JPTL

Less than 200 miles ago, I did a complete t-belt job in which I replaced the belt, water pump, tensioner idler & main roller & rebuilt the tensioner. Everything went back together w/no problems, and it sounded fine up until today.
I started it up, and heard a brief churning or rattling sound...only for two seconds or so.
Pulled the car out of the garage, and it came back for a bit longer, then went away for only about 5 seconds. Then the sound came back big time.
It's a loud, consistent bearing grinding coming from the front of the engine. I immediately pulled back into the garage and cut the engine. The A/C wasn't on and I didn't hear any moaning from the power steering, or chirping of belts.
By the time I'd cut the engine, the churning/grinding was so loud and consistent that it sounded like whatever bearing it is, was about to seize up. Scary as hell, as I'm thinking water pump. Fortunately, no change in engine performance (no missing, stumbling, etc.). This came on quick. From no sound whatsover, to a grinding sound consistent and loud enough not to be missed.
So I'm now sitting here thinking 'what next'? I'm very leery to start it up again and try to isolate the sound w/a stethescope. What if it's the water pump, and it's seconds away from an all-out seize?
What does bearing failure sound like in a w/p? Is it muffled, and hard to hear, or can it resonate throughout the engine bay like this was?
I'm thinking/hoping that it's one of my external components (air pump, or alternator), and pulling belts and spinning the component's pulley one at a time would be next in order. My fingers are crossed that the air pump or alternator bearing is tired and was ready to go prior to the t-belt job. I may have over tensioned one of the belts, or tensioned it to where it should be, and the the new tension was the final straw.
How else can I isolate my problem without starting up the engine & risking a w.p. sieze and t-belt jump?
Any thoughts?

PorKen

IMNSHO, here's your first mistake.

I would look through the timing belt breather holes and check the belt position, or better yet, remove the ¼ cover and look for trouble.

Loose accessory belts can make weird noises, and may only do so when cold.

marton

First take off the top cam belt cover & check the cam belt is tracking correctly.
If that is OK then try turning the engine over with a 27mm socket wrench on the crank nut.

Sounds like something has come loose and is grinding on the cam belt cover; for example, oil pump nut.
Maybe the bearing on the air pump has failed; that is a noisy mother. Try cutting the belt.

When my water pump siezed it was noiseless.

Marton

figgen

Possibly air pump. Remove the belts and try turning the accessories by hand if you don't want to risk start up. The air pump will howl if the air pump feed line is disconnected.

I'd also check the throw out bearing ect on the clutch.
Did the sound change when you engage / disengage the clutch?


My 2 cents.

Mike Frye

Hey JP,

I'd try getting into the garage somehow and then take off all of the accessory belts and pull it through by hand. That will tell you if it's inside or out and possibly where.

You can check belt tension and tracking at the same time by pulling that passenger cover.

Mine made an ungodly grinding/squealing noise when I first put it back together because I put the bolt for the idler pulley in backward and the end of the bolt was rubbing on the back of the dampener. If you've got 200 miles on it without any issues that's probably not it, but who knows?
Good news is: Even though it sounded like crap it didn't damage anything and just required another tear-down and rebuild of the front end.

Here is the thread:
https://rennlist.com/forums/showthre...ferrerid=45339

Tampa 928s

Are you sure your harmonic balancer was not put in reverse? It will rub as soon as it heats up just a little.

Dean_Fuller

Could also be a bearing on the idler pulley. Did you put a new one on? ...it comes down to pulling the covers off to see.

Jim R.

If it was my car, I'd first pull the air intake tubes to quick check the belt for damage. If it looks frayed or off center, you need to pull it all apart.

If the TB looks fine through the vent holes, pull the accessory belts and hand spin the pulleys checking for a rough or noisy bearing.

If they all feel good/normal, I would probably pull it apart to check everything. It is a lot easier to fix it now than the bill for the worst case scenario. Could be a roller bearing, WP bearing, WP impeller grinding the block, etc...

Hopefully it is something easy!

Jim

Mrmerlin

First remove all of the fan belts then turn the crank with a socket see if you hear anything, spin all of the accessories see if any of them are making noise.
Remove the top pass timining cover check the belt see if the tensioner idler is cocked . Report what you find, please.

JPTL

I think I'm going to be hating April 15th for the rest of my life. 5 minutes after I posted this thread, my accountant called and told me that I've underpaid my '07 taxes to the tune of $22k. Just got back from dropping off two checks @ his office.
Now back to the more important things:
First off, I greatly appreciate the advice - all of the replies are very helpful.
Porken: It's not loose belts...if anything, a tight belt has brought on bearing failure in a component. I checked my belts, and all seem good - except the power steering belt is too tight. That may be the culprit.
Marton: I'm sorry to hear that your w.p. bearing failed, but hearing that it was noiseless, makes me happy.. Hearing that the air pump is a noisy mother makes me happy as well. Whatever this is, is a noisy mother.
figgen: Hand turning the components is what I'll do if I don't get a shot of confidence that it isn't the w.p. and decide to start 'er up one more time. As loud as this was, I'm sure I'll feel the failed bearing w/a hand turn. Doubt that it's the t/o bearing. Too far forward, and not related to clutch action.
Mike: Silver lining is that I didn't damage anything major; and this came up in my driveway & not in some parking lot in the rain. I hightailed it back all of 30 feet into the garage & parked in 'surgery position' before cutting the engine.
Dean: You're right, it could a bearing on the idler. I hope the hell not, because I won't know whether it's a idler pulley or the w.p. until I'm in there.
Jim R: Agree 100%. The belt looks good thru the holes (no fraying/rubs on the edges) and it's centered on each cam gear.
MMerlin: Will report. Inquiring minds need to know!

I talked to Dave Roberts & his suggestions echoed most of yours.

I'm leaning toward air pump or power steering pump (since the p.s. belt seems to be overtensioned).
I plan to start it up again with a mechanics stethescope in one hand. It's going on the w.p. housing immediately. If that's where the noise is, I'm shutting off the engine like nobody's business. If it's not coming from there, then the steth is going to the air pump, then the p.s. pump.
If that's inconclusive for any reason, running the components one belt at a time should tell me. Hand turning will likely be tell-tale, since this bearing was loud.

Mrmerlin

Please, dont run the engine till you complete the things i have asked you to do, you could be on the verge of a major repair bill. that will go with your 22K tax man bill

JPTL

OK. Your suggestion of 'better safe than sorry' is helping me not rush in haste to find the culprit.
I've thought about this situation, and have realized that ultimately belts will be coming off, regardless of what the problem is.
I'd much rather find myself saying "I really didn't have to do that after all." than saying "I really shouldn't have done that." At this point, in light of today's events, it appears that I'll have more time than money to throw at this.
So I'll hold off on starting her up until I rule out (or in) the external components.
Thanks for talking some sense into me.

the flyin' scotsman

the crank bolt came loose or the pwr strg console.............echo the above.

JKelly

If the nut and bolt that holds the tensioner roller on is not put back on correctly (large washer on the wrong side), the bolt can rub the backside of the vibration damper.

Bill Ball

Yeah, I did what John mentions. The noise was rather subtle compared to what J.P. is describing. It's a steady grind right from the beginning. Nice paint flakes from the backside of the dampner get scattered around too.

Turning the crank over with a wrench, as others have suggested, is a good idea. Noise or not from under the covers, they need to come off unless a guilty accessory is found.