dopefishzzz

Compression check done. Nothing unusual.

I DID use that product in one of my old car, helped a LOT with cold engine start (-30 Celcius), engine runned smoother, no real MPG advantage... But I'm not sure of the life time consequences of such a product...

Thanks for the tips, but wouldn't an EGR problem cause the check engine light to turn on ?

Many cars have two springs on each valve, a heavy one and a lighter one inside of that. I cannot explain the engineering aspects, I just assume it takes both springs to cover the wide range of frequency, 500 to 6000 RPM, of valve opening and closing operation. I could see how one spring might begin to allow the valve to float, say at 4000 RPM, before the second, lighter(??) spring comes into "play". Many years ago I would have suggested a valve job, but at today's labor rates and with 200,000 miles.... Do you think a compression check would reveal if you are right ?

My '94 runs at about the same RPM. 2600 @ 65mph. Your overdrive is fine. On the left side of my tranny, I have a ECONO/PERFORMANCE button. Maybe your's got it too. My tranny react a lot better with performance mode ON. Also you have a Overdrive ON/OFF on the left side of the stick so just use it and you'll see that your overdrive is working ;)

Then why would the engine runs great at a much higher RPM ? Power is great at 5000rpm, 6000rpm etc.. Doesn't make sense to me, but I'm no expert at all.

Hi ! I've got a 94 ES300 with 200,000 miles on it. Air filtter and fuel filter have been changed recently. When accelerating under WOT (Wide Open Throttle), the car hesitate, only between 3000rpm and 4000rpm. Below & Above, I get normal acceleration. When I say hesitate, I mean that the car lose about half of it's power, but still has enough to go pass the 4000rpm mark. Gas mileage is fine and I've got no check engine light. Engine runs smooth, no strange noise and no shaking. What could be the problem ? (Note that I have a small exhaust leak, just behind the muffler, could It be affecting THAT much ?) Thank you.