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Discussion Starter #1 (Edited)
New Engine whine (Update: Found MP45 leaking)

Hello all. I’m looking for some technical support.

Over the weekend I felt like my supercharger (Eaton MP45) got noisier. Hard to explain, but my car never had SC’er whine, but now it does. It’s not a “clean” sounding whine, but there isn’t any accompanying rattle, clacking or vibration. I'm new to superchargers, so my mind immediately went to it. This very noticeable change occurred fairly suddenly but has not affected performance and has no visible symptoms (wobbly pulley, or obvious leaks as examples). The car only has 48k Kms on it (30k Miles), and continues to get 28+ mpg daily driven.

The "whine" follows the RPM's up, and slightly trails the RPM's down. I have probed the pulley directly below and aft of the supercharger (tensioner) with a stethoscope and it is noticeably louder than the alternator or the SC in comparison.

I’m looking for my next steps in diagnosis of what may be going on or experiences with the same sudden change in noise. I’m new to superchargers however I have mid level home Mechanic abilities (comfortable with most anything but not pulling the head off or cracking the engine).


-Where my head went initially, thinking it was the SC-

-possible low oil in SC (visually no leaks. Nothing apparent using probe mirror or on underpan)
-check for pulley play. (When running there is no apparent play in the pulley and pulley appears tensioned correctly)

-suggestions from Facespace group-

-check airbox, intake, snorkel (snorkel, and intake all appear and feel intact and tight)
-vacuum bypass under SC by throttle body (Intact and connected properly)
-remove belt and run engine to determine if actually SC (Without belt the noise disappears)
-check pulley, tensioner, water pump, alternator, and belt (PS pulley has lateral movement of 1-2mm, but is whisper quiet, Tensioner pulley has slight wear noise, but no play)
 

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2007 Lotus Exige S
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Is the noise only when driving or does it also happen when parked?

Couple of things I'd also check and I'm sure you'll get some experts to weigh in as well.

You checked airbox but did you inspect the filter?
Have you removed the belt to check the pulleys for play?
The car will not run well with the SC not turning but should start and idle. Water will not move and you'll be on battery power only so if you do this keep it to a short duration.
 

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Discussion Starter #3 (Edited)
Is the noise only when driving or does it also happen when parked?

Couple of things I'd also check and I'm sure you'll get some experts to weigh in as well.

You checked airbox but did you inspect the filter?
Have you removed the belt to check the pulleys for play?
The car will not run well with the SC not turning but should start and idle. Water will not move and you'll be on battery power only so if you do this keep it to a short duration.
All my inspections have been with the car on the ground, so most of my visuals are from the engine lid with a flashlight and a mirror. I'll be lifting her tomorrow so I can get through the inspection panels to be more thorough.

"Is the noise only when driving or does it also happen when parked?" - It happens at idle, so I know it's not the trans, brakes, susp....
"You checked airbox but did you inspect the filter?" - I'll be sure to add the filter to the list.
"Have you removed the belt to check the pulleys for play?" - That's the plan for tomorrow
"The car will not run well with the SC not turning but should start and idle. Water will not move and you'll be on battery power only so if you do this keep it to a short duration." - I assumed as much. The plan was to run it only as long as to determine if the sound persisted. This would tell me if it's the SC, Ancillaries, or tensioners
 

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I imagine this is the stock Elise s/c. Was it retrofitted or stock supercharged? The s/c itself has direct drive gears which will whine quite loud. Check the bracket and make sure the pulley is not rubbing on the medial or inside. If the s/c bracket has loosened or there is any play that will cause a horrible sounding sound. Next I would loosen the tension on the belt and check for play in all the accessory bearings as well as the s/c pulley. That is fun in itself! haha. you need a 19 mm 6 face short socket and a long ratchet or breaker bar. Attach to integrated nut on tensioner mechanism and pull to front of car. If removing belt, it is easiest to put back on via the A/C pulley not the crank pulley as last step. Once loosened rotate the s/c pulley by hand and feel for any binds. This may tell you whether it is a s/c problem. Doubtful but check. Also check for oil leaks and oil level in s/c. Tommy
 

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Discussion Starter #5
I imagine this is the stock Elise s/c. Was it retrofitted or stock supercharged? The s/c itself has direct drive gears which will whine quite loud. Check the bracket and make sure the pulley is not rubbing on the medial or inside. If the s/c bracket has loosened or there is any play that will cause a horrible sounding sound. Next I would loosen the tension on the belt and check for play in all the accessory bearings as well as the s/c pulley. That is fun in itself! haha. you need a 19 mm 6 face short socket and a long ratchet or breaker bar. Attach to integrated nut on tensioner mechanism and pull to front of car. If removing belt, it is easiest to put back on via the A/C pulley not the crank pulley as last step. Once loosened rotate the s/c pulley by hand and feel for any binds. This may tell you whether it is a s/c problem. Doubtful but check. Also check for oil leaks and oil level in s/c. Tommy
Awesome! Very informative.

The car is a 2007 that had a 2008 MP45 fitted to it a year into life. Previously I struggled to hear my SC, and that's what made this new "whine" all the more apparent. It also added to my confusion in this situation, as I hear folks complain about the SC noise, but I barely noticed mine.
 

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Try with stethoscope first, way easier than removing parts.
 

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Discussion Starter #7
Well, I'm starting to see why I may have an SC making more noise than usual.

Untitled by Duane Jacka, on Flickr
 

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'07 Exige S
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Oil leak? If so you will need to at least add fluid
and at most pull the SC, reseal the snout and middle section and
reinstall.

Henry
'07 Exuge S
 

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Discussion Starter #9
Oil leak? If so you will need to at least add fluid
and at most pull the SC, reseal the snout and middle section and
reinstall.

Henry
'07 Exuge S
That's what it is looking like to me. Since I don't know how much has leaked out, I decided to drain the whole thing and ensure the right amount goes in. I have just got back from GM and got three of the AC Delco Supercharger oil recommended for this application.

What sucks about this is where the plug is. I can barely reach it, but I do have a syringe and was able to start some syphoning action.

Short video of where it is and how I'm draining it.

Untitled by Duane Jacka, on Flickr
 

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Discussion Starter #10
So as an update, the leak seems to have me at 3oz, which from my research is 1oz down from full. I dropped a few drops during the process and can assume I was at max .75oz down. I also poured the 3 oz into a plastic bottle and ran a magnet around it. I don't see any particles sticking to the magnet, and I'll run the oil through a paper towel to check further.

Is .75-1oz enough to create the exaggerated SC whine I was getting? Is there anything else I should do (Aside from pulling the SC, which will be done in the long Canadian offseason)?
 

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Just my suggestion. Pull it and check the snout for cracks. Mine did the same thing. Just got worse and leaked more. I got it out with the clam on but wasn't easy.


Company I used to rebuild it: Stiegemeier Porting Service

These guys are the bomb!
 

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Discussion Starter #12
Disappointingly the noise has persisted past the drain and refill. Surprisingly I drained about 3 oz, and it only took 3 oz of fluid.

When I was endeavouring to drain the SC, I opened the plug and it started to leak out the fill hole. Just enough to feel like it was filled to the bottom of that hill hole. My first thought was that it was overfilled and causing issue. After draining her and measuring 3 oz of fluid, I was then concerned it was underfilled, which would have supported the concern with the seepage I saw initially (post #7). Surprisingly though, the SC only took 3 oz of oil before it started leaking out the fill hole like before. Now I'm completely befuddled.

I also pulled the belt and ran the car for a moment to see if the noise persisted. Thankfully it didn't, and I know it's an ancillary noise. I found that the PS delete pulley had some lateral movement (1-2mm), but was completely silent to spin. The tensioner pulley had no play whatsoever, but is starting to get the faint sound of bearing grind. All other pulleys seem normal and spin silent.

I have started to ease my mind that it may just be a pulley noise, however the drain and fill of only 3 oz has me concerned now.

Just my suggestion. Pull it and check the snout for cracks. Mine did the same thing. Just got worse and leaked more. I got it out with the clam on but wasn't easy.

...
It's looking like that is my next direction.
 
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