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General Forums => The O' Club => Topic started by: AKS\/\/ulfe on June 16, 2005, 02:10:41 PM

Title: Car engine noise, cause?
Post by: AKS\/\/ulfe on June 16, 2005, 02:10:41 PM
I just notice it yesterday, in the morning after a thunderstorm that night, that there was a whistling hiss coming from the engine. As I sped up, it went away, the closer to idle the engine got, the louder it became.

Gunning the gas made the noise go away, then it would come back as the engine returned to idle.

Any ideas? "Bend me over and take my cash" mechanics are out of the question.
-SW
Title: Car engine noise, cause?
Post by: eagl on June 16, 2005, 02:14:37 PM
The exhaust recovery tube, a thin tube from the vicinity of the first catalytic converter back to the intake, often has a seal that will give out.  My first suspicion is either an intake or exhaust seal problem.  If the sound has any "ticking" element to it, that tends to mean it's an exhaust gasket.
Title: Car engine noise, cause?
Post by: lazs2 on June 16, 2005, 02:16:35 PM
really difficult to be accurate from such a descritption but it sounds very much like a vacumn leak..

At low (engine) speed you have high vacumn and the noise would be more prominent.. when the motor is under load vacumn drops and the noise is less noticeable.

A vacumn gauge would tell you right away... failing that... start tracing hoses.

lazs
Title: Car engine noise, cause?
Post by: Casca on June 16, 2005, 02:17:49 PM
Sounds like it's leaking vacuum.  Find a piece of hose a couple of feet long, you can listen in one end and move the other end around your intake components till you hear it.
Title: Car engine noise, cause?
Post by: Siaf__csf on June 16, 2005, 02:18:30 PM
Would probably help if you'd tell the make and model of the car (and age.)

Whistling is usually related to belt slippage (the belt that turns waterpump, a/c etc.) If it's worn out you can change it yourself by loosening the alternator bolt which will make the belt loose. This is the same trick that will stop slippage if you tighten it instead of loosing and jerk the alternator to a 'tighter' position at the same time.

If the belt is worn out tightening it might temporarily stop the noise but then damage the water pump axle or just cut the belt in pieces while youre driving. Losing the belt means losing engine coolant circulation = very bad thing and you should stop driving immediately.
Title: Car engine noise, cause?
Post by: AKS\/\/ulfe on June 16, 2005, 02:24:48 PM
Thanks for the suggestions guys, I'll put it up on stands tomorrow afternoon and check around.

The description is pretty bad, mostly because I really don't know how else to describe it. Although, it does go away after a while. I'd say maybe after a mile or two, it stops making the noise and I don't notice it later as the day heats up.

By whistling hiss, I mean it sounds like gas escaping but in intervals where it gets louder then softer. Very quick, kind of in sync with the turning of the engine.

Seems to be primarily happening in the morning when I first get the car started.

It's a 97 Civic(non-riced), not really sure that'll help identify the noise.

Thanks again!
-SW
Title: Car engine noise, cause?
Post by: eagl on June 16, 2005, 02:26:33 PM
Good point about the vaccum leak possibility.  That will often be audible only at idle.
Title: Car engine noise, cause?
Post by: Steve on June 16, 2005, 03:02:09 PM
What Lazs said. Take a look under the hood before you put it on stands.. it may just jump out at you and save you some time.

I'd be inclined to consider a slipping belt if you described it more as a screeching sound than whistling hiss.
Title: Car engine noise, cause?
Post by: SFRT - Frenchy on June 16, 2005, 03:02:56 PM
Don't vaccum leaks also generate engine shake at idle, but goes away when you accelerate. My F250 had a vaccum hose disconected, and it was the symtoms. Gee, I spent a whole day trying to tune my Holley, befiore i noticed it:lol
Title: Car engine noise, cause?
Post by: AKS\/\/ulfe on June 16, 2005, 03:04:25 PM
Closer to a venting gas hiss than a screech, but I'll check under the hood before I put it up.

Thanks!
-SW
Title: Car engine noise, cause?
Post by: Steve on June 16, 2005, 03:14:35 PM
Good luck wulfe. I'm crossin my fingers for ya that it's something simple.
Title: Car engine noise, cause?
Post by: AKS\/\/ulfe on June 16, 2005, 03:27:41 PM
I'm hoping so too. After witnessing/helping/making stop gap suggestions to a friend that had to replace the boots on his car so he could sell it - I just want one of those easy tighten something fixes.

I never realised how hard it could be to replace boots, those rings that they ship with to fasten the boot to the axle require a special tool that we couldn't find to get them to tighten. What would have taken someone who knew what they were doing a day, took him/us a week.
-SW
Title: Car engine noise, cause?
Post by: Siaf__csf on June 16, 2005, 04:09:01 PM
The belt slippage is usually easy to spot, it hisses and screams loudly when you rev the engine. After you raise the revs for a longer period the belt sticks in and stops slipping so the noise goes away.

Check the belt tension by pressing the belt (from a free spot) with your thumb quite hard (with the engine turned off DOH). It should give in half an inch at maximum if not less. If it moves closer to an inch it will slip and cause all kinds of hissing and squealing noises.

Another source of noise could be your timing belt or chain not sure which one civic uses, probably the belt. The belt needs to be replaced every 70k miles or so depending of car. If the belt breaks or slips you can end up with busted pistons, broken valves, twisted crankshafts and all kinds of nice things. Basically it will total your engine. Some engines use small suspension/shock absorbers in the belt/chain which can also start to make rattling etc. noises inside the engine.

If its more like gas leak it could be anything starting from vacuum tubes to your exhaust manifold. Open the hood and rev teh engine by hand to spot the exact location of the noise. Just make sure you keep your hand away from the cooling fans and the turning belt. The thermostat controlled cooling fan can start even when the engine is off so never stick your fingers there with the battery connected.
Title: Car engine noise, cause?
Post by: Hangtime on June 16, 2005, 05:35:52 PM
Cat.

Check fer fur in the belts.
Title: Car engine noise, cause?
Post by: SOB on June 16, 2005, 06:27:47 PM
Somebody put Anthrax in your engine.  Quick, douse your car in gasoline and light it on fire!
Title: Car engine noise, cause?
Post by: Roscoroo on June 16, 2005, 07:20:54 PM
does it hiss after its shut off ?
Title: Car engine noise, cause?
Post by: Maverick on June 16, 2005, 08:52:29 PM
It's been my experiance that a car makes noise after the key is inserted and turned. Take the key out and the noise will stop. Problem solved!



Seriously, if you have power brakes check the master cylinder assy for a vacuum leak thjere as well.
Title: Car engine noise, cause?
Post by: AKS\/\/ulfe on June 24, 2005, 12:14:01 PM
Siaf_csf is the big winnar.

I just need money to go buy a belt, then I'll replace it.
-SW
Title: Car engine noise, cause?
Post by: SOB on June 24, 2005, 12:17:50 PM
You couldn't identify the sound of a slipping belt?  You should have followed my advice and burned the car. :p
Title: Car engine noise, cause?
Post by: AKS\/\/ulfe on June 24, 2005, 12:24:17 PM
I never had a chance to get under the hood when it was making the noise. If you get a gnome that sits in your engine bay and whistles at idle speeds every once and a while, would you know what it was?

Jerk. :(
-SW
Title: Car engine noise, cause?
Post by: SOB on June 24, 2005, 12:36:06 PM
Now I feel bad.  C'mere and give me a hug, SW...I promise to goose ya.

BTW...You should remove the gnome from your engine bay too.  Mythical creatures are notoriously bad for anything mechanical.
Title: Car engine noise, cause?
Post by: AWMac on June 24, 2005, 12:41:50 PM
Quote
Originally posted by Hangtime
Cat.

Check fer fur in the belts.


Been there, Done that!!!

:rofl :D
Title: Car engine noise, cause?
Post by: yb11 on June 24, 2005, 02:44:42 PM
vacuum leek cheek hoses the little ones
Title: Car engine noise, cause?
Post by: RightF00T on June 24, 2005, 02:55:07 PM
ditto on vacuum leak..check hoses.
Title: Car engine noise, cause?
Post by: beet1e on June 24, 2005, 04:33:31 PM
Quote
Originally posted by lazs2
really difficult to be accurate from such a descritption but it sounds very much like a vacumn leak..

At low (engine) speed you have high vacumn and the noise would be more prominent.. when the motor is under load vacumn drops and the noise is less noticeable.

A vacumn gauge would tell you right away... failing that... start tracing hoses.

lazs
Lazs is correct. Also consider buying a German car next time.
Title: Car engine noise, cause?
Post by: Siaf__csf on June 25, 2005, 06:55:40 AM
German cars are very low on reliability these days (believe me I know I have a Mercedes).

If you want reliability and a good ride, pick something like a lexus. If you want a superb ride and don't mind spending a thousand bucks here and there with your car, pick a german vehicle.

I.e. you got to love the german car seriously, because she'll ask a helluva lot from the owner.

The last reliable mercedes was built in -93 when the W124 final facelift was introduced. From there on there have been corrosion problems (changed to eco-paint) and with newer models mucho electrical failures.

W140 S-series had a wiring harness made from biodegradable plastic -> engine heat destroyed the insulations and caused a premature $1200 fix. And this was just one example - later models are even worse.

Enviromentalism is the cause of all evil.
Title: Car engine noise, cause?
Post by: beet1e on June 25, 2005, 07:05:14 AM
Quote
Originally posted by Siaf__csf
German cars are very low on reliability these days (believe me I know I have a Mercedes).
I've heard a few bad things about Mercs recently.

But I'm on my third VW Golf and about to buy a fourth. I have been delighted with all of them. The only troubles I've had with them are as follows: All repairs under warranty. Nothing here that would put me off buying another. Total mileage on all 3 cars ~150,000.
Title: Car engine noise, cause?
Post by: Siaf__csf on June 25, 2005, 02:00:40 PM
Well I was more thinking Audi, BMW and Mercedes when speaking of 'german cars.'

WV as a part of VAG does suffer from many related problems. Mostly transmission failures, especially tiptronic gearboxes are prone to fail and cost $15k to replace.

As long as you have warranty it's nice - except when you get into a shop circle as has happened to many people. The vehicle keeps on malfunctioning due to CAN etc. hardware errors sending mechanics to expensive wild goose chases. People have had to return $60k+ vehicles to repairs every 2 weeks for durations starting from 1 day to a month.

Guarantee or not, that's not nice.
Title: Car engine noise, cause?
Post by: beet1e on June 25, 2005, 02:42:22 PM
Rgr that Siaf.

I must admit, I do like the Mercs - but there isn't really one with a body style to suit my needs - except perhaps the C-class coupé. Momus has just posted that he gets 40mpg from his - I wonder if that's a petrol engine - bet it isn't the 3.2.

Tiptronic gears - I would have been tempted with that for the Golf, but it's not available on the 4-motion models - only the FWD models. Given the choice between 4WD and tiptronic, I'll go for 4WD.
Title: Car engine noise, cause?
Post by: Siaf__csf on June 25, 2005, 03:36:48 PM
My E320 gets 31mpg combined hwy/city with emphasis on hwy drive as long as the speed is under 90km/h (revs below 2000rpm).

Anything over 110km/h drops it to around 28mpg.