spiller

Have noticed on two seperate occasions about 6 months apart, when pulling into the garage after coming home from a track day, noise from the fuel pump. Both days were warm with ambient of 95-100 degrees. Never noticed any noise at the track, only when coming back into the garage. The next time driving the car the noise was gone. There were a couple of track days in between with cooler temps and no issues or noise.

Should I be concerned?

Also unrelated question...is it common place for the brake caliper piston dust boots to be toasty looking if the car has seen some track time? In other cars I've owned in the past I've changed the dust boots only for the same thing to happen again.

mkk62

Hey spiller. Is it a chirping noise? My rms changed and have this chirping noise 3 yrs. no issues. Everything changed in car and still chirping. After changing fuel pump I can track with much lower fuel. Before. 1/3-1/4 used to get fuel starvation on right sweepers. Mk

spiller

Hey Michael, no chirping just a whining noise. I tend to let the level run fairly low, usually not much more than 1/3 of a tank in there and has gone into reserve light before but never noticed any fuel surge/starvation. I think it was more to do with the heat than anything.

Aspen Autosports

If I were you I would replace the pump and keep the current one as a track spare. The noise could very well be unrelated to the pump but these cars do have issues with the pump assembly. The pump is about $550-$600, but how much is a wasted track weekend?

The caliper dust boots definitely get toasted when driving on the track. The rotors build up so much heat and they cause the boots to bake themselves. Keep an eye on them and change them when they start to crumble. If you do not keep up on this then the ceramic insulation pucks will fall off the piston as well as dirt and grime causing the piston to get sticky. At that point a complete rebuild or replacement caliper is required.

spiller

^^^ thanks for that info, when you say issues with the pump assembly, what do you refer to specifically? What could I expect if it does fail other than a car that doesn't run?

Also regarding caliper pistons, what is the function of the ceramic pucks and where are they located? I'm assuming they locate between the piston and the backing plate of the pad?

Macster

Running the fuel level consistently low subjects the fuel pump to higher heat. Over time this could shorten the fuel pump's life. It is immersed or should be immersed in fuel and part of its output is redirected back to the tank to circulate fuel and help cool the fuel pump.

The hot day and tracking probably had the fuel and fuel pump pretty darn hot. That the noise was absent after things had cooled down and did not appear on a cooler day suggests the pump is now senstive to higher temps and is probably on its way out.

You can wait for this to happen, probably on a blistering hot day, possibly at the track, or you can replace the pump now. Saving the old one I'm not sure buys you much. The hoses tend to dry out/get brittle once out of the fuel tank and exposed to air and the pump won't like sitting unused for maybe years.

After you replace the pump I'd urge you to keep the tank fuller. No need to run around with a full tank. I've let my fuel tank level drop to a quarter of a tank even lower to the point the light comes on more than once and the fuel pump in one car lasted over 172K miles the other one is still good with over 140K miles on it.

Aspen Autosports

Yes the ceramic pucks are located between the piston and backing plate. These pucks are actually stuck to the piston, this is the reason you probably haven't noticed them. You will however notice them when they do fall off. The function is to prevent heat transfer.

spiller

I don't quite understand your point, you said its recommended to run the tank more full but no need to run with a full tank? I usually try to keep at least 1/4 of fuel in there which in my RoW car is about 3.5-4 gallons.

Is there a risk of engine failure if the fuel pump were to fail?

Aspen Autosports

No risk of engine failure if the fuel pump were to fail. The car will simply shut off from fuel starvation. A failed fuel pump will act the same as not having any gas in the car.

On the off chance that the pump reduces the volume of fuel you may end up with some lean misfires in which case you will see a flashing check engine light. At that point you know to shut it down before something catastrophic occurs.

spiller

Thanks for your advice, much appreciated!