1.7K KB noises?
 

Last fall I had a used 1.7L KB twinscrew intercooled kit with a 9-psi pulley installed on my 02 GT. The blower uses the flat-face design for the pulley, FWIW. After buying it, I'd turned the rotor by hand and with a power-drill and it seemed quiet and smooth. I was assured it was pretty low miles and nothing I saw on the kit indicated otherwise. Everything looked quite clean. Today, after a long winter of waiting, I finally picked the car up and drove it home (~200km) today and have some questions about noise I've noticed from the blower.

First, the power is great. But it seems that there are several places in the RPM range where I get a fairly "hollow resonance" sound from what I believe is the blower. The more throttle I give, the louder it seems to get. It occurs at off idle, ~1900RPM and ~2900RPM (I haven't heard it obviously above this but haven't really beaten on the car at all yet...) It only seems to last for a few hundred RPM around these points. Because it's linked to throttle angle, I was thinking perhaps thrust loads on the rotors is high under boost and perhaps the rotors are moving and contacting the case...? Thoughts?

Also, with the car idling, I hear hints of a dry-bearing-ish periodic "chirp" noise from the back of the blower, in the vicinity of the inlet. Sometimes I think I can hear this noise coming reflecting off curbs with the window down.

If I rev the engine under the hood I don't really hear anything unusual from the engine or blower. I just hear this resonance sound at a few points in the RPM band and the odd chirp.

The fluid level is right at the full mark. I'm running 20W50 synth in it right now and plan to suck it out and replace it with Redline 50W race oil in the coming days. The car has the factory air-inlet (right down to the paper filter in the OE airbox) though the rubber silencer has been removed.

I really don't want to have to take it off and send it in somewhere for rebuilding/reconditioning. I'll have to park it for a while if this is the case because funds are, uh, low right now. I'm hoping others with the same blower might chime in and tell me "Mine does that too" :tup or "Yeah, it's not supposed to do that. Mine's dead-silent..." :banghead:

Any recommendations, if the worst case scenario is the deal, on a GTA facility to rebuild/recondition a KB blower?

first things first

get that 20w50 outta there asafp....these blowers spin north of 14,000 rpms and need the 50w oil

that in itself might cure your problem cause she ain't gonna be happy running with that thin oil

do that and live with the blower for a while and see how she behaves....I'm sure you're gonna be "hearing things"....typical of any type of modding...aka "is it all in your head"

my 1.7 is not noticeable to the untrained ear under 2000rpms....but I can hear it spinning versus how the motor sounded NA....it doesn't whine down low but keep in mind it's still likely spinning at 4000rpms when the motor is doing 2000....so the faint difference in sound will be there

3000-6000 rpms the sound is glorious and there's no doubt there's a lung there:chacha:

change that oil man.....I would park the car until you do

Will do.

I've deduced that I don't hear the "resonance" noise when the engine and blower is cool. As things warm, the sound becomes more pronounced.

One more question: I noticed that the temperature gauge on the dash is now basically topping out at about 1/4-scale, roughly half-way to where it would normally sit before the swap. Does yours do that? Is this a KB sending unit issue?

There's lot of heat coming out of the heater so I don't have any concerns that the engine itself is running cool. In looking at the KB manifold, the temperature sender screwed in there doesn't look like a Ford part to me. Is the sender perhaps simply not calibrated properly? I need to hook up my scanner to see if the PCM really thinks the engine is running that cool...

Thanks.

thinner than recomended oil + the heat....might make sense that simply swapping for the proper 50w will fix the issue

my temp gauge doesn't do that...it works as it did without the blower....so I think you're on the right track with the sending unit.....couldn't tell you if it's a ford sending unit or a KB though

Sucked out the old and put in some Redline 50W and still have the noise. Hard to tell if it's the same intensity or not. As you suggested, I'm just going to live with it for a while and see what happens.

Re the temp: the sender looks to be the OE Ford part right out of my OE manifold. Time to start looking elsewhere (thermostat?)

Other things I've noticed:

- the car goes through quite a bit of gas now. I know it will with the BAP and 36# injectors but damn... it's used something like 3/8s of a tank to go ~110kms and I'm not really getting on it all that much. I can't plug in my scan tool due to misplacing the software CD to check fuel trims and whatnot yet but that'll happen as soon as I can. No SES indications at all and the light does function so maybe this is just normal.

- it's got something of an unstable idle, especially when cold. On first start, it's very reluctant to stay running for the few couple of attempts. Often when warm and coming to a stop, it'll shudder around 250RPM for a few seconds before recovering.

who tuned the car?

edit:....re the idle......are you running the stock fuel pump?

It's a tune supplied by KB themselves for use with their kit. I filled out the information sheet with the particulars and they sent back a chip to plug into the J3 service port on the PCM.

The install was done by DaSilva. Props to those guys as they did a top-notch, clean and professional installation.

needs a custom tune to get all the quirks out....you're burning lotsa fuel cause the KB tune is running ultra safe...aka rich.....a custom tune will take care of any driveability issues as well......there's no way around it....every car is different and a plug and play tune is not the way to go

with regard toi the temp gauge....I'd still bet on the sender being the issue...but the t-stat could be done and stuck open (assuming it's a fail safe) which would cause it to run cool

I've actually talked to Joe about a custom tune. I'm okay with being fat for safety at this point as funds are tight (damn economy...) and its the stock bottom end. Then again, I don't want to hurt the OE cats by running too rich as it will need to pass DriveClean. I am holding out some hope that the PCM will learn the idle. If not, it's not a huge deal since the car is really a sunny weekend deal, not a DD. I can live with some quirks for a toy :)

FWIW, the BAP is wired to run all the time instead of being switched by the boost-sensing switch. I may or may not go back and wire that in. The switch seems like one more part and connections to fail, taking the motor with it. I don't think the fuel economy would be impacted by having the FP running at 17V since the PCM would simply take duty cycle out and/or adjust fuel trims as needed to compensate. As long as I keep gas in the tank to cool the pump it should be fine...

I've thought perhaps there's an air bubble trapped near the sender though I'm not sure if that might cause it to read low. I drove the car ~300kms since Saturday and think that if there's a bubble there it would've moved by now. My bet is still the thermostat though.

you sound like you've got your head into the game well

fwiw....I did an SVT focus fuel pump with a custom tune with a BAP on the first round cause the stock pump couldn't keep up....she drank well but passed an etest

eventually went with the 03/04 Cobra tank and pumps with no BAP....gets great fuel mileage and passes etests better than stock

enjoy your ride.....tons of fun with the KB:tup