Water pump bolts backing out? Huh?

[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?

[GOLDCYLON]

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]

I recently had 2 bolts back out of the alternator.

[Paul Workman]

Blue Loctite...is your friend.

[billschroeder5842]

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]

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]

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.