Question on Fuel Pump and Filter Replacement

Congrats on Article.

Can you help me out?

There are 3 symptoms that are showing up, and I think and hope they are related. They don't show up 100% of the time. Actually I would say 1 out of 4/5 runs I feel them. They are almost always showing up together.

1.Sometimes when running, noticed a weird noise. It only appears on 0-30% throttle, and when I quickly press the gas pedal to fullquickly enough to not raise the rpm it stops, and come back shortly. It sounds a lot with a knocking sound.

2. High idling. When at traffic light, I have to press the brakes more than normal to hold the car stopped. If in normal conditions the idle RPM is lower than 1000 looking at the gauge I would say around 700-800, when this symptom shows up it goes as high as 1200-1300. This shows up even when the engine is warm.

3. The last and most annoying is that the doesn't fire up. It cranks but won't start. I noticed that this usually happens when the car is already hot, but not sure if this is related. I always pay attention to the fuel pump starting noise when unlocking the car, and when this happens it doesn't make any noise, but I'm not sure that the pump goes on if the engine is warm probably there is still pressure in fuel line from the last ride. Nice to say that when finally it starts after lots of trying and some minutes waiting it almost stalls 2-3 seconds working hard to keep the idle, as a carburated car would do after refueling an empty tank, but little throttle pumping helps to get into nice idle.

Any ideas?


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[Nick at Pelican Parts]

The knocking noise and brake issue may be the vacuum pump.

The starting issue I need more info. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and fuel pressure, volume, quality and engine compression. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.

- Nick

[guigagonca]

Originally Posted by Nick at Pelican Parts

The knocking noise and brake issue may be the vacuum pump.

The starting issue I need more info. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and fuel pressure, volume, quality and engine compression. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.

- Nick

Thank you for answering Nick!

Ok, I don't think there are any brake problems. The fact that I have to press the brakes harder is just because the car has a too high idle. Brakes are just perfect.

That said, still think the knocking noise has something to do with the vacuum pump? I think it is related to the not-starting problem.

Actually I don't have any diagnostic tools to check all that stuff. I have just bough an OBD scanner to check those things.

As I said before, the problem appear 1 out of 4/5 runs. It's not always. And I think the knocking sound and high idling are related to the non-start because, every time the car shows up the 2 symptons, I am pretty sure that if I turn off and on again, it won't start. Just after a long time cooling the engine (overnight, for example) it will run. After trying to start it with no success, I smell gasoline.

As soon as I get the scanner I'll reply you with more info.

[Dave at Pelican Parts]

What year, what type of MINI? Lots of miles, or just a few?

A 2007-2014 Cooper S or JCW might have a problem with the high-pressure fuel pump (HPFP). It could also have carbon deposits in the intake ports and on the intake valves, which can be removed by walnut-shell blasting.

--DD

[guigagonca]

Originally Posted by Dave at Pelican Parts

What year, what type of MINI? Lots of miles, or just a few?

A 2007-2014 Cooper S or JCW might have a problem with the high-pressure fuel pump (HPFP). It could also have carbon deposits in the intake ports and on the intake valves, which can be removed by walnut-shell blasting.

--DD

Thank you Dave, that makes a lot of sense.

It is a Cooper S 2011, 75k km (around 46k mi).

I say it makes sense because I had refueled it with high octane fuel, and the problems ALMOST disappeared completely. That indicates that has something to do with the fuel system, or carbon deposits. I have bought one of those OBD - II scanners, and I'm just waiting to arrive. If I check the fuel pressure it'll be possible to identify a faulty HPFP? Or the fuel pressure sensor is before HPFP in the fuel line?

Thank you very much, it is by far the best assistance I've found online. I'll surely recommend you guys.

Is this (PN # 13-51-7-592-429-M26) what we are talking about? If the original pumps are sometimes faulty, wouldn't be better to buy an alternate 'better spec' pump?

And isn't a strange fact that a DI car is carboning on intake ports?

[Dave at Pelican Parts]

That part number says "high pressure pump on engine", so that is the HPFP.

I haven't messed with an S model, so I don't know if the fuel pressure available on the OBD2 bus is the high working pressure. I suspect it is, but I don't know for sure. I do know that some readers don't read the MINI- and BMW-specific codes, and some don't (by default) read all of the different data types that are available. For instance, the ScanGauge II won't read oil temp (or is it pressure?) unless it gets programmed in, which Linear Logic (the manufacturer) will do on request. Fuel pressure might be another one of those.

BTW, intake coking is a relatively common problem in direct-injected engines. Fuel is an excellent solvent, and port-injected engines have a near-continuous blast of this solvent going off in the ports. DI engines don't, so any oil vapor that winds up in the intake can wind up depositing itself on the valves and the ports, and doesn't get cleaned off. That also tells us that fuel system cleaners do nothing for carbon deposits in the ports.

--DD

[guigagonca]

Originally Posted by Dave at Pelican Parts

That part number says "high pressure pump on engine", so that is the HPFP.

I haven't messed with an S model, so I don't know if the fuel pressure available on the OBD2 bus is the high working pressure. I suspect it is, but I don't know for sure. I do know that some readers don't read the MINI- and BMW-specific codes, and some don't (by default) read all of the different data types that are available. For instance, the ScanGauge II won't read oil temp (or is it pressure?) unless it gets programmed in, which Linear Logic (the manufacturer) will do on request. Fuel pressure might be another one of those.

BTW, intake coking is a relatively common problem in direct-injected engines. Fuel is an excellent solvent, and port-injected engines have a near-continuous blast of this solvent going off in the ports. DI engines don't, so any oil vapor that winds up in the intake can wind up depositing itself on the valves and the ports, and doesn't get cleaned off. That also tells us that fuel system cleaners do nothing for carbon deposits in the ports.

--DD

Wow, and this chat just gets better. Thank you, a lot!

Very nice explanation on intake coking. I'm on my way on looking for someone that can clean those ports for me. I have the feeling that the only way of doing this is disassembling the engine.

Thank you for the info on the scanner. I'll post information on my ELM 327 as soon as it gets here.

[Dave at Pelican Parts]

The common way to deal with the carbon deposits in the intake ports is by blasting with walnut shells. There are even DIY setups, though you may have to pull the intake manifold off to get the blaster and vacuum in there. I also know of people who have used dental picks and other implements of destruction to scrape the buildup off. It's less effective, but requires less investment in tools.

Many of the better independent MINI and BMW specialists will offer that service. I've heard of the prices for that ranging from $250 (one place, may have been a "buddy discount"?) to $800 at the dealer.

I believe that there are even Youtube videos about that process.

--DD

[guigagonca]

Originally Posted by Dave at Pelican Parts

The common way to deal with the carbon deposits in the intake ports is by blasting with walnut shells. There are even DIY setups, though you may have to pull the intake manifold off to get the blaster and vacuum in there. I also know of people who have used dental picks and other implements of destruction to scrape the buildup off. It's less effective, but requires less investment in tools.

Many of the better independent MINI and BMW specialists will offer that service. I've heard of the prices for that ranging from $250 (one place, may have been a "buddy discount"?) to $800 at the dealer.

I believe that there are even Youtube videos about that process.

--DD

Hello Dave!

Im in my third thank of "premium fuel" (live in brazil, so premium fuel here is not quite as premium as in US or Europe), and the "knocking sound" has gone.

I might have finally discovered the source of the two other problems (high idle and not-starting): The coolant temperature sensor.

With and OBD scanner, I have noticed that the reason for the car accelerates the idle, is because the temperature sensor suddenly goes from working temperature to -30 oC....Obviously there is something very wrong here. But if the car is already running, it just revs up the idle. That's kind of o.k.

But when the sensor decides to go crazy when the engine is off, it won't start by nothing. Sometimes if I wait a couple of minutes, the moment that the sensor shows "normal" temperatures and I try to start it, the car runs with no problems.

I have heard some comments that the sensor and the thermostat are in a single unit (think it is called CTS), and MINI has come with a new "CTS unit" that solves this problem.

Have you heard about that? Do you guys have this "new unit" for sale?

Thank you!

[guigagonca]

I've found this:

Mini Cooper Coolant Temperature Sensor Adapter Wit


Do you think that this can solve my problem? Does pelican parts have something similar?

[Dave at Pelican Parts]

Looks like that could work. I think we have the coolant temp sensor parts available as well:

2011 Mini Cooper S Hatchback - Water Pump, Thermostat & Hoses - Page 1
2011 Mini Cooper S Hatchback - Cooling System Miscellaneous - Page 2

The thermostat housing is a known leak point with these cars, BTW, so check for coolant residue on top of the transmission underneath the t-stat housing.

--DD

[guigagonca]

Just for a follow up...

My local MINI dealer says the only thing they do (and have done in some MINIs with this problem) is replace the whole thermostat, which would cost me around $650 (converting from BRL, as I live in Brazil). I asked him if he had the part 13.62.8.603.908 (Mini Cooper Coolant Temperature Sensor Adapter Wit), he says "Yes, in stock!". That cost me around $70 and I installed myself in a 15minute job.

Since then my car is working flawlessly!

Thank you for the support! I will always recommend Pelican Parts!