Have you ever walked up to your car in the morning and noticed a big pool of oil accumulated near the bottom? Well, this is a widespread problem for several cars out there, even luxurious ones like BMW. To help you navigate this issue, we wrote this post about the oil leak problems in a BMW 1 series car.

Oil leaks can be scandalous issues if they happen in the middle of the ocean. But out there in your parking lot, it is not of huge concern. It can just cause your engine to malfunction a bit. The most common cause of oil leak problems in BMW 1 series cars is either related to a loose cap/bolt/sensor or a faulty gasket. Thus, it is often easy to fix these leaks by just tightening the required part or reapplying a new gasket.

Before diving deep into these problems and finding out their solutions, it is important to find out how dangerous is the oil leak and how to detect one. We will explore this in the next section.

Oil Leak Indications and Effects

There are two effortless ways of identifying if you have oil leak problems in your BMW 1 series. The first one as mentioned above is that you might see a pool of oil accumulated under a standstill car. Alternatively, you might spot a trail behind a moving one. The second one might be a burning smell or the sight of some light smoke near the car. You would notice this with no actual drop in performance.

The latter happens when the oil leaks out and falls onto the exhaust manifold or the exhaust pipes downstream which are super-hot. This causes the oil to burn instantly and release smoke. With high enough volumes of oil, there are real possibilities of fire. Thus, if you notice this problem, do not wait any further before getting it fixed.

Now while the case seen above is an extreme one, engine oil also plays a key role in cooling the engine and lubricating it. Thus, if the oil leakage has been going on for a few days then the engine might cease due to overheating and a lack of lubricant. Just before that, you will start to notice a drop in performance and a slightly noisier engine.

Now that you know how to spot a possible oil leak and its potential effects, time to look at the probable causes and their solutions.

Loose Oil Cap or Oil Pan Plug

One of the silliest mistakes, but still is rather common. Often after topping up the oil or flushing (or replacing) it, people forget to tighten the oil cap and the oil pan plug back. These are some of the most common points of leakage of oil.

Another common source of oil leak problems spotted in the BMW 1 series is that when putting the oil pan plug back on, people often forget its gaskets. This gasket helps give it that additional sealing to prevent leakages.

If the oil leak is spotted in any of these sources, simply try re-tightening them. If that does not work and the gasket is still present, you might want to replace these parts once. Since they are fairly accessible and inexpensive, this one can easily be done at home.

Solenoid or sensor replacements

This next one is an equally silly reason. Let us assume you recently had your cam or crank position sensor changed due to other problems in your BMW. Often, if the gaskets (O-rings) or these sensors themselves aren’t tightened properly, they lead to oil leak problems in your BMW 1 series. The same issues can happen with the solenoid actuators for the valves.

The solution once again is rather simple. Just remove the part, check the gasket, and re-tighten it according to the correct specification mentioned in the owner’s manual.

Oil Filter housing

A common source of oil leaks in most BMW engines is the oil filter housings. While the cause of this can be the same as the previous ones – the housing wasn’t tightened properly, but the possibility of wear still exists. Moreover, accidentally tightening the housing a bit too much can damage the gasket of the filter. Thus leading to leaks and reducing filtering efficiency down the line.

In the latter case, it is important to replace the filter housing entirely. Otherwise, if the filter is undamaged, you can just retighten it to the correct specification as needed.

Gasket Damage

While there are numerous gaskets used all over the engine, when it comes to oil leaks, only three are of primary concern. The valve cover gasket, oil pan gasket, and timing chain cover gasket are all potential sites of oil leakage. Leakages occur in these sites generally because, after a recent repair, the gasket wasn’t applied properly or was misaligned. This over time leads to the leaking of oil after some wear and tear.

Unfortunately, in such cases, the repair becomes a little bit harder. In the case of the valve cover gasket, it is super easy and accessible at the top of the engine. However, it is not so easy to remove the entire oil pan while the engine is still attached to the car. It is even harder to remove the timing chain cover. That requires you to take off a considerable number of auxiliary components attached to the engine.

In every case, the only solution is to remove the concerned part, re-apply a new gasket and tighten the part again. It is important to do it properly this time to prevent any further leakages. If you are not confident in your skills to do so or do not have the correct tools, an authorized mechanic would be able to help you out.

Crankshaft seals

Finally, one of the rarest problems for last. A major source of oil leak problems in your BMW 1 series might be from the crankshaft seals. These seals prevent the oil from leaking out from the crankshaft housing toward the front and rear of the engine. This problem is rear since the assembly of this part is rarely messed up and even wear cannot spontaneously cause the problem.

Only if there was a faulty seal attached, will the wear and tear aggravate the issue. If you do however come across it and see there is oil coming out from near the crankshaft, you have some work to do. Replacing the entire seal housing is a lot of work. But there are special tools that allow you to only change the crankshaft seal. To do this, you will have to take off your serpentine belt and the crankshaft pulley. This should give you access to the seal to be replaced.

However, to avoid the same error again, you may want to have a professional help you with it. Just in case.

Final Thoughts and Conclusions

There you have it, all the most common causes of engine oil leaks in your BMW 1 series. Hopefully, this article helped you gain insight into the solutions to these relatively simple problems. With the increasing oil and gas prices, spotting these problems early on could save you a lot of money. As you can see, most of the solutions are simple DIY ones. For the ones that aren’t it is best to take it to the nearest BMW dealership for a once over. We hope your oil problem is fixed soon and you are not leaving a trail of oil either!