044 and AEM Fuel Pumps Screaming

[Tom]

Well, I took a hack saw and cut the filter apart and see nothing particularly interesting, other than how it's constructed. Looking at my pictures, I'm wondering it that rubber mat I wrapped around the pump is preventing it from cooling?

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[Tom]

So, in case the rolled-up ant-slip mat was making my fuel pump too hot, I came up with my own little cushion mount for the AEM 044-style pump. It will give the pump a flexible mount to prevent vibration contact/noise, but without covering the whole pump with hard rubber like I had it. Time will tell how loud it is, but it's got to be better than the scream coming from my current pump. Not coming up with much on why the old pump only lasted 2 years, so figure a cooler pump may last longer. And, yes, it's 3D printed.

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[gruhsy]

Nice job

[cda951]

Well, I took a hack saw and cut the filter apart and see nothing particularly interesting, other than how it's constructed. Looking at my pictures, I'm wondering it that rubber mat I wrapped around the pump is preventing it from cooling?

Most of the cooling of a fuel pump is achieved by the throughput of fuel carrying the heat away, which is why it is not a good idea to make a habit of running out of fuel or frequently letting the fuel level go very low with an in-tank pump.

That said, a big diaper around a high-performance fuel pump likely prevents excess heat from dissipating.

When installed my Bosch 044 pump and saw that the factory diaper didn't fit, I used a clamp and a rubber sleeve much like you now have. The pump is loud, but more due to resonance through the body via the mount rather than "screaming" like your old one.

I hope you find a good solution!

[Tom]

I have the AEM 044 pump plumbed in and started the car with it like this just to make sure there were no leaks or issues. Still not sure at all why the last two pumps started failing/screaming (a real 044 and an AEM 044), but hoping maybe is was the rubber mat I wrapped it in. I put in a new strainer and filter while I was in there. I have to say when they are new like this, it's not loud at all. When I strap it to the bottom cover, maybe it will transmit more noise, I dunno, but for now it sounds like a typical fuel pump on a factory car more or less.

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[Tom]

By the way, has anyone ever found a torque spec for the strainer? Looks like the question has been asked a lot and no one has found one. I see that the 928 uses the same strainer, so wonder maybe it's listed in the 928 manuals...?

[cda951]

By the way, has anyone ever found a torque spec for the strainer? Looks like the question has been asked a lot and no one has found one. I see that the 928 uses the same strainer, so wonder maybe it's listed in the 928 manuals...?

Hi Tom,

I happened to install the same part in a 993 earlier today, and the answer is I would not rely on a torque-force wrench for this application. You are tightening a large-diameter threaded fitting into female threads which are swaged into a plastic fuel tank. Snug it down slowly using a short-handled ratchet/wrench, and feel the square rubber gasket compress, then just a bit more. I trust that you have enough experience to know when this is

[ROB III]

Looks good Tom....Loving those K&W pieces....

[Tom]

Chris -- if by experience, you mean I've broken way more than my share of parts, then yes I'm experienced. I pretty much did just as you said -- I screwed it in by hand until it stopped, then put a wrench on it and tightened enough to compress the seal but not enough to feel like I was crushing it. No impact wrench this time. Seems to have worked -- no leaks, nothing cracked or broken.

Rob -- the KW coilovers just transformed the car. Can't say enough about that set up....

In the meantime, still hunting for clues on why the pumps failed, so I pulled apart the old AEM pump. It was pretty interesting to see how small the actual pump section is inside, but other than that, there was nothing obvious (to me) about why the pump failed.



These are not made to come apart, which just motivated me to take it apart....

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The little section on the bottom here is the actual pump -- everything else is just a big electric motor....

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I understand this type of pump is a "roller vane pump" if you're interested in seeing how they work.

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I don't really know 'why' this happened, but I presume these little scratches are the source/result of the noise -- the little roller pins started scratching at the pump wall for some reason. Heat expansion? Dirty gas? Rollers sticking in housing from lack of pressure? I dunno....

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[ROB III]

Poor hardening process of metal prior to assembly?