A bang, then a whine...stopped...re-started and no more problems.

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Jun 14, 2020
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Hi All
1984 fj60, re-built 2f engine...has been running great.

Today was driving on the highway at 65 MPH. Heard / felt a bit of a bang. Pulled off within 1 minute. Engine running opened hood. Nothing missing, nothing leaking. Belts still in place and look good. Could hear a whine coming from front of engine (water pump, air pump?). Lots of highway noise so decided to try and get to a side road. Limped off to a side road, the whine continued and varied with RPM. Parked and shut off engine. Looked around. Nothing obvious to me. Not overheating. Started up again...and everything ran fine and no noise. Drove slowly home on side roads. Made it. No noise. No leaks.

Something is failing.

Last time I posted, I thought I was having problems with water pump. I looked at the water pump and it seemed everything was fine. But maybe I was wrong and it is the water pump.

Could it be the air pump? Truck is desmogged but air pump is still there.

Thanks for your advice. Had to cancel the family camping trip...

Hi, If the air pump seizes , car usually overheats. ac belt still on?
Hi Mike

Thanks for the quick reply. The PO removed the AC...so no AC and no belt.
I presume the air pump is still there just to keep the belt tight.
Use a long rod or buy an auto stethoscope and isolate the whine. Place the rod on the Air Pump and cup the other end to your ear
Hi Spike
So I went out and put my breaker bar on the air pump and alternator. No whining coming from either. I could hear the bearings in the air pump pretty good. It was making a sound I would describe as a 'rattle' when the bar was up to my ear. Could be the bearings are going?

Would it be best to take the belts off and poke around for play in the pulleys? If I do replace the air pump, would you recommend replacing with the simple pulley replacement and nothing more?

Yes, if you can't isolate with the rod, I would take all the belts off and run it briefly and see if the whine is still there

If it is the Air Pump, a simple pulley is the way to go. The vanes inside it can sometimes disintegrate with a 'bang'.

Spike is right about the vanes inside the pump failing. But also the bearings can fail too. Either way air pumps can and do seize. when they do they will throw the belt and next time you come to a stop light you will overheat because your fan has lost it's belt and is no longer turning. You were smart to pull over and check it out. Best to replace it with an aftermarket pulley. Why do you need it at all? Because it will basically become the tensioner pulley for the fan belt.

The first time my smog pump failed I thought the water pump had seized. At that time it had not thrown the belt because I was idling at a light and heard a screeching sound.

The second time it seized I was traveling a side road and immediately pulled over. The belt was thrown and torn up. I limped my truck to a friends house about a mile away and watched my temp gauge carefully. By the time I got there it was almost in the red and after turning the motor off, it did go into the red. Not a smart move and not recommended. This can lead to cracked head, dislodged head gasket, or worse a cracked block.

The third time my air pump failed it threw the pulley off. I managed to find it in the woods a couple days later. After that I was done with the idea of an air pump being part of my truck and bought a smooth aftermarket pulley.

A leaky P.S. pump can drip atf onto the pump causing some of the problems, also the leaking atf can drip down on the driver's side motor mount causing the rubber in to fail the first time you torque your motor. Make sure your p.s. pump isn't leaking. Toyota p.s. pumps are very expensive, Georg w/ valley hybrids offers a mounting adapter kit so you can install a saginaw (G.M) pump...that are reliable, cheap and available everywhere.
Thanks g-man. Much appreciated. I went ahead and ordered the pulley from TLC yesterday. Seems like a good idea just to change that thing out.

Does the air pump give a signal before it fails? Or it just goes?
Not always a warning. I carried a spare smog pump and fan belt in my truck for years, along with associated ratchets and mm sockets and wrenches ...so I wouldn't be left stranded somewhere.

Now that you are removing the smog pump, you need to research and decide how far to de-smog. I left my EGR, EGR pipe in place (for now). My ABV is still there but not hooked to anything. You can remove your air rail and prob is a good idea since they do form holes causing exhaust leaks. Jim C sells a kit with plugs for the air rail injection holes in the top of the head as well as larger steel plug for BVSV and rubber covers that go over the air cleaner ports where the smog pump hoses attached.

Removing the EGR means blocking the egr pipe to exhaust manifold port. After market kits are available. Also re-plumbing the PCV line to air intake connection. If you go this far the carb and dizzy are affected. They are tuned for a smogged truck and complete desmog means leaning the carb or getting a non USA carb. Also Re-curve of the dizzy.

Disclaimer: I am not a 2f certified engineer. Any info I learned was reading through various desmog threads.

Here are a few to rattle your brain:

The Definitive 79-80 Desmog Guide | IH8MUD Forum

My Desmog Thread | Page 4 | IH8MUD Forum

'83 FJ60- Dizzy Recurve- Can anyone demystify this process? | Page 2 | IH8MUD Forum
Hi g-man
Thanks for this. The truck is already de-smogged, thank goodness :)
The smog pump was left to function solely as the belt tensioner it seems.

Still a bit of a mystery what is happening...as yesterday I had it idling for awhile and drove it around close to my house to see if I could get the whine again. I got nothing...ran perfectly.

Will go ahead and replace the air pump with the pulley anyway. And, yeah, I am also carrying around enough gear to fix a water pump if I need to...

Hi All
Just for a bit of closure...I finally got around to pulling the old air pump and installing the TLC air pump idler pulley. The problem with the air pump was intermittent but I figured it was on its way to seizing at some point. The install of the idler pulley was pretty straightforward and...the truck started up and ran again...so that's good. Fingers crossed it fixes the issues for now.


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