Toyota MR2 Message Board - View Single Post - 4A-GE MK1 Engine 4AGE Rattling Throughout RPM Range, Video and Solution Inside

driftmonster · 06-11-2007, 02:34 PM

So, I had this Issue with my MK1 and I am hoping to provide this information to possibly help other MK1 owners if they ever experience as similair issue.When I bought my car it had a horribly mexified exhaust system, Im talking quad tips that extended 4" past the rear bumper and were shaped like bicycle horns, I took it to my dads shop and we made a custom exhaust system of 3" pipe custom fabbed into a magnaflow muffler and custom 3" oval tips. After that loud exhaust was off i noticed a slight rattle throughout the RPM range, I was thinking it was coming from the valvetrain because thats where the sound seemed loudest...but that wasnt it. Did a compression test and the numbers were even across the board, After that i performed the basic visual inspection of all moving external parts IE harmonic balancer, pulleys , exhaust manifold ETC i was still scratching my head

Then after doing some research i came across some information that pointed to the internal alternator bearing being prone to wearing due to the vented engine lid, Basically the page i found this on said that water could go through the vent and trickle down to the alternator amongst other parts, So i took the belt off the pulleys and the sound was gone! I revved it a bit to be sure that it was actually gone and it was, Then I bought a new alternator and belts, Installed them and havent had that rattling problem since! Now I am not saying that if your 4AGE is having similair symptoms that this IS your issue but I know that when i was investigating my rattle the alternator being the problem just never even made sense to me as i had never heard of an alternator rattling when it was securely mounted. I hope this can help you guys with rattles somewhat! And I am currently working on a piece of Lexan that will not disturb the MK1s normal airfllow but will keep foreign objects from dropping into mechanical components. The following video is a soundclip of the car when it had the rattle. I hope that helps

And if you have any questions regard this feel free to PM me anytime.

06-11-2007, 02:34 PM	#1 (permalink)
driftmonster I'm back I'm back Join Date: May 2007 Location: Bangkok,Thailand Posts: 831 Thanks: 57 Thanked 26 Times in 24 Posts iTrader Rating: (0/0% )	4AGE Rattling Throughout RPM Range, Video and Solution Inside So, I had this Issue with my MK1 and I am hoping to provide this information to possibly help other MK1 owners if they ever experience as similair issue.When I bought my car it had a horribly mexified exhaust system, Im talking quad tips that extended 4" past the rear bumper and were shaped like bicycle horns, I took it to my dads shop and we made a custom exhaust system of 3" pipe custom fabbed into a magnaflow muffler and custom 3" oval tips. After that loud exhaust was off i noticed a slight rattle throughout the RPM range, I was thinking it was coming from the valvetrain because thats where the sound seemed loudest...but that wasnt it. Did a compression test and the numbers were even across the board, After that i performed the basic visual inspection of all moving external parts IE harmonic balancer, pulleys , exhaust manifold ETC i was still scratching my head Then after doing some research i came across some information that pointed to the internal alternator bearing being prone to wearing due to the vented engine lid, Basically the page i found this on said that water could go through the vent and trickle down to the alternator amongst other parts, So i took the belt off the pulleys and the sound was gone! I revved it a bit to be sure that it was actually gone and it was, Then I bought a new alternator and belts, Installed them and havent had that rattling problem since! Now I am not saying that if your 4AGE is having similair symptoms that this IS your issue but I know that when i was investigating my rattle the alternator being the problem just never even made sense to me as i had never heard of an alternator rattling when it was securely mounted. I hope this can help you guys with rattles somewhat! And I am currently working on a piece of Lexan that will not disturb the MK1s normal airfllow but will keep foreign objects from dropping into mechanical components. The following video is a soundclip of the car when it had the rattle. I hope that helps And if you have any questions regard this feel free to PM me anytime.