I have been having a strange vibration, humming, sound comming from my engine lately. It is only when the engine in cold. I can feel it in all the pedals. Brake clutch and gass. It is mostly only heard and felt at idle. My idle is normal, and the engine runs fine I just have this humming vibration sound. I don't know if it continues when i get on the gas because I dont know if the sound of the engine and mostly exhaust drowns it out. but I think if im crusing at about 1500-2000 rpm i think i can slightly feel it in the gas pedel if not accelerating or lightly accelerating. But it only happens when the engine is cold. I can not seem to find whats making the noise because when i get out of the car and pop the hood to listen to the engine i cant hear the same noise. I was thinking maby crank bearings, or crank pully,or powerstearing i don't know. I was woundering if anybody else has experienced this or might have a few pointers on how to isolate the problem. Thanks.

 

I bet you it's your motor mounts! Have some one get behind the wheel w/the emergency brakes on and give it gas in "D" and "R" and check your engine movement and visually check out your mounts!

 

What kind of car do you know that has a clutch pedal and D and R?

 

yea.. how can you tell if your mounts are bad in a 5 speed?

 

Well a lot of times you can tell by just looking. also lift the hood and give it gas from the TB and look how the engine moves. it should move just a little and also then you can see which way it tilts.

 

A bad mount will allow flex from the torque of the engine. Giving it a bump from the TB will show most of the time if a mount is bad - engine wise. For a trans mount, dropping it in gear (or a 5spd w/ parking break on, let the clutch out (1st / R) till the car almost dies) will show excess movement of the trans.

I think you're problem is one of two things ...
1. TC tensioner - common rattle upon start up. Is there noise, or just vibration? If there's noise, is it coming from the front of the engine?

2. Bad mounts, either front / rear (trans) / or Left / Right .... You'll be able to tell when you check under the hood with the car in N. Bump the TB a bit and watch for excess twisting or vibrating. A little movement is good, too much is bad. If there is noise, track it down to a general area.

G'luck mate!

 

OK I was thinking mounts also, and i will check them like you said but why would this vibration and humming noise only happen when the engine is cold? I should have been more specific but i ment that it happens untill the engine warms up like to almost operating temp. not just on startup. Thanks for the responses.

 

The engine bay warms up as the engine runs so the mounts can become more plyable (looser) with higher temps. Did you get a chance to listen for any sounds under the hood? Try lifting the hood (when the car is cold) and start it with the windows down, you can hear better then. Also, if you can - even better, have someone else start it and you listen under the hood. It's hard to say at this point, but I bet if there is humming / vibration, there is a louder noise causing both. Sounds to me like a TC tensioner ... but as mentioned, hard to tell at this point.

 

doesn't matter if you have an Auto or 5 speed, put your emrgency brake on chock the wheels (xtra safety) and for you 5 speeders slightly slip the clutch just enough to torque the engine in D or R....If you can set on a steep incline in one position without using any brakes just the clutch you should have no problem doing this! Auto guys you know the routine.....