[drecc]

I have a 2018 4 series F36 parked in my front drive.

My neighbour just told me that in the early hours of the morning, people with masks on had pulled up in a car and were looking underneath my car. The neighbour said they could be looking to steal catalytic converters.

If they come back, I'm wondering if the alarm (just the standard alarm that comes with the car) is sensitive to one side of the car being lifted?

I tried rocking the car with my own bodyweight by pushing above the front door repeatedly, and couldn't manage to trigger the alarm. I wasn't able to rock it very significantly, so perhaps it's ignoring my attempts thinking it could just be a strong wind.

I've been looking at YouTube CCTV of thieves operating, and the pattern seems to be that they pull up in a car, use a device to lift the car on one side, and then complete the entire theft in just under 2 minutes: https://www.youtube.com/shorts/dNwqVCHLHlg

A few questions:

1. Would the car alarm almost certainly trigger if they tried this? What sound does the alarm make, and would it trigger immediately? I've never been able to trigger the alarm on my car, I'm not sure how I would do it.

2. I've heard that BMW catalytic converters are much harder to steal than those on other cars. Is this true?

3. In many of the YouTube videos, they look under the car before immediately returning with a jack to lift it up. I wonder if this is because the catalytic converter is much closer to one side of the car, and they have to decide which side to lift. If this is the case, I could make it more difficult for them by parking the car with the side they have to lift being closer to the house. Then they would hopefully trigger my ring doorbell recording and motion alerts.

4. If someone stole the catalytic converter, and I got into the car to drive off, would I immediately be aware of the theft? Would some kind of warning message appear? Or worse, would the car refuse to start? Would damage be clearly visible with bits and pieces hanging underneath the car?

Thanks for any thoughts

[Billfitz]

They're very hard to access in a BMW.

[drecc]

Originally Posted by Billfitz

They're very hard to access in a BMW.

Is it difficult enough that it's not worth the effort to try? Or does it just mean it'll take them 4 minutes instead of 2 minutes?

I've been trying to google for diagrams of where it is located, and I guess my google skills are not so great. I looked under the car with a torch and saw something that might be the catalytic converter, but I'm not sure what I'm looking for.

[Qsilver7]

4. If someone stole the catalytic converter, and I got into the car to drive off, would I immediately be aware of the theft? Would some kind of warning message appear? Or worse, would the car refuse to start? Would damage be clearly visible with bits and pieces hanging underneath the car?

Yes…you’d know because you could HEAR it. The cats are before the mufler(s) so if the cats are cut away from the exhaust…it is no longer attached to the muffler. Again, you’d HEAR it…and it would sound like you don’t have any muffler(s).

BTW, the OP doesn’t mention WHICH engine or model they have…and the exhaust system design can be slightly different depending on which engine/model is the topic of discussion. But if my memory is correct, most f36 CATS are up close toward the engine…so as someone mentioned earlier in the thread…they aren’t that easy to steal.

For example, the diagram below is for the 440i…you can see the exhaust pipes with the front silencer/muffler (#1)…and the rear silencer/muffler (#2). The CAT is off the engine before the front muffler…so again, you can extrapolate how close the CAT is to the front of the vehicle.



EDIT: you can see how close the CAT is to the engine bay in the illustration below. You can also see the functional operation of the TILT sensor…it says that it is designed not to false alarm from strong shaking (which would have it going off with strong wind)…but has an algorithm for longitudinal & transverse lift:

[Billfitz]

Originally Posted by drecc

I've been trying to google for diagrams of where it is located, and I guess my google skills are not so great.

This is an F30, it will be similar.

With the F30 it's hidden above the bottom trim panel. I imagine the F36 is the same.

[eff32fl]

Indeed part of the cat is within the lower part of the engine bay. The thieves probably realized it was too much work and left it alone. Thieves go for easy targets. It's not worth their time to spend an hour trying to mess with a difficult car. SUVs and trucks are much easier.

[tturedraider]

Not directly related to the OPs question, but apparently they’re pretty easy to get off of Priuses. Here in Chicago I think Priuses get hit more than any other car and they get hit A LOT!! And, of course, here in the city there is a lot of street parking.

[drecc]

Originally Posted by Qsilver7

Yes…you’d know because you could HEAR it. The cats are before the mufler(s) so if the cats are cut away from the exhaust…it is no longer attached to the muffler. Again, you’d HEAR it…and it would sound like you don’t have any muffler(s).

BTW, the OP doesn’t mention WHICH engine or model they have…and the exhaust system design can be slightly different depending on which engine/model is the topic of discussion. But if my memory is correct, most f36 CATS are up close toward the engine…so as someone mentioned earlier in the thread…they aren’t that easy to steal.

For example, the diagram below is for the 440i…you can see the exhaust pipes with the front silencer/muffler (#1)…and the rear silencer/muffler (#2). The CAT is off the engine before the front muffler…so again, you can extrapolate how close the CAT is to the front of the vehicle.



EDIT: you can see how close the CAT is to the engine bay in the illustration below. You can also see the functional operation of the TILT sensor…it says that it is designed not to false alarm from strong shaking (which would have it going off with strong wind)…but has an algorithm for longitudinal & transverse lift:

Whoa, INCREDIBLE answer, thank you so much!!! It's a 420i btw.

I can see from your diagram that what I saw when I was looking underneath the car was just the rear silencer. I'll check again underneath the car nearer the engine to see if I can spot the cat, and hopefully it's hard to access just like the 440i diagram shows.

[drecc]

Originally Posted by Billfitz

This is an F30, it will be similar.

With the F30 it's hidden above the bottom trim panel. I imagine the F36 is the same.

That's the perfect video - thanks! I know what to look for now.

[drecc]

Originally Posted by tturedraider

Not directly related to the OPs question, but apparently they’re pretty easy to get off of Priuses. Here in Chicago I think Priuses get hit more than any other car and they get hit A LOT!! And, of course, here in the city there is a lot of street parking.

I hear that hybrids have a lot more precious metal content in them, making them a bigger target.

My BMW is unbadged, so it's possible that they might have checked to see if it was a hybrid or not. I wonder if hybrid BMWs have a larger and more exposed cat than a petrol-only BMW.

[Wires]

Jacking up the car will trigger the alarm (did it changing tires with the car locked).

Honestly, impossible to steal the car on one of these cars. It's part of the DP, there is ZERO way they could cut it out with the DP in the car. Maybe if you had the hood open, and that is a really slight maybe.

It is bit of PITA to get the DP out when the clamps, etc are all off, so just a hacking it out would be almost impossible.

Other vehicles have the cat in the exhaust pipe going to the muffler, so it's just a matter of cutting through the exhaust and grabbing it.

[drecc]

Originally Posted by Wires

Jacking up the car will trigger the alarm (did it changing tires with the car locked).

Honestly, impossible to steal the car on one of these cars. It's part of the DP, there is ZERO way they could cut it out with the DP in the car. Maybe if you had the hood open, and that is a really slight maybe.

It is bit of PITA to get the DP out when the clamps, etc are all off, so just a hacking it out would be almost impossible.

Other vehicles have the cat in the exhaust pipe going to the muffler, so it's just a matter of cutting through the exhaust and grabbing it.

Thanks - what's a DP?

I've also just realised that my UK BMW key fob doesn't have the button closest to the key ring hole on the fob, as shown in this 430i key fob video: https://www.youtube.com/shorts/XjQ4pkWPOPo

Therefore I can't do what is shown in the video to test my alarm. I guess this is some kind of panic feature they have in the US but not in the UK.

[agentorange]

The thieves love easy targets like 12-passenger vans (AKA the Minibus for my UK readers) that have plenty of ground clearance. I think they have hit just about every church and charity in this city, some more than once.

[eluded]

Downpipe solves this issue

[Billfitz]

Sure, if you don't mind failing MOT.

[lens]

Originally Posted by Billfitz

Sure, if you don't mind failing MOT.

Good thing in Canada and in most states there's no emissions testings

Plus, people have places that you slide a little extra and they'll pass you anyways.

Originally Posted by drecc

Thanks - what's a DP?

I've also just realised that my UK BMW key fob doesn't have the button closest to the key ring hole on the fob, as shown in this 430i key fob video: https://www.youtube.com/shorts/XjQ4pkWPOPo

Therefore I can't do what is shown in the video to test my alarm. I guess this is some kind of panic feature they have in the US but not in the UK.

DP = Downpipe

[rjd_F30]

They'd have to be awfully stupid to go for a cat on a modern BMW. They're in the downpipe, and physically cannot be cut out with a sawzall, there just isn't enough room. It's basically impossible to do quickly. I'd be more worried they'd mistake the resonator for a cat and cut that out.

[drecc]

Originally Posted by rjd_F30

They'd have to be awfully stupid to go for a cat on a modern BMW. They're in the downpipe, and physically cannot be cut out with a sawzall, there just isn't enough room. It's basically impossible to do quickly. I'd be more worried they'd mistake the resonator for a cat and cut that out.

I wonder then if they were interested in something other than the cat - is there anything else that is easy to quickly steal? (other than breaking the window and checking for personal items in the car)

I came across this article about stripping cars https://www.dailymail.co.uk/news/art...es-pieces.html

I wonder how long that takes and how noisy it is

[freakystyly]

There's someone on the 2 series forum that had their entire steering column yanked out... nothing else.

But as mentioned, yeah, these cars have a tilt alarm.

[Billfitz]

BMW isn't favored by professional parts thieves as pretty much any item that has a wire attached to it requires programming to use it. Besides, there's a lot more Honda on the road than BMW, which makes for a lot more demand for Honda parts than BMW. In the US BMW doesn't even make the top ten list of most stolen makes.

[rjd_F30]

Originally Posted by drecc

I wonder then if they were interested in something other than the cat - is there anything else that is easy to quickly steal? (other than breaking the window and checking for personal items in the car)

I came across this article about stripping cars https://www.dailymail.co.uk/news/art...es-pieces.html

I wonder how long that takes and how noisy it is

Under the car? Not really unless you have an aftermarket exhaust. The stock exhaust would have to be cut, which is quick and easy, but isn't all that valuable. I worry most about my Carbon parts on the exterior. The spoiler is just taped on, and the lip is just screws that could be taken off in 2 minutes. Same with diffusers. And carbon parts are worth good $$$

[lens]

Originally Posted by rjd_F30

Under the car? Not really unless you have an aftermarket exhaust. The stock exhaust would have to be cut, which is quick and easy, but isn't all that valuable. I worry most about my Carbon parts on the exterior. The spoiler is just taped on, and the lip is just screws that could be taken off in 2 minutes. Same with diffusers. And carbon parts are worth good $$$

That's where Alibaba special carbon fiber ABS plastic lookalike comes in handy.

They're gonna start taking the pieces off then find out it's fake carbon (that looks real) and leave it