Are you planning to purchase a BMW with the S65 engine, and you want to learn more about the BMW S65 engine problems? Well, if that is the case, you are at the right place because there will be a lot to cover on this engine.
Proper research is essential when you want to purchase a used car. Especially cars with complex engines, like in this case with the S65. Replacing one of these engines is something that you don’t want since they are very costly to replace. It can cost you up to $10,000 even for a rebuild. That’s why we are here to help you out.
First, we are going to learn the basic BMW S65 engine specs and learn more about the different variations of the engine. Then we shall discuss the BMW S65 engine problems and lastly, we are going to answer some frequently asked questions. So, let’s dive into the topic.
Basic BMW S65 Engine Specs
Let’s start with the specs of this engine and learn more about the different variations in which you can find.
What is worth noting first is that this is a V8 engine that was manufactured by BMW between 2007 and 2013. The S65 replaced the S62 engine and was followed by the S63. The S65 was primarily used in the BMW E90/E92 M3.
This engine had two primary variations. A 4.0L and a 4.4L version. Both of them created different power numbers.
- S65B40
This was the 4.0L version of the engine introduced in 2007. This engine produced 309 kW (414hp) @ 8,300 rpm and 400 N-m (295lb-ft) @ 3,900 rpm.
- S65B44
This was the 4.4L version of the S65 engine introduced in 2010. This version of the engine produced 331 kW (444hp) @ 8,300 rpm and 440 N-m (325lb-ft) @ 3,750 rpm.
The S65 engine shares the same cylinder dimensions as the S85 V10 used in the BMW M5, as well as the individual throttle bodies and other technologies made for the V10.
The S65 engine is also lightweight, weighing only 202 kg or 445 lbs. This makes it lighter than its predecessor, the S54.
Common BMW S65 Engine Problems
Now let’s briefly cover the common BMW S65 engine problems.
Common BMW S65 engine problems include:
- Rod Bearing Failures
- Valve Cover Gasket Failures
- Oil Consumption
- Oil Cooling Issues
- Coil Pack/Spark Plug Problems
- Idle Air Control Valve Failures
- Throttle Body Actuator Failures
Now that we briefly covered the BMW S65 engine problems, let’s learn more about the problems more in-depth and see how serious these issues are.
Rod Bearing Failures
The worst problem with this engine that greatly undermines its reliability is the problem with rod bearing failures. Rod bearing failures are common on all S engines that BMW produced in this era and even a couple of years after. The S85 V10 is most affected but the S65 is also affected by this issue to a lesser extent.
What happens is that the rod bearings tend to wear at an exponential rate on these engines. This is practically an unavoidable process that happens on these engines.
No matter how well you maintain the S65, the rod bearings will wear. And you must detect the problem before the infamous rod knock appears. If the engine starts knocking, an engine rebuild will be inevitable.
That’s why it is recommended that you replace these bearings every 50,000 to 80,000 miles (ca. 128,748 km). Just to be on the safe side.
Symptoms include, a ticking noise that appears at low rpm, rod knock when the issue becomes too large and if not treated, the engine will eventually seize or throw a rod. This is why we suggest making sure that this engine you intend to buy has these bearings replaced. Since it is not cheap to get these bearings sorted out.
Valve Cover Gasket Failures
Another problem is the valve cover gasket failure. This is a very common problem on every BMW engine. We don’t know why BMW doesn’t fix these problems but almost every one of their engines is leaking oil from the valve covers. And the S65 is no exception.
Usually, there is a small loss of oil when these problems occur and you might notice the engine oil light on the dash, as well as some grease spots on the sides of the engine where the valve cover gasket goes.
What is good is that replacing these gaskets is not expensive. Even if you have some minor experience wrenching on cars, you can sort this problem out very easily.
Oil Consumption
These engines are consuming a good amount of oil as well. This engine is using a PCV system that captures fumes in the crankcase and redirects them to the intake.
This system redirects oil and carbon particles into the intake to burn. So, by doing this, you lose some of the oil in the process. Not to forget the nasty dirt that is accumulating on the throttle body actuators and intake ports.
The solution for this problem is to install a baffled oil catch can. This catch can will prevent the oil from going into the intake and prevent carbon deposits and oil consumption to appear.
Also, oil consumption/loss can appear on these engines from other places. Namely, leaks as we noted previously. Leaks from the valve cover, oil pan, and oil cap, as well as internal leaks from the valve stem seals and piston rings.
Oil Cooling Issues
Another very common problem with these engines is the situation with oil cooling. Oil cooling on this engine is good if you daily drive the car. But not so good if you decide to track the car.
Track use requires a lot of cooling and your engine will most likely overheat if you don’t upgrade the oil cooler with a larger one.
This is an issue that only affects people who intend to use these cars on the track. So, if you are not one of these people, you shouldn’t be worried about this problem because it will never affect you.
Coil Pack/Spark Plug Problems
The next problem is another very common issue with BMW engines. Namely, a problem with ignition coils and spark plugs.
This is a high-performance engine and it tends to go through spark plugs and coils more often compared to your regular low-performance engine. Replacing them isn’t exactly cheap.
Luckily, this is another beginner-friendly job. You only need to remove the coils and get a socket key to remove the spark plugs. The whole job will not take more than two hours, even for a beginner.
When these components go out, you will face misfires, problems with starting, engine stalling, limp mode, and similar running issues.
Throttle Body Actuator Failures
This engine is using something known as individual throttle bodies. Just like the V10 engine. So, what does this mean?
Well, this means that for each cylinder, you have a throttle body installed on top of the engine. In total, there are eight of these throttle bodies since this is a V8 engine.
And because of this, this engine uses throttle body actuators to regulate the throttle bodies. And they can often fail on these engines. Replacing them can be pricey since OEM parts are very expensive. Remanufactured components are probably the cheapest route to sort this out.
Idle Air Control Valve Failures
And last but not least is the idle air control valve failure. Believe it or not, this engine uses idle air control valves. Almost no car nowadays uses these components but this engine uses them.
This is the case because the engine uses individual throttle bodies as we mentioned. So, it has to have an IAC valve in order to control the idling speed.
This component can fail and cause the check engine light to appear, it can stall the engine or can elevate the idle RPM of the engine.
Unfortunately, this is also quite an expensive repair. It will easily cost you about $750 only for the part. This is why beware of this component and its condition before you buy the car.
Which Models Have The BMW S65 Engine?
Now let’s take a look at what models include the S65 engine. We will cover both main variations and the racing variations.
Regular M-Versions of the S65 engine
S65B40
- 2008-2013 BMW M3 E90/92/93
- 2009-2014 Wiesmann MF4-S
S65B44
- 2010-2011 BMW M3 GTS E92
- 2011-2012 BMW M3 CRT E90
P65 Racing Versions of the S65 Engine
P65B40
- 2008 BMW M3 ALMS
- 2009 BMW M3 GT2
P65B44
- 2010-2015 BMW Z4 GT3
- 2013-2016 BMW Z4 GTE
Conclusion
In this article, we covered the BMW S65 engine. First, we covered the basic specs of the engine as well as the power numbers it delivers, as well as the problems, and common applications.
Overall, the S65 is a superb engine if you know what you are doing. Make sure that you do some preventive maintenance and replace the rod bearings if they are worn out. If you are not into servicing these problems, owning this engine can become a very expensive nightmare.
FAQ
What Are The Common Problems With The BMW S65 Engine?
The most concerning problem with this engine is the problem with the rod bearings. They tend to wear out rather quickly. This could lead to engine failure. Other problems include problems with the individual throttle body actuators, IAC valve, oil consumption, oil leaks, and coil/spark plug failures.
Is The S65 Engine Reliable?
Besides the rod bearing issues, the engine is very reliable. But if you are not aware of this problem, it can destroy your engine very easily if you don’t detect the rod bearing failure on time.
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