher2k)*

On these engines I think a half a pint or less would not be an issue. Certainly I would be concerned a pint or more overfull. Absolutely a quart overfull.
My 01 TDI took 4.7qts to the fill mark. I always put the full 5qts in. Drove for 115k with no issues and sold someone a damn good car.
Slickfisher


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## jabbajaw (Mar 22, 2002)

*Re: Effect of overfilling oil? (jabbajaw)*


_Quote, originally posted by *jabbajaw* »_I changed my oil and put in 5 quarts instead of the usual 4.5. I had spilled a bit of the oil and the dip stick showed a normal amount so I didn't think much of it.








Today the engine check light came on and when i checked the dip stick it was overfilled. I suppose i'm getting oil in my cat. I'm gonna go drain of a bit of the oil and hope that I didn't damage anything permnently.









Well after removing the extra 1/2 quart, I disconnected the battery to clear the error codes. It was ok for a while but the check engine light came back on again.....
Does anyone have any idea what the problem is and what I can do to fix it.


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## keycom (Sep 27, 2001)

*Re: Effect of overfilling oil? (jabbajaw)*

Well, it may be totally unrelated, but after overfilling my engine, the front O2 sensor has gone bad.
It wasn't overfilled much at all, less than 8 oz, so it may just be coincidence.


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## Kilmer (Sep 5, 2001)

*Re: Effect of overfilling oil? (kwokA3T)*


_Quote, originally posted by *kwokA3T* »_Do Not overfill any vag/audi engine ... excess oil will eventually accumulate in exhaust manifold (as result of incomplete combustion) & contaminate catalytic core ... an "oily" cat core will not be replaced under warranty ... some vag/audi models have oil level warning light (too low & too high) ...*agreed...don't overfill especially with the sludge problems of 1.8T's...transverse and longitudal motors are proned to this now that there are a lot of them going up and over 100K...was @ the dealer saw like 4 cars with this problem 2 passats 1 audi and 1 jetta..although I think this is because VW dealers around here say they use Synthetic and actually use a non synthetic Castrol 5W30 on most...sometimes they use semi synthetics...weird...a response from a local mechanic was...this is what we had so I used it...







*
remember synthetic engine oils resist combustion process far better then fossil oils


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## Kilmer (Sep 5, 2001)

*Re: Effect of overfilling oil? (keycom)*


_Quote, originally posted by *keycom* »_Well, it may be totally unrelated, but after overfilling my engine, the front O2 sensor has gone bad.
It wasn't overfilled much at all, less than 8 oz, so it may just be coincidence.

*this also happened to me a while ago...bad front 02 sensor*


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## gli87jetta (Nov 26, 2001)

*Back from the Dead Thread*

Hi, 

I'm having the first oil leak issue since I bought my car in 06 with 17k on the odo. 
I'm now at 118k miles and am experiencing my first oil leak!  

I had my K03s turbo blow up and had a shop recently install my F21T. So far the turbo seems great and is holding a nice 16psi. 

I noticed the oil leaks in my parking space after leaving for work this morning. I was hoping the oil filter might of just been loose since the shop changed the oil after replacing the turbo but that's not the case. 

When I got home tonight I jacked it up and noticed quite a bit of oil on what looked to be the lower oil cooler hose(s). The oil seems to be leaking from slightly behind where the oil filter screws in if I were to guess. Not sure if it has something to do with the PCV valve system mentioned in this thread? 

I was checking the dipstick and noticed it was over the top crease which indicates over fill. I kept wiping off the oil and pulling the dipstick but it didn't go lower than the top bend. Does anyone know if you can tell how much overfill their is by how far it goes up the dipstick?  










I've always done my oil changes and make sure I did exactly 4.5qts and made sure it went right to the top perfect fill mark on the stick. 

I wiped down most the oil from the oil filter area and wiped off the hoses I also let my car idle while it was jacked up to see if I could find any leaks. I let it idle until the cooling fans engaged and didn't notice any leaks. But after going for about an 18 mile drive and pulling some full boost I pulled into the gas station and noticed it leaking again. Appears to be a condition of boost pressure causing this as well. Again, I kept cleaning off the dipstick and dipping it to see if I could lower it at all. 

My owners manual states that overfilling the engine can cause engine damage. I'm going to call the shop tomorrow and see if they can advise me how much was used. I would drain some out but they used a special oil called Pentosin which I would probably have to order online since the shop is about 50miles away. I don't want to loose too much and not have any of the same brand oil to top off with. I suppose I could drain it and fill it with some sythentic oil I get local but it was expensive for the change and filter. Not expensive as a new engine obviously! Not to mentioned I had to get a new head 8k miles ago. 

Just wondering if anyone thinks my leaks might be due to overfill and leaking out some seals or the PCV valve or something similar. So far I think I'm ok since I haven't drove over 70 miles yet and haven't thrown any engine error codes. Then again, when my turbo blew up and let two quarts into my intercooler and out my exhaust I didn't throw any codes either. :screwy: 
Thx


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## warranty225cpe (Dec 3, 2008)

The shop that did my rods put an extra qt of oil in and insisted that it was a normal practice. I drained a qt out and its ok now. But the extra oil in my hoses made my charge pipe to turbo hose saturate with oil. Nothing I could do would make it stay on. I had to buy a new hose. The line on the dipstick is there for a reason.


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## gli87jetta (Nov 26, 2001)

I was just mainly wondering if overfilling the oil would cause too much pressure in the engine causing it to blow out a seal or PCV valve or something. When I went outside this morning I had spots all over the ground in different areas under the oil filter & oil cooler hose area. 

After going to the shop this afternoon it's not leaking for now! They took a little oil out so that might of just been overflow dripping out a seal or something?? 

The shop did replace my oil feed line with the turbo. After the owner showed me where the turbo feed line goes it would appear to have been coming from that area. But he checked it and didn't notice any oil coming from the feed line. He mentioned it's coming from the Power Steering hose on the left passenger side which didn't seem right. I'm hoping it holds up for now but it hasn't been long enough. Fingers crossed!


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## jetita (Aug 9, 2013)

*overfilled my wolfsburg 1.8t with 2 1/2 quarts*

I need some help, this morning i overfilled my car i guess with 2 or 2 1/2 quarts of oil, and i drove for about 40 minutes when i began hearing i weird noise like a tattoo machine noise and i stoped and checked the oil and the the engine was throwing our oil through where i checked the oil level, i turned on the again and it says that it need oil so i poured a little more, i parked the car for 8 hours and then i checked the oil and it was like less then a 1/2 of an inch above the regular level.. so i began to driving it again and everything sounded right but when i shifted to the 3rd speed after 4rmp the car began smoking so much and the tatoo machine noise got louder. and it only smokes on the third speed after the 4rmp... i need help if someone can tell me what is goin on with my car.. thank you.


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