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Starter runs but engine does not turn over

david_t

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"1994 3.0 Starter was making a

"1994 3.0 Starter was making a whirling noise but engine would not crank/turn over. Checked out the starter at auto store and starter is good. Bought new batt., reinstalled starter and the engine started fine for 2 days. At the end of the next wkend starter would only whirl again and engine would not crank. I replaced the old starter but same problem still occurs. Starter whirls but engine does not turn. Replacing the starter I found the long bolt is missing and I can't replace right now beecause the threads are broken off in the block and will need to be removed. Also the short screw does not thread totaly tight. Viewing the fly wheel thru the hole where the starter fits in it appears teeth are ok to the best I can see and the fly wheel can be turned. If not the battery and not the starter..., why does the starter run but the engine not turn?"
 
"David - giving just "1994

"David - giving just "1994 3.0 starter" makes it a bit tough as three liter engines are pretty common.

If its a mounting arrangement where the bolts are perpendicular to the crankshaft, and the outer one is not present, the starter can rotate around the remaining mounting bolt and never engage the ring gear. This is only encouraged with the remaining bolt not drawning up tight.

A pic would go a long way if the above doesn't help. If no pic, a better description of the mounting scheme would be useful, too."
 
Thanks for the reply. The egin

Thanks for the reply. The egine type is 3.0GL D-MMDA if that helps. The Facing the front of the engine the starter is located on the lower left side. The two mounting bolts are perpendicular to the crank shaft and mount up into the block. The short boly is on the outside and the long bolt on the engine side. There is also a mounting bracket bolted to the block to the front of the starter. When I slide the starter into place (in the hole to the fly wheel) it can not move front to back or toward or away fron the fly wheel if that makes sense. I am going to try moving the fly wheel into another position on Thursday and see if the starter engages the teeth. Question: can a starter motor run but not engage the gear if the ground is not good? Thank you again for your help and input.
 
"The starter motor may be good

"The starter motor may be good but the Bendix part may not be working. That is the spring and gear at the end of the starter. If it is the type that uses a Bendix,like Ford. It may need to be cleaned or replaced. Usually they can be bought as a kit. If it is a solenoid type then the solenoid may not be working to engage the flywheel"
 
"If you have a poor ground con

"If you have a poor ground contact the starter may turn but not quickly enough to kick the bendix gear out. All starters have a bendix gear. That's what engages the flywheel not the solenoid. The solenoid is basicly just a switch.
If the starter is removed and "bench tested" the bendix might still jump out but under load (installed) the starter may not have the torque to crank the motor quickly enough for the bendix to engage. Do you run in salt or fresh?
My guess is the bendix is frozen or bad, poor ground, or the starter is just worn out (ie worn armature/brushes). If it were a bad solenoid the starter wouldn't turn at all.
If it's not the ground or a bad connection, you're probably going to have to pull the starter to inspect it and or replace."
 
"Thanks guys. Only run in fres

"Thanks guys. Only run in fresh water. The old starter bench tested good but I still replaced it the following week with a new one when the problem returned in case the problem was occuring intermtently with the starter. With a new batt and new starter, I think the problem is narrowed down to either:Teeth missing on fly wheel, which makes sense except that the initial time starter only whirled and did not turn the engine I reinstalled the starter without ever moving the fly wheel and it cranked fine. OR due to the bolt issues (not tight and one missing)the starter is not ground sufficiently to do more than spin the starter fast but not receiving enough "ground" to engage the bendix. Not understanding "Grouds" I thought something is either "grounded" or not "grounded" without any inbetween such "grounded" enough to spin the starter fast but not "grounded" enough to kick out the bendix gear...is that possible? Sorry for the less than layman terms and I appreciate the patience and recommendations."
 
"It is very possible to have a

"It is very possible to have a "partial" ground condition. Witness the yellow/brown headlight on some older cars, typically a bad ground.

The starter you describe sounds a lot like a chevrolet type arangement which uses a round cylinder solenoid on top (where the big wire connects) and has a plunger inside which physically pulls the starter pinion gear into the flywheel by using electromagnet force.

You really should get the bolt situation fixed sooner rather than later since the remaining bolt is over stressed. You state that it won't tighten fully which supports the poor ground theory. It also indicates that you may have lost the shims which are sometimes used with those starters. Replacement shims can be bought at any good parts store if you can't find them in the bilge. Replacement bolts of the right length and strength are also commonly available at the parts store.

To test the ground theory, use a pair of jumper cables to provide a good ground from the battery directly to the starter motor. If it works, then you've found the problem.

Flywheels will get worn, typically an engine will stop in one of three places, causing wear on those three specific spots. You should have heard grinding or clunking noises in the past to indicate wear was getting to a bad point. In any event, to check if this is the problem, just rotate the engine by hand a few degrees and try the starter again. If you have a crankshaft damper bolt in front that's an easy place to put a wrench to turn it. (not the pulley bolts, the big one in the middle)

K"
 
"To go a little further on the

"To go a little further on the starter construction (maybe more than you want, if so, hit delete now) there are several starter drive configurations. The "Bendix" drive is only one specific type of drive pinion assembly in use. The true Bendix drive was made and patented by the Bendix Company and is typically identified by the relatively large exposed spring connected to the drive pinion. (drive pinion is the small gear)

There is also the overrunning clutch style which is the more common type used since about the 1960's. This is the more compact type which has 3-7 rollers contained inside the collar type device just behind (relatively speaking) the pinion.

A good explanation of these two and some others, like Chryslers reduction gear starter can be found by googling "wikipedia" and "self starter".

Common usage of "bendix" for the starter drive assembly is often accepted, but understanding how the drive works is sometimes important in troubleshooting a particular problem. At least that's what they told me in mechanic school when I didn't want to study these types of things.

K"
 
"Jumping the ground directly t

"Jumping the ground directly to the starter, Picking up a couple of temp Shims and rotating the engine a few degrees should pin point the cause and possibly even get me through the upcoming holiday weekend, Thanks to everyone for the feedback."
 
"Like Fred suggested, you real

"Like Fred suggested, you really need to get the bolt situation resolved. without both bolts torqued to spec, the starter can move around enough to cause engagement problems. The "starter with solenoid" type won't spin over without the drive gear being extended (unless the pivot pin is busted).

One other item to look for is a mounting bracket on the end of the starter furthest forward (away from the flywheel). It is used on similar mounting schems on some of the V-8s. It minimizes the starter "pitching" which can cause alignment issues with the flywheel.

finally, on the electrical 'ground' - you need a low impedance ground. This is provided by having the mounting flanges clean and true and using both bolts, tight. Loose bolts will raise the impedance and induce a voltage drop. Not good for the starter (or the rest of the system). I'd also discourage use this weekend unless you go out with other boats that may provide a tow back to teh pier, if needed."
 
"David:

If it still gives y


"David:

If it still gives you fits, pull all the spark plugs and see if you've any water in the cylinders....starter bolts usually don't break but under a few conditions - hydrolocked being one of them"
 
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