crabb143

I am about share an interesting experience with Audi A4 quattro 2004 model (18.cc engine). I bought this car in july 2012. It had 91000 miles on it, fairly well maintained with a all maintenance records available. After driving this car for 220 miles in three days the engine threw a CEL . Took it to Autozone and diagnosed it as needing an engine coolant temp sensor. When replacing the sensor the mechanic at a local garage broke the Dip stick funnel tube. After the engine was started it started throwing a low engine oil light constantly. Later the dipstick funnel tube was replaced and oil changed but, i guess the right oil was not put in it. The car was towed to Audi dealership, who determined that oil pressure was Zero and engine has to replaced as there was some scorching on the bearings. After keeping the car in the car garage for three months, i contemplated about putting an used engine it.
Before i did that i wanted a second opinion and tool to another local audi certified mechanic and they determined that oil pick tube might have been clogged and hence the low oil pressure light coming on intermittently. They replaced the pick up tube and put some old oil in it to see how it was doing with oil pressure. The car was driving fine and after 15 miles that Red beeping low oil pressure light came back again.
I took it back to mechanic and they recommended swapping an used engine. I did not want to give up yet.Then i asked them to drain the old oil and replace Mobil 0 40W in it and also replace the oil filter. I have been driving the car for the last 10 days and put around 100 miles on it and the low oil pressure light never came back.

Here is my question: Does low oil pressure light disappear after putting in a thicker oil?

I felt that i could not trust the Audi dealership who recommended a new engine when the old one is performing fine.

What do you think is the possible explanation to my case.

Thanks

Mike

uberwgn

Mike, if this is true, the engine is on borrowed time:

Has anyone put a real oil pressure gage on it to see what's going on? Is this a "sludge" car? Do you know the history?

Prospeeder

We had one beetle 1.8T do this, pickup tube was perfectly fine but down the highway get the red oil pressure light. Replaced the oil pump, solved.

crabb143

I do not think the car has sludge in it. Yes it qualifies under those sludging VINS , but the car was regularly maintained with all records available and oilchange done at required intervals.

coloradobob

I wouldn't make any decision without putting an oil pressure gauge on and finding out whether it has adequate pressure. Also cut open the filter to see what may be in it. If the bearing were damaged, they're probably still generating pieces (see comment about borrowed time)

DownshiftArtist

That literally means nothing. The fact that you have the service records only means that the dealer has not choice but to perform the "sludge" service. Trust me, I worked for VW for 2 years and we did a few of these services on cars that were "regularly serviced". It's not the frequency of the oil changes that was the culprit (although not doing them regularly exacerbated the situation) but something to do with the design of the vent system of the engine.

ddillenger

Yes, thicker oil will mask a low oil pressure problem. Put a manual gauge on it, or start preparing for a motor swap.

jschick

you need a oil pump at the least! and thicker oil will mask it, drop the pan replace the pump.

Oneplank

I have a 1998 A4 2.8 AHA. In the winter I run 10W30, but when it warms up in the spring I have a problem. When I pull off the highway and the engine drops to idle for about 1 minute after 30 minutes of highway driving, the low pressure warning actuates. Increasing engine speed deactivates the warning light. My local Audi dealer told me that they install 15w40 in warmer weather. This problem goes away when I switch to 15w40 oil. I have been living with this behavior for over 100,000 miles with no apparent ill effects.

Of course your problems may be more serious.