: Developed an engine whine... what is it?



wingman0121
06-10-14, 02:28 PM
My car (98 Deville base) started making a strange whine from under the hood in the past 2000 miles or less, it is present when the engine starts and the pitch of the whine changes with the engine RPM, sort of sounds like people who installed gear drive on a small block to drive their camshafts but not nearly as loud. The car has 218k miles. I took it to a car shop and the guy listened it with a stethoscope and he said the noise is coming from inside the engine. The car runs fine and it didn't change any driving characteristics this whole time, the oil is clean and I don't see any silver particles. Another shop said my power steering pump is going bad but I don't hear any weird noise or have problem turning the wheel while parked. I read about checking the pulleys by taking off the belt but my 1/2" ratchet is too short and there aren't enough room for my hands to move it.

In the past 1000 miles or so I noticed a clacking noise from under the hood when I first start in the morning, it sounds a lot like the engine is knocking but goes away as soon as I drive off. It doesn't do it every time but I've never heard that sound before in the past 8 years, again the engine didn't lose power or anything abnormal when it does make that sound. I read about carbon buildup and I do give it the foot at least once every few days so it shouldn't be carbon.

In any case I'm a little worried since I'm about to go on a 2000-mile round trip to visit my grandmother.

rodnok01
06-10-14, 03:50 PM
Could be a idler/tensioner pulley or alt or related, could be WP tensioner pulley. Take stethoscope and listen to each pulley and item. You can get cheap serp belt tool at Harbor Freight.

wingman0121
06-10-14, 04:41 PM
I went to the shop and had them take the belt off and the engine still makes that noise while running, the whine sounds like it is coming from under the intake manifold.

Submariner409
06-10-14, 04:55 PM
WHICH belt ?? There are two - the main accessory drive serpentine belt and the water pump drive belt at the rear (driver's) end of the engine.

Under the intake manifold is either a vacuum leak or a broken/faulty Bendix drive on the starter pinion gear.

In the front (passenger) end it (discounting the p/s pump) would be one of 3 timing chains, 4 cam sprockets, chain tensioners/guides/slippers.

Ranger
06-10-14, 10:51 PM
Another shop said my power steering pump is going bad


I went to the shop and had them take the belt off and the engine still makes that noise while running, the whine sounds like it is coming from under the intake manifold.

Could it be a vacuum leak from the manifold over pressurization relief valve seal behind the P/S pump?

http://www.cadillacforums.com/forums/attachments/northstar-engines-system-technical-discussion/42633d1213058899-whistling-pressure-relief-n-intake-manifold-valve-closed.jpg

http://www.cadillacforums.com/forums/attachments/northstar-engines-system-technical-discussion/42634d1213058899-whistling-pressure-relief-n-intake-manifold-valve-open.jpg

The other possibility (if the noise is from the other end) is the starter not disengaging from the flywheel.

wingman0121
06-10-14, 11:40 PM
WHICH belt ?? There are two - the main accessory drive serpentine belt and the water pump drive belt at the rear (driver's) end of the engine.

Under the intake manifold is either a vacuum leak or a broken/faulty Bendix drive on the starter pinion gear.

In the front (passenger) end it (discounting the p/s pump) would be one of 3 timing chains, 4 cam sprockets, chain tensioners/guides/slippers.


The accessory belt. I hope it isn't anything inside the engine because most car shops in my area HATES working on Northstar engines and opening one means they'll want to charge a bunch of money.



Could it be a vacuum leak from the manifold over pressurization relief valve seal behind the P/S pump?

The other possibility (if the noise is from the other end) is the starter not disengaging from the flywheel.



How do I go about checking the vacuum leak? As far as the starter not disengaging from the flywheel, does that mean the starter motor is being driven by the engine while the car's running?

rodnok01
06-10-14, 11:57 PM
I would take the WP belt off and check again. that little pulley makes a racket when wearing out(seizing more like it) and is very easy to remove using 1/4 inch rachet.

Ranger
06-11-14, 10:41 AM
How do I go about checking the vacuum leak?
Spray some Brakleen or TB cleaner into the tunnel behind the P/S pump. If you have a vacuum leak the RPM will increase.


As far as the starter not disengaging from the flywheel, does that mean the starter motor is being driven by the engine while the car's running?
Yes

wingman0121
06-11-14, 07:49 PM
I would take the WP belt off and check again. that little pulley makes a racket when wearing out(seizing more like it) and is very easy to remove using 1/4 inch rachet.

I'm pretty sure it isn't the water pump since the noise isn't coming from that area, but since the car had its water pump replaced almost 100,000 miles ago (AC Delco part) I will check it tomorrow.



Spray some Brakleen or TB cleaner into the tunnel behind the P/S pump. If you have a vacuum leak the RPM will increase.


Yes


I sprayed some carb cleaner at the relief valve and the engine rpm didn't change. As far as checking the starter, since electric motors produce electricity while being turned by an external source is there a place in the fusebox or wiring harness where I can hook up a multimeter and see if the starter is producing power?

Ranger
06-11-14, 09:27 PM
I don't know about that. I'd just listen in the starter vicinity with a stethoscope. That should pretty much pin point the starter if that's the cause.

wingman0121
06-11-14, 11:09 PM
I don't know about that. I'd just listen in the starter vicinity with a stethoscope. That should pretty much pin point the starter if that's the cause.


I'll get a set of stethoscope tomorrow, I assume ones for medical purposes works just fine? If the starter is really not disengaging at all then wouldn't it be broken after the many WOTs I did in the past 1000 miles? The car still starts just fine and its startup behavior is the same like before. I felt the clacking noise in the gas pedal last night while accelerating, again the car didn't act any different and the noise went away after a few seconds.

rodnok01
06-11-14, 11:17 PM
They sell a cheapo mechanics stethoscope with a metal rod on the end so you can pinpoint it on a bearing or area.

wingman0121
06-11-14, 11:20 PM
They sell a cheapo mechanics stethoscope with a metal rod on the end so you can pinpoint it on a bearing or area.


Oh I didn't realize that it's a bit different after looking at harbor freight, I will visit auto parts store tomorrow and see.

Ranger
06-12-14, 11:18 AM
Either buy a mechanics stethoscope or convert a medical one like I did by removing the chest pad and replacing it with a copper tube.

----------


If the starter is really not disengaging at all then wouldn't it be broken after the many WOTs I did in the past 1000 miles? I'm not sure how long a starter motor can survive like that. :noidea:

wingman0121
06-12-14, 07:15 PM
Okay will do. I suppose a last ditch effort to see if the starter is not disengaging without taking off the intake manifold is by turning the key to start when the engine's already running? If it makes that awful noise then that should mean it's disengaging correctly.

Submariner409
06-13-14, 11:36 AM
Most of these cars disable the starter circuit when the engine is running - so you CAN'T get that awful noise.

maeng9981
06-14-14, 02:53 AM
98 Deville should still grind the starter when you attempt to start the car when it's already running. Not that I suggest doing it though.

Ranger
06-14-14, 05:18 PM
I though Cadillac (maybe GM) "idiot proofed" them all long ago,

rodnok01
06-14-14, 07:05 PM
If i have mine started with remote start it will not allow me to start the car again. I do believe anti grind was introduced by the mid 90s for a lot of gm vehicles. Now my 99 PA would grind... That sounds haunts me still.

maeng9981
06-15-14, 04:44 AM
My aunt did in my 99. :hmm:

wingman0121
06-18-14, 04:51 PM
I though Cadillac (maybe GM) "idiot proofed" them all long ago,


Not on my car because I did it once a few years ago.


The whining noise is not from the starter, so I can only assume it is something inside the engine.

Submariner409
06-18-14, 05:32 PM
Has anyone mentioned the timing chain tensioners (3) and guide slippers (3). Those nylon-faced parts wear out over time and the chains can rub on the metal parts, causing a distinctive whine that varies with rpm.

Remove the oil fill cap and listen. Posts 4 and 6.

rodnok01
06-18-14, 07:59 PM
Could be chain whine, that main tensioner on mine was about wore slap out at 100 k and metal on metal would definitely cause a whine.

wingman0121
06-19-14, 07:22 PM
I listened with the oil cap removed and the whine sounds a little bit louder. If it is the chain rubbing on the guide slippers/tensioners then does that mean it is going to break something soon?

Submariner409
06-20-14, 10:50 AM
Metal-to-metal rubbing is never good.............. but if it IS one or more worn tensioner guides the fix is quite involved.

The nylon tensioner faces are hard to see (the tensioners are secured by 2 bolts each and are set by engine oil pressure) , but the blue-green one is typical. The brown slippers get replaced, too. It CAN be done with the car up in the air, wheel removed, inner fenderwell liner out, flexplate locked, lots of wrenching and testing. New tensioners - all 3 are not too expensive. Same for the larger guide slippers.

wingman0121
06-20-14, 08:02 PM
I took a video of my said noise, ignore the low rumble, that's from the aftermarket muffler.


https://www.youtube.com/watch?v=scLl-ZD9zZI

Submariner409
06-20-14, 08:15 PM
I hate to be picky, but please do that again, 30 seconds' worth, with the hood open and an assistant on the gas pedal. "Listen" to the loudest area.

maeng9981
06-21-14, 07:33 AM
That almost sounds too much like my last failed transmission. It failed 7 days after making this noise. Take off the serpentine belt and start the engine to eliminate the possibility of it being the accessories.


http://www.youtube.com/watch?v=7NrlYIgbP4E

wingman0121
06-21-14, 11:40 PM
That does sound just like the whine on my car, did your transmission do anything weird before it gave away? Did the noise stopped after you replaced the transmission? I've already taken off the accessory belt before and the noise persisted so it isn't anything around those components.

maeng9981
06-22-14, 03:29 AM
The noise seemed to be from the trans fluid pump (straight cut gear sound - reverse gears in manual trans vehicles). It is driven by the engine so the speed varies accordingly with the engine RPM.

The transmission developed some hesitation in day 3, followed by the fluid exchange I did (I found LOTS of metal particle and clutch material on the magnets and the screen). Suddenly it just threw "Service Transmission" P1811 - Maximum adapt and Long shift, but the trans acted like nothing happened. No hesitations but the noise was there. Day 5 it threw P0741 but without SES light. It worked okay until the day 7, it started pumping fluid out of its case through the case vent. Then after a while I lost 4th, 3rd, and 1st. At this point I knew the trans was done, so I just drove it home in 2nd with the fluid "overflowing" to the ground. The trans was acting weird though, I lost gear shift indicator once, and it slipped in all gears once. All came back when I just waited about 5 minutes or so.

I opened the broken one up, and found the torque converter to be the problem. During the previous ownership, the owner went with some el cheapo reman. torque converter and the viscous clutch inside had failed. The viscous clutch fluid went everywhere into the transmission.

I replaced the transmission with a used one and the noise went away. After a year the used transmission has developed the infamous axle seal leak though. What a lucky guy I am.

wingman0121
06-24-14, 10:18 PM
I checked the transmission dipstick today (drove the car for an hour, and left engine on, in Park) and the fluid level is touching the bottom cap of the dipstick, so it is above the "full" line. It would overflow out of the dipstick hole if I rev the engine even a tad bit, but with the dipstick back on I don't see the fluid overflowing out of the overflow hose. The fluid color is red and absent of any particles, although it doesn't seem as red as new trans fluid. I had the fluid changed when the car had 98,000 miles, no problems with it, now it has 218,000 miles.

maeng9981
06-25-14, 08:06 AM
That sounds alarmingly full for the transmission. Have you added transmission fluid recently? Try to bring it back to the normal level.

Submariner409
06-25-14, 10:46 AM
The transmission is WAY overfilled.

As posted many times, there should be NO fluid on the stick with the engine off. With the engine idling in P on a level surface you should be able to pull the dipstick and not only measure fluid level, but if you look down into the fill hole you should see fluid swirling around down in there.

It's a dry sump transmission - the pan is normally almost dry with the engine running - the scavenge pumps move more oil than the pressure pump, so the upper tank is full while the engine is running and all the fluid drains down when the engine is turned off.

The transmission vent is the wiggle cap rubber tube clipped to the side of the throttle cable bracket on the throttlebody. In your case it's a wonder that fluid has not squirted out all over the place.

Stuff a bunch of absorbent rags around the fill hole and use a turkey baster to remove fluid until you get a proper (mid-mark) hot level.

Here's what you should see with the engine off.

wingman0121
06-25-14, 04:45 PM
The transmission is WAY overfilled.

As posted many times, there should be NO fluid on the stick with the engine off. With the engine idling in P on a level surface you should be able to pull the dipstick and not only measure fluid level, but if you look down into the fill hole you should see fluid swirling around down in there.

It's a dry sump transmission - the pan is normally almost dry with the engine running - the scavenge pumps move more oil than the pressure pump, so the upper tank is full while the engine is running and all the fluid drains down when the engine is turned off.

The transmission vent is the wiggle cap rubber tube clipped to the side of the throttle cable bracket on the throttlebody. In your case it's a wonder that fluid has not squirted out all over the place.

Stuff a bunch of absorbent rags around the fill hole and use a turkey baster to remove fluid until you get a proper (mid-mark) hot level.

Here's what you should see with the engine off.


The fill hole is dry with the engine off (car's been parked since yesterday), but that really doesn't mean much since it is a dry sump. I have some printer ink syringe that I can use to pull the extra fluid out of there.

wingman0121
06-25-14, 07:56 PM
I pulled about a quart and maybe a little more of trans fluid out so now the fluid level sits just a tiny bit below the "full" line, it doesn't seem to shift any different and it didn't change the whining noise, but at least it is not overfilled. I didn't add any since I owned the car so my guess is the dealership must've overfilled it when I had it flushed, but that was a bit over 100k miles ago.

Ranger
06-25-14, 10:13 PM
The transmission is WAY overfilled.

:hmm: But he said "(drove the car for an hour, and left engine on, in Park) and the fluid level is touching the bottom cap of the dipstick". What am I missing?

Submariner409
06-26-14, 11:06 AM
:hmm: But he said "(drove the car for an hour, and left engine on, in Park) and the fluid level is touching the bottom cap of the dipstick". What am I missing?

Yeah, but read the part about touching the cap itself and overflowing if he revved the engine a bit.

He posted back after pulling some fluid.

Still doesn't explain the whine.

Ranger
06-26-14, 11:39 AM
:thumbsup: After rereading it, it DOES sound over filled, BUT it's been like that for 100K.

wingman0121
06-26-14, 11:04 PM
:thumbsup: After rereading it, it DOES sound over filled, BUT it's been like that for 100K.


Yes, no effect what so ever with that extra quart or so of trans fluid, but it's not like it's a good thing to have extra fluid.

wingman0121
07-12-14, 02:46 PM
A little update on this... so far the car still drives just fine like before, however when the engine is cold I've noticed some clacking noises that I can feel in the gas pedal when I accelerate. It doesn't do it all the time and when it does it is only if I accelerate faster to catch up to traffic. I never hear the noise once the engine/trans is warmed up. Again when I hear the clacking noise the car doesn't act any different.

maeng9981
07-14-14, 11:54 AM
I just hope nothing serious happens. The whine was fun while it lasted, it sounded like a supercharger.

RVMAN
07-14-14, 01:53 PM
I had an oil change on my last deville and they overfilled the transmission by a qt. when the guy/kid told me after oil change that they had to add a qt of fluid I immediately checked fluid to find it way over, almost to the cap. they removed it after I gave them a lesson on trans fluid checking. I don't usually have my oil changed but was in a hurry. When I do have oil changed now I hover around them and will not let them touch anything but oil and filter.

wingman0121
07-15-14, 02:18 AM
I just hope nothing serious happens. The whine was fun while it lasted, it sounded like a supercharger.


Same here. I just went on a 5-hour highway drive today and everything is okay, so I donno.