Turn the key and get a clunk

HDRider

HDRider

TJ Enthusiast
Joined
May 26, 2022
Messages
261
Location
Arkansas
I've had the 2001 Wrangler a year now. Loving it. I leave two almost new vehicles in the garage to drive my Jeep. She is coming up on 200,000 miles.

I go to start it a few days ago and all I get is a clunk sound when I turn the key. Do it again, same sound. Then she starts and things are good. Next day, got a clunk, then she starts.

So far it has always started. The clunk is very sporadic.

Will she fail me soon?

Any idea what the culprit might be?

Thanks
 
It is an automatic. Jiggling the shifter or the steering wheel is not what leads to a start. It will start without any ritual. It just has this odd occurrence on occasion.
 
Last edited:
Before doing anything else, try this... even if your battery connections look ok, physically remove them both and wire brush both the inside of the connectors and the battery posts. Then reinstall them and make sure they are on the battery posts tight enough that they can't be moved around on the posts even with considerable hand pressure. Battery connections can look fine but still have internal corrosion, dirt, or even be too loose... any of which will cause intermittent starting problems.

A $5 battery brush like this sold at all auto parts stores will make quick work of that job.

battery brush.jpg
 
  • Like
Reactions: skrelnik, Rygrego, HDRider and 1 other person
Jerry Bransford said:
Before doing anything else, try this... even if your battery connections look ok, physically remove them both and wire brush both the inside of the connectors and the battery posts. Then reinstall them and make sure they are on the battery posts tight enough that they can't be moved around on the posts even with considerable hand pressure. Battery connections can look fine but still have internal corrosion, dirt, or even be too loose... any of which will cause intermittent starting problems.

A $5 battery brush like this sold at all auto parts stores will make quick work of that job.

View attachment 418561
Click to expand...

Jerry is correct. corrosion on the battery terminals isnt an uncommon issue and it's a simple point to start from before you dig in deeper and try other options. corrosion/oxidation buildup on the battery connections can lead to significant amp drop therefore causing the starter motor to see 12.x volts but the amperage isnt what it should be from the increased corrosion resistance at the connections which could simulate essentially what you would see with a near dead battery.

the starter requires a significant amount of amperage to operate correctly therefore having good electrical connections is paramount to the starter operating correctly. sounds like you are describing the bendix throwing out on the starter (clunk) but may not be providing enough amps to spin the starter motor.

if you dont have a battery brush on hand as jerry suggested, the coarse green side of a dish sponge, sand paper, Brillo pad, wire brush will also work. just get the mating surfaces connectors to a shiny appearance which should take just a few seconds with a little bit of elbow grease.
also if you have any dielectric grease, automotive light bulb connector grease laying around, a very light coating on the battery terminals before reattaching the battery leads in place would be beneficial too but not a deal breaker if you dont.
 
Last edited:
  • Like
Reactions: Jerry Bransford and HDRider
Building on what Jerry is saying...that clunk is most likely the solenoid/Bendix engaging without any starter action...just enough power to engage the magnets and not enough to turn the starter motor.

Would be interesting to see a voltmeter on the battery before, during and after turning the key.

Cleaning connections is the first step. I have a battery brush in every vehicle.

-Mac
 
  • Like
Reactions: Jerry Bransford and HDRider
  • Like
Reactions: JKP
Yep, if you're using dielectric grease, make a nice clean connection, then coat the outside of it with the grease.

If cleaning/tightening the cables doesn't work, have the battery load tested.
 
macleanflood said:
I usually use no-ox on contacts.

https://www.amazon.com/dp/B00HDF9EXE/?tag=wranglerorg-20
-Mac
Click to expand...

Jerry Bransford said:
That's a great protective conductive grease and a much better choice than non-conductive dielectric grease.
Click to expand...

(y) had no idea there was such a thing. knew dielectric was non conductive but was unaware there was a alternative. in the dialectics use though im sure its so minimal of a insulator with a light coating its not doing any harm at the critical level.

thanks. another item I shall add to my supply of aerosols, liquids, goops and gunks.
 
  • Like
Reactions: Jerry Bransford
Well now. Done.

Turns out the bolt on the positive terminal was broke, so the terminal was loose. Cleaned everything and put a new terminal on it.

Time testing time. We shall see.

I guess it had the OEM battery cable on it. The two wires were embedded into the terminal.

Thanks guys.

I also learned here that dielectric grease is non conductive. Guess when I learned that? Right, after I put the cables back on.

It is all good. Everything lights up and the old gal starts just fine.
 
  • Love
  • Like
Reactions: macleanflood and Jerry Bransford
Top Bottom
Back