Water pump bolts backing out? Huh? - ZR-1 Net Registry Forums

billschroeder5842 · 06-12-2017

I had an odd thing happen today to my normally bullet proof 91.

I got in to start the car for my 17 mile commute home and and once running heard a loud CLICK-CLICK-CLICK from the engine. The CLICKS would speed for slow depending on the RPM.

I thought it might be a alternator going bad but further inspection show that not one or two, but 3 of the 4 bolts that hold the pulley on to the water pump had significantly backed out at least half to 3/4 of an inch. Clearly this was the cause of the CLICKS

I was able to put an open end wrench on the bolts and crank them down good. I restarted the can and sounded normal as per usual. I checked when I got home and no issues.

So, what would cause 3 (!) bolts to back out? I keep pretty good tabs on the engine but this one has me confused as it seemed to "come out of nowhere."

Anyone else have bolts back out of the water pump?

GOLDCYLON · 06-13-2017

Quote:

Originally Posted by billschroeder5842

I had an odd thing happen today to my normally bullet proof 91.

I got in to start the car for my 17 mile commute home and and once running heard a loud CLICK-CLICK-CLICK from the engine. The CLICKS would speed for slow depending on the RPM.

I thought it might be a alternator going bad but further inspection show that not one or two, but 3 of the 4 bolts that hold the pulley on to the water pump had significantly backed out at least half to 3/4 of an inch. Clearly this was the cause of the CLICKS

I was able to put an open end wrench on the bolts and crank them down good. I restarted the can and sounded normal as per usual. I checked when I got home and no issues.

So, what would cause 3 (!) bolts to back out? I keep pretty good tabs on the engine but this one has me confused as it seemed to "come out of nowhere."

Anyone else have bolts back out of the water pump?

Bill I have heard of bolts backing out of the water pump bolts and folks normally notice a problem when the water pump starts to leak. Just like the oil pan I am mindful and tell everbody to tighten the bolts before they panic. However I think I have not heard of the bolts backing out of the pulley area. I do remember a water pump shaft breaking but that's about it. GC

dredgeguy · 06-13-2017

I recently had 2 bolts back out of the alternator.

Paul Workman · 06-13-2017

Blue Loctite...is your friend.

billschroeder5842 · 06-13-2017

Quote:

Originally Posted by Paul Workman

Blue Loctite...is your friend.

Yeah,I think that is a weekend project. I drove it to work and back today (34 miles) perfect in every respect.

Maybe it was just.... a thing.

Bruce · 06-15-2017

Ive just found something similar on my 91. I call it a 'Monday Engine' - you know, the one that was assembled after a long weekend on the booze!

Ive just replaced my air conditioning pulley bearing, alternator and water pump bearing and seals.
While I was in the engine bay, I went over all the bolts I could and I was amazed at how loose the water pump bolts were. Except one - that I had to grind the head off to get the water pump off. And I couldnt remove the stud as its one of the 'long' bolts, so Ive just didnt bother about trying to replace the headless bolt. But I sure went over every other bolt I could get at and was truely amazed at how loose many of them were.

While I had it up on the hoist I looked at the engine number/manufacture date - and it was actually built on a Monday, hahaha!

Paul Workman · 06-15-2017

Quote:

Originally Posted by Bruce

Ive just found something similar on my 91. I call it a 'Monday Engine' - you know, the one that was assembled after a long weekend on the booze!

Ive just replaced my air conditioning pulley bearing, alternator and water pump bearing and seals.
While I was in the engine bay, I went over all the bolts I could and I was amazed at how loose the water pump bolts were. Except one - that I had to grind the head off to get the water pump off. And I couldnt remove the stud as its one of the 'long' bolts, so Ive just didnt bother about trying to replace the headless bolt. But I sure went over every other bolt I could get at and was truely amazed at how loose many of them were.

While I had it up on the hoist I looked at the engine number/manufacture date - and it was actually built on a Monday, hahaha!

I had a high idle issue after owning the Z for a couple years. I never found the specific location for the air leak, but in the process of re-torquing the screws under the plenum, several were barly finger tight.

So...I did the blue Loctite on all of the engine screws/bolts and re-torqued them. That seems to have done the trick for the past 8 years.

06-12-2017	#1
billschroeder5842 Join Date: Nov 2016 Location: Southlake, TX Posts: 591	Water pump bolts backing out? Huh? I had an odd thing happen today to my normally bullet proof 91. I got in to start the car for my 17 mile commute home and and once running heard a loud CLICK-CLICK-CLICK from the engine. The CLICKS would speed for slow depending on the RPM. I thought it might be a alternator going bad but further inspection show that not one or two, but 3 of the 4 bolts that hold the pulley on to the water pump had significantly backed out at least half to 3/4 of an inch. Clearly this was the cause of the CLICKS I was able to put an open end wrench on the bolts and crank them down good. I restarted the can and sounded normal as per usual. I checked when I got home and no issues. So, what would cause 3 (!) bolts to back out? I keep pretty good tabs on the engine but this one has me confused as it seemed to "come out of nowhere." Anyone else have bolts back out of the water pump? __________________ Bill Schroeder Texas Proud! 1991 Corvette ZR1 #1388 2015 Challenger Scat Pack Shaker

06-13-2017	#3
dredgeguy Join Date: Aug 2012 Location: Ellicott City, MD Posts: 1,704	Re: Water pump bolts backing out? Huh? I recently had 2 bolts back out of the alternator. __________________ Charlie __________ Dredgeguy WAZOO Member 1992 Bright Red/Black ZR1 #246 Dana 4:10 gears Polished LT5 by Haibeck Polished Fikse FM5's with Michelin Pilot Sport 2 Stainless Works headers and cats with Corsa

06-13-2017	#4
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Water pump bolts backing out? Huh? Blue Loctite...is your friend. __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

06-15-2017	#6
Bruce Join Date: May 2016 Location: Whangarei New Zealand Posts: 29	Re: Water pump bolts backing out? Huh? Ive just found something similar on my 91. I call it a 'Monday Engine' - you know, the one that was assembled after a long weekend on the booze! Ive just replaced my air conditioning pulley bearing, alternator and water pump bearing and seals. While I was in the engine bay, I went over all the bolts I could and I was amazed at how loose the water pump bolts were. Except one - that I had to grind the head off to get the water pump off. And I couldnt remove the stud as its one of the 'long' bolts, so Ive just didnt bother about trying to replace the headless bolt. But I sure went over every other bolt I could get at and was truely amazed at how loose many of them were. While I had it up on the hoist I looked at the engine number/manufacture date - and it was actually built on a Monday, hahaha!