mazdaspeed7

Theres a strange howling that appears to be coming from the back of my engine block. It does not change pitch with speed or rpm, but is much quieter on acceleration. But at constand speed or decelation, it makes the noise. This is on a rebuilt motor with 20K miles, and I always changed the oil at 2500-3000 miles. My oil pressure was fine, and the car never got hot. Its definately not slipping belts. The clutch, throwout and pilot bearings were replaced when the engine went in, 20K miles ago.

Any ideas?

J-Rat

iTrader: (2)

Man, this happened to me once...When I opened the hood, a cat jumped out..

Dont know how he lived...

Rt

Aaron Cake

iTrader: (1)

I had the same problem with a groundhog.

But seriously, I think your starter gear may be hung up on the flywheel.

Or a bad throwout/pilot bearing.

banzaitoyota

road debris hung up in the passenger side access port/opening?

J-Rat

iTrader: (2)

True story! Scared me so bad I dropped my hood! I went white as a sheet! And it took hours to get all the cat hair out from my engine bay.

mazdaspeed7

It wasnt the starter. Is there a way to check the pilot bearing without dropping the tranny? I need to drop my tranny next week anyways, so Ill check it then.

Could it be from overfilled oil? I changed my oil yesterday, and today I checked it again, and it seems not all of my oil drained out before I put the new oil in. My oil was at least a quart high. I drained some of the oil, and its where it should be now. Ill see if that fixes it in a little while. If it was the oil, Im going to have to smack myself ....

RX-7Impreza

hurry up and check to see if kristin is stuck under there!!!!!!!!!!





sorry it was just too easy, dont hate me anymore, kristin

Justin

mazdaspeed7

Well, it wasnt the oil.

I went and talked to a mechanic friend, and he told me it was most likely a vacuum leak. He said it wouldnt be a problem with any engine bearings, but might be a bad throwout bearing if it wasnt a vacuum leak.

Any more ideas?

banzaitoyota

Random thought:


Superglue??????


J/K yuck yuxk yuck!

mazdaspeed7

LOL, smartass..... I only do that on OTHER peoples cars.....



j/k

Back on topic, tomorrow Im going to see if its a vacuum leak. Im pretty sure thats it. It makes the most sense, considering the noise changes according to engine vacuum, but not speed or rpm.

SonicRaT

iTrader: (6)

You have an NA right? You'd think it'd be louder on acceleration as vacuum is higher (not bieng forced induction) And if it was the throw-out bearing, it'd probably squeel more as you press the clutch in, which you didn't mention. Doesn't change pitch, so that doesn't sound like a bearing, since they tend to change pitch depending on their speed. Ok, I'm not helping any! Low on power steering fluid? (even though you don't have power steering, haha!)

Manolis_D

iTrader: (2)

Other way around bro -- Vacuum does get higher, but that means there's less of a pressure difference btw. the source of the vacuum and the atmosphere --> less noise! A vacuum leak actually sounds pretty reasonable to me!

mazdaspeed7

Im sure its a vacuum leak now. It doesnt start howling until its hot, but today, I could hear a whistling coming from the engine bay before the engien warmed up. Im also pretty sure its the engine to intake manifold gasket All of the other gaskets were replaced 3 weeks ago.

Suds7

expensive, that sounds like the culprit. With all those injection removals I had the same damn thing happening to me and I bought a new LIM to engine gasket and used sealer, no noise! you might want to check for other vaccum leaks as well.

mazdaspeed7

Vacuum leaks are easy to find in my car. I removed nearly all of the vacuum nipples, since I have all my emissions stuff removed. I only have 3 nipples left, and all are being used. One for the pressure sensor, one for FPR, and the last for the crankcase vent. All of the vacuum hoses are new, as are all of the gaskets on the intake manifold itself. The only gasket that wasnt replaced when I did that 3 weeks ago was the intake manifold to engine gasket. I didnt replace it because I left the lower intake manifold bolted to the engine.

I just pulled my intake manifold off. Damn I love my car, it only took 20 min to get the WHOLE intake manifold off the car I found a pair of cuts in the gasket on either side of the secondary ports. Im sure that was the culprit. Its going back on this evening, its just too hot to work right now.