engine rattle

My oldest toyota, a 1990 camry, with 175,000 miles has developed a sound in the engine. If I accelerat briskly, I get a mettalic ratting sound from the motor. It sounds like its from the driver side part of the engine. If I accelerate moderately, you do not hear the rattle. I only hear the noise, when the car is accellerating briskly. It does not sound like its an internal part of motor, but an external part. Any ideas what it can be. ? Otherwise the car runs like a top, except the last year, is has been burning a bit more gas, and a little slower on pickup, but boy she still is a runner, with everything running. I even just invested in a new set of tires, since I have faith, I can get at least another 30-50 thousand on this car. They dont make them like this anymore. Its the inline 4 cylinder engine with auto, front wheel drive.

Thanks to all

Reply to
J.Lef
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Does the nature of the sound change if you are accelerating in a curve, especially in a right hand curve (if your car is LH drive)? If so, check your CV joints.

Reply to
Ray O

sounds like the symptoms of pinking (also known as pre - ignition or detonation), the engine probably needs a decoke, the excess oil it is burning has probably coated the combustion chamber, it then glows and preignites the fuel, causing the metallic rattling sound. A swap to better fuel and maybe a slight retard of the ignition timing may improve things.

mrcheerful

Reply to
mrcheerful

This sounds like pinging.

Use a different/better/higher octane fuel (if you can do so without remortgaging your home...)

If you live in an area serviced by Chevron, use mid or high-octane Chevron gas. This has Techron, an additive used to remove carbon build-up, which is causing your problem. If there aren't any Chevron stations in your area, move...er, no...go to a good parts store and buy Techron on the shelf. Add 1 bottle per every other tankful until the pinging stops, and then once every 2-3 months thereafter depending on how much you drive. This stuff is WONDERFUL!

Reply to
HachiRoku

I heard that other gas brands (all major, probably) also use something for cleaning engine, but do not make it a point of advertising. Do not know if this correct.

Reply to
vmkng

My Dodge Colt Vista has a heat shield over the manifold that rusted after 10 years and started to rattle. The fix was some big washers over the bolts.

I'd check the exhaust system as well. Perhaps a hanger has rusted through and broken away.

Reply to
kgold

They all have 'detergents', but I know that Techron is specifically designed to soften and remove carbon build-up.

Reply to
HachiRoku

.>

Thanks for all replies. I never would have imagined I was having pinging, because I have heard this in other engines, and didnt think this was it. However, I wanted to try the possible simplest solution first, and waited till fuel tank was down to about an eighth full, and then filled it with super unleaded. Miraculously the rattling has stopped. I have floored the engine a number of times, to try and get the rattle, but it has been over a hundred and fifty miles and cant hear. So, I am hoping this is the problem. However, I hate to pay an extra thirty cents or so a gallon.

One question, could the situation that had created the pinking, also cause the engine, to not get as many mpg as it used to. Up until a year or two ago, I was getting a combined mileage of around 25 mpg. And straight hiway runs I could get well over thirty miles a gallon. Its been down to about 15 -17 mpg. But it seems like with this new super fuel, My mileage is picking up. Is this possible?

Much regards to all.

Reply to
J.Lef

If using higher octane fuel cured the problem, then check ignition timing to see if it is too advanced. If the timing is per spec, then you may have deposits in the engine as mrcheerful described.

You can try some off-the shelf engine cleaners but their effectiveness is usually limited in removing deposits. I've heard good things about Motorvac so it may be worth a try.

The reason you fuel mileage improved is that an engine that is pinging is not producing power so you tend to press harder on the throttle. If the engine is running properly then you won't have the tendency to press harder on the pedal.

Reply to
Ray O

the reason for less power (hence less MPG) is that when the pinging occurs it is the same effect as very advanced ignition timing, the engine is nearly trying to run backwards, so a lot of the power of the burning fuel is trying to push the piston back, rather than forward, this is also the reason it gets hotter than normal, which makes the pinging worse, if you continue to force the engine when it is pinging, it is quite possible to melt pistons, valves and cylinder heads/gaskets. So a non pinging engine is more economical. the better fuel reduces pinging by suppressing the glowing carbon in the cylinders (the cause of the pinging) The real answer is clean out the coke and check the timing and use the recommended grade of fuel, it may be more economical just to use better fuel, or at least use it every other tankful.

mrcheerful

Reply to
mrcheerful

few things to try:

I run ALL my cars on Super, even my '95 Tercel. People tell me I'm throwing my $$$ away, but I only had this problem during the last 'fuel shortage' when I went to regular for a while. Never again. With ALL my Toyotas, I have noticed I consistantly get 4-6 MPG more than people I know with similar cars, with similar maintenance.

You can try adding Techron or using Chevron gas with Techron in it. This will clean up any deposits in the engine. Or, you can have it BG'd, maybe by your dealer. They put a solution in it and it softens and removes the carbon deposits. When the techs run the car around the lot afterwards you wonder what the hell blew in the motor until it burns away...

As far as fuel, don't want to pony up the extra $$$? I always keep a full tank; it keeps my tank from rusting, and when I don't have any money, I still have fuel! (an old habit from my teenage days when we used to sfrape to buy gas after the FIRST oil crisis...) So what you can do is, if you want to run regular...fill the tank with mid grade. On the next fill, make it regular...on the next mid-grade...etc. I run higher octane so I use Mid-grade and super on alternate fill ups. I figure I run 91 Octane all the time. In the other scenario, you would be running 88 octane.

Reply to
HachiRoku

Good grief 88 - 91 ? I am running the Lexus on 97 in the UK, the lowest we can get is 95. 88 must be like running on paraffin (kerosene), no wonder the OP has got pinging !!

mrcheerful

Reply to
mrcheerful

I think there's more to it than than the octane reading. Here in NZ we have the choice of 91, 96, or 98. Probably of a similar quality of the lower octane fuel available in the US.

Greg.

Reply to
Greg

Yes, I believe there's at least a couple of rating charts for Octane...(same thing, different numbers)

Reply to
Gord Beaman

Remember, that in NZ and the rest of the world they use either the Motor Octane (MON) or Research Octane (RON) systems. In the USA, they split the difference and invented a new system just to keep things interesting - our Pump Octane. IIRC the formula is {MON+RON}/2 .

The usual selections are 87, 89, or 91/92. Most all new cars with EFI only need 87, though you can pick up a bit of power using 91. High altitude areas usually drop the octane for each of the selections one point, because the local conditions don't warrant it.

And there are "selected stations" (meaning if too many stations sell it nobody can make money at it, the volume is too low) with a separate pump island off in the corner selling "Unleaded Racing Gas" at 106 or

108 octane. And you pay a stiff premium for the brew - I'll have to go see what our local station is charging now....

This is for those people running old 60's Big-Block Detroit Muscle or some twin-turbo Italian or German exotics - some high compression cars start spitting out pistons if you don't feed them the good stuff.

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Reply to
Bruce L. Bergman

in the uk we can still get leaded at specialist places, about 25 per cent more money though.

mrcheerful

Reply to
mrcheerful

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