Engine/Transmission (1994 - 1998) Whats knocking????

[SEmerson]

I have a 97 engine out of a crash. It had the front hit hard. It bent the oil pan and pickup tube. It broke the gear housing timing cover. And also spun the crank tining gear 15-20 degrees. When this happened it bent the exghast pushrods.



I had the crank out. all bearings look fine. Valves looked fine. No bending that I could see. I looked them over when I put on my valve springs.



So I put a timing gear on the crank, pushrods, timing cover, oil pan, pickup tube, gear cover on it. I also added all my 97 perf parts, also I used my 180 pump. I set the timing at 17.



So I put it in. Runs fine sound good. But has a knock. Not one you hear bad but you can feel it. Doesnt sould like a rod. But has a consistant pulse. Also sounds like heavy metal.



I put a stethiscope on checked it all over. It sounds like it is in the front. I did think maybe I have a chiped timing gear that I missed. But it sound to heavy for that.



I changed fuel pump. Pulled valve covers and looked at valve train. All have clearance and seem to operate fine. No miss. Nexted I pulled oil pan and tube. All bearing caps seem fine. Starting it and laying under the engine with no pan it sounds fine. Turning it over with a screwdriver nothing seems to bind of sound funny.



I am at a loss to what it could be. Next I will remove the tc and slide it back to see if that does any thing. Also I will remove the vacuem pump. But I don't think they could be it since my old engine didn't have the knock.



Also I put in my old 370 injectors in. They where carboned up so I wire brushed the tips. Is it posible to get a injector knock but still seem to run smooth?



Any ideas?

 

[JTeague]

try cracking the injector lines 1by1 at idle to see if the noise changes. You may at least be able to narrow it down to 1 cylinder causing the noise. BTW did I read that correctly? you said you ran the engine with the oil pan off?

 

[SEmerson]

yes but only for 5 secound or so at a time and only a few times.

 

[Vaughn MacKenzie]

Did you mic the bores to make sure the block wasn't tweaked (distorted) from impact?

 

[SEmerson]

No I looked close for cracks and bends everywhere.

 

[hsmith]

Well, that sort of thing can certainaly create a "new" knock. Also curious what were you wearing? A wet suit maybe?

 

[Bob4x4]

I personaly would never use a wire brush on an injector tip... ... ... . soak it in cleaner than maybe a tooth brush.



Bob

 

[SEmerson]

Well, that sort of thing can certainaly create a "new" knock. Also curious what were you wearing? A wet suit maybe?

I really wasn't that bad. But a very interesting experance.



It is not a injector. Changed them out still knocks.

 

[SEmerson]

When I lossen #1 line the knock stops. I changed the injectors. It still knock. Swaped 1 and 2 dv. No change. So I am now taking out the engine.

 

[DMcPherson]

could be a few things if the bearings looked ok, check them again after running with no pan. their could be a bad wristpin or the face of the crank journal could be worn, letting the rod knock back and forth.

 

[SEmerson]

Knocked before no pan. And it sounded fine from the bottom. I will pull out #1 piston and take a look. When I get it out. But for now I have a 2nd engine I can put in.

 

[EXSTROKER]

Man and I thought the guy's with the ford 6. 0

had it bad... sorry about your luck

 

[PKirby]

Did you check the crank endplay with a dial indicator? The impact could have damaged the thrust bearing. I would also check the cam and all other gears in the front cover for runout while turning the engine with a barring tool. I would have a engine machine shop check the crank for cracks and straitness. Sometimes cracks can't be seen without magnafluxing.