Let's face it... 10+ year-old DSM's (especially AWD models) are right up there near the top on the list of cars with strange noises and vibrations. With a majority of our cars having modified suspensions and motor mounts, these noises and vibrations can be even more frustrating and hard to locate. In this article I'll try to give possible or likely causes for some of the most common "weird" sounds. Some are obvious; some aren't. If you would like to contribute something that I've left out, feel free to PM me with your experience.
Here are a few general tips for tracking down those elusive squeaks, squeals, thumps, and groans:
1. When searching for the source of strange sounds and vibrations, try to think in terms of how the car works. It will be a lot easier to identify problems if you can rule things out right away because they aren't "in the loop".
2. Pay attention to whether the sound occurs while the engine is running or not, whether you are in gear or not, with the clutch pushed in, etc.
3. Notice if the sound changes with engine speed or vehicle speed.
4. Try to isolate where the sound is coming from (interior/exterior, one corner at a wheel, from the engine bay, rear end, etc.)
5. Invest $10 in a mechanic's stethoscope. They are very helpful in locating those elusive sounds, especially around the engine and transmission. A cheap and somewhat less effective alternative is to move the end of a long screwdriver along the engine or tranny while listening to/feeling of the other end of it.
6. Become familiar with what ypes of sounds are made by different materials. The type of material, it's thickness, and weight all contribute to different sounds and vibrations. Does it sound like a hiss or a tea kettle (escaping air), chirping (thin metal scraping against something; a turbine wheel maybe), or a squeal (rubber on metal; usually belts).
********************************************
Disclaimers:
1. This article is not an all-inclusive troubleshooting guide.
2. Expect some frustration: noises and vibrations in cars are not easy to isolate.
3. These are just some possible common causes; there could be many others.
4. This article assumes you aren't doing something really silly, like driving around with a battery not bolted down that is thumping against the hood.
5. Don't make fun of my sound descriptions; keyboards don't have a dedicated key for "thwap"
6. This article isn't specific to any certain type of car, so some items may not apply to you.
********************************************
With all of that said, here we go...
You hear a clicking type noise while turning. Your CV joints are probably used up. Check around the wheel hubs on the inside where the axle goes through the hub. You may see a torn boot or notice a lot of grease. If they are REALLY bad, you may not see any grease at all and the boot could be missing pieces.
You hear a clicking type noise behind the dash, but only while moving. This could be a dry/rusty speedometer cable You can remove the gauge pod and put a little oil on it to quiet it down.
You hear a clicking type noise below the radio. Check the ECU power relay in the console, under the radio. The ECU may also be the culprit.
You hear a high-pitched click or squeal while braking. Sounds like it's time for new brake pads. Or, you have the incorrect pads and/or clips installed.
You hear a clicking or buzzing noise coming from a fuse box. You probably have a relay that is sticking. See if you can feel a vibration, or use a stethoscope to isolate which one it is, and replace the relay.
You hear a loud clicking type noise from under the hood when you try to start the car. Probably a weak battery, starter problem, or something in between. Make sure the battery is fully charged and test the starter. Also check the fuses in the engine bay and look for any damaged or loose wires, especially around the battery/starter areas. Note that the ISC (Idle Speed Control) on the thottle body can also sometimes click.
You're in boost and hear a loud pop, and the car no longer has power. By "pop" I mean as in a really big can of biscuit dough being opened (remember those?), or maybe a can of Pringle potato chips...not like an explosion. You probably blew a coupler somewhere, or a pipe in the intake tract came loose. Check all connections from the turbo outlet to the intake manifold, and do a boost leak test. If this is your problem, you can limp the car somewhere to fix it as long as nothing is loose that can get into a fan or cause other problems. Just stay out of boost and take it easy.
The car runs OK, but there is a ticking or light clacking type noise coming from under the valve cover. Usually worse when it's cold, this the infamous DSM lifter tick. It is loudest right on top of the valve cover on either side of the plug well. Either get used to it, or upgrade to some 3G lifters. If the click is more of a tick and is coming from the fuel rail, that is the sound of your injectors firing and is normal.
You hear a loud clicking from the engine bay only when the a/c is turned on. Check the a/c clutch and relays.
You hear a rattle or scraping sound from under the car, especially on bumps. Check to see if your downpipe flex section is rubbing on your oil pan. Also check the tunnel heat shield and the rest of your exhaust for any rubbing.
You hear a clunk or thumping sound occasionally coming from one corner of the car when going over bumps. You probably need struts. Bounce the car up and down with your hands a few times on each corner and let it go. If it keeps bouncing more than one or two times, your struts (shocks) on that corner are toast.
While the car is idling in neutral with the clutch out, you hear a rattling or light grinding sound from the engine bay. If pushing the clutch in makes the noise stop, it's your throw out bearing, or TOB. If there are no problems with shifting or going into gear, it's probably ok. (These are just noisy sometimes). But you definitely want to keep an eye on it, and be ready to replace it with a new OEM one when you have the tranny out or if other clutch-related problems pop up.
You hear a grinding sound while braking, or it feels like your brakes aren't grabbing evenly. Your brake rotors are most likely warped or badly worn, possibly eating into the pads.
You hear and feel a slight cyclic thump from one corner of the car, even while coasting in neutral with the motor off. You have a flat spot or uneven wear on a tire.
You feel a rapid vibration within a certain speed range (usually highway speed), even while coasting in neutral with the motor off. Wheels/tires are out of balance.
There is a whining sound coming from the rear driver's side of your car's interior. It's your fuel pump. Aftermarket pumps can normally be quite loud, especially with no carpet or insulation. If the sound goes up and down when your blinker is on, you need to do the fuel pump rewire mod.
You hear and/or feel a metallic grinding or clunking sound while turning. It's probably your wheel bearings, but could also be a ball joint, sway bar link, or tie rod ends.
There is a pinging or dieseling sound coming from the engine bay while in boost. This is detonation ( or "knock"), and is BAD BAD BAD in a turbo DSM. If you had of been watching your logger or reprogrammed factory boost gauge, you would have noticed the counts of knock before actually hearing it. Get your car tuned to a safer level immediately.
You hear a single knock or clunk from the engine bay when first accelerating. Probably a broken motor mount that is allowing the initial engine torque to rotate the motor upwards, causing something to hit.
You hear a squealing or "thwap thwap" sound coming from down low on the drivers side of the engine. It may sound more like "thweak thweak" (I can't even type that without laughing). Check to see if your harmonic balancer is coming apart. The outer ring tends to separate from the inner rubber, and will cause all kinds of nasty things to happen if it comes loose at high RPMS. Note: This is one of those items that you want to go with an OEM replacement only. "New" parts store HB's can come apart in less than 1k miles...I know this firsthand.
You hear a high pitched squeal from the driver's side of the engine, especially when starting cold. You probably have a loose or worn accessory belt, most likely the one for the power steering pump. Tighten or replace the belt. Also check the alternator pulley; it's bearings are notorious for going bad and squealing...especially cheap aftermarket ones from parts stores.
You hear a squeal or metallic grating sound from the front of the motor (turbo side) that changes with boost. Time for a turbo replacement (or upgrade...depending on how you look at it). Check for shaft play and look for excessive oil or any metal shavings in or around the turbo inlet. If the turbo is bad, do not drive the car because the metal pieces will get sucked into your motor and can cause way bigger problems than just a blown turbo.
You hear a metallic clank or clunk that changes with RPM from the area of the oil pan. This is usually not good, and is usually a spun rod bearing. Drop the oil pan and check for metal in the oil, and play in the bearings.
While decelerating in gear, you hear a whirring or light grinding sound that gets quieter as the engine RPM/vehicle speed drops. Probably a transmission input shaft bearing or gear lash from worn gears, but could also be the rear diff or transfer case.
At idle, you hear a ticking sound from under the car or around the exhaust manifold. You have an exhaust leak. Use a stethescope to carefully find the leak (without getting burned). Attach a piece of vacuum tubing to one end of the stethescope, and run the other end around the area of the leak. You will hear a huge difference when the escaping air blows over the open end of the tubing. (You should hear it change from a muffled hissing sound to a loud, deep sucking sound).
While shifting into gear from a stop, you hear and feel a heavy grinding noise. Your clutch isn't fully disengaging, or you need bigger leg muscles. Check your clutch adjustment and clutch fluid level.
You hear a squealing noise coming from the driver side of the engine bay, and you've already removed the accessory belts. If you have this noise even with the belts and front timing cover off (and your harmonic balancer is good), you've most likely got a worn out timing belt idler pulley or tensioner pulley. If this turns out to be the case, go ahead and replace the other timing components as well, since they probably aren't far behind.
You hear a squealing, grinding, or rubbing noise in the lower timing belt area, towards the back of the engine. Could be that the nut on your oil pump shaft has backed off and the oil pump sprocket is grinding a hole through your timing cover from the inside out. Pull the timing cover and look for shaved/burnt plastic and an oil leak in that area.
You hear hissing or whistling from some place in the top of the engine bay. Check for a broken, disconnected, or missing vacuum line.
When accelerating from a stop, you hear/feel a thump under the floor. Your carrier bearings are probably shot. This is a well known problem that is caused from the bearings wearing out and allowing the driveshaft sections to jump up and hit the undercarriage. Replace them. Note: I highly recommend NOT doing the WindowWeld carrier bearing "fix". It's very hard to get that stuff to cure while keeping the shafts perfectly centered in the bearing, and you'll probably end up with a lot of vibration afterwards.
********************************************
I'm sure I'll be adding to this list and updating it every now and then, but in the mean time this should get you pointed in the right directions. As mentioned, feel free to PM me if you think something should be added.
Now pick up that stethescope and get to it!
Here are a few general tips for tracking down those elusive squeaks, squeals, thumps, and groans:
1. When searching for the source of strange sounds and vibrations, try to think in terms of how the car works. It will be a lot easier to identify problems if you can rule things out right away because they aren't "in the loop".
2. Pay attention to whether the sound occurs while the engine is running or not, whether you are in gear or not, with the clutch pushed in, etc.
3. Notice if the sound changes with engine speed or vehicle speed.
4. Try to isolate where the sound is coming from (interior/exterior, one corner at a wheel, from the engine bay, rear end, etc.)
5. Invest $10 in a mechanic's stethoscope. They are very helpful in locating those elusive sounds, especially around the engine and transmission. A cheap and somewhat less effective alternative is to move the end of a long screwdriver along the engine or tranny while listening to/feeling of the other end of it.
6. Become familiar with what ypes of sounds are made by different materials. The type of material, it's thickness, and weight all contribute to different sounds and vibrations. Does it sound like a hiss or a tea kettle (escaping air), chirping (thin metal scraping against something; a turbine wheel maybe), or a squeal (rubber on metal; usually belts).
********************************************
Disclaimers:
1. This article is not an all-inclusive troubleshooting guide.
2. Expect some frustration: noises and vibrations in cars are not easy to isolate.
3. These are just some possible common causes; there could be many others.
4. This article assumes you aren't doing something really silly, like driving around with a battery not bolted down that is thumping against the hood.
5. Don't make fun of my sound descriptions; keyboards don't have a dedicated key for "thwap"
6. This article isn't specific to any certain type of car, so some items may not apply to you.
********************************************
With all of that said, here we go...
You hear a clicking type noise while turning. Your CV joints are probably used up. Check around the wheel hubs on the inside where the axle goes through the hub. You may see a torn boot or notice a lot of grease. If they are REALLY bad, you may not see any grease at all and the boot could be missing pieces.
You hear a clicking type noise behind the dash, but only while moving. This could be a dry/rusty speedometer cable You can remove the gauge pod and put a little oil on it to quiet it down.
You hear a clicking type noise below the radio. Check the ECU power relay in the console, under the radio. The ECU may also be the culprit.
You hear a high-pitched click or squeal while braking. Sounds like it's time for new brake pads. Or, you have the incorrect pads and/or clips installed.
You hear a clicking or buzzing noise coming from a fuse box. You probably have a relay that is sticking. See if you can feel a vibration, or use a stethoscope to isolate which one it is, and replace the relay.
You hear a loud clicking type noise from under the hood when you try to start the car. Probably a weak battery, starter problem, or something in between. Make sure the battery is fully charged and test the starter. Also check the fuses in the engine bay and look for any damaged or loose wires, especially around the battery/starter areas. Note that the ISC (Idle Speed Control) on the thottle body can also sometimes click.
You're in boost and hear a loud pop, and the car no longer has power. By "pop" I mean as in a really big can of biscuit dough being opened (remember those?), or maybe a can of Pringle potato chips...not like an explosion
. You probably blew a coupler somewhere, or a pipe in the intake tract came loose. Check all connections from the turbo outlet to the intake manifold, and do a boost leak test. If this is your problem, you can limp the car somewhere to fix it as long as nothing is loose that can get into a fan or cause other problems. Just stay out of boost and take it easy.The car runs OK, but there is a ticking or light clacking type noise coming from under the valve cover. Usually worse when it's cold, this the infamous DSM lifter tick. It is loudest right on top of the valve cover on either side of the plug well. Either get used to it, or upgrade to some 3G lifters. If the click is more of a tick and is coming from the fuel rail, that is the sound of your injectors firing and is normal.
You hear a loud clicking from the engine bay only when the a/c is turned on. Check the a/c clutch and relays.
You hear a rattle or scraping sound from under the car, especially on bumps. Check to see if your downpipe flex section is rubbing on your oil pan. Also check the tunnel heat shield and the rest of your exhaust for any rubbing.
You hear a clunk or thumping sound occasionally coming from one corner of the car when going over bumps. You probably need struts. Bounce the car up and down with your hands a few times on each corner and let it go. If it keeps bouncing more than one or two times, your struts (shocks) on that corner are toast.
While the car is idling in neutral with the clutch out, you hear a rattling or light grinding sound from the engine bay. If pushing the clutch in makes the noise stop, it's your throw out bearing, or TOB. If there are no problems with shifting or going into gear, it's probably ok. (These are just noisy sometimes). But you definitely want to keep an eye on it, and be ready to replace it with a new OEM one when you have the tranny out or if other clutch-related problems pop up.
You hear a grinding sound while braking, or it feels like your brakes aren't grabbing evenly. Your brake rotors are most likely warped or badly worn, possibly eating into the pads.
You hear and feel a slight cyclic thump from one corner of the car, even while coasting in neutral with the motor off. You have a flat spot or uneven wear on a tire.
You feel a rapid vibration within a certain speed range (usually highway speed), even while coasting in neutral with the motor off. Wheels/tires are out of balance.
There is a whining sound coming from the rear driver's side of your car's interior. It's your fuel pump. Aftermarket pumps can normally be quite loud, especially with no carpet or insulation. If the sound goes up and down when your blinker is on, you need to do the fuel pump rewire mod.
You hear and/or feel a metallic grinding or clunking sound while turning. It's probably your wheel bearings, but could also be a ball joint, sway bar link, or tie rod ends.
There is a pinging or dieseling sound coming from the engine bay while in boost. This is detonation ( or "knock"), and is BAD BAD BAD in a turbo DSM. If you had of been watching your logger or reprogrammed factory boost gauge, you would have noticed the counts of knock before actually hearing it.
Get your car tuned to a safer level immediately.You hear a single knock or clunk from the engine bay when first accelerating. Probably a broken motor mount that is allowing the initial engine torque to rotate the motor upwards, causing something to hit.
You hear a squealing or "thwap thwap" sound coming from down low on the drivers side of the engine. It may sound more like "thweak thweak" (I can't even type that without laughing). Check to see if your harmonic balancer is coming apart. The outer ring tends to separate from the inner rubber, and will cause all kinds of nasty things to happen if it comes loose at high RPMS. Note: This is one of those items that you want to go with an OEM replacement only. "New" parts store HB's can come apart in less than 1k miles...I know this firsthand.
You hear a high pitched squeal from the driver's side of the engine, especially when starting cold. You probably have a loose or worn accessory belt, most likely the one for the power steering pump. Tighten or replace the belt. Also check the alternator pulley; it's bearings are notorious for going bad and squealing...especially cheap aftermarket ones from parts stores.
You hear a squeal or metallic grating sound from the front of the motor (turbo side) that changes with boost. Time for a turbo replacement (or upgrade...depending on how you look at it). Check for shaft play and look for excessive oil or any metal shavings in or around the turbo inlet. If the turbo is bad, do not drive the car because the metal pieces will get sucked into your motor and can cause way bigger problems than just a blown turbo.
You hear a metallic clank or clunk that changes with RPM from the area of the oil pan. This is usually not good, and is usually a spun rod bearing. Drop the oil pan and check for metal in the oil, and play in the bearings.
While decelerating in gear, you hear a whirring or light grinding sound that gets quieter as the engine RPM/vehicle speed drops. Probably a transmission input shaft bearing or gear lash from worn gears, but could also be the rear diff or transfer case.
At idle, you hear a ticking sound from under the car or around the exhaust manifold. You have an exhaust leak. Use a stethescope to carefully find the leak (without getting burned). Attach a piece of vacuum tubing to one end of the stethescope, and run the other end around the area of the leak. You will hear a huge difference when the escaping air blows over the open end of the tubing. (You should hear it change from a muffled hissing sound to a loud, deep sucking sound).
While shifting into gear from a stop, you hear and feel a heavy grinding noise. Your clutch isn't fully disengaging, or you need bigger leg muscles. Check your clutch adjustment and clutch fluid level.
You hear a squealing noise coming from the driver side of the engine bay, and you've already removed the accessory belts. If you have this noise even with the belts and front timing cover off (and your harmonic balancer is good), you've most likely got a worn out timing belt idler pulley or tensioner pulley. If this turns out to be the case, go ahead and replace the other timing components as well, since they probably aren't far behind.
You hear a squealing, grinding, or rubbing noise in the lower timing belt area, towards the back of the engine. Could be that the nut on your oil pump shaft has backed off and the oil pump sprocket is grinding a hole through your timing cover from the inside out. Pull the timing cover and look for shaved/burnt plastic and an oil leak in that area.
You hear hissing or whistling from some place in the top of the engine bay. Check for a broken, disconnected, or missing vacuum line.
When accelerating from a stop, you hear/feel a thump under the floor. Your carrier bearings are probably shot. This is a well known problem that is caused from the bearings wearing out and allowing the driveshaft sections to jump up and hit the undercarriage. Replace them. Note: I highly recommend NOT doing the WindowWeld carrier bearing "fix". It's very hard to get that stuff to cure while keeping the shafts perfectly centered in the bearing, and you'll probably end up with a lot of vibration afterwards.
********************************************
I'm sure I'll be adding to this list and updating it every now and then, but in the mean time this should get you pointed in the right directions. As mentioned, feel free to PM me if you think something should be added.
Now pick up that stethescope and get to it!
