Idler pulley causing rattling?

[Shoobie]

Hey everyone. My dad owns a 91 MR2 non-turbo that I have the pleasure of working on. There are many problems with it. One is a loud rattling noise that comes from the front of the engine at about 2250 RPMS. I work on it in the advanced auto class at school, and everyone (including the teacher) has suggested the idler pulley as the culprit. Has anyone else run into this problem?

Other things worth mentioning are a loud whining noise also from the front of the engine. Some have said it makes the car sound electric, more like a toy than a Toyota. Power steering pump is my best guess. Anyone have any input?

Last thing ATM is the broken speedometer. I know this is a well covered topic, but it's basically a sending unit in the transaxle, two cables, then the guage cluster that could all be causing the problem, correct?

Thanks for your time.

[mr2rider91]

i dont think there is a power steering pump in the engine compartment im pretty sure they use an electric power steering pump well thats wut im thinking or they just have some kind of power steering asist. so i dont think it would be your ps pump thats making noise

[mister3]

could bring your MR2 to www.chicoraceworks.com nd have us check it out for ya

most likely the whining is from the alternator

rattling at 2250 rpm might be slack in the timing belt.... once changed it'll go away

speedo -- i'd start at the speedo cable at the trans and check it with a power drill -- if the speedo needle jumps then cables are Ok and look into replacing the plastic gear on speedo drive or possibly the diff.... could also be a flag key in there sheared off also... if using the drill on cable and it doesn't jump next step is to go to the speedo cable split under the plastic paneling near the fuel filter and try it there wit hthe drill... if it still doesn't move could try pulling the cable wire to see if it's broken or go to the cluster and check the cable connection there and/or speedo in cluster itself....

have a CEL for speed sensor yet?

[Shoobie]

No CELs to speak of. Also, the previous owner installed a TRD cluster, but only the needles light up. I'll have to pull the cluster to examine that anyway.

[Gairloch]

1. "One is a loud rattling noise that comes from the front of the engine at about 2250 RPMS."

I know this is maybe kind of dumb, but have you checked the heat shields? The exhaust manifold heat shield is infamous for rattles. Make sure that you check that the bolts are tightened down and that it's intact.

Have you inspected the idler pulley? If it's far enough out balance enough to create rattles it should be visibly damaged.

2. "Other things worth mentioning are a loud whining noise also from the front of the engine. Some have said it makes the car sound electric, more like a toy than a Toyota. Power steering pump is my best guess. Anyone have any input?"

As has been stated, it can't be your PS pump because that's in the frunk. Another possiblity is gearbox whine. My POS soon to be replaced tranny makes my car sound like it's an electric.

3. "Last thing ATM is the broken speedometer. I know this is a well covered topic, but it's basically a sending unit in the transaxle, two cables, then the guage cluster that could all be causing the problem, correct?"

The cable needs to be turned in a specific direction. Anyone remember which way is the right way? Since the gauge cluster has been replaced that's where I'm placing my money