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How to fix them? Read the whole article below 🙂
AFFECTED MODELS: BMW 320i/ BMW 325i/ BMW 328i/ BMW 330i
The BMW 3 Series: E90/E91/E92/E93, is a model that is fondly remembered for its reliability, technology, and performance. When it came out, it had a huge chip on its shoulder because of the beloved outgoing E46 BMW 3 Series. The BMW 3 Series E9x cars were a hit amongst enthusiasts and critics alike.
However, as time went by, and consumers added miles to their cars; they got to be greeted by the following message:
“Engine temperature too high drive moderately”
These six words are standard options that come with the E90/E91/E92/93 BMW 3 Series. The overheating problems in the engines come after a hefty amount of mileage has been achieved. The internet forums and reviews are full of complaints regarding these. So, let’s take a look at what that BMW engine overheat message is about.
Main Reasons of Engine Overheating
Faulty Thermostat
If you’ve got an E90/E91/E92/E93 BMW 3 Series that is overheating, then a good guess is to check the thermostat before doing anything else. The 2006 BMW 325i models are known for their overheating problems due to this.
Water Pump Failure
Then we come to the most recurring problem. The water pump on the 2006-2012 BMW 3 Series models has always been known to fail at an average of around 75 thousand miles. This issue will require all of the components mentioned here, to be changed.
Damaged Radiator Fan
The next problem that can lead to your BMW engine overheating is when the radiator fan upfront stops working. This problem has pestered several BMW 3 Series 325i and 328i owners. When you get the thermostat or the pump changed, it is key that you replace this as well.
Coolant Issues
Coolant-related problems can cause many overheating issues for a BMW engine. While some of these are reactions to the problems discussed above, leakages and blockages are not. These can be found on any BMW E90/E91/E92/E93 variant.
Problems Explained
Let’s dive a little deeper into these overheating problems, starting with the thermostat. The thermostat’s job is to ensure that the engine is working with the right temperature conditions.
The E90/E91/E92/E93 BMW 3 Series models became the first of the historic lineup to have an electric water pump. Coming under PCM technology, an electric water pump meant that the ages-old feature was now under the command of the ECU. No water pump means that the coolant won’t be able to flow around and maintain the engine temperature.
A common set of overheating issues can be attributed to the cooling fan malfunctioning. Your BMW 3 Series needs cooling air to flow through its engine, and that can’t happen efficiently if the fan is not working. Thankfully, this is one of the easier issues to diagnose.
Often at times, overheating can be due to coolant troubles. The coolant ensures that heat gets exchanged. A dried-up reservoir can be due to coolant leakage, which can be due to one or more cracks in the cooling system. Blockages can also stem from air getting into the hoses.
How to Avoid These Problems?
What to do when your BMW overheats? How about you don’t let it get to that point. Most BMW engine overheating issues result from a faulty water pump. This is a problem that all E9x BMW owners face at least once. However, the mileages at which it happens differ, as most encounter this issue after crossing 65k miles; some get it at around 55k, and some don’t get it even until 90k miles.
However, you can take precautions like using good-quality pure coolant to prevent the insides of your BMW 3 Series pump from corroding. You should also ensure that the coolant levels are substantial while running your BMW E9x. But since this is an electrical system, the most important factor is a well-maintained PCM. Make sure you don’t let it get wet very often, drive on smooth roads, and don’t let it receive excess voltage due to bad wiring.
Similarly, while the thermostat is a simpler piece of equipment that lasts according to wear and tear; it can also be maintained with a well-kept coolant circuit. However, there’s nothing you can do to prevent the radiator fan from malfunctioning if you drive a lot. These machines succumb to wear and tear.
As far as the coolant is concerned, the leakages can be prevented if you drive safely and make sure that you don’t hit the system on anything to crack it. Coolant flushes and replacement definitely keep the system in shape.
How to Fix This Problem?
As discussed above, there’s no one way to fix an overheating BMW. The first thing you need to do when hit with an “Engine temperature too high, drive moderately” is to diagnose what is causing that high temperature.
Replacing the BMW’s Thermostat
A fried thermostat on a BMW will be indicated by overheating, and the Bimmer taking a long time to warm up. Replacing the stat requires coolant flushing, radiator drainage, and a cooling fan replacement. If this doesn’t fix your engine’s overheating, then the next paragraph should help.
Replacing the BMW’s Water Pump
A good sign of a faulty pump is when your BMW 320i / 325i / 328i / 330i overheats, but you don’t lose coolant. The pump must be replaced, and this is a time-consuming task. For that, you’ll also have to get into the engine, drain out the radiator, and flush out the coolant. You’ll have to replace bits such as the thermostat, and the cooling fan (here too).
Replacing the BMW’s Radiator Fan
Changing this is a lot simpler than the aforementioned components. You just need to remove parts to get to it, replace them and then reconnect everything. No messy drainages will be required, but the catch is, that you’ll need to be careful!
Filling up the BMW’s Coolant
This is a no-brainer. If you notice bubbling and the car is overheating, you’ll need to bleed out the system because it has air in it. If there’s no coolant, then check for leaks and fix them before topping up with the coolant. Keeping the coolant in top-notch condition is vital regardless.
How Expensive Is It to Repair?
You better hope you’re not dealing with a water pump replacement because that will set you back at around a thousand dollars. A good cooling fan can cost anywhere between 200 to 250 dollars. Thermostat replacement can cost around $30 to $165 depending on the quality, and you must add the fan’s cost to the mix. Make sure to get only the best quality parts, as the cheaper ones won’t last long. The coolant is the cheapest at around $20, for a BMW recommended antifreeze.
These costs can vary based on your location, and the nature of the overheating problem.
Is There A Recall About This Issue?
Yes, there is. In 2017, about 672,775 BMW 3 Series cars including BMW 320i, BMW 325i, BMW 328i, and BMW 330i models were recalled. The details of the recall according to the NTHSA documents stated that the blower motor’s wiring in each of those cars was at the risk of overheating.
Is the BMW 325i A Reliable Car?
Yes, it is moderately reliable. While its parts are not the cheapest in the market, they are built to last. The maintenance costs are similar to the BMW 328i, and BMW 330i, but are lower than the BMW 320i.
All of the BMW 3 Series 325i owners that have been consulted on various enthusiast forums have said that their cars haven’t bothered them much.
The cars do not break down much, as far as frequency is concerned. However, the trips to the mechanics for spontaneous repairs have been said to have cost a lot due to the repairs being big ones.
Of course, since the car is old, if you plan on getting one, your experience will depend on how the previous owner has kept theirs. So, a well-maintained BMW might not give you the same issues as one that has been used in a rugged fashion.
Conclusion
So, what do we make of the issues mentioned above? Well, while these do cause damage to the E90’s legacy, they do not cast a shadow over it. The biggest problem that causes overheating is the fuel pump.
While many cars don’t overheat even after they’ve crossed about 10 years of running, remember that they haven’t been fitted with the kind of tech on these BMWs. 60 thousand is a large number of miles and remember, there have been plenty of new cars that have brought misery to their owners right after they were driven out of the showroom.
Regardless, if you own a BMW 320i, BMW 325i, BMW 328i, or a BMW 330i, we have shown you what to do if your BMW is overheating. Fixing these overheating issues must be done as quick as possible if you want to preserve the rest of your engine.
If you plan on buying an E90 BMW 3-series, do not worry about a possible BMW engine overheat message. Think about getting a car with less miles, or one that has had this job done already. Thanks for reading this article! Hope we sorted all the things out.
This is a no-brainer. If you notice bubbling and the car is overheating, you’ll need to bleed out the system because it has air in it. If there’s no coolant, then check for leaks and fix them before topping up with the coolant. Keeping the coolant in top-notch condition is vital regardless.
We recommend you read our previous article regarding the smoking engine of the Audi A4.
