Screeching +Smoke = a bad night.

[enginerd]

Update: Solved the screeching and smoking, but still struggling with a high idle. Any help with this issue is appreciated. More details below.

Hi Everyone,

Year: 1996
OMC 5.0 FI (ford 5.0)
Model #: 50FAPNCA
Serial #: T01288736

I have been trying to learn as much as I can from this forum without being a pest. Thankfully, I usually find what I need without asking...but my searches came up empty this time. Please Help! :blue:

My wife and I bought my boat last fall. We replaced the interior, fixed the trailer, gas lines, etc. I had a local (and well respected) marine shop perform a compression test, engine tune-up, drive service, and water pump this summer. On their water test, they discovered cylinder #1 wasn't getting any fuel. They were willing to keep working on it, but wouldn't get to it until after July 4, so I tackled the job myself.

I took my stethoscope and confirmed cylinder #1's fuel injector was not firing. A local injector specialist checked/clean all the fuel injectors and confirmed the Cylinder #1 fuel injector was dead. I bought a new injector and installed it. I confirmed the new injector was firing with my stethoscope.

We took the boat out for the first time since the work tonight. The boat was an entirely different animal. It was pure bliss. We cruised around the lake at 25-35 mph for about a half hour. I then decided to open it up. It took off like a rocket all the way 65 mph, which is about 10 mph faster than we have seen. WOT was less than 5 minutes total.

We then idled in/out the channel which took probably 30 minutes. On the way back in, I noticed the idle speed was surging +/- 100RPM. This seemed to follow the waves though. I assumed it was the wave hitting the thru-hull exhuast.

We then cruised a bit more, but when I opened the boat up again, top end was only around 50mph. Frustrated, we called it a night and cruised back to the launch. At the ramp, we discovered our idle was no longer surging, but at 1500 rpm. (normal 600)

High idle. Loss of power. No other symptoms.

As we pulled it out of the water, I noticed the swim deck had black silt on the right side (cylinder #1). I thought to myself..."Eureka, who knows how long that fuel injector was dead. It probably has years of carbon built up in that cylinder. I bet it fouled the plug. I'll replace the spark plugs again and sea-foam the engine tomorrow. This is going to be easy. :facepalm:."

In the driveway 45 minutes later, I decided to make sure my new fuel injector was firing. I started the engine up (on a hose) and heard the worst screeching noise I heard in my life. It seemed like an eternity, but in reality I killed the engine in less than 3 seconds. Then white smoke started pouring from the exhaust.

Any ideas? I really hope the motor isn't toast. I don't understand how an engine can go from awesome, to mediocre, to worthless in one evening. My wife (and I) will be crushed if the motor is gone.

Please help if you can. Thanks!
Eric

 

[HT32BSX115]

Re: Screeching +Smoke = a bad night.

Hi Everyone,

Year: 1996
OMC 5.0 FI (ford 5.0)
Model #: 50FAPNCA
Serial #: T01288736

I started the engine up (on a hose) and heard the worst screeching noise I heard in my life. It seemed like an eternity, but in reality I killed the engine in less than 3 seconds. Then white smoke started pouring from the exhaust.

Any ideas? I really hope the motor isn't toast. I don't understand how an engine can go from awesome, to mediocre, to worthless in one evening. My wife (and I) will be crushed if the motor is gone.

Please help if you can. Thanks!
Eric

Howdy,

Welcome aboard!

Well I don't really think your engine is "toast".

You have an engine driven raw water pump......

sounds like (for some reason)it is frozen (or seized).........so the belt is slipping and making the screeching sound.....no raw water flow in the exhaust will result in "smoke" pretty quickly....

Remove the belt and see if it is seized and while your at it, check the other belt driven components and see if they turn freely.


Regards,


Rick

 

[enginerd]

Re: Screeching +Smoke = a bad night.

Thanks for the response Rick. I'll take the belt off tomorrow morning and report back.

It is so frustrating trying to find parts. If the motor is shot (which I really hope it isn't) I'll have more questions about your mercury conversion. Granted my little u17 can't fit a big 7.4 like your Liberator.

Thank you again. I really appreciate it!
Eric

 

[chrisrooter]

Re: Screeching +Smoke = a bad night.

I have a 2.3 omc and it overheated stuck thermostat and housing all junked up. Temp. Climbed and it was squealing like a stuck pig. Removed and installed new flushed system checked riser for clog. What was your temp running? And she was smoking too on the water steered off channel and took engine doghouse off, she was hot! Funny thing is ,ust have been big air pocket. Once she could down I guess the thermostat popped open and started circ. water. Ran fine at 160 ish back to the dock. Of course I did not push nor did I trust it either. I was freaking thinking the motor was shot and warped right before my eyes. Amazing the stress on the poor little 2.3 when temp climbed over 225 pushing 250.

 

[HT32BSX115]

Re: Screeching +Smoke = a bad night.

Thanks for the response Rick. I'll take the belt off tomorrow morning and report back.

It is so frustrating trying to find parts. If the motor is shot (which I really hope it isn't) I'll have more questions about your mercury conversion. Granted my little u17 can't fit a big 7.4 like your Liberator.

Thank you again. I really appreciate it!
Eric

Hi Eric,

Well, screeching noises are of course mechanical and are usually v-belt (or serp-belt) driven components. So if it isn't your raw water pump, it might be the alternator or PS belt (if they're separate)

Amazing the stress on the poor little 2.3 when temp climbed over 225 pushing 250.

Yeah. You REALLY don't want the engine getting that hot.

You didn't say what the "smoke" was. If it was indeed smoke, you would have had to run the engine more than 3 sec for the rubber exhaust components to start burning.

If it was steam, that would be logical if there was little or no water flow through the risers (indicating a possible stuck/failed raw water raw water pump.

But it usually takes more than 3 sec to produce enough heat to get steam.

I would pull the belts and try to turn the driven components by hand (raw water pump, ALT, power steering pump etc) to see if they're free.

 

[chrisrooter]

Re: Screeching +Smoke = a bad night.

Hi Eric,

Well, screeching noises are of course mechanical and are usually v-belt (or serp-belt) driven components. So if it isn't your raw water pump, it might be the alternator or PS belt (if they're separate)



Yeah. You REALLY don't want the engine getting that hot.

You didn't say what the "smoke" was. If it was indeed smoke, you would have had to run the engine more than 3 sec for the rubber exhaust components to start burning.

If it was steam, that would be logical if there was little or no water flow through the risers (indicating a possible stuck/failed raw water raw water pump.

But it usually takes more than 3 sec to produce enough heat to get steam.

I would pull the belts and try to turn the driven components by hand (raw water pump, ALT, power steering pump etc) to see if they're free.

My screeching was a tea kettle/whistling boiling. Sounding like train brakes getting slammed on. And yes it was a steam whistle due to no water, until it sat cooled a few and t-stat opened. Got worried about all the cooler water pouring into a hot block everything worked out ok. Luckily I shut it down when temp spiked.

 

[enginerd]

Re: Screeching +Smoke = a bad night.

I was watching the temp gauge pretty closely. It stayed between 145 and 160 the entire night.

I took the belts off and started it up for about 5 seconds. The screeching noise disappeared. :joyous: The motor still let out quite a bit of smoke. The smoke was white and smelled like the smoke when you blow out a candle. The exhaust didn't disappear/dissipate, it lingered like candle smoke too. I'm thinking my carbon build-up theory might be correct, combined with Rick's comment about no water in the exhaust.

The power steering pump and alternator both spin freely. The raw-water pump seemed stuck. Once it broke free (by hand) it spun by hand fairly easily. However, it didn't spin freely, but they are not supposed to. Correct?

The screeching noise wasn't like any belt noise I have heard before. It sounded like metal on metal. I'm going to tear apart the 2-week old raw-water pump and see what I can find. I'll take some pictures of what I find.

You guys are the greatest, especially Rick. I told the "respected" mechanics what happened and they didn't have a clue. Thanks again!

Eric

 

[HT32BSX115]

Re: Screeching +Smoke = a bad night.

I was watching the temp gauge pretty closely. It stayed between 145 and 160 the entire night.

Um, you ran the engine all night? If that temp is accurate, it's fairly normal.

I took the belts off and started it up for about 5 seconds. The screeching noise disappeared. :joyous: The motor still let out quite a bit of smoke. The smoke was white and smelled like the smoke when you blow out a candle. The exhaust didn't disappear/dissipate, it lingered like candle smoke too.

You don't want to run the engine very long like this. The exhaust system is cooled by water. stop the water flow through the exhaust system and things will start burning.

I'm thinking my carbon build-up theory might be correct, combined with Rick's comment about no water in the exhaust.

I am not sure where you think "carbon" might be "building up". Remember, this is a 4 stroke engine. carbon doesn't build up (anywhere) unless the choke is stuck. The engine will barely run that way.

The raw-water pump seemed stuck. Once it broke free (by hand) it spun by hand fairly easily. However, it didn't spin freely, but they are not supposed to. Correct?

The raw water pump may have been "starved" of water. it only takes a minute or so and it can be "toast".

Also, if you have a power steering oil cooler (pretty common) or an engine oil cooler (not common on small v-8's or smaller engines) it could be clogged by rubber raw water impeller fragments from the impeller that failed or other impellers that failed in the past.....

The screeching noise wasn't like any belt noise I have heard before. It sounded like metal on metal. I'm going to tear apart the 2-week old raw-water pump and see what I can find. I'll take some pictures of what I find.

I know we'd all like to see that!

btw, what sort of enginerd are you?

 

[enginerd]

Re: Screeching +Smoke = a bad night.

Um, you ran the engine all night? If that temp is accurate, it's fairly normal.

We ran it it for only 1-2 hours, once I sensed something was wrong we headed in. Temp seemed to rise at idle and go back down at speed.

You don't want to run the engine very long like this. The exhaust system is cooled by water. stop the water flow through the exhaust system and things will start burning.

Yup, that is the first/last time it will be started without water. My initial thought/fear to the metal-on-metal sound was that something horrible happened to cylinder#1. I'm very relieved that the screeching went away

I am not sure where you think "carbon" might be "building up". Remember, this is a 4 stroke engine. carbon doesn't build up (anywhere) unless the choke is stuck. The engine will barely run that way.

Here is my thought process. I only think carbon is built up in cylinder #1. According the FSM, the fuel injector is designed to flow more fuel if it gets dirty to prevent detonation. I'm tempted to believe that the injector failed "open" several years ago. I don't think the previous owner had a clue about the #1 cylinder fuel injector. So it could have had 8+ years of rich running. Or at least until the plugs fouled.

After a new plug and injector, cylinder #1 started making fire again and tried burning off the residue. The swim deck was covered with black residue on the cylinder #1 side.

Seem logical?

The raw water pump may have been "starved" of water. it only takes a minute or so and it can be "toast".

It could have. I think the temperature would have spiked...? Or it could have happened just as we pulled into the dock.

Also, if you have a power steering oil cooler (pretty common) or an engine oil cooler (not common on small v-8's or smaller engines) it could be clogged by rubber raw water impeller fragments from the impeller that failed or other impellers that failed in the past.....

I know we'd all like to see that!

Pictures to follow.

The mechanic showed me the old impeller. It looked like a dog chewed on it. We replaced the entire assembly as the brass housing had some scoring. I don't see an oil cooler, but I'm fairly sure it has a power steering cooler. I'll try to get to it.

btw, what sort of enginerd are you?

Mechanical Engineer...but I have been spending more time managing projects lately.

Thanks Again. I'm hoping you are all getting to enjoy the summer today.

 

[HT32BSX115]

Re: Screeching +Smoke = a bad night.

The mechanic showed me the old impeller. It looked like a dog chewed on it. We replaced the entire assembly as the brass housing had some scoring. I don't see an oil cooler, but I'm fairly sure it has a power steering cooler. I'll try to get to it.




Mechanical Engineer...but I have been spending more time managing projects lately.

Thanks Again. I'm hoping you are all getting to enjoy the summer today.

Yeah. I'm going to Anchorage today.... Up the "fast" way and back the "slow" way.....

That impeller is probably most important.

It's very possible that you "grabbed" a plastic bag or something else that "starved" it (or ran it dry for too long) . They don't live long running dry.

Also, make sure that any pieces of the old impeller are recovered so they don't plug something up! like the PS cooler or T-stat housing etc.....



Electrical here, but I only do it for a "hobby".......Like working on boats! (my own!)
......I have a different and totally unrelated job!

Cheers,


Rick

 

[enginerd]

Re: Screeching +Smoke = a bad night.

I use my degree for my hobbies than my job too. I've mentored a FIRST robotics team for the last (4) years. That challenges my brain way more than my day job. Even though it can be a complete PITA, I still enjoy working on it. Maybe I'm still on the honeymoon...

Both the intake and exit lines were full of water. I couldn't find anything too wrong with the raw-water pump. The bearings spin freely without noise. Nothing was clogging it and there were no wear marks on the brass. However, I did notice some stress marks on the rubber impeller. Is that normal for an impeller with only a few hours on it?



I don't see anything that would have caused this thing to stick. I'm going to take the power steering cooler off to see if I can find anything. I'll probably replace the thermostat too. Are there any other places chunks of past impellers would like to hide?

I hope you are going to Alaska for fun...not work. I've always wanted to take a train tour there.

Thanks Again,
Eric

 

[HT32BSX115]

Re: Screeching +Smoke = a bad night.

I use my degree for my hobbies than my job too. I've mentored a FIRST robotics team for the last (4) years. That challenges my brain way more than my day job. Even though it can be a complete PITA, I still enjoy working on it. Maybe I'm still on the honeymoon...

That is some pretty cool stuff!

Both the intake and exit lines were full of water. I couldn't find anything too wrong with the raw-water pump. The bearings spin freely without noise. Nothing was clogging it and there were no wear marks on the brass. However, I did notice some stress marks on the rubber impeller. Is that normal for an impeller with only a few hours on it?

from the pictures, it all looks pretty normal..

I don't see anything that would have caused this thing to stick. I'm going to take the power steering cooler off to see if I can find anything. I'll probably replace the thermostat too. Are there any other places chunks of past impellers would like to hide?

They can get into the T-stat housing but they usually aren't associated with "noise"

I hope you are going to Alaska for fun...not work. I've always wanted to take a train tour there.

It's "work" but it's pretty easy.


Did the noise stop when you briefly ran the engine with the belts removed?

Were those belts tight? Alternator and PS belts can make a pretty good racket if they're loose (I am guessing you checked that stuff first)

 

[enginerd]

Re: Screeching +Smoke = a bad night.

Did the noise stop when you briefly ran the engine with the belts removed?

Yes, they did. Another impeller and new belts and the screeching went away. Smoke is gone too. Hooray!

I'm still struggling with an extremely high (1500rpm) idle. When I rev the engine, it seems to linger instead of returning back to 1500rpm right away. This is what I did so far:

-Inspected throttle cable.
-Sprayed the connectors with electrical cleaner.
-Sea-foamed the engine.
-Unplugged the IAC, which I read should effect idle if bad? It didn't do anything. My next step is to clean this.

Anyone have any other ideas? I'm stumped.

 

[enginerd]

Re: Screeching +Smoke = a bad night.

I decided to be a considerate neighbor and put the boat away for the night. I haven't found much information here, so I started Ford Forums.

Here is my checklist:

1. Clean IAC
2. Clean Throttle Body
3. Clean MAF
4. Test TPS, replace if necessary.
5. Check throttle cable again.
5. Read this more: Help me create the "Surging Idle Checklist" | Mustang Forums at StangNet
6. Read this some more Mustang Basic Maintenance and Technical Articles

If you guys have anything else to add, please do. The Idle was fine until we putzed through the channel for a half hour.

 

[HT32BSX115]

Re: Screeching +Smoke = a bad night.

I'm still struggling with an extremely high (1500rpm) idle. When I rev the engine, it seems to linger instead of returning back to 1500rpm right away. This is what I did so far:

-Inspected throttle cable.
-Sprayed the connectors with electrical cleaner.
-Sea-foamed the engine.
-Unplugged the IAC, which I read should effect idle if bad? It didn't do anything. My next step is to clean this.

Anyone have any other ideas? I'm stumped.

Hi idle is a killer for stern drives. It will eventually damage the cone clutch if you shift into gear at higher than normal RPM.

You may have a throttle cable and/or linkage adjustment problem. Adjustment usually entails disconnecting the throttle cable/linkage from the carburetor (or throttle body if EFI) and doing any idle adjustments.

Then you reconnect the cable (with the control in neutral) making sure it doesn't move the throttle plate when it's connected

If you don't have an OEM OMC service manual it would help to get one.

 

[enginerd]

Re: Screeching +Smoke = a bad night.

Hi idle is a killer for stern drives. It will eventually damage the cone clutch if you shift into gear at higher than normal RPM.

You may have a throttle cable and/or linkage adjustment problem. Adjustment usually entails disconnecting the throttle cable/linkage from the carburetor (or throttle body if EFI) and doing any idle adjustments.

Then you reconnect the cable (with the control in neutral) making sure it doesn't move the throttle plate when it's connected

If you don't have an OEM OMC service manual it would help to get one.

I don't plan to run it until I get this idle figured out. I disconnected the throttle cable, but that did not change anything. I cleaned the throttle body which was stuck open partially with grime, but that had no effect either.

I'm working through the manual, but I'm not having too much luck.

 

[HT32BSX115]

Re: Screeching +Smoke = a bad night.

I don't plan to run it until I get this idle figured out. I disconnected the throttle cable, but that did not change anything. I cleaned the throttle body which was stuck open partially with grime, but that had no effect either.

I'm working through the manual, but I'm not having too much luck.

I hop that's either an OMC or a Volvo manual. The aftermarket ones seem only good for starting your woodstove...

I am not at all familiar with any the old Ford EFI marine engines.

I would look for anything holding the throttle plate open a little, vacuum leaks etc.

Maybe a there's a scan tool you can get and hook up, I think that yours being a 96 model, it may still be supported by Volvo...... but I do not know for sure. I know the earlier OMC Ford EFI engines (injection and Spitfire ign) are not supported by anyone now....but I think you're all Volvo.

 

[enginerd]

Re: Screeching +Smoke = a bad night.

Here is what I eliminated as a cause:

IAC
- Clean as a whistle, cleaned it anyways.
- Made sure it was getting voltage.
- Replaced valve with neighbors finger...then duct tape after his finger got sore, no change in idle.

MAF
- This model does not have a MAF...bummer. It does have a MAP, but that can't be cleaned as far as I know.
- I think it might replace it.

Throttle Body
- Full of gunk, kept it from closing.
- Cleaned with throttle body cleaner and paper towels until spotless. Now closes tightly.

TPS
- Stays within the specified voltage.
- Increases/decreases voltage smoothly when turned.

Throttle Cable
-Removed entirely. No change in idle.

Vacuum Leaks
- No obvious leaks.
- Tried the carb cleaner method, couldn't find anything.


The "to-do" list:
- Engine coolant sensor? The gauge seems accurate, but maybe the singal to the ECU is bad?
- Learn how to pull codes DIY KOEO/KOER/Cylinder Balance Self-Test Procedure
- Pull codes
- Look for another mechanic. I'd appreciate any recommendations for west Michigan.


I'm leaving for a long weekend in northern Michigan. I was hoping the boat would come with, but that is life. I hope everyone has a great 4th!

 

[HT32BSX115]

Re: Screeching +Smoke = a bad night.

Well,

Looks like you're getting there....

Hope your trip goes well!

I'm going to Shasta Lake for a week or so. My boat is carbureted!


Cheers

Rick

 

[enginerd]

Re: Screeching +Smoke = a bad night.

Trip was great. I hope everyone else had a great 4th.

I replaced the thermostat last night. I had the parts, so I figured that it'd be worth a shot. The engine doesn't seem to warm up, so I thought maybe the thermostat was sticking. (I thought the computer was trying to warmup the engine) I was excited when I started it today and it stayed at 750 RPM. To my dismay, the engine returned to the high idle in 30 seconds.

I noticed a draft by the throttle cable linkage. I followed it to the crankcase breather tube under the flame arrestor. I put my finger over the tube and the engine died in less than 5 seconds. I checked the PCV and it seems to be operating fine. The manual says to cover this tube with a "3x5 memo card." It should be sucked against the hose with a noticeable force. It sucked onto my finger, it should hold the card just fine.

Is it normal for an engine to die when the crankcase breather is blocked?

Thanks Again,
Eric