I have a 2003 V8 4runner with 8,000 +/- miles, and run mobil one oil. I recently let my car sit for 3-4 days while on a trip. When I returned and started the car I got a very loud metallic hammering sound for 3 - 4 seconds, then the car started. This sound can best be described as a hammer on an anvil. Once the car started the noise disappeared. I stopped the motor and checked the fluids - everything seemed fine. I restarted the motor and ran the car for a few days hoping the problem would come back. No such luck. I tried leaving the car at the dealership for three days, then having them start it. Once again, no luck. The dealership mechanics thought it might be an oil related problem, with the mobil one draining down in the engine and taking a little while to recirculate on the restart after a several day break. This sounded wrong to me - a little clattering would make sense, but not the loud metal on metal sounds. Does anyone have any idea on this one? I hate the idea of driving my new car waiting for it to strand me somewhere. Thank you.
2003 V8 Engine Failure?
- Thread starter dogfish23
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DenverRunner
New member
2003 engine failure
The idea of your engine oil, Mobil 1 or any brand, draining down out of the engine and causing the metallic sound on startup as you describe, even after sitting for extended periods of time, is not your culprit. I think perhaps a small woodland friend found a home near your fan blade, or perhaps some other piece of debris or object found it's way or was left under your hood (who changes your oil??). 3-4 seconds would be enough time for the loose object to be thrown out/under the truck, eliminating the noise and the evidence. Any one else have any thoughts???
My first post!!!
The idea of your engine oil, Mobil 1 or any brand, draining down out of the engine and causing the metallic sound on startup as you describe, even after sitting for extended periods of time, is not your culprit. I think perhaps a small woodland friend found a home near your fan blade, or perhaps some other piece of debris or object found it's way or was left under your hood (who changes your oil??). 3-4 seconds would be enough time for the loose object to be thrown out/under the truck, eliminating the noise and the evidence. Any one else have any thoughts???
My first post!!!
Quote......
"The dealership mechanics thought it might be an oil related problem, with the mobil one draining down in the engine and taking a little while to recirculate on the restart after a several day break."
Are these mechanics space pilots? I would be very careful about letting them touch my 4Runner.
"The dealership mechanics thought it might be an oil related problem, with the mobil one draining down in the engine and taking a little while to recirculate on the restart after a several day break."
Are these mechanics space pilots? I would be very careful about letting them touch my 4Runner.
I had a similar problem with my 2001 4.7L Sequoia.
Only on cold mornings, immediately after starting the engine, I would hear what almost sounded like pre-ignition...loud knocking in the engine.
I video taped the problem and showed it to the service reps. They didn't believe it. So, I had a regional rep come and check it out. I was able to reproduce the loud knock by starting the engine, putting it in reverse, and while holding the brake, apply throttle power to the engine. You should have seen their expressions when the engine started knocking.
So, they took my engine apart and diagnosed it as "excessive piston to bore clearance in shortblock on pistons #2 and #3 cylinders. Remove entire engine assembly".
That's right off the service ticket.
After 26 days of repair, I got the truck back and was unable to recreate the knock, but by that time, the weather got warmer.
I traded the truck in the next day.
I hope this problem is not the same as yours.
It tooks months to get Toyota to own up to it.
Good Luck!
Only on cold mornings, immediately after starting the engine, I would hear what almost sounded like pre-ignition...loud knocking in the engine.
I video taped the problem and showed it to the service reps. They didn't believe it. So, I had a regional rep come and check it out. I was able to reproduce the loud knock by starting the engine, putting it in reverse, and while holding the brake, apply throttle power to the engine. You should have seen their expressions when the engine started knocking.
So, they took my engine apart and diagnosed it as "excessive piston to bore clearance in shortblock on pistons #2 and #3 cylinders. Remove entire engine assembly".
That's right off the service ticket.
After 26 days of repair, I got the truck back and was unable to recreate the knock, but by that time, the weather got warmer.
I traded the truck in the next day.
I hope this problem is not the same as yours.
It tooks months to get Toyota to own up to it.
Good Luck!
TechWrench
Senior Member
Since you mentioned that the sound only happened while trying to start the engine, and went away as soon as it started, it might be a problem with the starter engagement with the ring gear on the torque convertor or a bad ring gear itself.
I'd like to thank everyone for their theories. I ave only heard this sound once - and still can't figure out what it was. It will come back eventually.
I still have about 25,000 miles remaining on the OEM warranty, and will probably buy a Toyota 100,000 mile extended warranty beyond that. The cost up front seems comparatively cheap given the possibilities. . .
I still have about 25,000 miles remaining on the OEM warranty, and will probably buy a Toyota 100,000 mile extended warranty beyond that. The cost up front seems comparatively cheap given the possibilities. . .