Horrendous sound coming from front of engine :-(

[centaurus3200]

went to work today and upon pulling into the parking space, i noticed a horrendous rattling coming from the engine bay.

i opened the hood and it's definitely coming from around the water pump. sent the car down on a flatbed to nick chrimes. when nick got the car, he took a listen and examined the water pump in a cursory sort of way. he said it's probably not the water pump. could be a busted timing belt tensioner or ????

the water pump does not leak any coolant.

the car was idling smooth. if not for the sound, you would be none the wiser.

i don't think it's the rod bearings as i had them replaced about 35,000 miles ago. the sound is NOT a knock but a "rattling and gurgling" sorta of sound. like something is loose. it coming from around the water pump pulley which would lead me to believe it's tensioner, water pump, timing belt issues. what else is around there that would cause this?

anybody have any ideas? nick will tear into it on Monday, just curious to see what you guys think.

thanks,
Robby

 

[SASHO91]

Why not run the motor without the acc. belts?

 

[jruppert]

I agree. I had the same issue. I removed the belt and ran it. The sound went away. I then knew it was the acc belt tensioner. While removing it, the tensioner broke in pieces. Now I am in the process of finding a new one.

 

[centaurus3200]

nick got the car around 4pm. he had enough time to remove the belt for the water pump. sound was still there. he'll remove all the accessory belts tomorrow and see. if the sound is still there, he wants to put it on the lift to see if it's a crapped out cat rattling around.

Robby

 

[gas it]

nick got the car around 4pm. he had enough time to remove the belt for the water pump. sound was still there. he'll remove all the accessory belts tomorrow and see. if the sound is still there, he wants to put it on the lift to see if it's a crapped out cat rattling around.

Robby

Is it an ATX? If so it could be the TB tensioner.

 

[centaurus3200]

nope, it's an MTX. thanks though.

Is it an ATX? If so it could be the TB tensioner.

 

[SuperHO]

check and see if your crank pulley's wobbling around under there.

 

[centaurus3200]

hopefully i can explain this right.

nick pulled off all the accessory belts and ran the car with out the accessories. he also removed the y-pipe to rule out a broken cat.

it still makes the sound. he says he manually turns the crank and he hears a click every revolution and is wondering if the woodruff key is damaged or backed out.

he will pull the crank pulley and the timing belt cover to inspect the woodruff, all the tensioners and the timing belt.

it's a pickle. he doesn't want to say "crank cancer" because it does NOT "knock" just rattles..

i think it's off to the junkyard if the motor is shot though.

Robby

 

[gurucomputers]

Engine Bay Noise

Check your A/C Compressor clutch. I had a similar issue and the cluch had almost come apart. Replaced cluch and noise went away. Good luck....

 

[centaurus3200]

found the problem. as with anything regarding my SHO, the wierdest things tend to happen!

from nick:

my mechanic's scope indicated that the sound seemed loudest when on the
back cat.... pulled the SHO Shop Y Pipe, nothing wrong. Pulled the
plugs to look for internal damage....nothing wrong. Pulled the lower timing
belt cover, no crank cancer, but the timing belt was loose. Looked at
the MTX belt tensioner: it had gone to the least tensioned position, and
it's torque was only 5 ft. lbs. instead of 27-35. Pulled the rest of
the timing belt covers, the cams weren't lined up. The click I felt/
heard was the timing belt slipping over the cam teeth.

Took off the timing belt, compared it with a new one, same length (not
stretched, no visibe damage), reinstalled it, turned the engine over a
couple of times, belt way to loose. Removed it and the tensioner to
find that the tensioner spring had lost its tensile strength: I was able
to bend it by hand and it stayed where I bent it instead of springing
back to shape. The tensioner pulley was getting noisy as well: no prob
there, I had a good spare, but no spring.

Around that time Alan Fanning shows up and goes home to pull a spring
off his spare engine during his lunch break. Reinstalled the timing belt
with the new tensioner and spring, tightend the pulley nut to 33 ft.
lbs. with Loctite, belt nice and tight now.

 

[gas it]

So the weak spring was making the noise?

 

[centaurus3200]

nope, the noise was the timing belt slipping the cam sprocket! good thing we have non-interference motors.

see ya,
Robby

So the weak spring was making the noise?