Noise on a 88 Supra - 7M-GTE

First, you have to describe the noise for anyone to tell you what its cause is.

To check an oil pump, you can remove the oil pressure sender and install an oil pressure gauge to measure oil pressure. Otherwise, it's drop the oil pan, remove the pump (I don't know if you have to remove the front cover to do this or not) and measure clearances between the gear, crescent, and pump body. Oil pumps are generally not a high failure item.

With the engine off, grasp the cooling fan pulley and see if there is any play in it. Excessive free play would indicate a bad water pump.

Other possibilities are a worn/stretched timing belt or bad timing belt tensioner - if you have more than 90,000 miles on the belt, that is a strong possibility. Someone at a Toyota dealer can tell from the sound if they think the belt is the cause.

Sorry for that but i should have said that you hear the noise (like a clank sound,i guess like metal on metal ) it usually hapens when you start the car and when you stop on a red light and start over it does the same and then stops or at least i dont hear it nomore . im sorry if this dont help i just dont have other way to explain the noise . spawn51

The noise you are describing does not sound like an oil pump. Oil pumps, water pumps, timing belt noises are related to engine speed, not vehicle speed.

A single metallic clank noise that occurs only when you start or stop moving is more likely to be a u-joint, differential backlash, or engine or transmission mount. If you put the vehicle in neutral or park and rev the engine and it doesn't occur, then it is not engine-related.

Do you have an automatic or manual transmission? Does engaging or disengaging the clutch have any effect?

You may have a rusted or loose catalytic converter heat shield. If that's what is causing the clanking sound, just remove the shield and leave it off; don't replace the shield. This happened recently to my Honda Accord.

Um, heat shields may be the cause of noises but I would NEVER advise someone to remove one without replacing it. It is easy to check if without removing it grabbing it and wiggling it to see if it rattles.

Believe it or not, automotive manufacturers and designers do not wish to spend any more money designing and making the car than they have to, especially for something that the owner would rarely see. The heat shield is there for a reason, and removing it can cause carpets to melt and discolor, adhesives to dissolve, wire insulation and hoses to melt, brake fluid, fuel, transmission fluid, to get overheated, or worse, a fire.

Removing a heat shield on your own and taking the risks yourself is one thing, telling someone to do it is irresponsible.

Im sorry i have been on the road (truck driver) and didnt have a chance to corect my first post. the clanking noise starts when you first start the car and fades away in a couple seconds,then when you are runing and go thru the gears as you are on the gas it keeps doing it and like first it fades . when i get to 5th gear and touch the gass a bit it will do it and when you start from a red light it will make the sound and then fade as the rpm's go up and fade . i know its not the mufller or cat conv i check those already and the heat shield as well ,the noise is coming from the motor guessing from the botom part of it so that is why i was auming it was the oil pump. Also another question what is the normal operating oil presure for this car? it stays on around 40 most of the time . thanks for all your help guys and thanks for the new round of answers. spawn51

That's okay, I'll do some of it. (Take notes...) ;-)

This sure sounds like spark knock, or pinging, to me... Are you running the cheapest gas in town, or name brand 89 Octane? If you're running cheap 87, try running a full tank of major brand 89 or 91 gas through the car and see if it goes away.

If that solves it (or helps) try a "tune-up" service first - change the sparkplugs, and the distributor cap/rotor/plug wires if they're still the factory original items from 1988. Check the base timing.

I'll guess it's one of the basics - the base timing is set wrong, and the computer has to hunt around for the right setting that makes it stop knocking. And worn spark plugs or another problem in the secondary ignition system won't help any.

(IIRC you have to short two pins at the diagnostic connector to tell the computer to go to the base timing setting. Otherwise the computer adjusts the timing, even at idle, and it can end up way off.)

Get OEM plugs and ignition parts from the dealer. It'll cost you maybe $5 more, and we've seen problems here with aftermarket parts. That 30KV spark will always take the easiest path to ground.

And do the usual air filter, oil change, chassis lube, grease the door hinges and latches, check all the fluids, etc., the usual maintenance laundry list while you are at it. It's probably due for it, and cars last longer if you do this stuff occasionally. ;-)

Once it's running right, the engine computer should be able to adjust it's timing to run on regular gasoline without any knocking.

That's normal. It will go midway up the gauge and stay there. When the engine gets really worn and all the bearing clearances open up, you'll start seeing the oil pressure drop off at idle. But that could take 200,000 to 300,000 miles if you take good care of the car.

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If it is pinging al everything Bruce mentioned is OK, then another possibility is a problem with the knock sensor or knock sensor circuit.