Supercharger Problem

[GT374]

If I push the engine into boost during the first 10 minutes after cold startup, the supercharger gives off an extremely loud screatching sound. There is an accompanying vibration that can be felt through the frame and travelling to the steering wheel. The sound continues for about 45-90 seconds after the engine goes back to idle. It sounds like the impellors are rubbing on a piece of thin plastic. Standing beside the idling engine with the clamshell open, you have to yell to be heard over the sound. I have used a stethescope to positively locate the sound in the forward portion of the supercharger impeller body. I removed the air filter to make sure nothing had separated from the filter elements that may have been ingested by the supercharger. All seemed normal. Once the sound goes away, it does not return for the rest of that day's driving. The sound only occurs when the engine is cold and the engine is pushed hard. However, when this loud noise goes away, I detect a rattling sound from the front s/c impellor bearing area (using the stethescope). In comparison, when I listen to the bearing just behind the supercharger pully, it sounds smooth and normal.

I took the car to Galpin Ford for warrantly service on another problem and told them about this problem. They were able to get it to make the sound but because "there was only one tech in the car at the time" they were not able to determine the origin of the sound. They also stated that the warm running engine emminates the normal amount of supercharger noise. The problem was noted in the warranty report with no solution provided. Just as a sideline, they charged Ford over $1000 to fix my other problem and the problem has recurred.

I am wondering if the supercharger bearings are of the sealed type. If so, perhaps when the grease is cold and thick, the bearing housing is rotating in its mount. Has anyone else experienced this phenomenon?
Thanks, Tim (GT374)

 

[Shadowman]

If I push the engine into boost during the first 10 minutes after cold startup, the supercharger gives off an extremely loud screatching sound. There is an accompanying vibration that can be felt through the frame and travelling to the steering wheel. The sound continues for about 45-90 seconds after the engine goes back to idle. It sounds like the impellors are rubbing on a piece of thin plastic. Standing beside the idling engine with the clamshell open, you have to yell to be heard over the sound. I have used a stethescope to positively locate the sound in the forward portion of the supercharger impeller body. I removed the air filter to make sure nothing had separated from the filter elements that may have been ingested by the supercharger. All seemed normal. Once the sound goes away, it does not return for the rest of that day's driving. The sound only occurs when the engine is cold and the engine is pushed hard. However, when this loud noise goes away, I detect a rattling sound from the front s/c impellor bearing area (using the stethescope). In comparison, when I listen to the bearing just behind the supercharger pully, it sounds smooth and normal.

I took the car to Galpin Ford for warrantly service on another problem and told them about this problem. They were able to get it to make the sound but because "there was only one tech in the car at the time" they were not able to determine the origin of the sound. They also stated that the warm running engine emminates the normal amount of supercharger noise. The problem was noted in the warranty report with no solution provided. Just as a sideline, they charged Ford over $1000 to fix my other problem and the problem has recurred.

I am wondering if the supercharger bearings are of the sealed type. If so, perhaps when the grease is cold and thick, the bearing housing is rotating in its mount. Has anyone else experienced this phenomenon?
Thanks, Tim (GT374)

Hi Tim

Just a couple thoughts

1. IMO 10 minutes is not enough time for the gal to have completely warmed up as such I would not be exercising her during this time but rather methodically driving her.

2. The screeching sound; could it simply be the belt? Do you have the OEM or a smaller pulley?

As for the bearings within I do not initially suspect them as the culprit

Lastly; what the dealer charges for a specific service is interesting at best because there are no rate specific charges that apply to this gals. The fact that the problem came back is a PITA but it happens; hang in there.

All the best

Shadowman

 

[nota4re]

Hi Tim,

I agree with shadowman that bost within the first 10 minutes of cold start is probably not great on the engine as you should wait until the OIL has reached operating temperature. As a rule of thumb, figure about 2X as long as it takes the water tmp to hit its mark. Roughly said, that's probably about 10 minutes of driving.

Nevertheless, the sound that you hear is definitely abnormal and should not be happening. If I follow what you are saying, it is almost as if something does not have sufficient tolrance until after it is warm.

In my experience, there's a couple of things that you may want to look at.

Stuff a rag below the fill plug on the front of the supercharger snout and remove it. You should have oild just barely ooze out of the fill hole. If no oil comes out, you are low and you should add fluid up to this level. Note that the SC uses special synthetic supercharger oil.

See if you can detect any points of contact between the pulley and the SC snout. You can use a mirror to inspect the underside as well.

Finally, inside of the SC there is a rubber coupler that links the snout drive to the gears on the front of the SC. If the problem persists and there is no visual external signs, I'd recommend pulling the SC off the car and removing the snout to inspect these internal items. It is not the big of a job - perhaps a little bit intimidating the first time but easier than it may sound.

What was the problem that Galpin didn't fix?

 

[tpraceman]

anyone know the super charger oil we should use?

 

[nota4re]

Motorcraft Synthetic Supercharger Fluid. Comes in a 4 oz bottle. No number designations on the front, small "XL-4" on the back label.

 

[GT374]

Thanks to everyone for their input. I will check the items each of you mentioned.
The other problem I referred to that was not fixed by Galpin was a check enigne warning light. I have a code reader and pulled the codes. I then erased them to see if it would return and it did on several occassions. The codes were P1234, P1236 & P1238 which are all related to a secondary fuel pump driver off-line condition. Due to the fact that the car never suffered any fuel starvation symptoms at any rpm, convinced me that the problem was intermittent and of very short duration. Galpin replaced both primary and secondary fuel pumps, which I thought was odd due to the fact that the codes were pump driver related and there was no indication of a lack of fuel getting to the engine. Since getting the car back, the same codes have recurred. I am now convinced the problem is getting worse, due to the fact that sometimes the supercharger will not provide boost. The gauge rises fast out of vacuum but stops right at "0". I believe the computer is going into a "fail-safe" mode when it sees no secondary injector pressure, thus preventing an overly lean condition. I have another appointment at Galpin on Monday. I would take it to Saleen but they cannot look at it until after the SEMA Show.

 

[tmcphail]

Motorcraft Synthetic Supercharger Fluid. Comes in a 4 oz bottle. No number designations on the front, small "XL-4" on the back label.

XL4 is the correct part number

 

[davisp]

Curious problem. Keep us posted on the outcome. PD

 

[thegtguy]

They should have checked to see if the secondary driver module is plugged in first. I would ask for a new fuel tank if someone has been inside it. Somone else had a lot of problems when a dealer went inside the tank and they eventually replaced the tank and that cured the problem. There is so much going on inside of that tank you don't even want to know about it.

 

[Neilda]

As Shadow suggested, it could be as simple as the belt.

With fan belts, you could spit (dribble) on on the bearing and it would stop - thereby identifying the problem.

 

[Shadowman]

Any update?

Thank you

Shadowman

 

[FLASH]

Kirby spoke with someone about the fuel delivery problem and after replacing the pumps and than the entire fuel tank they discovered that the electrical ground was loose and only providing 10 volts to the pumps. Kirby and myself had our pumps outputs tested while driving and we were both near 98% with not much room for error. However after talking with the techs at Accufab about their "boost a pump" they said the main problem they have seen with the GT's on the dyno is that the supercharger is blowing out the spark. That is evidenced also by our dyno graphs which shows a jagged line. They suggested their "boost a spark" to resolve that problem.
Flash :cheers

 

[GT374]

Supercharger Noise Update

Thanks to everyone for your input and advice. I have been driving the car regularly and making sure the temp is at least 180 before pushing her into boost. I have had no recurrence of the noise. Galpin Ford has acknowledged the noise, and included it in a warranty report, but was unable to determine its cause as it only lasted about 40 seconds, and only after a cold start-up situation. So, I guess the old saying.... "Time will tell", is the order of the day. Thanks again, Tim (GT374)

 

[Shadowman]

Thanks to everyone for your input and advice. I have been driving the car regularly and making sure the temp is at least 180 before pushing her into boost. I have had no recurrence of the noise. Galpin Ford has acknowledged the noise, and included it in a warranty report, but was unable to determine its cause as it only lasted about 40 seconds, and only after a cold start-up situation. So, I guess the old saying.... "Time will tell", is the order of the day. Thanks again, Tim (GT374)

Thank you for the update; keep us posted if anything changes.

It may very well be that is simply a part of her character; to a gal they are all a bit different. Regardless enjoy her.

All the best

Shadowman

 

[paul b]

Have you ever tried the stethoscope in the area of the idler pulley?