92 Camry 4 Cylinder ... severe vibration

ANY four cylinder engine VIBRATES when operated at low RPM and under load. That some engine isolator/suspension systems transmit less of this vibration to the body than others does not change the origin of the vibration. The crankshaft throws on a four cylinder are 180 degrees apart while a V8's throws are only 90 degrees apart. The further apart the throws are, the more vibration at low rpm will be present. Also, having the engine mounted transversely in the car promotes more vibration transferring to the body whereas in cars with the engine mounted longitudinally, the same vibration is transmitted to the car in a side to side manner instead of fore/aft manner.

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  - Philip

Philip, thanks very much for your promp reply. However, the vibration I refer to is way beyond normal design parameters. The dash and steering wheel (and my teeth) vibrate enough to loosen parts. A friend and weekend mechanic thinks it may be a vacuum leak. Any other suggestions would be very much welcomed. Thanks, Sirlandsalot

I second the vacuum leak theory... North American fours may vibrate but my experience says Camrys don't. Also test the wires for resistance and check the plugs. Sometime "new" parts aren't perfect and I once got a bad ngk for my Camry.

BC

92 LE Wagon with 410,000 kms.

Respectfully, you have now overstated your case. If it were even possible to generate that much vibration, the engine would have to be running on three cylinders consistantly and the center/rear motor mount collapsed. There ya have it.

The "vacuum leak" theory does not float. With the engine having fuel injection, a vacuum leak of any substance would simply raise the engine rpm ... not induce a misfire. Were the leak due to the brake booster unit, you could hear it. Were the vacuum leak the EGR valve, you would not hear it. Neither would result in a dead misfire on one cylinder.

A certain amount of vibration is normal for the reasons given. I know what you mean, though. Similar situation here. Best solution I've found, is regular and continued use of Redline complete fuel system cleaner. One of the ways your engine generates more power from four cylinders is through the use of sixteen valves, and also through the use of very efficient electronically controlled multi-port sequential fuel injection. Both of these items are subject to loss of optimization over time. It is within specification for the injector nozzle tips to leak a small amount of gasoline after the engine is turned off because the fuel rail pressure is set around 38 psi and remains for some time. Don't recall the exact parameter, one drop per so many seconds is acceptable, and fuel evaporating from the tip of the injector can leave a tiny amount of residue. Also, it seems that even detergent unleaded gasolines can leave deposits of the surface of the intake valves when the fuel mixture contacts the heated valves during normal operation. Some of these deposits are increased by the use of oxygenated or pollution control fuel blends. Both of these factors can contribute to the creation of minor inequalities between individual cylinders. The 5S-FE (four cylinder) engine is typically very smooth during normal operation due to the use of two balancing shafts that work to cancel engine vibrations, but they don't come into play at idle speeds. Finally, if one fuel injector is operating less than perfectly, the oxygen sensor at the exhaust manifold effectively averages the signals to the electronic engine control module because it reads the exhaust gas stream and would thereby richen the signals to all of the injectors to compensate. All of these factors can contribute to the rough idle parked in Drive. As I say, the best solution I've found is the continued use of the Redline fuel treatment. BMW tested many, many fuel treatments, and selected only this one as approved for use after extensive testing. It contains no harmful solvents, but rather relies on a high temperature detergent to safely clean gradually over time. Reline is well known for their synthetic lubricants, and the fuel cleaner contains synthetic upper cylinder lubricant, which combined with the absence of harsh solvents, makes the product safe for coninuous use. A very nice side benefit is increasing power from the engine as well as smoothness at idle. Removal of intake valve deposits can take from 10,000 to 20,000 miles, so you need to stay with it. There are marks on the side of the bottle amounting to apx. 1/10th, so one $4 bottle would treat 100 gallons of fuel. I used to have to drive to PAW (Performance Automotive Warehouse), a distributor of high performance engine parts, to find the Redline, but it has since become available at Pep Boys. You most likely will notice an immediate improvement in "pick up" because the first full bottle cleans the injectors. It is the removal of intake valve buildup that takes more time, yet this can be precisely the effect that creates the minor imbalances between cylinders that is so noticeable at idle - as previously stated, magnified by the distance between crankshaft throws. Also, I'm quite sure Toyota has minimized the idle to maximize fuel economy. If the electronic controls set the idle 100 rpm higher, the smoothness would be increased, but at idle fuel mileage is zero so they seek to minimize fuel consumption. Additionally, engine power at low speed idle is minimized with the smaller four cylinder engine, so even additional power demands from the alternator when using heater fan and headlights has an effect, plus the vacuum demands from the power brakes. The Toyotas are created with a high degree of precision. This is why they have earned such a reputation for long term quality and reliability. The down side is that small imbalances in engine operation are felt more severely. Personally, I now find the the vibrations at idle are quite tolerable and relatively smooth - not objectionable, after using the Redline for quite some time. Plus, the engine power seems noticeably improved. I once read that the advantage of four valves per cylinder is equivalent to the effect of turbo charging when measured against two valves per cylinder, and the lighter valve train extends the life of the parts, so it only makes sense to have the engine's breathing capabilities maximized. Seems like most people don't take the time, but Redline has furnished quite a comprehensive technical description of their product and its testing, including an example with a four cylinder Toyota. Give it a try. I'm quite sure you'll be pleased.

For others who may be reading this, the original poster had already checked the engine carefully. If ignition components, vacuum lines, engine/ transmission mounts, idle valve, or other aspects of engine operation are not optimized, those other factors, could be contributing.

Dear Nospampls2002, Thank you for replying to my post. As you suggested, I will check plugs, wires, etc. Coincidently, I use only NGK platinum plugs. I will also try the Redline product as you suggested. Thanks again for being so thorough in your explaination. I'll post any changes that may occur. Best Regards, Sirlandsalot

Dear Mr Riprock, Thank you for your post. After reading your note, I feel much better about the expected longevity of my Camry. 410,000 mi. !! You must be doing something right. Regards, Sirlandsalot

The key factor here is once the engine's revs are raised, the donk smooths out. In addition to those things already said, and if after checking those out the problem is still there,..I'd be having a closer look at the ignition.

There are 2 types of dead cylinder ie 1. one which is normal in all other respects but has lost ignition (thru none present or just way, way out of timing) or correct fuel-air mix for combustion and 2, a cyl which has both the aforementioned, but has worn/broken rings or damaged valve/s or a damaged headgasket near that cylinder and as a result produces no copression. The vital difference to the driver when faced with one of these is, ..in the case of 1. the dead cyl will cause bad vibration because the other good cyls have to carry the uneven load that cyl presents as it goes thru the 4-stroke cycle,...especially the compression stroke.

If the cyl is the 2nd case,..the vibration will be markedly decreased as it has no compressing action to load up the rest of the cyls.

So if your vibration is severe,..it may follow the cyl is OK but has stopped firing. In this case, and assuming the fuel system, ignition timing and valve timing (correct installation and operation of the cam-belt) is correct, it may be the case that the ignition amplitude is marginal at low idle. The causes for this can be: inadequate battery volts at the igniter,...low alternator performance at low revs,...a damaged rotor-button of pick-ups in the dizzy,..a damaged coil or resitive connections at the coil,...

Your mechanic should be able to tell you exactly how good your ignition voltage is in terms of amplitude or strength.

Did you try new spark leads? Have you tried looking into the engine bay at night? This can suss out any spark leakage. There will be some corona ( presnts as a pulstaing faint whitish-bluish haze) around the ignition components which is normal.

I had a Ford V8 with the Cleveland engine that would miss and vibrate at idle,..but smooth-out at raised revs (1500 or so). That turned out to be a coil which was pulling too much current from the igniter which in turn pulled the supply volts too low at idle when the alternator's performance had sagged...After testing ( I simply applied battery to the + side of the ballast resistor) I noted the old wiring (the car was a '79 model) in the battery supply to the igniter-coil was *lossy or resistive somewhere* I just ran a new circuit.

Jason

Sounds to le like bad fuel injectors . My camry was doing the same thing , high vibrations when idle or low speed , clears up when driven at a higher speed.

Bad Compression, inbetween cilinders, bad Scope Job , or none = bad wires, plugs , coil, , injectors, = bad- dumb, mechanic. Plugs can be bought bad....etc.

Well at the place where I work part time we would run car with hand brake set and block wheels, or have someone sit in car with foot on brake (safest). then we would ground a jumper wire (long 6 foot one) and have other end of jumper wire attached to a screwdriver. Then we would pull wires off either distributor or sparkplugs with screwdiver close to distributor towers or sparkplugs so as we pull wires it takes jumping sparks. Although you may still get alittle shocked. This is a cheap cylinder kill function. Then we note if engine runs alot rougher or not (shakes alot if runs rougher). If engine doesn't run any rougher we know that cylinder was not contributing. If all cylinders runs rougher we know all cylinders were firing (although some may be weaker than others) If some are weaker than others the engine will roughen only a little. Also be careful of moving engine parts like fan and belts, etc. especially you might get shocked and move alittle. I've been shocked many times, it hurts, but if you hold the grounding screwdriver right and quickly pull wire it eliminates or minimizes shock. But the good thing about this is to tell wether it is a single cylinder miss or random miss, or just weak combustion from all cylinders. Also if idle speed goes below specs any engine will shake because it is not generating enough power. I also have enough experience to tell a single cylinder miss (especially in a 4 cylinder engine where a single cyl miss takes out

25 percent of engine power especially at idle where the engine is running at minimum power) A single cylinder miss usually is a rhythmic regular shaking of engine, while a random miss is an uneven shaking.

Edmechanic, you are a HACK and cannot diagnose a cars problems that way. I will not go into your bull shit aproach , but it is a HACKS way and you know shit- nada about the cause of the problem . Is your Co called Hack Repair, well it should be , you are a Hack . A scope is needed, but you work for a HACK cheap shit shop

Mr. Ransley, I must say you are very passionate when it comes to doing things the right way. I very much appreciate your response to my problem. However, I would respectfully request that you go a little easier on other folks who are kind enough to respond as well. I welcome ALL comments and suggestions and would like to apologize to edokamoto for being treated unfairly. I don't disagree with your opinion, just your harsh delivery. Thanks for taking the time to read this post. Sincerely, Sirlandsalot

Well I have a scope an ADL-7100, and I try to use it sometimes but it is hard to tell sometimes on a scope to pinpoint a problem. Recently I had a 90s Supra where the owner had washed the engine. I took my scope and checked all 6 wires. I found number 3 and 2 with short burn lines under 0.8 milliseconds (actually burn times jumping around. But when my boss had me pull wires it was obvious 1 was the worst cylinder and did not show up bad on my scope. When we pulled the wires out it was like a swimming pool in spark plug holes. Besides the only machine we have to have cylinder kill function is an old 70s giant scope and you need a normal accessible coil to use it. I've had this happen very often when pulling wires will quickly show the dead cylinders. Our shop also has a cheap autoxray with CAN capability. But sometimes only experience and bullshit techniques if used properly can help you diagnose alot quicker, like using carburetor spray to diagnose fuel problems and screwdrivers in spark plug boots to check for spark has helped us diagnose dozens of cars fast and well.

Endo , Screwdrivers are never used in Boots if you have the Correct tools, hack - again. Mr Hack, Not on my car........ insults given

Actually it is 410,000 Kilometers... Canadian eh! (254,769 miles)...

try the radiator top mounts sometimes thats the problem on 4 cyl. camry