1998 Ford Escort Vacuum Hose Diagram
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Discussion Starter · #1 ·
My 99 Escort wagon is "singing," "whistling," "ringing," or "whining" at what seems like repeated speeds, accelerations, upshifts, and downshifts. At first I though it might be a bad wheel bearing, but when I noticed how it seemed tied to what might be vacuum pressure, basically the speed of the engine, and its ups- and downshifts, I changed my premise.
I did a search here on "vacuum leak," but surprisingly, found nothing. Weird.
So, I got some sticky, uh, saranwrap-type wrap, like they use to bundle stuff to palettes, and I opened up the hood to look for places where the ends of vacuum hoses might be becoming cracked from age, thinking I could temporarily wrap a few hose ends to confirm my suspicions, and I was blown away (sucked away?) by all the vacuum hoses there.
Now, I don't know where to start to intelligently diagnose where the whistle is coming from.
Suggestions welcome. Thank you.
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Use a can of starting fluid in short bursts at the vacuum lines. Start about a foot away to then gradually get closer to each hose. If you spray a leaky hose the engine will rev up. Depending on how severe the leak is, the engine may rev slightly or it might rev significantly. Just listen carefully and you'll find it. Once you narrow it down to a few hoses you can start testing them one by one. There are some under the intake manifold that shouldn't be overlooked.
A word of caution with this method though; do not spray starting fluid next the alternator or the coil pack. It may short out and cause the spray to explode in your face. (Ask me how I know.)
Tapatalk
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The one vacuum hose that consistently rots out is attached to the bottom of the throttle body.
Also, the rubber PCV elbow or hose that attaches to the intake manifold nipple in front of the oil dipstick gets soft rots away from oil vapors.
But vacuum leaks don't sing or whine unless they're just the right size. They will consistently result in a poor idle if minor or a warm fast idle if major as the computer tries to compensate.
See if you can reproduce the whine, whistle, etc., in park or neutral and note the engine speed. Then go under the hood with a stethoscope or piece of heater hose to try to locate the source with the engine at that same speed. It may be an alternator, ps pump, a/c pulley or idler pulley causing the noise.
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Discussion Starter · #4 ·
Great PM to investigate.
I had a tech friend listen to the sound, and he looked under the hood and found a timing pulley (?) on the passenger side of the engine that was supposed to be still, but was vibrating slightly. He thinks the pulley bearings have gone, and the whining I'm hearing is the bad bearings.
So, your alternate suggestions look like they might be right on the nose.
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Timing belt tensioner pulley. Common problem, the grease dries up, the ball bearings start to disintegrate and squeal (esp. in cold weather until the remaining grease warms up and flows around). And then, one cold morning you go to start the car and it just cranks and cranks (a little faster than normal) because the timing belt loosened and stripped some teeth. Usually around 100k miles. All this is under the plastic cover on the passenger side of the engine.
You'll need a new timing belt and tensioner pulley installed. Routine maintenance job for this car.
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Vacuum leaks are common in the vacuum lines that go to the charcoal canister. You will need to remove the air cleaner box to see them.
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I had a 3rd gen someone stripped the timing belt tensioner threads from tightening it to tight.
I ended up helicoiling the thread, problem solved.
Posted by: cesaathome.blogspot.com
Source: https://www.feoa.net/threads/vacuum-leak.110025/