Oil sensor issue - oil sludge? A4 1.8T 2003

[Sly_North]

Hi all, For about 1 week I've got an oil sensor error beeping from time to time: it lights up for 1 or 2 seconds with a beeeep, then disappears. I think it did this 5 times already. Car is a 2003 Audi A4 1.8T Quattro. From searching this forum, I've found out this could be a sign of oil sludge, which could lead to much engine damage and lots of $$$$ of repairs. Otherwise it could only be the oil sensor dying or having a connection issue. My usual repair shop being overloaded, I've brought my car to another one near my work. Not sure how used to Audis he is... He told me the oil is clean only after checking the oil dipstick. I've insisted that he check the oil sensor, which he'll do today. Now my question is: is taking down the oil sensor enough to see if there's oil sludge in the engine? Thanks all. PS: last oil change was done 3000 km earlier, with good synthetic oil.

[johnny quattro]

Mine was a bad sensor and connector.

It cost me $30 and some electrical tape to fix.

[wanthema]

yea it might be a loose connector/wiring. check it out.

suggestion: check your own dipstick and look at the colouring.

yellow = really clean
brownish = good
brown/black = still good
black = fair, nothing to be alarmed about, just needs an oil change soon. (in terms of burning oil, unregulated heat control in the engine means the engine works a bit harder than normal)
pure black and mold build up = then u got a oil sludge problem that requires a engine oil flush. ( engine oil flush treatment might be recommended, u can buy this anywhere)

nothing to be really concerned about.

[Sly_North]

Yep that's what the repair was talling me: the oil is super-clean, he could hardly see it on the dipstick, nothing to worry about.
After a trip from Montreal to Quebec and back, I'm much less worried

Thx.

[mikeh]

It is highly unlikely that sludge would cause your problem. Particularly after hearing how clean your oil is.

[adamstasiak]

It is your oil filter. Sometimes they make them so they filter too much and become plugged.
Just change your filter and you will be OK.
What is the size of the filter? Does it look too small? They have two kinds - I use the big one.
Do not drive the car with oil warning light on. It will prove to be huge expense in the future.

And... I recommend Castrol Oil... ya

[Sly_North]

Hi guys thanks for the replies: it was the oil sensor. Replacing it fixed the issue.

[adamstasiak]

I do not believe it.
Wait 3 days and let us know please

[Sly_North]

It's been fixed in late May - check the thread date

[adamstasiak]

Ok I learned something new.
Did they change oil at the same time?