Full Open Throttle Creates Truck Noise - Corolland: the Toyota Corolla Forums

Hey guys,

Sorry if this has already been asked I tried looking first. I've got a 1996 Toyota Levin (FZ) which comes with the 5A-FE motor which I know isn't very common in North America but its pretty much a 1.5 4A. I've had this problem for a while and I can't seem to figure it out.

While I worked in a garage for a while, the mechanics there reckoned it was an induction thing. So we changed out the air filters, tried

putting in cold air intakes nothing changed.

I've been convinced for a while it must be something to do with the exhaust but everyone says because of the nature of its occurence it has to be involved with the car's intake system but where could I look?

Basically the car sounds normal on the flat. On a hill with about half throttle it sounds like a low hum, and under full throttle on any angle surface it sounds like a dirty homemade exhaust or truck with sound vibrating through the whole car you can't hear anything but the throttle when its wide open.

If anyone knows what I could do about this problem I'd really appreciate it.

Cheers

How are your motor/tranny mounts/isolators?

Well I've had the car two years and never failed a warrant on any of the mounts but on that note I'll go take a look now and I'll get back to you. You think it could be some loose vibration under load?

Plug the exhaust some with the car running at idle and listen for loud hissing or loud exhaust sounds. It should be quiet except for some hissing at the muffler drain hole.

Check for bent or partially detached heat shields above cats and exhaust front to back which may be touching the exhaust. Check also for loose heat shield on cats. Hit on cats and exhaust with closed fist to listen for any loose rattly parts inside.