Violent shudder at high revs & warning light

Technical Forum for the Porsche Macan
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GTB
Posts: 541
Joined: Thu Aug 26, 2021 3:49 pm
Location: Scotland

Post by GTB »

GTB wrote: Sat Jul 30, 2022 7:37 pm THHGTTG,

I have worked on fuel filling stations for just over 40 years so witnessed the old blender dispensers that had 2, 3 and 4 star fuel, was always a laugh getting the apprentice to check the 3 Star tank!!! of course that never existed as 3 star was just a 50/50 mix of 2 and 4 star fuel, the introduction of unleaded fuel, then the bio fuels and of course Ethanol.

Tanks used to be single skin steel tanks, before a transition to fibreglass (major mistake due to de laminating) then double skin steel tanks as we have now. So water and microbes causing rusty particles to find their way into the fuel dispenser or customers cars was a lot higher back then. There is a "witches hat" filter of just a few microns in each fuel line below the dispenser that should catch anything coming from the tank, but some dodgy dealers remove them as they have found to be getting clogged with microbes that thrive in the bio fuel content and with some water, they multiply like a virus and looks like a green sea weed in the filter almost like an intense bright green.

Major oil company sites owned by the majors really are the best you can get followed by some of the supermarkets but certainly not them all, but that said some family filling stations the fuel is well looked after.

The biggest issue with modern fuels is water getting in from either poor infrastructure or condensation and a slow throughput.

Personally I always go to a oil company, company owned site, and in 40 years never ever nor will I go to a supermarket site, so take from that what you will.

Now for Joe Public they see some 1300 branded BP filling stations in the country, but only 300 of those are owned and operated by BP, The rest are "Dealer" sites so they look like BP, but BP only supplies the fuel and the image for the site, the rest is under control of a private operator. Same applies to Shell etc

I onlyever fill my tank always to the top (helps with any condensation issue) and like you once car gets to 25% left in the tank I then fill up, that said in a modern car i.e over last 20 years there really should not be any sediment, rust particles in a cars fuel tank.

Happy to help, any more questions fire away.

Cheers GTB
Current Macan GTS Collected July 2022 https://www.porsche.com/microsite/porsc ... =/PNM4GBM0

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Nuclear Nick
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Post by Nuclear Nick »

I’m sorry, but I think this thread has gone rather awry due to some scaremongering that has frightened the poor OP witless. While fuel contamination has happened on rare occasions the chances of it being a factor here are extremely small. While I mentioned it as a possibility in my earlier post, now that it’s known that the fault is due to a failed fuel pump, the chances of that being caused by contaminated fuel must be vanishingly small. So I think that draining the tank and throwing away a significant quantity of fuel is way over the top. OK, for peace of mind, perhaps request a sample of fuel be drawn off for analysis, but use the car in the meantime. Liability for the repair remains with the OPC so there is protection in the unlikely event that contaminated fuel is present.
Nick

Defender 90 V8

991.2 C2 GTS

Macan Turbo - sold

BMW K1300S, BMW R1250 GSA
Alfanut
Posts: 218
Joined: Mon Jun 03, 2019 6:45 am

Post by Alfanut »

Exactly. If the OPC thought the issue was possibly related to contaminated fuel they would have highlighted this and likely charged for the repair. Brim the tank and forget about it.
2022 Macan GTS & 718 GT4.
Past: Macan S, Audi S4 B8 Avant / Alfa 147 Q2 Diesel / Alfa 147 2.0 Selespeed
gasgas1
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Location: Devon

Post by gasgas1 »

there always seams to be a lot of scaremongering on the site, people loose track of how many cars are produced and in real terms how many have issueus, a very small percentage.

like all thinks issues arise and it's how thay are delt with
Rarecolour
Posts: 1428
Joined: Sat Jan 23, 2021 9:39 am

Post by Rarecolour »

gasgas1 wrote: Sun Jul 31, 2022 9:19 am there always seams to be a lot of scaremongering on the site, people loose track of how many cars are produced and in real terms how many have issueus, a very small percentage.
Nail on the head. Folk who haven't even got their cars yet are worried about things, feel sorry for them, should be a time to be excited.
Too much rubbish is spouted in here at times.
Ex -
Macan Turbo (Mamba Green)
Audi RS6 (Misano Red)
Audi S4 (Silver)
Audi S3 (Imola Yellow)
Peugeot 309 goodwood (Green)
Peugeot 306 gti-6 (Silver)
Peugeot 205 gti (Ltd edition Sorento Green)
Rarecolour
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Post by Rarecolour »

Nuclear Nick wrote: Sat Jul 30, 2022 10:16 pm I’m sorry, but I think this thread has gone rather awry due to some scaremongering that has frightened the poor OP witless. While fuel contamination has happened on rare occasions the chances of it being a factor here are extremely small. While I mentioned it as a possibility in my earlier post, now that it’s known that the fault is due to a failed fuel pump, the chances of that being caused by contaminated fuel must be vanishingly small. So I think that draining the tank and throwing away a significant quantity of fuel is way over the top. OK, for peace of mind, perhaps request a sample of fuel be drawn off for analysis, but use the car in the meantime. Liability for the repair remains with the OPC so there is protection in the unlikely event that contaminated fuel is present.

Agreed, just seems like real bad luck. Parts fail.
Ex -
Macan Turbo (Mamba Green)
Audi RS6 (Misano Red)
Audi S4 (Silver)
Audi S3 (Imola Yellow)
Peugeot 309 goodwood (Green)
Peugeot 306 gti-6 (Silver)
Peugeot 205 gti (Ltd edition Sorento Green)
Deleted User 4752

Post by Deleted User 4752 »

We were discussing the “possibility” of fuel contamination in general ( i have had contaminated fuel cause serious damage to my Merc ). If you read the posts you’ll see the general consensus is its extremely unlikely that is fuel contamination that has caused the problem, far more likely to be crappy Porsche quality control on its parts, something many of us have been victims of. Also a brief look on Google will show its a common issue with Porsche HPFP’s. But its easier to criticise than to actually read the posts.

However, given that contaminated fuel can ( in undoubtedly rare circumstances) cause damage to the fuel system, like I said I suffered from the Tesco fuel contamination issue a few years back, and have a look on the internet and you’ll find its not totally unheard of that fuel contamination damages the HPFP, then for the cost of a tank of fuel it seems a sensible precaution to remove the fuel just in case that was the cause. For the sake of £100 of petrol OlI personally would much rather have the peace of mind of swapping it out and not running the ( probably small ) risk that not doing so may cause the problem to re-occur.

You are, of course free to to express other opinions, and clearly there are some that will always contradict opinions because they cant help themselves. The OP asked for help and opinions. Some were offered. Feel free to disagree with them, but do please read the actual responses so your comments are at least relevant.
GTB
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Post by GTB »

Afternoon All,

I have read back my posts carefully and to the words I used in answering what appeared to be legitimate questions. OPC identified faulty fuel pump, great and that as I said was unfortunate as somebody ends up with the 1:100000 faulty part. Now the question was posed could it have been contaminated fuel given the OP's car had just filled up with fuel, then Im afraid that is a possibility albeit again rare, but for a belts and braces approach I suggested two in fact three things. 1) Top up remaining space in the tank with fresh fuel. Thus duluting any contamination that might be present. 2) have the OPC completely drain the tank of the existing fuel and fill up with fresh stuff at £100 loss of fuel, then I agree it costs money but then totally removes the fuel as having any further role to play. 3) Have the OPC Technician do a quick dip test of the fuel in the tank to check its quality, they should all have these little test kits that will certainly show up water.
No scaremongering from what I can read and I thought I was being helpful.

Now to those of you that say contaminated fuel and fuel issues is rare? they may be rare on national media, but I know a fuel tank is contaminated every day in the UK and cars affected, may only be a few cars, and filling station operator that knows what they are doing quickly shuts down those dispensers.
In fact from the approx 8500 filling stations in the UK on average ten tank misfuellings take place each week, despite the strict human and paperwork controls it does happen, so diesel put in a petrol tank, or vice versa, on 80% of occassions its noticed and tank and dispensers that served taken out of action but on the remainder customers are the first to notice. Here is a copy of an article found from a recent filling station issue.

"Tesco has confirmed it will be covering the costs of any repairs to cars directly related to this incident.

A spokesperson said: "There was a brief window of time on Sunday when a small number customers of the petrol station at our Sandhurst Extra refuelled their cars from a fuel tank that had previously been closed due to water contamination."

So as I said water contamination is a real issue now especially with bio content to the fuels and Ethanol, some modern sites have water sensors in the tanks that would provide an alarm if it reaches a certain threshold but many dont.

As I say I do not believe I or anybody else intimated anything that wasnt appropriate, we all said its unfortunate more than likley a faulty fuel pump, but having occurred just after refuelling then I would be taking the precautionary stance on the fuel thats left in the tank.

Thats why in my 40 year career have never once purchased a single litre of fuel from a supermarket filling station for reasons Im well aware of and wish to look after my cars best I can, always fill up at a mainstream oil company, company owned and operated site for reasons known to me.
Just the same as my friend an environmental health inspector will only eat out at a certain number of restaurants and take away establishments in his local authority area and walks buy and wont let his family go into many of the others in the authority area despite them all having food hygiene certificates. He isnt saying you will get food poisoning in the others just your chances have increased. Exact same why I only buy fuel from 10% of the UKs filling stations.

GTB
Last edited by GTB on Sun Jul 31, 2022 2:01 pm, edited 1 time in total.
Current Macan GTS Collected July 2022 https://www.porsche.com/microsite/porsc ... =/PNM4GBM0
AllanG
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Location: Southampton

Post by AllanG »

.........And might I ask which filling stations you use when taking your cars abroad, GTB? Or don’t you ever drive outside the UK?
Allan
2023 Macan S in Crayon
martinto8
Posts: 399
Joined: Fri Jul 23, 2021 12:49 pm

Post by martinto8 »

GTB wrote: Sun Jul 31, 2022 12:34 pm Afternoon All,

I have read back my posts carefully and to the words I used in answering what appeared to be legitimate questions. OPC identified faulty fuel pump, great and that as I said was unfortunate as somebody ends up with the 1:100000 faulty part. Now the question was posed could it have been contaminated fuel given the OP's car had just filled up with fuel, then Im afraid that is a possibility albeit again rare, but for a belts and braces approach I suggested two in fact three things. 1) Top up remaining space in the tank with fresh fuel. Thus duluting any contamination that might be present. 2) have the OPC completely drain the tank of the existing fuel and fill up with fresh stuff at £100 loss of fuel, then I agree it costs money but then totally removes the fuel as having any further role to play. 3) Have the OPC Technician do a quick dip test of the fuel in the tank to check its quality, they should all have these little test kits that will certainly show up water.
No scaremongering from what I can read and I thought I was being helpful.

Now to those of you that say contaminated fuel and fuel issues is rare? they may be rare on national media, but I know a fuel tank is contaminated every day in the UK and cars affected, may only be a few cars, and filling station operator that knows what they are doing quickly shuts down those dispensers.
In fact from the approx 8500 filling stations in the UK on average ten tank misfuellings take place each week, despite the strict human and paperwork controls it does happen, so diesel put in a petrol tank, or vice versa, on 80% of occassions its noticed and tank and dispensers that served taken out of action but on the remainder customers are the first to notice. Here is a copy of an article found from a recent filling station issue.

"Tesco has confirmed it will be covering the costs of any repairs to cars directly related to this incident.

A spokesperson said: "There was a brief window of time on Sunday when a small number customers of the petrol station at our Sandhurst Extra refuelled their cars from a fuel tank that had previously been closed due to water contamination."

So as I said water contamination is a real issue now especially with bio content to the fuels and Ethanol, some modern sites have water sensors in the tanks that would provide an alarm if it reaches a certain threshold but many dont.

As I say I do not believe I or anybody else intimated anything that wasnt appropriate, we all said its unfortunate more than likley a faulty fuel pump, but having occurred just after refuelling then I would be taking the precautionary stance on the fuel thats left in the tank.

Thats why in my 40 year career have never once purchased a single litre of fuel from a supermarket filling station for reasons Im well aware of and wish to look after my cars best I can, always fill up at a mainstream oil company, company owned and operated site for reasons known to me.
Just the same as my friend an environmental health inspector will only eat out at a certain number of restaurants and take away establishments in his local authority area and walks buy and wont let his family go into many of the others in the authority area despite them all having food hygiene certificates. He isnt saying you will get food poisoning in the others just your chances have increased. Exact same why I only buy fuel from 90% of the UKs filling stations.

GTB
How do you know which petrol stations are owned by the respective companies and not franchised?
Macan GTS on order: http://www.porsche-code.com/PPDF6163
Ordered 25th Aug 2021 - Build slot August 2022, Landed in OPC - 29th September 2022 - Collected 29th November 459 days since ordering!
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