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Strange Noise When Starting Engine - 2006 5L V8 Mercruise

ChrisUK

New member
Hi, new to this forum so apologies if there is already a thread on this. I have a 2006 Maxum 2000SR3 running a mercruise 5L, V8. I have just swapped the batteries out, and ever since the engine makes a strange noise when starting (probably coincidental) - the engine starts, but there is what I can only describe as a loud grinding (ish) sound; The video at the link shows it far better than I can describe https://youtu.be/3s50oG6Dq3U


Not being massively mechanically minded, I suspect it might be an issue with the starter motor, but would welcome any advice or comments from those in the know.


Many thanks for for your help.


Chris
 
Sounds to me that your starter motor bendix gear is not retracting fast enough to avoid being driven by the flywheel. There are two reasons for this:

1. It's binding do to (lack of lubrication?)

2. The starter isn't shimmed correctly IF your engine is set up that way.

Jeff
 
The noise occurs at 2 seconds into the video, just as the engine begins to turn over with starter motor engagement.
I'd be inclined to think that the starter motor nose housing bushing, or a starter motor bearing, is causing this.
 
Hi Jeff, thanks for the response. Looking at the manual, I don’t believe my engine is shimmed. Would you suggest taking the starter off and lubricating - I can’t see any way of lubricating otherwise.
 
Thanks Rick - is this a new starter motor job, or would you recommend replacing bushing and service the current motor. Looking online a new motor seems to be anywhere from $70 - $200. If the cheaper motors are reliable, I’m tempted to swap out the entire unit to save issues further down the line.
 
Sounds to me that your starter motor bendix gear is not retracting fast enough to avoid being driven by the flywheel.
I don't believe that is it.
Watch the video again. If the audio matches the video, the noise occurs during starter motor action, not afterwards.


There are two reasons for this:

1. It's binding do to (lack of lubrication?)

2. The starter isn't shimmed correctly IF your engine is set up that way.

Jeff
Your #1 and #2 suggestions may be right on target!

FYI....... in 2006, the GM SBC 5.0L starter motor would be one of the HTGR/PMGR starter motors, of which would use the solenoid lever action sprag clutch style pinion gear. (the Bendix style starter motor hasn't been used for years).


Hi Jeff, thanks for the response. Looking at the manual, I don’t believe my engine is shimmed. Would you suggest taking the starter off and lubricating - I can’t see any way of lubricating otherwise.
Yes, you would want to remove it in order to lube the shaft/pinion gear area.

Thanks Rick - is this a new starter motor job, or would you recommend replacing bushing and service the current motor? Looking online a new motor seems to be anywhere from $70 - $200. If the cheaper motors are reliable, I’m tempted to swap out the entire unit to save issues further down the line.
If this is a 2006 Merc OEM starter motor, you would pay dearly for a Merc OEM replacement.
You can buy an after-market HTGR/PMGR unit for much less.
However, since you have the OEM, I'd be more inclined to have it rebuilt.

If you do buy an after-market unit, make sure that you get the bolts with it.
Reason: not all starter motor nose housings are the same today, therefor the OEM mounting bolts may be of the incorrect length.
Too long, and they will bottom out before fully clamping the nose housing to the cylinder block, causing them to eventually break.

Also, you can safely use Automotive Never-Seez or Anti-Seize on the threads.


.
 
You reference a new battery.
Why a new battery and are you sure the connections are good and tight?
Did you mistakenly damage the starter or any of its connections when reconnecting battery cable?

Do a restart and get as close to the starter as possible and see if it really is the starter. See if the starter is loose or is moving as the engine turns over
Using a long screwdriver with the steel part touching the body of the starter and the plastic end against your ear it will act kind of like a stethoscope and magnify the sound.


If the starter is the issue then,

""Not being massively mechanically minded""

Chris nailed it.

any of the other "advice" offered rally makes no difference.

Based on what that engine looks like and appears to run like and "Not being massively mechanically minded" the purchase of an OEM starter should be the correct direction regardless of price. Keep it as nice as it appears.

If you go with aftermarket, good/quality ones are typically $150 ish US dollars. I would not trust anything that is to much less.

As far as type, the "HTGR/PMGR" doesn't really matter anymore. virtually all standard SBC replacement marine starters are the newer smaller types. Just confirm the OEM part number based on year or serial number.

What is key is the bolt pattern.
Either straight across or offset. You can visually see this.


Boats are not cheap to maintain.
 
Many thanks for the various advice guys. So I pulled out the starter and just had it bench tested. The bench test suggests it working fine - the motor spun freely and the drive pinion extends and retracts smoothly.

I’m going to lube the various components as suggested, and try it back in the boat. I’m also going to check the ignition switch and any relay to ensure that isn’t sticking, although it didn’t feel like it previously..... any more ore suggestions before I put it all back together?
 
You reference a new battery.
Why a new battery and are you sure the connections are good and tight?
Did you mistakenly damage the starter or any of its connections when reconnecting battery cable?

I replaced the batteries as when the boat was last used (not by me...!:mad:) the batteries weren't isolated when the boat was left and fully drained. When I checked them, they had both been damaged and not holding charge.

When I swapped them, I was very careful to ensure everything went back in the right place and tight. I don’t believe anything was damaged. I’ve also tested the slave solenoid just in case that was part of the issue, and all is good with it.
 
Many thanks for the various advice guys. So I pulled out the starter and just had it bench tested. The bench test suggests it working fine - the motor spun freely and the drive pinion extends and retracts smoothly.

I’m going to lube the various components as suggested, and try it back in the boat. I’m also going to check the ignition switch and any relay to ensure that isn’t sticking, although it didn’t feel like it previously..... any more ore suggestions before I put it all back together?

Yeah. Replace the starter.
 
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