Be Excellent To Each Other

That'll be the noise regs he's hitting you with. Cars only have to pass the emissions test, cat or no. The 'visual' part is great as it refers to 'are there clouds of smoke coming out?' so it's an easy one to pass!

They're not a thing, are they? "Too loud" is entirely down to the opinion of the person testing, I thought?

Legal level is 74dB and has been since 1996 (was 82 dB before that)

The problem is how it's defined. From what I remember, it's defined as the level of noise that a car makes as it passes a testing station, rather than being tested stationary.

It is, however, completely illegal to modify a car's exhaust to be louder than it was when it left the factory (assuming it has type approval) - this (again, AFAIK) doesn't stretch to aftermarket exhausts, so if you replace the entire exhaust system with something aftermarket, that's fine - but if you modify your factory exhaust to be louder than stock, that's against the law.

Yes. There is a decibel limit but I've never found a tester that owned the meter required for the testing. I think the cops have them though.
Gaz's answer is better.

74dB as it drives past is really quite loud.

From what I can gather there's an "old" (recently superseded) noise standard/test method, and a new, more stringent one they're bringing in.

Does anyone know the test method for the old one, e.g. what speed, distance(s) from car for measurement etc., and whether the same test is applicable for bikes?

I've got four x £10,000 Type 1 Precision Grade Norsonic real time sound analysers if that helps anyone.

When you rev an engine next to a duck, does it echo.

The S4 offered up the information this morning that I need to add 1L of oil, but that I can carry on driving normally.

This is exactly 1552 miles after it last said this (I know this because I reset one of the trip computers at the time).

Arguably rather harsh in terms of oil use, although apparently some of the other Audi engines of this generation can use up to a litre per 1000 miles.

(I believe Audi eventually had to settle a lawsuit in the USA over excessive oil consumption in cars of the 10/11 era, which went along the lines of 'You're saying a litre of oil per 1000 miles isn't excessive? Get the fuck out of here'. There are some revised parts they can fit, or something.)

I'll add the oil when I get home, but it is quite annoying as it's getting serviced next Thursday at which point all the oil will get drained and refilled anyway. (There's no reason I couldn't drive it for another 9 days with it being a litre down, except that it'll mess with my head too much to do so.)

At least I don't have to keep checking it with a dipstick as the computer just bongs at me with a nice message when it wants oil.

be a rebel put 1/2 a litre in.. should last 9 days

Oooh yes that's a good idea, just to stop it nagging at me.

Until the sensor fails...

I am 95℅ sure I once read an article in a motorbike magazine about oil. They took three 1000cc sportsbikes, drained the sump, filled the petrol tanks and ran them at full throttle or 10k+rpm in a garage until the fuel ran out. They then took the engines apart and there was some wear but not catastrophic levels of damage. But, it could have all been a weird dream.

I've had a car engine literally smash itself to bits while driving along after the oil drained out and bits warped badly. It's not that fun.

Our (six month old) Mazda shat itself and needed a new engine.

Halfway through topping up the oil in my Golf GTI it started hammering it down so I rushed back inside. Unbeknownst to myself I hadn't replaced the filler cap. 20 miles later a clanking sound became apparent - yes, the engine was eating itself. I looked inside and there was oil all over the underside of the bonnet.

Took it to a garage and the first question was "do you want to keep it?"

My ( admittedly already pretty broken and old ) diesel Nova made some loud banging noises, ground to a halt and then would never start again

Basically oil stops the moving parts of the engine from touching the other moving parts. And that's rather important.

I just don't get why anyone would rely on the oil warning idiot light before topping up (which is possibly past the point of increased wear being incurred as a result of low oil pressure), especially if the engine drinks oil, as this one seems to. How hard is it to pop the bonnet and check the dipper every fill up/whilst topping up screenwash etc., it's a high performance engine after all, and the cost of a new 'un is horrendously high.

Mechanical sympathy, much? Crickey, if I did that on most bikes I've ever owned, they'd have been toast.

It's like cartilage in joints. You don't want bone rubbing together or you get intense pain.

It's actually quite hard with my wife's car as the dipstick gets stuck and needs a load of WD40 to shift it.... but yeah, I agree.

I must check mine this evening.

It might not even have a dipstick. My BMW doesn't as far as I can see. Modern engines probably reply on a whole host of sensors to prevent them damaging themselves anyway.

https://www.amazon.co.uk/Carlube-Xcg500 ... 595&sr=8-5

Put that shit on everything you do up in some way. I swear my Tomcat is 90% Coppercoat.

The Porsche has an oil pressure gauge, which I (anally) have displayed at all times and watch like a hawk - this is very different from just a simple pressure switch/idiot light (it has them *as well*).

Hnnnngh, must resist…

Something like this happened to my dad once. The good news was, he discovered the issue before it wrecked the engine. The bad news was, he discovered it because the fountain of oil worked its way out of the engine bay and coated over the font brake discs, so when he brushed them to slow down in motorway traffic nothing happened... He ended up doing an emergency stop with the rear brakes only and spun the car in the process. (Everyone was fine.)

Crikey

Heathy has every confidence in Germanic automotive sensors.

Ouch, that's nasty. Easily done, too.

Years ago, some numpty from Kwik Fit left the oil filler off Mrs C's old Fiesta (HCS "Kent"-derived 1.3) engine, so consequently it coughed and splattered oil all over the engine exhaust manifold for a week, making her feel as sick as a dog.

"Hello, is that Audi UK?"
"Yes, how can we help?"
"I have an out of warranty claim for a complete seized and written off engine. I'd like £10,000 please."
"I'm sorry to hear that sir, how did this happen?"
"The engine oil was low, but I didn't appreciate the oil pressure sensor was haunted."
"Er, I'm sorry, what was that again?"
"The oil pressure sensor was haunted. An internet forum cohort told me this is the correct technical term."

/click

"Hello?"

Genuine question but is the gauge there just as an option for the benefit of people who like such things? Surely the car will take care of itself and tell you if the oil situation needed attention in good time.

I think the rationale is that the more highly stressed the engine, the more likely the need to monitor engine oil pressure. (I agree with this personally; the thing regularly gets ranted to 8,000 RPM and I ask a lot of it - and I don't fancy the £30,000 bill to replace the engine. Although an S4 or whatever it is is less highly strung, it's still a performance engine that's very expensive to replace)

Well yes but that's the sort of thing that computers are much better at than humans. Surely rather than having you look at a gauge it could just say "woah there pal" if something was edging towards a red zone?

As long as the sensor worked.

8000 revs is pretty good I guess. I mean it's not 9000, but y'know. Pretty sweet.

If the oil pressure sensor doesn't work, the dashboard gauge is gone too.

I suppose I'm drawing a distinction between a simple low oil pressure light and constantly monitoring oil pressure/trends and topping up all the time, by an extremely anal petrolhead. But I do see your side of the argument.

If there was a sudden, catastrophic loss of oil pressure, the computers/lights would kick in anyway. But what I'm talking about is running the engine *chronically* (not acutely) low on oil for possibly long periods, before the actual light flicks on.

Hey, it's his car/money though, each to his own.

My engine management light has been on for 10 months.

Sounds like a banshee; the hollow, naturally aspirated flat-six wail is like no other (and now, sadly, largely a matter for history).

The downside, though, is relative lack of performance - "only" 325 bhp for a 3.4 litre six (my son in law's chipped 2-litre turbo AMG Merc pumps out 400 bhp plus, with little over half the engine size), and a lot less torque. For me, though, character, noise, upper rev range and throttle response count for a lot, but I am stupidly old school.

The GT3 revs to over 9000RPM!

Depends how it fails - I might be gummed open.

Moral: Check the dipstick.

Why wouldn't the light be calibrated to flick on at an oil pressure level that's lower than normal but still high enough to not yet be causing damage?

Also, you're assuming the low pressure light is a binary thing where pressure below some value = light on. I don't think that's a safe assumption, particularly on a £70k Porsche -- let alone a £95k one. I suspect it's the ECU that decides when to flash that light, based on data coming from the same oil pressure gauge you're monitoring by eye. That could be using all sorts of data about the engine's condition and your driving habits to set the state of the warning light. Christ, given the software complexity of modern cars, I could believe there's a machine learning algorithm in there.

In this case though, the dipstick is behind the wheel.

It doesn't have a dipstick, the car is not supplied with one, and Audi don't make them, Audi's official position is it's not required.

It's not a 'low oil warning' light, (or an 'idiot' light as you so kindly refer to it), it's an advisory that the oil level is one litre below maximum capacity, and that the driver should add one litre of oil (but no more) at the next opportunity. (The message on the screen explicitly states that it is safe to continue driving normally.)

It is possible to buy third-party dipsticks (Audi don't make one that you can buy), and some people go down that route, but by all accounts the sensor as fitted is (a) reliable and (b) flags itself up as defective on the very rare occasions when it fails.

Also, you can read the oil level at any time using the MMI system in the car, and it'll show you a graphic of a bar on a scale of 0-100% (where 0% is one litre below max, and 100% is max). In old parlance, it shows the equivalent of MIN and MAX on a traditional dipstick.

The oil capacity of the engine is 6.2 litres, so I'm currently running with 5.2 litres, hardly into mechanical damage territory.

That could be true, Doc. When I think oil warning light, I think of a simple pressure switch (crude binary transducer) - but that's probably 1970s tech (lol), and I'm likely stupidly out of date?

Notwithstanding, though, I would *still* recommend regularly checking engine oil level yourself, by whatever means provided (manual dipstick or specific oil pressure test through the car's menus), especially on higher performance cars. But, this is simply my opinion.

@Hearthly

"Idiot light" is a well-known, oft-used term, don't take it personally as no offence was intended.

https://en.wikipedia.org/wiki/Idiot_light

As for the rest of the stuff - fine, fine, fill yer boots mate. Just don't say I didn't warn you.

Surely modern cars rely on loads of sensors, though. Aren't oil pressure gauges and dipsticks a bit of a throwback to make people who are used to such things feel better?

Suppose you wanted to do away with them then wouldn't you just make it so that an unchanging value is also an error?

They are, but they're often not reliable.

In the case of the Mazda, it thought it was fine, but it wasn't. Mazda knew this could be the case, so still state you should check the oil level every week.

It's been that way for some time, hence the saying that "It's not a 'warning' light, it's a £5,000 'idiot' light".

Basically; if the light's on, it might already be too late.

[edit]I totally agree that it shouldn't be this way, and maybe modern cars are better. Maybe not, though.

@cavey

o/

\o

Just passed the 110k mark in my modern classic Mk1 Leon.