Rod Knock? what do you think | Page 2 | Ford Explorer - Ford Ranger Forums - Serious Explorations

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Rod Knock? what do you think

Mudboy

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Just 4 months ago I bought my first gen with only 146k on it, with brand new tires, radiator, and top end gaskets replaced. I paid $900 for the whole truck. Some searching on craigslist should get you something good.
 



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H munster

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Have you by chance taken a look at your flex plate? Just replaced a broken 1 that sounded like a rod knock of death.
 






Facimeor

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^^ I agree. That was the only other thing I thought could sound like that. Pull the inspection cover and check it out.
 






Roadrunner777

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^^^ This crossed my mind too, only because I had a very similar sound in a car that kept backing out it's torque converter bolts. I could not draw a line with my limited experience from your situation to a problem with a flex plate, but if others can, I could agree.
 






Facimeor

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Well this is the way my mind works. When something breaks I run through scenarios in my mind to try explain the mechanism of the failure. When things break or fail due to age, that's harder to visualize, but when a failure is preceeded by an event it gives me a place to start.

In this case we have a previously not knocking rig that falls deep into a mug hole. Now I read the thread on the incident and I didnt see any place where the OP said he was trying to get it unstuck and was really working the motor hard. What I read was, truck went in, died, motor was shortly thereafter restarted and immediately had the knock.

Hydrolock could explain that if he could point to a point of entry for the water, but that to seems to not be fully discussed. Enough water in the motor to hydrolock it would also show up somewhere in the oil. It would show up as emulsification under the oil cap or on the dipstick, out the tailpipe, or in the pan. Thats why I asked the OP to drain a little oil and look at it.

What seems possible is that the motor hit the hole and water and mud and other possible debris entered through either a missing inspection cover or through the gaps there between the block and bell (there are openings meant to drain fluids, but in a submerged vehicle those can become entry points). If that water was cold enough and the flex plate hot enough its conceivable it could warp. Another mechanism would be some mud or small stones getting wedged behind the plate causing it to chatter. If the inspection cover was missing in the first place just the force of hitting the mud as the truck sank could crack it, bend it or wedge it.

You would also hear it more with the screwdriver stethescope down at the pan area. The spark plug wire pulling test also would do nothing, as the OP mentioned.

Beyond that, I think the OP is looking at a motor rebuild/swap
 






FIND

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Just get a stethescope from the parts store for 10 bucks, find where the sound is coming from and stop guessing.
 






StryctNy9e

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I dont have $10 for a stethascope. Im going to vegas next week and cant afford to spend ANY extra money before the trip. When I get back I will be getting paid and definetly pick one up. When I took out the air filter to check for water in the intake I did not see anything that stuck out to me. Meaning no dried water droplets inside air box, no puddles of water inside air box or water sitting in the intake. The filter was very dirty though(Repaced it) and I did not check these things until the next day and that was after the 25 mile drive home. The motor was revved to try to get the truck unstuck but iI dont ever remember hearing it hit the rev limiter(if there is one). I am also not sure what RPM the moto was revved to but did not sound like it was exsessive because I had a friend in the driverseat while I was knee deep in mud trying to push/pry the truck out. The more I think about the senario the noise did start after I restarted the motor 15-20 miniutes after I hit the muddhole and the knocking started.

I am pretty sure the flex plate inspection cover is still on and the flex plate was not exposed, But I will double check this and if it is still there I will take it off and check the flex plate for damage. I will probably do this In a few miniutes and let you know the results.
 






FIND

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You can describe your findings all day long and people can guess all day long, but until we know EXACTLY where the noise is coming from, no one can give you the correct answer, I am sorry. If you know anyone who has a stethoscope, borrow it from them, if you cannot afford one, you cannot afford the repairs or to throw the "solutions" people give you at it, and should probably re-examine your priorities if you need this vehicle. You need a stethoscope and a mechanical oil pressure gauge to get much of a meaningful diagnosis. A compression gauge may also be handy. Any other diagnosis will be through visual inspections. Pull your plugs and look down into the cylinders and at the plugs for any obvious signs, look at your exhaust manifold for cracks, pull your starter off and crank your engine over by hand (battery disconnected) so you can look for cracks in the flex plate and visually inspect the rest of your engine. Pull your MAF sensor off, if you have a multimeter you can test it, but, you can give it a visual inspection too, then see if the elements are shorted or broken.

Since when does a 1st gen have an inspection cover for the flex plate? All the first gen transmissions I have seen, the only way to access the flex plate with it attached to the engine is to take off the starter.
 






StryctNy9e

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there was no inspection plate for the flexplate. I did just pull off the starter and did crank the motor by hand and did not see any cracks in the flexplate or any visual damage. I did buy a oil pressure gauge and it was 60 [email protected] The haynes says normal is [email protected] From what I can tell with the scrwdriver-2-ear trick is that it seems to be loudest at the oil pan. I will have a check waiting for me when I get back from vacation, so I will have the money to fix the problem, even if it is a motor swap. I appreciate all the information and help. I was mainly looking to narrow down the problem and figure out what it can be so when I get back from vacation and have the money I can fix it. From all the test I have ran it seems to be rod knock. The only other step I can think of is pull the valve covers and check operation/visual inspection if anything is obviously broke. But the car is my daily driver so I am leaning to the option of just replacing the motor to solve the problem and get mt EX back running the way it should be. By the way 1993 XLT automatic tranny w/144,000 on it.
 












StryctNy9e

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Thanks for the time and advise to everyone. I was hoping to solve the problem but oh well mistakes are made and will be corrected. Now research for my first FORD motor swap.
 












jelkins

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StryctNy9e i was just curious if you ever found your problem seeing that here recently i was mudding and actually sucked a whole lot of mud/water into my intake for a fact i pulled off my recently bought air filter (bought 45 mins before mudding) and it fell apart soaked in muddy water and a week or two later i noticed it had an knock but it only knocks when my engine warms up.
 






Mudboy

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Why aren't you guys running snorkles? Where we go there is alot of deep water(esp with Irene just hitting), Snorkle is on of the first madatory mods along with raing the vents on the diffs, trans, and t-case. If I go out wheeling tehre are two things I don't want to end my day. first one being water related issues, second being something of poor maintnance. If I break it better be in teh diff, or an axle shaft or a roll over. If you go out with this attitude it will make your day alot longer and enjoyable. Nothing worse than wrenching on the trail due to an already half broken truck being taken onto teh trail or not bei9ng prepared for the terrain.
 






unclemeat

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You can pull the air tube between the headlight and the filter box and give yourself at least 12-inches more water depth.
 






StryctNy9e

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Jelkins, After extensive trying, couldnt find the problem, so I swapped the motor and it went away and to mudboy if you read learning the hard way, in the whoops section, I have pics and tell the whole story.

Unclemeat thanks for the tip
 






Mudboy

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Jelkins, After extensive trying, couldnt find the problem, so I swapped the motor and it went away and to mudboy if you read learning the hard way, in the whoops section, I have pics and tell the whole story.

Unclemeat thanks for the tip

I'll check that out. I never really read that section
 






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