I got a weird one. I'm fairly car literate and I'm usually able diagnose and know the problem to pull in to my local independent shop and tell them this and this need to be fixed and replaced. But this has me stumped.

I have a 2016 Q5 2.0 engine that went bad with carbon deposits yada yada... So I stepped up got a new motor from Power Engines it came all crated up they were super helpful pleased with them. My mechanic moved all the bits and reattached them to the new engine from the old. Everything had been working just fine on the old engine up until I put it in storage for close to two years due to a compression issue (Carbon ring deposit blow by)

Well here is the problem granted this info is incomplete and secondhand. The mechanic gave me the keys I drove it ten, to fifteen miles and had to have it towed back. The whole time it had a skip a tumble in power it hated slow acceleration between 1600-2000 rpm kind of missing and not solid power. Well the dang High pressure fuel pump apparently broke loose. Mechanic thinks it was pumping air and not fuel and that the low pressure fuel pump wasn't providing enough fuel. He ended up replacing the High pressure twice (for a total of three the original plus two replacements) then the low pressure fuel pump once and spark plugs. He said twice the high pressure fuel pump blew, and the low pressure was fine but replaced.

Well I got the keys back and something isn't right there is still a power tumble similar to the original problem, but the weirdest thing is I can floor it and it will not speed up. It does it between 40-50mph once it got stuck at 40 twice another around 46 or 50mph five times I've seen this but it's not always. If I usually back off and reengage the pedal it will then gain speed but just so weird. What am I missing what did my mechanic do wrong..?? Where do I start in trying to diagnose..??

53 minutes ago, crashoverride said:

Where do I start in trying to diagnose..??

Connect it to diagnostic code reader.

26 minutes ago, cliffcoggin said:

Connect it to diagnostic code reader.

and after that shows nothing...???

Real world trouble shooting and diagnostics has to occur

20 minutes ago, crashoverride said:

Real world trouble shooting and diagnostics has to occur

OK, then do so, and tell us the results of such things as compression tests, injector tests, CO emission, and oil consumption. It would also help to know of modifications that have been made and ECU mapping. The only actions you have mentioned are three fuel pump changes without telling us the reason. Was the fuel pressure tested before changing the pump?

14 minutes ago, cliffcoggin said:

OK, then do so, and tell us the results of such things as compression tests, injector tests, CO emission, and oil consumption. It would also help to know of modifications that have been made and ECU mapping. The only actions you have mentioned are three fuel pump changes without telling us the reason. Was the fuel pressure tested before changing the pump?

You missed the part that it’s a NEW ENGINE. with just fifteen miles on it.

So obviously no engine modifications have been made. Nor could oil consumption be noted. Furthermore having the fuel pump blow the bolt off and the next deform. All within the first fifteen miles.

Clearly "YOU" will not be able to provide any assistance. But thanks anyways.

Good morning Josh,

Let me start by pointing out that you are in grave danger of discouraging others to help and advise you due to the unfortunate attitude you display in your last paragraph.

Only you know the absolute facts about the circumstances you find yourself in, and other’s interpretation will be based solely on your ability to clearly convey those facts in a written form.

The use of capitals (and particular bold capital) in the context you use them - on this forum and most others are taken as a demonstration of frustration against those who are trying to be constructive, and that is both rude and unacceptable.

You emphasise NEW ENGINE (your caps), and Power Engines, but don’t quantify what you mean by ‘new engine’. Could this be totally ‘new’ à la ex VAG, stripped and fully reconditioned and fully bench tested, or simply removed from a scrapped vehicle, given a power wash down, wrapped in clingfilm and sold as ‘new’ I.e. new to you.

I think it would be worth you walking back to the first bus stop Josh, and giving yourself a chance to reconsider what you write.

Thanks and kind regards,

Gareth.

It's true I can not help you Josh if you are not prepared to either do any testing or provide suitable information to aid a possible diagnosis. If all you want is speculation and guesses then you don't need my help. After all you claim to be "fairly car literate and I'm usually able diagnose and know the problem..."

I looked up Power Engines and saw the company supply new and re-conditioned engines, so can you be sure the engine you received was genuinely new? The company lists this for your car:

https://powerengines.com/collections/all?filter.p.m.custom.make=Audi&filter.p.m.custom.model=Q5&filter.p.m.custom.year_multi_selects=2016

The price of $3199 is impossibly low for a brand new engine, even before it is shipped from Germany, so what do you conclude from that?

4 hours ago, cliffcoggin said:

It's true I can not help you Josh if you are not prepared to either do any testing or provide suitable information to aid a possible diagnosis. If all you want is speculation and guesses then you don't need my help. After all you claim to be "fairly car literate and I'm usually able diagnose and know the problem..."

I looked up Power Engines and saw the company supply new and re-conditioned engines, so can you be sure the engine you received was genuinely new? The company lists this for your car:

https://powerengines.com/collections/all?filter.p.m.custom.make=Audi&filter.p.m.custom.model=Q5&filter.p.m.custom.year_multi_selects=2016

The price of $3199 is impossibly low for a brand new engine, even before it is shipped from Germany, so what do you conclude from that?

Hi the engine could well have been new or classed as such under American consumer law despite being classed as refurbished in the U.K. , the other key bits of information such as milage of the original unit would affect the value of bolting well worn parts on to a new bare unit, my suspicion is someone has used a faulty/old gasket in the system or fitted parts incorrectly, this particular poster seems very reticent to provide answers to simple questions that are simple building blocks towards diagnosis, why these people come to this forum requesting help and then abuse the person trying to help is beyond me, they expect a solution with the minimum of Information and then throw their toys out of the pram when they don't get what they want to hear, he has probably run out of sites to abuse in the states, so now its our turn, lucky us.

Steve.

2 hours ago, Stevey Y said:

Hi the engine could well have been new or classed as such under American consumer law despite being classed as refurbished in the U.K. , the other key bits of information such as milage of the original unit would affect the value of bolting well worn parts on to a new bare unit, my suspicion is someone has used a faulty/old gasket in the system or fitted parts incorrectly, this particular poster seems very reticent to provide answers to simple questions that are simple building blocks towards diagnosis, why these people come to this forum requesting help and then abuse the person trying to help is beyond me, they expect a solution with the minimum of Information and then throw their toys out of the pram when they don't get what they want to hear, he has probably run out of sites to abuse in the states, so now its our turn, lucky us.

Steve.

10 hours ago, Magnet said:

Good morning Josh,

Let me start by pointing out that you are in grave danger of discouraging others to help and advise you due to the unfortunate attitude you display in your last paragraph.

Only you know the absolute facts about the circumstances you find yourself in, and other’s interpretation will be based solely on your ability to clearly convey those facts in a written form.

The use of capitals (and particular bold capital) in the context you use them - on this forum and most others are taken as a demonstration of frustration against those who are trying to be constructive, and that is both rude and unacceptable.

You emphasise NEW ENGINE (your caps), and Power Engines, but don’t quantify what you mean by ‘new engine’. Could this be totally ‘new’ à la ex VAG, stripped and fully reconditioned and fully bench tested, or simply removed from a scrapped vehicle, given a power wash down, wrapped in clingfilm and sold as ‘new’ I.e. new to you.

I think it would be worth you walking back to the first bus stop Josh, and giving yourself a chance to reconsider what you write.

Thanks and kind regards,

Gareth.

I apologize if I came across rude. However often times over the years I've found some less than helpful people think they are helping by saying just run the diagnostic scan and basically don't bother us until you've done such. It's an obvious statement that helps no one.

However the diagnostic scan can be both very telling and very misleading.

As for the diagnostic scan, of course several have been done and it is kicking out every bad fuel pump code and fuel related code and then some. Nothing that would narrow down the problem. From misfires, to running lean to it doesn't matter as we know the fuel pump isn't happy and none of the codes has led us to a fix and believe me we've chased every code down.

In my instance I have what they are referring to as a "New engine" it probably didn't come down the official Audi line and might have a few remanufactured or aftermarket parts. I'm not here to quibble but it sure is pretty and appears to have never been used. All I know is it was bench tested and fired up and run before it was shipped and my problems do not indicate the engine itself to be the problem.

So hence the problem. How do I find someone to respond to my question with something other than a flippant read the codes response who couldn't even be bothered with reading the detailed words I wrote (the person I responded to is obviously not going to be the person to be able to provide any meaningful help) I know we all want to help, but sometimes posting when you don't know much can actually derail a discussion and get in the way of getting the very real problem solved.

I guess I'm posting and looking for someone and people input that can say hey that's weird and here is how I overcame something similar. It might be when my buddy installed an engine this is what was done wrong or we overlooked that other thing that then gave codes and caused the fuel pump to not work right.

Cars are complex unfortunately codes are not always the holy grail solution that weekend backyard mechanics think they are. What happened to being able to have a meaningful conversation and discussion sharing of experiences etc. without being fixated on code reading.

Edited 1 hour ago1 hr by crashoverride

8 minutes ago, crashoverride said:

I apologize if I came across rude. However often times over the years I've found some less than helpful people think they are helping by saying just run the diagnostic scan and basically don't bother us until you've done such. It's an obvious statement that helps no one.

However the diagnostic scan can be both very telling and very misleading.

As for the diagnostic scan, of course several have been done and it is kicking out every bad fuel pump code and fuel related code and then some. Nothing that would narrow down the problem. From misfires, to running lean to it doesn't matter as we know the fuel pump isn't happy and none of the codes has led us to a fix and believe me we've chased every code down.

In my instance I have what they are referring to as a "New engine" it probably didn't come down the official Audi line and might have a few remanufactured or aftermarket parts. I'm not here to quibble but it sure is pretty and appears to have never been used. All I know is it was bench tested and fired up and run before it was shipped and my problems do not indicate the engine itself to be the problem.

So hence the problem. How do I find someone to respond to my question with something other than a flippant read the codes response who couldn't even be bothered with reading the detailed words I wrote (the person I responded to is obviously not going to be the person to be able to provide any meaningful help) I know we all want to help, but sometimes posting when you don't know much can actually derail a discussion and get in the way of getting the very real problem solved.

I guess I'm posting and looking for someone and people input that can say hey that's weird and here is how I overcame something similar. It might be when my buddy installed an engine this is what was done wrong or we overlooked that other thing that then gave codes and caused the fuel pump to not work right.

Cars are complex unfortunately codes are not always the holy grail solution that weekend backyard mechanics think they are. What happened to being able to have a meaningful conversation and discussion sharing of experiences etc. without being fixated on code reading.

Hi the idea of publishing the codes you have is to narrow down the components that may be causing this, you say that the vehicle was laid up for two years and you have blown two HPFPs therefore I would suggest that the high pressure side is in overrun which is eminently checkable on live data, my guess is that its the fuel pressure regulator playing about, this meters the fuel pressure within the rail and is electro mechanical therefore it can stick slightly and cause insufficient fuel to the rail causing flat spots or stick wide open and the HPFP tries to keep up with what it thinks is demand, the return system just loses what it won't use, using live data check the rail pressure at idle and then through the rev range and see if the figures add up, don't know what the rail pressures should be ideally on the DETA engine you have but I know if the lift pump in the tank is high around 600lpm you have a problem further up.

Steve.

1 hour ago, crashoverride said:

As for the diagnostic scan, of course several have been done and it is kicking out every bad fuel pump code and fuel related code and then some.

A pity you did not mention that earlier to save wasting our time. Error codes always have to be interpreted in the light of experience, rather than taken literally. So it was not flippancy to ask for them as you wrongly assumed, rather it was an attempt to get some of the basic information which you initially failed to provide.

In view of your attitude I shall not add any more to this discussion, even though I have a strong suspicion about the cause of the problem.

Good luck.