oh uh... i don't like this noise!

[BlackStripes]

Guys, i need a hand here,

My BRP MP62 started to make this loud grinding noise about 5 days ago... next day was barely noticeable, two days after, loud again...but i noticed yesterday is that the car has the constant (even at idle) ssssssss, like the supercharger boosting all the time.

I thought in checking the oil first, but i just read that the only way to do it is drain it and add the 4oz again. Btw, is there any picture of a setup showing all the little parts??... i dont even know where the drain is :no:

I guess, it can be bearings, but i have no clue why would it be loud one day and not the following one.

Any ideas where to start?

The problem is that is 28 degrees outside and i don't want to be looking at the engine for hrs and turn blue :biggrin:

[FormerDatsun510Man]

My vote is it is a problem with the bypass valve. The black plastic bypass actuator may have a leak inside it which is causing it not to hold the bypass open when idling/cruising like it should. You can test this by blipping the engine and noting with the bypass actuator moves in and out.

Bill

[BlackStripes]

Thanks, i will try that.

Do you think the grinding noise can be caused by that too?

[FormerDatsun510Man]

Grinding noise could be the front bearings. With the belt off the blower check for play in the main shaft by grabbing the nose pulley and moving it fore/aft. It should be pretty tight. If it moves back and forth, you've found the source of the grinding noise. This generally was more a problem with overtensioned 4-rib belts though. However, if your bypass valve hasn't been working for a long time I could see that also damaging the blower bearings and lobes.

Bill

[BlackStripes]

Ok, the bypass works perfectly, a little blip and the bypass moves. I took the belt off and the there is no play on the front, actually its pretty quite when i spin the blower with my hands.

I will check the tensioner, move it and put back another belt, we will see....

[FormerDatsun510Man]

You might want to also try running it without the belt to be sure it is the supercharger making the noise.

Bill

[V8KILR]

Not to be off topic, but you can run a SC'd car without the SC belt? and the car will still work?

[BlackStripes]

Yeah, i've running without the belt for day and a half. Zero problems. Be sure that the bypass is open...i used some tape :)

I will run without the belt for a couple of days, i just want to buy the belt and GM fluid.

Just for giggles, i blip the gas without the belt and the SC spins because the air moved... zero noise.

I never had an NA Miata, my first one was a MSM and then i bought this one with the Hotside already installed. I have to say that the car is very smooth, and quiter.... but damn i miss the low end power/tq.!! :)

[Race Grandpa]

Yeah, i've running without the belt for day and a half. Zero problems. Be sure that the bypass is open...i used some tape :)

I will run without the belt for a couple of days, i just want to buy the belt and GM fluid.

Just for giggles, i blip the gas without the belt and the SC spins because the air moved... zero noise.

I never had an NA Miata, my first one was a MSM and then i bought this one with the Hotside already installed. I have to say that the car is very smooth, and quiter.... but damn i miss the low end power/tq.!! :)


I am waiting to get the new engine tuned and have over 500 miles on it without the belt. BUT I did NOTHING with the bypass. :eek:

Could that mean I have created a problem for the SC ????????

[V8KILR]

Be sure that the bypass is open...i used some tapeI don't think I have a byass valve on my coldside.?. If its the same design as the M62 as shown on the EATON website, then isn't the bypass valve on the inside?

[BlackStripes]

I thought that the bypass from the outside opens the one in the inside.

http://www.magnusonproducts.com/images/4gbypass.jpg

I read about the bypass in MNet, and i didnt know why, I tried to floor the car with the bypass closed and the car shot down... I did this with the car parked,...I used my tape and kept it open.

[Race Grandpa]

I don't think I have a byass valve on my coldside.?. If its the same design as the M62 as shown on the EATON website, then isn't the bypass valve on the inside?

Good. I really do not know what I have on my CS and for that matter anything else. However, I did think that the bypass valve only applied to turbos. Probably wrong again.

:stupid:

[V8KILR]

I did think that the bypass valve only applied to turbos.
I thought the same until I read about the EATON M62 and it showed a pic of the inside with a small bypass valve at the back of the SC(near where the TB adapter would go) I wouldn't know how you would tape that open, and I don't know how thw SC transfers ALL incoming air threw that TINY hole when under light throttle.?.:confused:http://www.magnusonproducts.com/mp62.htm If you look closely, you can see the bypass valve, how do you tape that open?

[FormerDatsun510Man]

He taped the actuator open by wrapping tape around the lever holding it open (the little metal lever that comes out of the black plastic thingy on the outside that pulls on the bypass valve "throttle shaft").

Bill

[BlackStripes]

Wow Bill.... that's exactly what i did. I attached the actuator to the tower brace ... i was going to say that i didnt 'tape it'... i used tape :)