I've noticed in the past few days that my engine has gotten louder, I couldn't get a video or sound clip that didn't just sound like a normal engine running, but I can hear the difference. I can only explain it as it sounds like the crank pulley, or something in that area, is whirring much louder than normal. But it is in the mid to lower section of the front of the engine block. And there is no power steering pump or a/c compressor either, just in case someone wants to guess that.

Also on occasion recently, there's been a popping (kinda grinding) sound at start-up, does it a handful of times, no rhythm to it, and then stops, but not at every start-up. It sounds like the teeth on the timing belt are slipping over the gears, however, the car still runs and idles perfectly and timing is still dead on.

So, I'm thinking it's time for a timing belt, water pump, etc. change since the car is at 95k and knowing that it should be done around 60-70k and I don't honestly remember if the previous owner had told me if it had been done or not. I just know that the noises are coming from that area, and I really have no desire to kill my car. So that's my logical guess. Any ideas?

 

Uhm, ehh, uhh, hmm. Sounds like a noise and junk n stuff or something, eh? Really, while your diagnostics are poor, at least you can write in english well.

"Sounds" like you might have a noisy timing belt tensioner or idler, or a noisy water pump. You can confirm with a stethoscope at the front of the engine, or if you don't have one, any of the various ghetto vac hose and bolt methods will work.

So you'll need:
timing belt
water pump
water pump gasket
front crank seal
cam seals (2)
timing belt idler
timing belt tensioner
timing belt tension spring

I've got the same job coming up on my car too, though I'm also going to install new cams, pull the head off, replace the HG, and go back together with ARP studs.

 

I'm with Ben. I've used a small pvc pipe for a make-shift stethoscope.

 

I use 1.5" heater hose, fits on my large ears better.

 

there now I believe you have big ears... hey, that gives me an idea for a "detcan"

 

I don't know how the diagnostics are poor, other than I can't pinpoint exactly what it's doing. I said I can hear the difference, where it's coming from, however not affecting the car in any way. If you heard the car, you'd probably describe it in the same manner I have.

Anyway, I'll try that out and see what I can hear. I know one of the techs in the back has a stethoscope.

I'm pretty much set on replacing the timing belt and nearby stuff anyway. And thanks for the list Ben, actually made one last night that included all that stuff. On another note, are the Gates belts that MiataRoadster.com sells really any better, or would I be just as well off getting OEM?

 

Water pump is indeed the culprit and I can only assume the timing belt is missing a few teeth.

As of right now, my list for the timing belt project is:
Timing Belt
Water Pump w/ mounting and inlet gaskets
Front Crank/Main Seal
2 Cam Seals
Timing Idler Pulley
Timing Tensioner Pulley
Timing Tensioner Spring
Woodruff Key
Main Accessory Belt (since I'm without a/c and p/s)

However, I still wonder about the question in my previous post, are the Gates belts any better, or am I fine with the OEM?

Also, I figured it wouldn't hurt to replace the thermostat and gasket since I'm working in that area anyway, typical OEM ok here as well, even with turbo and all?

Going to replace the CAS, has anyone used the Viton one that miataroadster sells? Reviews?

When doing this project, has anyone found it necessary to replace the water pump top rubber seal (http://www.finishlineperformance.com...cat=319&page=2) or the main crankshaft bolt (was on a price quote I got, but no one ever mentioned it before)?

 

I'm not sure what that seal is for on the waterpump, I don't remember seeing that. When I did my timing belt job I replaced the water pump itself, and the 2 gaskets for it. And the main crankshaft bolt should be replaced as I've read they will contort and re-using the old one is a no no.

Vash-

 

Should always change the main crank bolt when doing the waterpump/timing belt. Clean out the threads in the crankshaft and apply threadlocker when assembling and torque to spec.

It is only a few dollars and I have seen used the used bolts stress cracked enough to break when dropped on a cement floor.


EDIT: Vash beat me to it.

 

Some places list the seals/gaskets separately.

 

Water pumps I have purchased included this seal, but your old one will probably work. This is part of the TB cover system to keep out dust.

 

Great. Thanks for the input! Any answers on the other questions folks?