Fluctuating dipstick readings in an '01 A4 2.8 Q (30 valve)

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764
Location
Fairfield County, CT
I told my friend he was crazy until I witnessed it firsthand: The oil level on the dipstick of a friend's '01 A4 2.8 Q can fluctuate by as much as 1/4 quart, anyone know what's going on here? Using the same exact method (park on level ground, shut off a hot engine, wait 5 minutes, check the dipstick) sometimes it'll read around 3/4 full, sometimes it'll read slightly overfull. "Unique molecular bonding" perhaps? But he's running M1 0W-40, not Castrol Syntec :-) Any ideas?? Thanks.
 
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753
Location
98245
quote:
Originally posted by quadrun1: I told my friend he was crazy until I witnessed it firsthand: The oil level on the dipstick of a friend's '01 A4 2.8 Q can fluctuate by as much as 1/4 quart, anyone know what's going on here? Using the same exact method (park on level ground, shut off a hot engine, wait 5 minutes, check the dipstick) sometimes it'll read around 3/4 full, sometimes it'll read slightly overfull. "Unique molecular bonding" perhaps? But he's running M1 0W-40, not Castrol Syntec :-) Any ideas?? Thanks.
It's a long shot but try waiting more like 15 minutes. Maybe the oil takes longer than 5 minutes to drip down from the heads, so when you're measuring it, the level's still changing. Incidentally, I have a couple of cars with DOHC V-8 engines. 4 cams on a big V-8 means a lot of oil in the heads that can take quite a while to drip down. Better yet, check the oil in the morning before starting the engine to see if the level is consistent.
 
Messages
199
Location
Michigan
I notice the same thing too. I just changed my oil using a wix filter. I warmed up the engine up first before draining it. I used a level to make sure the car was level and changed the oil. I added about 4.25 - 4.5 quarts (hard to tell with a 5qt jug). The oil level was exatcly at the top level after adding oil at ambient temps of ~80 deg. F. Then the next day after driving it home, I checked the oil and it read at least 1/4-1/2 quart over the top hole. [Mad] At first I was pretty bothered by this and I have been contemplating draining some of it out but I think it will be okay. I know there is a factor of safety in the design of the car engine (and in many other facets of engineering design) so I try not to dwell on it too much. I think >1 quart overfill would be reason to drain some out. I do believe that the temperature definately causes the level to fluctuate. I think in the future I will add half a quart less and then drive it before adding any oil to the top hole.
 
Often when I check my cold oil in my '02 Audi 2.7t, the dipstick will read 1/2 quart low. I immediately recheck it and it reads Full, and continues to read Full on subsequent checks. It seems that the dipstick is not seated fully the first time or something. Of course, if the car is warm, which it should be when checking the oil, I first pull the dipstick and wipe it off, then reinsert it and pull it out again to get a clear reading. In that case the oil reading is accurate. The dipstick is not easy to seat in these engines, which may be the reason for diverse readings. In fact, if it is not seated at all you will get a warning on the instrument cluster.
 
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23,591
I have a '96 A4 with the 2.8 12v engine. I have no problems with strange dipstick readings. However, I always pull the dipstick, wipe it, then check the level. You just don't know how high the oil is sloshing around in the sump, so you have to wipe the dipstick before checking the level. 5 minutes after shutting off the engine seems sufficient time for most of the oil to drain back in the sump.
 
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23,591
Don't both 2.8 Audi engines, 12v and 30v, have oil check valves in the valley between the heads? Maybe that's where a relatively large amount of oil is retained for a while in the 30v?
 
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3,542
Location
Colorado
Check it after it sits overnight. The oil will be in the pan by then and give you a true reading. I can never get a good reading just after I turn it off because the oil is all over the engine.
 
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23,591
My Audi manual suggest to check the oil when it's warm and a few minutes after turning the engine off. Works for me. But then again, the 12v is a simpler beast than the 30v. [Razz]
 
Messages
3,346
Location
Clarksville, Tennessee
Hot oil expands, cold oil contracts. Depending on the temp of the oil say 180-220 degree, I'm sure you would notice a difference on the dipstick. I can't say it would be any more than a 1/4 of a quart or so, but if the Audi Dipstick is like my VW. It only takes about 1/2 quart between add and full.
 
Messages
2
Location
Tucson, Arizona. USA
I have a 2003 Jeep Liberty with the 3.7L and it does the exact same thing. I just changed the oil and used a 5 qt jug of Mobil1 and made sure it drained completely before putting on the new filter. When I checked the stick it read perfect full. I checked it a week later (Cold sitting for 2 days) and noticed it was high on the stick so I started the motor for about 30 seconds and let it sit for 3 to 5 minutes and it read in the safe zone. If I check it after it has run for awhile and let it sit for a bit it reads high. The Jeep service department said this is normal so I am just going to monitor it and remember where it reads cold on the stick... if it's consistant I guess I will be ok. Good luck with your Audi.
 
Messages
23,591
On my A4, the difference between "min" and "max" marks on the dipstick is almost one quart when the oil is cold. When I make an oil change, I add a bit over 4 quarts until the oil registers at the "min" mark. I add then another quart to the "max" mark. I start the ngine and let it idle for 3 or 4 minutes. I check the level, and it's usually a bit below the "max" mark. I then drive the car 15 minutes, wait a few minutes and top off to the "max" mark. All in all I takes about 5 1/2 quarts.
 
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