Crank main end bearing cap found in sump

[Goldsnape]

Had trouble with a slow oil leak for weeks on my 8p 2012 1.6 TDI Audi A3.

My local garage couldn’t find this leak, as when ran on the ramp for over 6hrs there was not a drop, even running it at 2000rpm for 2 of those hours. The engine still ran perfectly.

Last week, suddenly my engine had no oil pressure, and bearly ran, therefore got it back into the garage, and when they took the sump off they found a crank main bearing cap in the sump, along with the bearing, which had been rubbing against the oil pump belt, causing fibers to come off it and block up the oil pump pick up, resulting in no oil pressure.

the garage is absolutely confused as to how a crank main bearing end cap found its way into the sump as they have never ever seen that before.
 

One of the Bolts that held the bearing cap was also found in the sump sheared.

now looking at a an engine change for the car, but wondering if anyone has any idea how this could even happen?

 

Thanks

Paul

Edited December 13, 2023 by Goldsnape
Add pics

[cliffcoggin]

I am not surprised the garage is confused. I am too as I have never heard of a cap bolt snapping.

I see little signs of wear on the bearing shell. What is the condition of the other main bearings and big end bearings?

The rubbing you mentioned against the oil pump is also strange. Something must have shifted out of alignment to cause that rubbing. Had any work been done on the lower part of the engine in the past?

Was the earlier oil leak truly a leak that dripped down the outside of the engine, or was it just a reduction in oil level as the oil was burned inside the engine? How many miles had the engine done?

[Magnet]

Hello Paul,

Absolutely catastrophic.

Would you be able to post a clear photo of both parts of the sheared bolts? 
Kind regards,

Gareth. 

[Goldsnape]

7 hours ago, cliffcoggin said:

I am not surprised the garage is confused. I am too as I have never heard of a cap bolt snapping.

I see little signs of wear on the bearing shell. What is the condition of the other main bearings and big end bearings?

The rubbing you mentioned against the oil pump is also strange. Something must have shifted out of alignment to cause that rubbing. Had any work been done on the lower part of the engine in the past?

Was the earlier oil leak truly a leak that dripped down the outside of the engine, or was it just a reduction in oil level as the oil was burned inside the engine? How many miles had the engine done?

They said exactly the same as you, and have been showing all of the other garages on the trading estate out of amazement lol

it was an oil leak that was visible as it was all over my drive, and leaving little drops everywhere I drove, it was going through about a litre a week

ive had the car a year and it’s done 140k miles, the garage are that intrigued they are going strip the engine right down once it’s out to see what’s actually got on, so far they have only took the sump off and found that.

 

during the oil leak though the car ran as sweet as a nut, with the garage finding nothing wrong with it.

[Goldsnape]

6 hours ago, Magnet said:

Hello Paul,

Absolutely catastrophic.

Would you be able to post a clear photo of both parts of the sheared bolts? 
Kind regards,

Gareth. 

I will try and get a pic of the bolts when I next go down to the garage 

[Magnet]

Many thanks Paul, 

Dare I say, if this was mine, I wouldn’t have been at all happy to have subjected this car to a non-variable static 2,000rpm for 2hrs., as part of a static 6 hr. running time, but too late now. 
Kind regards,

Gareth. 

[cliffcoggin]

7 hours ago, Goldsnape said:

I will try and get a pic of the bolts when I next go down to the garage 

Please do. While there, see if the garage will assess the condition of the other bolts. I have my suspicions about what happened but it is too early to speculate without more evidence.

[Goldsnape]

Hi all,

**update**

sorry I haven’t replied back on this, so got the car back in early Jan 2024 with a replacement engine, clutch and dual mass fly wheel (as was easy to change during the engine change) and now runs and drives like a dream.

the guys at the garage didn’t really investigate the original engine anymore, so sadly it remains a mystery as to how it got like that.

just happy to have the car back and fully working, we are now mid March and all is well with the replacement engine now fully settled in.

 

cheers

Paul

[cliffcoggin]

Glad to hear the problem has been resolved. Dare I ask who paid for the replacement engine?

My speculation is that the old engine had been worked on in the past by somebody incompetant, who had either over-tightened the new cap bolts or re-used the old bolts, and at the same time somehow mis-aligned the oil pump drive. What that does not explain is why oil only leaked when the car was stationary.

[Steve Q]

Glad it's all sorted and new engine is settled in nicely 🙂