Help! Engine Noise

[Scrrem]

Went out for a drive yesterday and found I have a new knocking noise coming from the front of the engine. I have to do some more probing today, but doesn't sound like it's an idler pulley, AC or alternator. To me, it sounds like it coming from the camshaft timing chain area. This may be too big of a job for me. Does anyone know of a good LT5 mechaninc on N. VA?
Rich

[Jeffvette]

Check your oil level. Might be starving the lifters a bit.

[Scrrem]

Check your oil level. Might be starving the lifters a bit.

Drove the card over to QB93Z's house yesterday to change the oil. Was making the noise before the oil change and after. Oil was at the proper level.

[Dynomite]

Get yourself a good stethoscope :thumbsup:

[HIZNHRZ]

Rich, I had a engine knock in my Red/Gry 91 several years ago. Is it a knock only or is there any sign of a miss under load?

[A26B]

Does it occur only at idle?

[Scrrem]

Does it occur only at idle?

The knock is present at idle and increases speed under load.

Just got back from Napa and picked up a Stethoscope, going out to probe now. Will update shortly.
Rich

[Aurora40]

Does anyone know of a good LT5 mechaninc on N. VA?
Rich
:sign10: Yeah right! Certainly none by profession, though obviously there are some excellent owners/hobbyists here.

I'd say try to track down where it's coming from before resorting to anything drastic. Can you grab a camera, pop the hood, and get a video of the sound?

[Scrrem]

Can you grab a camera, pop the hood, and get a video of the sound?

Damn, that's a great idea!!! Duh...why didn't I think of that!!! Will shoot some video and post shortly.

Rich

[Ccmano]

Pull the accessory belt off and run the engine briefly. That will instantly eliminate anything, including the water pump, run off the belt. You will then know if it's internal or external to the engine.
H
:cheers:

[Scrrem]

I'd say try to track down where it's coming from before resorting to anything drastic. Can you grab a camera, pop the hood, and get a video of the sound?

Ok, here it is. Hopefully you can view it. Don't know why you can't upload video to our site.

http://www.youtube.com/watch?v=JZC7sxxuRLo

Rich

[HAWAIIZR-1]

Rich,

Like Ccmano said, try to run it for a short time without the drive belt. My waterpump did sound like that when mine went bad even though my first sign was coolant seepage.

[GOLDCYLON]

Sure sounds like the water pump the idler pully is not jumping around wildly either. Easy to replace all you need to do is remove the air horn to get to it. That and a crap load of bolts

Whens the last time you changed the hoses? You will need to invest in a dorman hose puller to get those pesty OEM clamps of

[Scrrem]

Sure sounds like the water pump the idler pully is not jumping around wildly either. Easy to replace all you need to do is remove the air horn to get to it. That and a crap load of bolts

Whens the last time you changed the hoses? You will need to invest in a dorman hose pull to get those pesty OEM clamps of

No, I put the probe directly on the idler pully bracket. Good, glad to hear I don't need to pull the plenum.

Only had the car since last Feb, never changed hoses. Have an OEM set waiting in the parts bin. Figured I'd be doing this down the line. Have to look up a dorman hose pull, don't have that

[Kb7tif]

The clunking is too fast to be Crank/lifters/cam. Hopefully water pump!

[GOLDCYLON]

The Dorman puller makes life a little easier when pulling the OEM clamps. AutoZone or Checker/Oreilly have them. It looks like a pair of pilers with tines on the end that compress the tabs. Normally a breaker bar fits in the square slot of the idler pulley so the belt removal is a breeze. If you havent looked in the FSM there are a crap load of bolts. They are about four or five varying sizes. A good method is to place them in the same holes as your replacement pump on the garage floor and then when you have the old pump out and on the floor to replace the bolts back into the old pump as a guide.

as stated no the plenum does not need to come off just the Air cleaner and air horn need to be pulled from the front of the plenum

[Aurora40]

I have a hose clamp tool you are welcome to borrow. It's the remote kind which helps a lot for some of those clamps.

I also have a NAPA rebuild water pump. I think it was around $150. You are welcome to it for what I paid. I'm not sure why I even bought it. I'm not a fan of the stockpiling of parts.

[Scrrem]

Pull the accessory belt off and run the engine briefly. That will instantly eliminate anything, including the water pump, run off the belt. You will then know if it's internal or external to the engine.
H
:cheers:

Yep, just popped the accessory belt off....quiet as a church....thanks :cheers: Looks like I'm doing a water pump replacement. Merry F'n Christmas Oh well I guess it could have been worse. At least this is something I can do myself :thumbsup:
Rich

[Kb7tif]

Yep, just popped the accessory belt off....quiet as a church....thanks :cheers: Looks like I'm doing a water pump replacement. Merry F'n Christmas Oh well I guess it could have been worse. At least this is something I can do myself :thumbsup:
Rich

Dam water pumps.

[Scrrem]

I have a hose clamp tool you are welcome to borrow. It's the remote kind which helps a lot for some of those clamps.

I also have a NAPA rebuild water pump. I think it was around $150. You are welcome to it for what I paid. I'm not sure why I even bought it. I'm not a fan of the stockpiling of parts.

Bob,
Your the MAN. Yes, if I could borrow your hose clamp tool, that would be great :thumbsup: If your willing to part with your water pump that would be great as well. This must be an omem, I was watching one on Ebay last week and got distracted and missed getting a bid in. If I had won it , this would not have happened :mrgreen: I'll shoot you a PM, maybe I can get over your way next week sometime.
Rich

[A26B]

Where would we be without all the good folks & the forum to put us in touch?:dancing

[QB93Z]

Rich,

Let me know when you are going to do the job. I will try to come down and lend a hand.

If the pump doesn't come with a gasket, get it from Jerry!

Jim

[Scrrem]

Rich,

Let me know when you are going to do the job. I will try to come down and lend a hand.

If the pump doesn't come with a gasket, get it from Jerry!

Jim

Thanks Jim! When I get everything together, I will put it out as a WAZOO event and anyone who wants to help or supervise will be welcome.

Thanks to everyone who had input on this thread, appreciate all your input, this is what makes this site the best :worship:

[Hammer]

Where would we be without all the good folks & the forum to put us in touch?:dancing

Absolutely Jerry. The Registry in action.

[Z51JEFF]

While you had the belt off you did reach down and gave the WP pulley a spin right?It would be a kick in a balls to do all this work only to find out it was something else.

[Scrrem]

While you had the belt off you did reach down and gave the WP pulley a spin right?It would be a kick in a balls to do all this work only to find out it was something else.

No, but I can do that this week. If it's making a noise like that I guess I should feel some kind of resistance or a bad spot on the bearing as I turn the pulley?
Rich

[QB93Z]

Rich, Since the noise went away with the serp belt off, the faulty component still could be any of the things that the belt touches:

Water pump
Alternator
AC Compressor
Power Steering
Idler Pulley
Crank pulley/torsional damper

You may want to keep checking to figure out which one it is before you replace the water pump.

Jim

[GOLDCYLON]

No, but I can do that this week. If it's making a noise like that I guess I should feel some kind of resistance or a bad spot on the bearing as I turn the pulley?
Rich


Rich Im thinking Jeff feels you should still hear some of the noise when you give her a hand crank. It may be lower in volume and a different pitch but you should still hear it. If its a spun bearing you might even feel resistance. Which is futile. But as posted above Jim is right with the S belt off everthing is in play. Did you see any rise in temp with this new noise or did you not notice?

[Scrrem]

Rich Im thinking Jeff feels you should still hear some of the noise when you give her a hand crank. It may be lower in volume and a different pitch but you should still hear it. If its a spun bearing you might even feel resistance. Which is futile. But as posted above Jim is right with the S belt off everthing is in play. Did you see any rise in temp with this new noise or did you not notice?

No, the temp was still in the normal range. I'm just puzzled what could be making a knocking noise in a water pump. Usually they squeal or start leaking, neither if which I have. Is the bearing in this water pump a true bearing or is it a bushing? I will pop the belt off again this week and give it a good rotation analysis, see if there are any flat spots or resitance felt.
Rich

[GOLDCYLON]

No, the temp was still in the normal range. I'm just puzzled what could be making a knocking noise in a water pump. Usually they squeal or start leaking, neither if which I have. Is the bearing in this water pump a true bearing or is it a bushing? I will pop the belt off again this week and give it a good rotation analysis, see if there are any flat spots or resitance felt.
Rich

Rich I have never taken an LT5 water pump apart but I believe its a compressed Sleeve bearing. Somebody here may know for sure.

[Scrrem]

Rich, Since the noise went away with the serp belt off, the faulty component still could be any of the things that the belt touches:

Water pump
Alternator
AC Compressor
Power Steering
Idler Pulley
Crank pulley/torsional damper

You may want to keep checking to figure out which one it is before you replace the water pump.

Jim

Ok, your scaring me now. When I was probing, the only place I could get a real good knock sound was from the water pump. I think I check most of the items on you list with the probe, with the excecption of the crank pulley. How do I check that? Maybe you can make a house call :-D
Rich

[QB93Z]

Rich, I did not intend to scare you. I might have missed the discussion where you confirmed that you could hear the noise from the water pump with the stethoscope. By the way, did that work well?

If you can't definitively assign the noise to one component, my offer to swap the idler pully with mine stands. That isn't too big a job. I have a spare alternator that we can try a swap if you need to.

We will probably be having another Maintenance Day this weekend if Yun's front end parts come in.

Jim

[Scrrem]

Rich, I did not intend to scare you. I might have missed the discussion where you confirmed that you could hear the noise from the water pump with the stethoscope. By the way, did that work well?

If you can't definitively assign the noise to one component, my offer to swap the idler pully with mine stands. That isn't too big a job. I have a spare alternator that we can try a swap if you need to.

We will probably be having another Maintenance Day this weekend if Yun's front end parts come in.

Jim

Jim,
The water pump was the only place I could here the noise with the stethoscope. I was able to place it on the bracket for the idler pulley and couldn't hear it. I was also able to get the probe directly on the alternator, power steering pump and a/c compressor. I'm 98% sure it's coming from the water pump. I am still going to pop the belt and check to see if I can generate the noise by hand.
Rich

[QB93Z]

Rich, That sounds pretty certain. While you have the coolant drained I guess you are going to replace the hoses. You may want to put in a new thermostat while the system is opened up.

If you are doing the hoses, you may want to come up and use the lift. Some of the lower hose connections are a pain to get to.

Jim

[Scrrem]

Rich, That sounds pretty certain. While you have the coolant drained I guess you are going to replace the hoses. You may want to put in a new thermostat while the system is opened up.

If you are doing the hoses, you may want to come up and use the lift. Some of the lower hose connections are a pain to get to.

Jim

Jim,
I am going to pull the belt one more time and see if I can feel what is making the noise. The lift sound good, but my other concern is driving any distance with this thing knocking like it is. Knocking noises of any kind can't be good. You think this is a job that can be done in one day?
Rich

[phrogs]

Just a FYI

Many moons ago I was In Norfolk VA drivng my ZR-1 back to NC and I lost all my accesories..

Belt was shreaded I was stranded on the side of the road.

Come to find out the damn water pump pully had wobbled off the water pump shaft!

I am serious I had the luck of having another ZR-1 owner living in the area and he towed my Car back down to NC for me about a week later while I hitched a ride on the greyhound!:-(**|=



It could be a number of things going on with the pump, if the car has sat Ill bet your propeller has rust all over it its only a matter of time before it fails thats why our water pumps are our week link.

[secondchance]

Yep, just popped the accessory belt off....quiet as a church....thanks :cheers: Looks like I'm doing a water pump replacement. Merry F'n Christmas Oh well I guess it could have been worse. At least this is something I can do myself :thumbsup:
Rich

I am happy to hear it's just a water pump!
Merry Christmas.

[QB93Z]

Rich, Probably a one day job.

I do have a convenient ZR-1 loaner program. :wink:

[Dynomite]

It could be a number of things going on with the pump, if the car has sat Ill bet your propeller has rust all over it its only a matter of time before it fails thats why our water pumps are our week link.

Thanks phrogs :thumbsup:

You just convinced me to put on a new water pump along with my new radiator and samco red hoses :cheers:

[Scrrem]

It could be a number of things going on with the pump, if the car has sat Ill bet your propeller has rust all over it its only a matter of time before it fails thats why our water pumps are our week link.

Thanks Johnny, I will do a double check just to make sure, but I'm hoping that is what it is.

Jim Thanks, I'll try to troublehoot this week.

Rich

[Scrrem]

Rich, Probably a one day job.

I do have a convenient ZR-1 loaner program. :wink:

Jim, Pulled the belt and gave the pump another good spin....yep it's the pump for sure. Got a new pump from Aurora40 and got new coolant and throttle plate coming. Whenever you have an opening in the lift bay, let me know.
Rich

[Dynomite]

Rich, That sounds pretty certain. While you have the coolant drained I guess you are going to replace the hoses. You may want to put in a new thermostat while the system is opened up.

If you are doing the hoses, you may want to come up and use the lift. Some of the lower hose connections are a pain to get to.

Jim

Might as well pull and clean the radiator first....then I think it is a lot easier to get to the water pump as well as those radiator hoses :thumbsup:

I pulled the radiator and then decided to pull the water pump :sign10:

[-=Jeff=-]

I did the WP just by removing the crossover hose and tube along with the air horn and bellows..

was not too bad of a job

[secondchance]

Might as well pull and clean the radiator first....then I think it is a lot easier to get to the water pump as well as those radiator hoses :thumbsup:

I pulled the radiator and then decided to pull the water pump :sign10:

I agree. I did the same about 4 years ago. Replaced both the pump and the radiator. Pump is pretty easy to remove once the radiator is out of the way.

[ShawnZR-1]

Hmmm, I'm in the throws of replacing my pump right now. Damn thing only lasted 199,000 freakin miles! Damn GM, can't you build a pump that lasts 200K??? ;) :lol:

The only things I have had to remove have been the air horn and crossover tube. Oh, and the camber brace but that's aftermarket :)

16 bolts holding that thing on... overengineered! :D

[Z51JEFF]

No, the temp was still in the normal range. I'm just puzzled what could be making a knocking noise in a water pump. Usually they squeal or start leaking, neither if which I have. Is the bearing in this water pump a true bearing or is it a bushing? I will pop the belt off again this week and give it a good rotation analysis, see if there are any flat spots or resitance felt.
Rich

Years ago my 84 had a bad bearing in the water pump,it didnt leak at first put did make a racket.It started leaking after the bad bearing allowed the shaft to blow out the seal.