Engine Burning Oil

[Ben1977]

I wonder if I could get some advice on what the problem might be with my engine as it seems to be burning through quite a serious amount of oil.

It's a BMW 330 with 110,000 miles on the clock so by no means a new engine and I would expect an older engine to consume a small amount of oil but it seems to be going from the max mark down to the minimum over the course of only about 300 or so miles. There is no oil on the ground when the car has been stood still so I'm pretty sure there are no oil leaks going on.

The exhaust gases don't seem to be blue or white, they seem to be the normal greyish colour but I have noticed that there seems to be quite a lot of exhaust gases expelled when the car is warming up then after reaching normal operating temperature it goes back to normal. My initial thoughts are maybe valve seals or piston rings perhaps but I would appreciate the thoughts of those more experienced on here please?

 

[HDi fun]

110,000 miles is nothing for a BMW engine. There are plenty of M52TUB and M54 units around will three or more times that mileage.
During warmup you will get lots of water vapour in the exhaust, this is white.

Is your coolant level stable?

 

[Ben1977]

Hi HDi fun, thanks for the reply. I pretty much thought the same with regards to the mileage of the car not being an issue.

I've checked the coolant levels this weekend and they were pretty much down to the minimum mark so I'm going to top it up and monitor it over the next week to see how it changes. If the coolant and oil levels continue to drop then does this indicate a cylinder head problem?

 

[TCJBOLDIE]

Coolant levels dropping with no visible leaks suggests that there is a HG leak or a crack in either the head or block.

 

[HDi fun]

Possibly yes. These engines are prone to head gasket problems if they overheat. Apparently.

However, you are saying no signs of leaks underneath the car.

Let's eliminate the obvious: does your engine have an under-tray?

 

[Ben1977]

Ok, so as the car is still under warranty I've had it back at the garage today for them to check over. The engine does indeed have an under-tray so that would explain why I've not seen any signs of leaks under the car. They managed to identify and fix a leak in the cooling system so that would explain my coolant levels dropping. As for the oil levels they cleaned a few areas up around the engine but couldn't find any obvious leaks so they've instructed me to do another 500 miles with the oil level topped back up again and then check it to see if there has been any movement....

 

[HDi fun]

Good. This is looking promising. The M54 units are prone to leaks from the cam cover gaskets, this is not an expensive fix but I am told that you're better off using BMW gaskets rather than 3rd party ones. BMW parts are good value in my opinion, far cheaper than VW original parts (for example) and are arguably of far far higher quality.

What oil are you using? These engines perform best on 5w30 fully synthetic meeting BMW LL-04 specification. Mineral oils or semi synthetics are often to blame for excessive consumption. Don't be tempted to go down the thicker is better route it isn't. My favourite is Fuchs Titan GT1 Pro C3.

The dipstick on your car is quite hard to read - the difference between max & min is a whole litre of oil. Make sure you check cold and again warm, after allowing 15 minutes or so for oil to drain back to the bottom of the engine.

I would check before 500 miles rather than risk running low. I think you'll find though that the oil pressure light (red for low pressure) doubles up as a low level warning, in which case it lights up yellow.

 

[Ben1977]

Sorry for the late reply, I don't get much of a chance to get on here what with work and family commitments

I've been using Castrol Edge 5W30 so far but I'll keep in mind your recommendation for the next oil change.

I'll do another reading this weekend, both from cold and warm and go from there. It was the oil pressure light coming on yellow at first that alerted me to the problem, that's when I found I had way below the minimum level in there so I'll keep a close eye on it now and report back.

 

[HDi fun]

We need to get this sorted for you, Keep the messages flowing, and - Torque Cars folks - let's wrack our brains to help Ben with this

 

[TCJBOLDIE]

Is it a low oil pressure warning OR a low oil level warning light ??

Not familiar with your car but would recommend installing an oil pressure gauge IF there are only warning lights so you can monitor /see what is actually happening.

 

[davalav]

The oil rings on the piston could be on its way out as this can be a cause for excessive oil consumption.

 

[HDi fun]

The oil light serves as a pressure and level light. Red is pressure low (critical), yellow is level low (slightly less critical). So in response to TCJB's question the answer is no.

I'd be surprised if a BMW engine needs attention at 110,000 miles. Given there's no blue smoke from the exhaust I think it's unlikely that the oil control rings are failing.

 

[crowley]

PCV valve blocked?