Knock noise???

Ric1319

Ric1319

Donating Member
I'm still trying to figure out what the knocking noise is on my truck (93 Typhoon). I just finished replacing the oil pan gasket so when I had it all apart I look everything over it all looked good no shavings oil filter was clean bottom of pan was clean. So before I put it all together I decided to start it and warm it up. The oil pan was reinstalled and filled, coolant was filled also. I started the truck it was running great nice and quite when it warmed it started knocking. I still had the front diff out so I stuck my big head in the space between the oil pan and frame and heard the knock near the front. So I shut the truck off and removed the belt to see if it is something with the belt the noise got louder. :rant: Has anyone ever have a torsional damper go bad and if so does it sound like a rod knock. I think tomorrow I will go to an auto parts store and rent a puller and check it out. The truck sat for 18 years and a lot of the rubber was dry rotted maybe the rubber in this went bad, I don't know.:banghead::
 
Don W.

Don W.

Stab it and steer it
Re: Knock noise???

I have had a noise in my motor through 3 rebuilds. It sounds like piston slap to me. This site even has a test for it:

http://www.pistonslap.com/whatisit.htm

Me? If you're not making metal I'd run it and cut some filters in succession until you're confident. No need to change oil, just add to replace that lost with the filter.
 
Quickstop [UK]

Quickstop [UK]

Combating adversyty.
Re: Knock noise???

I doubt your damper would make a knocking noise. A timing gun would tell you if it has slipped. Pulling it is a distraction.
 
Typhoon#747

Typhoon#747

Donating Member
Re: Knock noise???

I have heard of bad dampers making knocking noise similar to that of internal engine knock. In your case, like Dave said, if you have removed the serpentine belt and the noise changed, your problem is bearing related. Removing the belt changes the side load on the crankshaft.

If you decide to inspect the crank bearings and roll new ones in, here's a helpful video to do that:
https://www.youtube.com/watch?v=jHeO1h3U4GE
 
Don W.

Don W.

Stab it and steer it
Re: Knock noise???

Regarding bearing wear. The two center mains are the only ones with a crank throw on both sides. In effect dealing with twice the load of the front and rear. (DaveP's post) Front bearing is farthest from the pump. Not uncommon to find wear there. The rear is closest to the pump and a lot wider than the others. Rod bearings on our even fire motors are narrower than regular V8 rods.

The rods only receive oil for half a turn of the crank. Cranks can be cross drilled to fix this but weakens the crank. King bearings offers an 3/4 grove main to help with this. FWIW I'm usig 1/2 grove mains.

Now if only I could find a cheap bow-tie block...
 
Ric1319

Ric1319

Donating Member
Re: Knock noise???

here is # 2 and 3 (front to back) bearing
imagejpg1_zpsa72d9619.jpg


here is #1 and 4
imagejpg4_zps32801caf.jpg


and her is the oil pan
imagejpg2_zps0a960678.jpg


Thanks for your input i'm getting new bearing monday, and i hope to be on the road soon.
 
Don W.

Don W.

Stab it and steer it
Re: Knock noise???

Those are perfect. Just don't forget to pre-lube them before install. Assembly lube, gear oil, Almost anything. Just use something light in color. That way you'll be able to see if you've brought along some dirt when you pre-lubed them.
 
Ric1319

Ric1319

Donating Member
Re: Knock noise???

Those are the old ones. I again thank you guys for the input. I hope to have it together this week end.
 
Ric1319

Ric1319

Donating Member
Re: Knock noise???

#2 and 3 have slight grooves in them.I can feel the grooves with my finger nails. I will be replacing them l with new ones.
 
Ric1319

Ric1319

Donating Member
Re: Knock noise???

Sorry about the delay been busy. Thanks guys for your help(DaveP, Typhoon#747, and DonW) I got it all back together that front diff sux to put back in by yourself. I still have a slight knock I'm going to check the fly wheel next. I took the bearing to a mechanic friend he said the bearings are normal for a truck with low miles and only get started once or twice a year. I'm have my truck upgraded with new injectors(60#), 3 bar map, FP, FPR, new turbo, TT chip and 3" DP with new exhaust pipes and muffler. Also I'm getting a new TC so when he does that he said he will look at the flywheel and the rear main seal. Again Thanks for your input. I love this site. :tup:
 
Syclone#2960

Syclone#2960

What ever it takes!!
Re: Knock noise???

Ric1319 said:
Sorry about the delay been busy. Thanks guys for your help(DaveP, Typhoon#747, and DonW) I got it all back together that front diff sux to put back in by yourself. I still have a slight knock I'm going to check the fly wheel next. I took the bearing to a mechanic friend he said the bearings are normal for a truck with low miles and only get started once or twice a year. I'm have my truck upgraded with new injectors(60#), 3 bar map, FP, FPR, new turbo, TT chip and 3" DP with new exhaust pipes and muffler. Also I'm getting a new TC so when he does that he said he will look at the flywheel and the rear main seal. Again Thanks for your input. I love this site. :tup:
Click to expand...

So the truck sat for 18 years? Do you hear the knock or see it through a scan tool? Is the fuel fresh? You think maybe injectors are jelled up from not running in 18 years?
Hard to help without the details. Those bearings look pretty normal. If it was showing copper then that would be a problem.
 
WyoSyclone

WyoSyclone

Active member
Re: Knock noise???

My Sy has always had injector noise (Kenne Bell Injectors) that sounds like a lower end knock.
I can take my mechanics stethoscope and scope the entire motor and it's quiet. I put it on each injector and I hear a bit of the noise. When I put it on the FP regulator, Holy Molly it sounds like a rod knock, but it's just the cumulative affect of the noisy injectors.
I've got a fuel line against the fire wall somewhere but can't seem to find "the spot", so it gets transferred inside the cab :( Need to get that fixed one of these days.
 
Ric1319

Ric1319

Donating Member
Re: Knock noise???

I heard the knock laying under the truck. I cleaned the fuel lines and injectors also put a fresh tank of 93. The truck was started a couple times a year along with a oil change. Yes the bearing looked good. There was no copper showing. With all of the work being done on my truck I will be able the check for a knock with a scan tool. I hope it's a lose bolt on the fly wheel or a cracked fly wheel.
 
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