keep on knocking but you can't come in

[pucho812]

Leaving the studio tonight and the motor started to knock/tick.  The volume changes  as i step on the gas, gets a little quiter as the motor warms, but the moment the gas pedal is released gets loud again.  Then the oil light came on, meaning low oil.  So I limpped down to a gas station and added  oil.  The knock still persists.  I see this being expensive, potentially.  Hopefully it's the less expensive valve alignment.

 

[Gustav]

Leaving the studio tonight and the motor started to knock/tick.  The volume changes  as i step on the gas, gets a little quiter as the motor warms, but the moment the gas pedal is released gets loud again.  Then the oil light came on, meaning low oil.  So I limpped down to a gas station and added  oil.  The knock still persists.  I see this being expensive, potentially.  Hopefully it's the less expensive valve alignment.

Just had these symptoms in an old car - relatively fast paced tick, stepping on the clutch made it louder/quieter, can't remember, would diminish when I had the accelerator pressed..

Gear box blown - cost for replacement would exceed the value of the car. Mechanic told me to "drive it till it dies".

Hope yours is less critical.

Gustav

 

[pucho812]

Leaving the studio tonight and the motor started to knock/tick.  The volume changes  as i step on the gas, gets a little quiter as the motor warms, but the moment the gas pedal is released gets loud again.  Then the oil light came on, meaning low oil.  So I limpped down to a gas station and added  oil.  The knock still persists.  I see this being expensive, potentially.  Hopefully it's the less expensive valve alignment.

Just had these symptoms in an old car - relatively fast paced tick, stepping on the clutch made it louder/quieter, can't remember, would diminish when I had the accelerator pressed..

Gear box blown - cost for replacement would exceed the value of the car. Mechanic told me to "drive it till it dies".

Hope yours is less critical.

Gustav

car is a toyota,  10 years old and close to 200K miles on it...  so if it were to go I would not be upset but rather a cheap fix then a car payment right now.

 

[JohnRoberts]

A knock and a click are two different things... 

Cheapest possibility might be misbehaving hydraulic lifters in the valve train... low oil and changing with temperature might be consistent with that.

A bad crankshaft bearing or connecting rod bearing would knock all the time, a bent valve likewise would not come and go.

Maybe ask around on a motor head forum where people are familiar with your make/model motor  (I am not).

Was it an oil pressure light or oil level..? Kind of doesn't matter which, running low on oil can lead to low oil pressure and serious damage if bearings run dry.

If it's just hydraulic lifters running out of oil, it may come back by itself. If something is really broken it will be more serious.

JR

 

[pucho812]

Mechanic this morning said it sounded like the Pistons, I'll have a full diagnosis in a few hours.

 

[JohnRoberts]

Mechanic this morning said it sounded like the Pistons, I'll have a full diagnosis in a few hours.

Piston slap from worn cylinder walls/piston rings, would be accompanied by burning a lot of oil. A piston knock from the connecting rod (piston pin bearing) would not involve burning oil. Neither will be cheap.

Another piston related noise (knock)  is related to pre-ignition, but this has nothing to do with oil level... more like bad gas.

JR

 

[Gustav]

more like bad gas.

Easy fix - roll down the window.

.... 

Gustav

 

[MicDaddy]

I had ticks which we thought to be lifters, ignored, head-gasket went next.  3 weeks of labor and an $18 part.

Could be anything though, I hate working on cars

 

[pvision]

Sounds like hydraulic lifters to me! They sound like a mad sewing machine. On old Mercedes you can ignore them - they're not going to break so ignore them

I wouldn't expect any 10-year-old Japanese car to have a badly worn engine unless it's been thoroughly abused. And probably not even then

Nick Froome

 

[pucho812]

10 year old car , never abused, routine maintenance.

mechanic said piston and damaged small block in the motor.
Option 1. replace the engine for 7K
option 2. replace the engine with a used engine 6K and it may need new part
option 3. replace the car.

183K miles on it.... no point in sinking in 7k to a car that needs to go. time to shoot the horse with a broken leg.

 

[PRR]

Depends what "knock" is. Big or little?

Lifters are not big. Nick's "mad sewing machine" sums it up. My Honda don't even have self-adjusters, so it tic-tic-tics when cold. Not a wildly impressive sound; usually not a threat.

Pistons are big. They can KNOCK when worn conn-rods let them get loose and they hit the head. While you would *think* any post-1975 engine (and oil) would have this down to a million-mile event, some cars (and IIRC Toyota was one) were "cooking" oil, sludging-up, bearings run dry. This is hardly any different from a 1967 289 on SC oil which would sludge-up and chew the bearings (and often snap the oil pump).

My grandfather replaced a piston on the side of the road, topped-off the oil with water from a creek, and got home. But they a lot harder to get at now, and need more than fish-pee just to idle.

Popular car that age, a swap from a wreck may be your best path for any major internal boo-boo. And if you have a steady job, selling it to your mechanic for bus-fare to get to the bank/dealer for a loan may be best for you.

EDIT-- mechanic is probably right. He may be shading the truth because if he can get the car off you for $100 (don't take less, it has scrap value) and has a bud with a beater and good engine he can get for $2K, he can come out ahead. But for a customer he can't be waiting for bud to do a deal, and the ready-pull engine market is as he says.

OR torch out most of the floor and put a Chevy V-8 in there. New GM-warranty bottom-spec 350 is $2000 every day.

 

[pucho812]

OR torch out most of the floor and put a Chevy V-8 in there. New GM-warranty bottom-spec 350 is $2000 every day.

now were taking DIY on cars doing a mod.  8)

 

[JohnRoberts]

10 year old car , never abused, routine maintenance.

mechanic said piston and damaged small block in the motor.
Option 1. replace the engine for 7K
option 2. replace the engine with a used engine 6K and it may need new part
option 3. replace the car.

183K miles on it.... no point in sinking in 7k to a car that needs to go. time to shoot the horse with a broken leg.

If it still runs, keep it full of oil and drive it into the ground. Without oil it can seize up, but with  oil it will mostly just make noise.

If it is getting progressively worse it will sound progressively worse.

I have thrown a connecting rods through the side of my engine block, but that was from winding a 4500rpm motor up to 7000+ rpm.

If the mechanic makes you a low ball offer maybe get a second opinion from a junk dealer.

Swapping motors isn't rocket science but dirty work, and you probably need a hoist. (I was swapping motors in cars before I was old enough to get a license to drive).

$6k for used motor and 7k for new motor does not compute, only $1k difference seems low? .

I like PRR's small block chevy motor, or maybe drop in a tesla drivetrain and battery pack.  Lots of kids in socal hot rodding rice rockets (or there used to be).

JR

PS: My '97 will be 20YO soon

 

[pucho812]

10 year old car , never abused, routine maintenance.

mechanic said piston and damaged small block in the motor.
Option 1. replace the engine for 7K
option 2. replace the engine with a used engine 6K and it may need new part
option 3. replace the car.

183K miles on it.... no point in sinking in 7k to a car that needs to go. time to shoot the horse with a broken leg.

If it still runs, keep it full of oil and drive it into the ground. Without oil it can seize up, but with  oil it will mostly just make noise.

If it is getting progressively worse it will sound progressively worse.

I have thrown a connecting rods through the side of my engine block, but that was from winding a 4500rpm motor up to 7000+ rpm.

If the mechanic makes you a low ball offer maybe get a second opinion from a junk dealer.

Swapping motors isn't rocket science but dirty work, and you probably need a hoist. (I was swapping motors in cars before I was old enough to get a license to drive).

$6k for used motor and 7k for new motor does not compute, only $1k difference seems low? .

I like PRR's small block chevy motor, or maybe drop in a tesla drivetrain and battery pack.  Lots of kids in socal hot rodding rice rockets (or there used to be).

JR

PS: My '97 will be 20YO soon

7K and 6K were tough estimates

big knock,  burning oil smell,  and metal shavings all around when the motor was looked at.

 

[JohnRoberts]

7K and 6K were tough estimates

big knock,  burning oil smell,  and metal shavings all around when the motor was looked at.

The metal shavings would need to be inside the crankcase, but never good.

Car motors were engineered to be repairable, but I suspect these days the labor cost makes that a poor option. The parts are not that expensive, certainly not thousands of dollars. They used to sell oversized pistons to accommodate a scored cylinder walls that required being bored out, replacement bearings sized to accommodate a crankshaft that needs the bearing races re-turned, etc. Most basic re-builds didn't require heavy machining .

Good luck...  broken cars suck.

JR       

 

[pucho812]

I'm going off of the dealer and their mechanic. A good mechanic in L.A. is tough, I have a guy but he only does some things. Maybe I need to expand my network.  ;D anyway  their guys, the dealers guys,  have nothing, the car is old enough they have nothing to really gain in it for resale or other wise. It's beat pretty nicely, I rode it hard and put it away wet often.  the body is far form pristine, .  the interior far from perfect I suspect in the end I would get 5 bucks just cause they felt sorry for me.    While true it does not mean I will buy from there,  the car does need to go.  200K miles is the point where repairs can sometimes be more then the car is work. I got 183K, I was close. I wouldn't have even brought it up except like everything else in bad news it comes in three's,  while the other two things are personal  stuff I will  have to work out.  I figured it would not have been such a high sticker cost and maybe I could salvage it for a little longer.  you guys rock though.  jr every post is audio or otherwise is a learning experience I can't begin to fathom the cost if it were in school.

 

[pvision]

Remove the piston & conrod, disconnect the wire to the injector and keep driving it. The engine won't even need to come out on most cars

You can even claim to be going green with an eco 3-cylinder car

Nick Froome

 

[JohnRoberts]

Remove the piston & conrod, disconnect the wire to the injector and keep driving it. The engine won't even need to come out on most cars

You can even claim to be going green with an eco 3-cylinder car

Nick Froome

If it is one bad piston, and you know which one, removing the spark plug would significantly reduce stress on that one cylinder. Removing the injector wire would be green too.

In cuba they are still driving cars from the 50's must have better mechanics under communism.  8)

JR

 

[PRR]

> I would get 5 bucks just cause they felt sorry for me

Steel (and scrap) market is way down (Brasil didn't import the quantity of steel China did for their Olympics), but a sedan should still be worth $100, especially if you can drive it in.

There is a fair trade in things like airbags and even door-switches for the other guy with the same model and not yet knocking. A prolonged eBay parting-out might net a lot more than $100, but probably less than the value of your time and the mess in your driveway.

 

[MicDaddy]

Ride it 'til the wheels fall off and then off to the scrap yard.

(just this last winter, I ran a 2000 Grand Caravan with ZERO coolant in sub zero temps in Nebraska, until it finally went)  Got about six-seven months on that motor with no coolant. Granted I couldn't go anywhere that had a stoplight in the path, or that would take more than 5 minutes one way, but it got me to school and back for two quarters.