midias

Before you crank with the valve covers off make sure you disconnect the coil or spark plugs so it does not start with the covers off. After you get the covers off have someone crank it over and watch the valves and look for one that does not want to open or close.

You might consider disconnecting your cat and trying to run without it just to make sure it is not clogged. Also check your plugs they may be new but sometimes on an older engine they foul fast with all the crap in the cylinders.

jdumas

You might consider disconnecting your cat and trying to run without it just to make sure it is not clogged. Also check your plugs they may be new but sometimes on an older engine they foul fast with all the crap in the cylinders.[/QUOTE]


I had the intermediate pipe disconnected to replace the fuel pump and the cat looked clear from the back side but I will try removing it altogther. I've already pulled the plugs and cleaned them once. The car hasn't run more than 15-20mins since then (mostly at idle). Would they really foul again that fast? I guess it's possible given how much crud was in the motor.

As for the valve inspection, do I have to drain any of the oil first? Also, should I spray any cleaner into the valve area while I'm checking them or will that damage them?

Thanks.

midias

Yes they could foul that fast especially if you put oil in the cylinders before start up and put in too much. Pull a couple out and look you can probably just clean them off.

For the valves you do not have to drain the oil just pull the covers off.

jdumas

Took off the valve covers and turned the motor over several times. Valve springs all worked fine and everything seems to be moving as it should. Is there anything else I should examine or try before I put the covers back on? I do have the plugs out and they are black so I know they are fouling. I'm guessing that the "red hot" cat might have been caused by unspent fuel in it? I want to put it back together later on tonight so any suggestions would be appreciated.

Tom 400 CFI

Glowing cat is caused by three things that I know of:
*Plugged exhaust down stream of the cat (this is often accompanied by LOUD induction/intake noise at open throttle)
*Un burned fuel
*Extremely retarded timing.

You've checked and re-checked timing, and you could run it w/the cat back off to confirm exhaust flow...but with you're distributor cap situation (basically, un known), and fouled plugs, I'd guess that your cat is glowing due to unburned fuel. You couldn't get a timing light flash/reading on your second check...I'm guessing you're getting cross fire/arcing in your cap and that is also causing your backfiring intake and exhaust.

PLEASE go by new plugs. I've never had good luck cleaning fouled plugs; for ME, they work O.K. for a little while, then foul again. Second, get a good cap and rotor on there. Wires too if you're feeling adventurous. What auto parts store doesn't have a cap and rotor for a SBC?? Geeze.

Third, check your fuel pressure
Fourth, test drive w/exhaust removed/disconnected to test for plugged system.
Fifth, report back.

ALSO, I'd be changing the engine oil after every trip for 3 or 4 trips. Why?

*You very likely have rust inside the engine (that's what causes the "stuck" engine). Flushing the oil flushes that out. Keep doing it.
*You have a noise that may be a stuck lifter. Ya GOTTA keep fresh, clean, detergent (new oil) going through that lifter to free it up -if it is infact a lifter.
*Oil is CHEAP compared to a motor rebuild. Use a lot of it to get/keep the motor clean during the first critical trips!!

I once "saved" a motor that was siezed due to sitting and rusted bores. It was a Junk yard motor that I was installing in a retard's boat. I too, filled the bores w/oil, let it sit, then turned by hand. It was so bad (rusty bores above the pistons) that at fisrt, it would only turn a little forward, and a little bit backward. I kept oiling the cylinders, and working it forward and backward making headway (more degrees of rotation) until it would make a complete revolution, and then continued to turn it by hand until it turned 360*...smoothly -with no "tight spots". Where do you think all that rust went that the rings scraaaaaped off the bores? Into the oil. I drained and refilled the oil before even trying to crank it with the starter. The ("brand new") oil was filled with rust, debris, etc.
With fresh oil, I cranked it w/the starter for "awhile". Long enough to pump the oil thorugh the system, and rinse out more rust. Then I drained and refilled again!
Then I did a compression check; 50 lbs in all but one cylinder which had ~120. Didn't look good. I installed the plugs and fired it up. Ran it for about 1 minute and shut it down....drained the oil. It was getting cleaner, but still was picking up a LOT of sediment/rust, etc.
Filled with fresh oil and fired it again. Ran for about 10 minutes...shut it down, pulled plugs and checked compression. 150 across the board. Rings and cylinders SAVED.
drained the oil AGIAN (starting to look clean now), and refilled, new filter and put the boat in the water. Ran for about 20 minutes, pulled boat and drained oil AGAIN, refilled/new filter and gave it back to the retard. Boat ran great for him until he sank it.

POINT? Use a lot of oil to get and keep that engine CLEAN! Oil is cheap.

midias

Go get 16 plugs and an extra change of oil get it back together with a new cap and rotor and try again.

jdumas

Put everything back together tonight, changed the oil and started the car. Started right up with no backfiring. Set the timing without a problem this time at 6 degrees btdc. The knock was still there however and when I checked under the car to see if the cat was superheating again, I noticed that the knock was as loud (if not louder) there. Could I be dealing with a rod knock or spun bearing? If so, how can I confirm this and what am I looking at (times-wise and/or cost) to fix?

Tom 400 CFI

Bummer about the noise.

You could be dealing with a rod knock. It could also be other things so to diagnose it, you have to use ALL the "clues" that you can combine together to get you the best diagnosis.

First, does the noise go away, or lessen when the engine is under load? And get worse with no load? That is a symptom of a spun rod bearing.

You can use a stethoscope or any long metal rod and place it against the engine, other end against your ear, and you'll hear the noise clearly. Move around the engine checking different locations and eventually, you should be able to narrow it down to a fairly specific area of the motor. If it is in the bottom, that is not good.

Another thing you can do is "kill" one cylinder at a time and see how the noise changes. It should make a big difference when you kill the offending cylinder. I recommend doing this by grounding one plug wire at a time, by back probing the boots either at the plug or the distributor. Use some dielectric grease to "ease insertion" and you can use any conductor for this but I prefer a test light for it's rigid, thin, pointed tip. Makes back probing easy and quick.

What does your oil pressure show?

Report back.

jdumas

The knock noise speeds up with acceleration but doesn't get any louder. Please excuse my ignorance, but I'm not sure how to actually back probe. Would please you explain further (connect what to what and where)? As for the oil pressure, when the car isn't fouling plugs and backfiring, it is about 45. When I was having the backfire issue, it dropped to a little below 30.

Tom 400 CFI

O.K. but does the knock subside when the engine is under load. For example, if you put it in gear, and give it say, 1/4 throttle (or more)...does the knocking reduce intensity or stay basically the same?



"Back probe" means to literally probe, or penetrate into the back side of a connector until you establish continuity with the metal pin or part of the connector that passes current/voltage to the next component...and to do so in a non-destructive fashion; you don't ruin the connector, it's connection or the sealing ability of it when you're done. In the case of the spark plug wire, you want to connect the metal connector in either the spark plug boot, or the cap end boot, to ground, thereby grounding (eliminating) spark to that specific cylinder.

The ultimate goal here is to "kill" one cylinder at a time so you can note any significant change to the noise in question, thereby helping our diagnostic process. You COULD just jerk plug wires off one at a time, but you'll be at risk of getting an electrical 'surprise'. Not to mention it's hard on the ignition coil. You could pull injector plugs, one at a time...but that is not too easy on a TPI.

Do you have a test light? This tool works the best, as it has an insulated handle, and sturdy, but thin, tapered probe and a nice clip on the other end to attach to a good ground. Lube the pointed tip of the test light, attach the clip to a GOOD ground and with the engine running, slip the test light tip in between the plug boot and wire insulator from the "back" side (plug WIRE side). Or, up by the distributor, between the wire's insulator, and the distributor post boot. As you slide the tip in, at some point the tip of the test light will get close enough to the metal clip/connector that the spark will jump to your test light and go to ground, rather than jump the gap in the cylinder...and that cylinder will cut out. It will be obvious. Not the "knocking sound" and slip the test light back out and move to the next boot. If the test light tip gets "dry", apply some more dielectric grease to keep insertions smooth and easy...and to prevent any damage to the boots or wire insulation. Clear as mud? Here is the best pic that I could find, to help...and it's not that great but...


If you don't have a test light, you can try to substitute something else that will accomplish the same thing; maybe a skinny small screw driver, with a wire wrapped around the shaft and attached to a good ground? Many options there. I like the test light 'cause it works so darn good.


Those are good pressure readings. Encouraging, I'd say.

Keep us posted...

travis401

iTrader: (1)

id go with the pulling one plug wire at a time. no need to get all fancy with testing equipment for it. yea you might get a shock, but its not that bad. ive shocked myself several times with spark voltage, and it really doesnt hurt.

Tom 400 CFI

A test light is "all fancy with testing equipment"? Yikes.

travis401

iTrader: (1)

using a test light to ground a spark plug wire instead of just pulling it off the dizzy is "fancy" yes.

Tom 400 CFI

If you say so.

I'm sure that the OP can decide what's the best method for him...now that he know all the options.

jdumas

I chose to pull the injectors off as they were easy to get to. No effect on the knock whatsoever. I didn't jack the rear up to try it "under load" as was suggested. I did notice that the motor really struggled when when the #3,#7, and #8 injectors were pulled. Was pulling the injectors the same as the back probing or pulling the plug wire ideas to diagnos the problem?

After I tested the injectors, I let the motor idle for a minute or so and kept a close eye on the oil pressure gauge. It stayed right at 45.

Now what?

Tom 400 CFI

Jacking the rear up is not putting it under load. That is NO load. Go drive it. Give it some throttle and see if the noise goes away. I am betting it won't based on what you said from the injector test -that the noise didn't change.


That means those cylinders are working the hardest...right now. I'd bet after some driving and oil changes, that will change as other cylinders' rings start working better etc.


Yep. That's the same effect.



Go drive it and see if the noise subsides under LOAD. I doubt that it will. If it does go away under heavy load, report back. If not, get the stethoscope/bar/rod and start listening around the motor to try to narrow down where the noise is coming from. Also you could take a vid and post it up so we can hear it.

jdumas

I will take a test drive in the next couple of days and put it under an actual "load" to see what happens with the knock. I suspect that, despite the oil pressure readings, it's probably a bad rod. I still have the other 305 from my wrecked '85 IROC that still ran after the accident. If the current motor turns out to be in need of a new rod(s) and/or crank, does anyone have any thoughts on just swapping motors vs rebuilding this one? I would most likely have the other motor at least "freshened up" before installing it (it has about 140k on it). My neighbor owns a garage in Syracuse that specializes in performance motors and transmissions (DAVCO Automotive). He told me he could rebuild the wrecked car's motor for around $1200.00. I'm guessing the current motor in the car would be more to rebuild? Is his price fair? (Note: I have never had a motor rebuilt before so I don't know what the going rate is). I've also thought about a crate motor but, given the low mileage of the car and it's overall condition, I'd like to keep a "numbers matching" motor in the car so either one of these motors wins out over a crate motor. Opinions please......

midias

Depending on what he does 1200 could be very fair. A lot of people have different ideas of what a rebuild is so I would get a list of what he will do to it. If it is a rod I would just swap motors then think about what you really want to do with the old one.

Personally I would swap in a crate motor and just keep the other around if you are worried about numbers matching but unless you have a weird or rare combo of car motor and trans I would not worry about it affecting value.

Tom 400 CFI

But still looking forward to driving results and "Stethoscope/rod" listening test.

jdumas

Took the car for a short drive tonight (about 2 miles). It ran rough (700r4 didn't want to shift easily) and the knock didn't go away under load. The oil pressure stayed just below 45 the entire time though. Pulled back into the garage and the back 1/2 of the cat was glowing red again. Pulled out the good ole' broken screwdriver and listened to the engine by each injector. The noise seems to be localized to the area above the #8 cylinder. Checked for codes and #42 showed up.

Now what?

Tom 400 CFI

This is good info. Thanks for reporting back.

I wouldn't go replacing engines yet...that's for sure. I don't think that you have a bad rod bearing from the evidence that we've obtained, thus far. Load didn't change the sound, oil pressure is good, Noise seems higher up in the engine? Not the symptoms of rod bearings.

Did you run the car with the cat-back disconnected? Remember that a restriction in the exhaust will cause parts of the exhaust to overheat (glow).

What's next?
1. Take a video and post it for us to see/listen to.
2. Take off the passengers side valve cover and SCRUTINIZE the operation of #6 and #8's valves/springs/rockers/pushrod. Take a vid of this too.
3. I'd say flush the auto trans fluid (a few times), but lets work out the issues with the engine first.
4. Code 42 =Electronic Spark Timing...
CODE 42
Trouble Code 42 indicates that there may be a malfunction in the Electronic Spark Timing (EST) system. During cranking, the timing is controlled by the ignition module and the ECM grounds the EST line. It expects to see no activity on this line at this time. When the ECM enters EST mode, it applies +5 volts to the BYPASS line and expects to see voltage variations on the EST line.
Reasons for the ECM to set Code 42:
? System in BYPASS mode (i.e. EST line supposedly grounded) but activity sensed on EST line
? System in EST mode (i.e. BYPASS line driven with +5 volts) but no activity seen on the EST line

Possible causes include:
1. BYPASS line is open or grounded
2. EST line is open or grounded
3. Poor connections between ignition module and ECM
4. Poor routing of EST harness and/or poor quality ignition wires (EMI induced electrical noise
5. Faulty or incorrect ignition module
6. Faulty ECM

jdumas

I was thinking of taking the oil pan off and examining the rod bearings to see if they were severely worn or broken (especially #6 and #8). I figured a good look at what is in the bottom of the pan might be and indication of what's going on as well. Good idea or waste of my time? Before taking the pan off, I will jack the car up and listen with the screwdriver from underneath to see if that helps me too.

InfernalVortex

iTrader: (4)

Could be a cracked flexplate.

Tom 400 CFI

Dropping the pan will allow you to inspect and give you total clarity on the condition of the bottom end. Unfortunately (an it's been a LOOOONG time so I may be wrong), I THINK that you need to pull the motor mount bolts and jack up the engine in order to get the pan out from between the block/crank and the cross member. Not a huge deal, but so you know. I will say that I'd rather see you diagnose (drop the pan if you must) than start throwing motors at it when the problem hasn't been found. I'm glad that you're considering dropping the pan -and pursuing the diagnostic process.

jdumas

Ya...checked the old Chilton and Haynes manuals and I will need to raise the motor but no biggie. I'm hoping to do this on Saturday. Thinking ahead..... if I do see that one (or more) of the rod bearings are shot, is there a way to see if the crank is damaged as well without pulling the motor? Or....if I do see that the rod bearings are damaged, should I just go ahead and pull the motor as opposed to trying to repair (and by that I mean replacing) the rod bearings? I know the bearings aren't that expensive but I don't want to keep sinking money into parts if the motor is shot. Thanks.

InfernalVortex

iTrader: (4)

You need to make sure you dont have a cracked flexplate or loose flexplate bolts too. They sound JUST like rod knock.

Also, if you have a bad rod bearing that means every single bearing in the engine needs to be replaced, likely the crankshaft will need to be turned also. It's a complete disassembly of the engine and that means new rings. That means a rehone. No point in doing all taht without getting the cylinder bored out enough to get the cylinders back in round again... new pistons... might as well replace teh timing chain and gears... cam... valve springs....

Get the picture? 1 spun rod bearing means the motor is toast.

jdumas

Thanks for the heads up. I'm guessing (more like hoping) a cracked flex plate (or loose bolts) wouldn't require anything other than replacing the flex plate?

InfernalVortex

iTrader: (4)

Yeah replacing the flexplate and bolts are the worst case scenario with that. Child's play. Getting to it is another story...

Tom 400 CFI

If the bearing is spun and you've run it, the crank journal is toast.

I am still not at all convinced that your problem is a spun bearing though. Looking forward to hearing what you find in the pan.

jdumas

Pulled the oil pan off tonight and found some small metal pieces in the pan. Many were crescent/half round in shape and about the size of a child's finger nail tip. I'd say there were about a dozen little pieces altogether. I didn't pull the flexplate off because metal shavings in the bottom of the oil pan can't be a good thing. I tried to move the rod bearings but they did not budge. There was a little front-back play within each pair of bearings but I'm guessing that would have to be there to prevent friction. I'm not sure what to do next. My neighbor (the engine builder) said he'd stop by tomorrow to see what I have come up with so far. I'm sure he will suggest rebuilding one of the 2 motors that I have. There's also an ad in the local Craigslist for a tuned port Jasper motor with 5000 miles complete with wiring/ecm and 700r4 for $800 obo. I know nothing about Jasper motors (are they re-manufactured motors?).

travis401

iTrader: (1)

jasper is a engine rebuilder. so yes its a re manufactured engine. if you have metal shavings in the pan then that engine needs to be pulled apart and rebuilt.

jdumas

So.....my neighbor came over this afternoon, looked at the oil pan and confirmed that the metal pieces were either pieces of a rod or main bearing. Looks like the engine will be coming out. Anyone got a cherry picker they want to lend me (or sell me cheap) in the Syracuse area?

Tom 400 CFI

T!hat is a bummer, man. That killing cylinders didn't change the sound make me think it's a main bearing. That sucks. Sorry to hear that and best of luck on the rebuild/swap

spurgeon76

You may want to make sure those aren't pieces from your valve seals. When I pulled my pan off I found half round and quarter round pieces of the valve seals that had come apart and settled in the pan. They were so hard we at first thought they were bits of aluminum because they were not magnetic.

jdumas

My neighbor did find pieces of a valve seal in the pan at first which got my hopes up. It was brief though because then he told me that another piece he found wasn't from a valve seal but from what he thought was a main bearing from the looks of it. It sucks all the way around......

spurgeon76

Man, that sucks!

Davidgou

iTrader: (2)

Very interesting. Just read the entire thread. I'm sorry to hear about your results and findings in that oil pan. Hope to hear good news about the rebuild/swap. Good luck!

jdumas

Ok....so this thread may migrate to an engine rebuild thread with lots of questions. The first one is.....

My neighbor thinks the metal in the oil pan could be from a main bearing which he says requires turning the crank at a machine shop. A local guy is converting his '85 305 HO into a 334 stroker and has his crank/flexplate/pistons/rods/and bearings for sale. He is asking $100 obo for them. The engine had 100k on it when he pulled it but he claims it ran like a top before he pulled it. I am beyond low budget on this rebuild and wondered if this is a more economical way for me to go than machining the current crank? Sorry if this comes under the "are you stupid?" category but remember I have no experience with this type of stuff (but am anxious to learn....).

InfernalVortex

iTrader: (4)

I would be dubious about whether or not it REALLY has only 100k on it. Those odometers usually only go up to 99,999 miles... (stupid). But if it only has 100k on it and you're on a budget... you CAN do it reeeeel cheeep.

Since it's only a 305... you may one day want to move on to something better.

You could tear the engine down to the bare block, clean it up. Clean out ALL the oil passages with compressed air/water/brushes etc whatever you need to do. Rehone the cylinders yourself, replace the main bearings and piston rings and put the other rotating assembly in there. Check bearing clearances on the mains and throw it back together. As long as the tolerances in the bearings are okay, it should last a while. It may be an oil burner, but it should work.

travis401

iTrader: (1)

a machine shop should only charge you $50-$100 bucks to turn and polish a crank. theres no guarantee that the crank you get from him wont need turning anyway.....

either way, you really need to tear that engine down to determine what direction you need to go with it before buying parts.

lemons racer

I'll through this in just for fun, when someone tells you about a low millage car look at the petals, if its say 75,000 miles there will only be minor wear on the rubber petal covers, if its 175,000 the petal will be worn through the ribbing, at say 275,000 it'l be worn through to the metal.

Thats nothing more than an old used car lot check.