2G Grinding or rattle noise around timing belt and head

[Gwaihir]

After doing some searching on here I'm thinking it might be a balance shaft, bearing, or tensioner going bad. The noise can be described as either light grinding or a rapid rattle. It's definitely localized near the timing belt area, at first I thought it was coming from under the valve cover in the head but I don't think it is.

Here's a video:

https://drive.google.com/file/d/1iTqoFn_yEAn4_1qDGvmsW2fGnWPKKbd_/view?usp=sharing

 

[EC17PSE]

Power steering and water pump bearings can go bad after a while, try use some wd40 on each seperstly and see what one helps if at all

 

[AWD-Tony]

Yup. Sounds like a bearing. Use a long screw driver and put it on the power steering pump and alternator while it’s running. Just be careful and feel for vibration.

 

[pauleyman]

You should rule out accessories. Take all the belts off and run it for 30 seconds. If the noise doesn't happen that it isn't under the cover it's one of the accessories. You have alternator power steering air conditioning and an air conditioning tensioner you also have a water pump but that would require a timing belt job. This should be easy to narrow down. If it's under the cover then you do a timing belt job plain and simple

 

[motomattx]

Agree with Pauleyman, he beat me to it, could be an alternator bearing as well.

 

[Gwaihir]

Thanks for the suggestions. I pulled the timing covers today no abnormal wear or rub marks. I had the belt replaced July 2018 and only put on about 3k miles since. When I had my belt done I had them do the water pump at the same time. So it should be ok however the water pump does seem to be where the noise is localized. I haven’t tried pulling the accessory belts yet. Hopefully I get a chance to do that tomorrow.

If I pull the accessories and it ends up being the water pump would that be surprising given the recent install/mileage?

 

[AWD-Tony]

That’s strange a new bearing would make noise but not impossible. Once you pull the accessory belts, turn the pulley and see if you feel it. Also make sure the water pump pulley bolts are tight. Did they replace the other pulleys when they did the timng belt? Idler pulley, tensioner pulley and balance shaft tensioner pulley?

 

[Gwaihir]

Narrowed it down. Not the water pump or power steering. Those who suggested to check the Alt, thank you. I think it is a bearing in my alternator that’s gone bad. Is this a pretty straightforward swap that I can do in my drive way on jack stands? I’m not an expert mechanic but I was able to install my 16g turbo using the VFAQ. I have a shop not too far away that I could take it to to swap it out if it’s a pain to swap.

What is the best bolt on alternator that’s available for these cars this day and age? The one on the car now is the original factory alternator.

 

[motomattx]

Ive done the alternator on the side of the road on my way to work and wasnt even late, its not a bad job at all, I used to carry a spare because I was a cheap skate and ran junk Autozone rebuilds, your best bet is to get on Rock Auto and get a good Bosch rebuilt unit or a brand new one, or get a junk yard unit and have yours rebuilt locally, the parts store units are junk, it took me three of them just to get one that lasted a year, also the China regulators that they use make your belt squeal from turning on the charge rate all at once instead of slowly ramping it up like the stock regulator does. So, get yours rebuilt locally and in the meantime find a used one or buy a brand new one from Rock Auto or a Bosch rebuild.

 

[EVLGSX]

Any service done lately? One of the DSMs I picked up a while back came to me with the water pump pulley bolted on backwards.....was a bit louder as far as sound output than what can be heard in your video..... but something to check on.

OOps missed above. looks like u got it

 

[Gwaihir]

Ive done the alternator on the side of the road on my way to work and wasnt even late, its not a bad job at all, I used to carry a spare because I was a cheap skate and ran junk Autozone rebuilds, your best bet is to get on Rock Auto and get a good Bosch rebuilt unit or a brand new one, or get a junk yard unit and have yours rebuilt locally, the parts store units are junk, it took me three of them just to get one that lasted a year, also the China regulators that they use make your belt squeal from turning on the charge rate all at once instead of slowly ramping it up like the stock regulator does. So, get yours rebuilt locally and in the meantime find a used one or buy a brand new one from Rock Auto or a Bosch rebuild.

I ordered a Bosch rebuilt unit for the 97 galant. I have a Canadian build DSM and it came with the 90A alt. I searched and searched these are hard to find new so I went with the Bosch rebuild. On the other hand I came across Mitsubishi OEM 75A through Amazon. I didn’t think stepping down to the 75A was a good idea if mine came with a 90A to begin with. Hopefully this Bosch rebuild holds out for a few years. I also ordered a new Oem crank pulley from JNZ. Figured I might as well swap that too while I’m under the car.

That’s a really good idea to take mine and get it rebuilt to have a spare. I’ll do that after the swap with the Bosch.

 

[AWD-Tony]

I upgraded to a bosch 90 amp from advanced last summer. Think I paid $100 with coupon and core. Haven't had a problem with this unit.

 

[AWD-Tony]

It's not difficult. Make sure you disconnect the battery first.

 

[quickduc]

There are a couple factors that you may be dealing with. One is that the bearings in the waterpump are rather strange. They appear to require a huge side load to get the rolling elements to roll, instead of skid, in the races. I have no idea why this would be, but some years ago I had to replace my '91 AWD Talon's pump. Put a new one on, and it shrieked/screamed. Pulled it off, and got a different brand, thinking that if the maker had put a run of bad bearings in a batch of pumps, I didn't want the same problem. 2nd pump did the same thing. 3rd brand, same noise. Pulled the pump off my spare motor, same. ?

Finally read a post on one of the Mitsubishi forums that it required a VERY high tension on the belt to make it work. The instruction was to tighten the alt until you could just barely twist the middle of the belt (mid way between pulleys) 90 degrees by hand.

This makes the pump work, but the side effect is that it dramatically shortens the life expectancy of the bearings in the alternator. Of the two alternator bearings, one is only available from Japan directly. The bearing houses here don't have it, it's a special design. So, you can fix the electronics in it, but the bearing that goes bad can't be had. Considering the cost and hassle of replacing the waterpump, the alternator is cheap. As a mechanic in a former life, I have to say the belt tension this requires is INSANE. I have never encountered this situation in any other application.