Troubleshooting intermittent starter problem

BoarX · **Joined:** Sun Mar 20, 2016 12:44 pm **Posts:** 127

Hi all,

As of recently my 2006 CRD has developed a starter issue. It cranks just fine most of the time and since it is summer the engine fires right away, so there was no excessive cranking since the problem has developed. However sometimes it either starts cranking with like half a second delay or sometimes cranks after several repeated attempts - but when it finally cranks, it cranks normally. I am trying to determine if it is a battery or a starter itself (or some other electrical stuff involved). Weirdly enough there is never a problem with cranking the cold engine. Did someone ever observe such symptoms and what was the culprit?

I would readily admit that my question is a bit academic, because my battery is old and the proper course of action should definitely be to start with replacing the battery, it is just that the money for the moment is tight. If the battery turns out to be in decent shape, it should last me till the winter.

Thanks in advance,
Alex

P.S. My battery is Optima Yellow if that makes any difference.

mercdude · **Joined:** Thu May 02, 2019 1:36 pm **Posts:** 66

So had a weird experience with my 3.7 that could be related. Never had a problem starting during cold but I when hot I found that sometimes it wouldn’t crank over at all ... just got the classic clicking sound of a bad battery. Voltage was low on the battery so I replace it with a agm battery. Same thing. Started looking for a bad ground or toast battery cable... and eventually found that the battery cable on the starter was loose! I tightened it up and bam, no more startup issues.

Check your voltages and cable connections.

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Billybob · **Posted:** Wed Jul 24, 2019 8:27 pm

You need to check all the battery connections are clean and tight as well as the negative battery cable going to chassis and the cable grounding the engine to chassis.

As stated also the connections at the starter and solenoid.

If engine turns over fine when hot but does not fire it could be the cam or crank sensors failing.
The resistance of these two sensors can go up when hot...disconnect the sensors and measure their resistance when cold. Now heat them up with a hairdryer...resistance should not change drastically.
Failing cam or crank sensors usually post codes so try get codes read or use the "key" trick of rapidly turning the ignition ON 3 times without starting the engine. After third ON action leave the ignition ON and the odometer readout will display the codes in sequence from oldest to newest.

A bad Actuator Pin Assembly which is the rectangular section that rotates the ignition switch is known to slowly start deforming until it breaks completely...lots of posts on this assembly.

Try start it in Neutral instead of Park as the Park interlock can be faulty.

You can place the Jeep in Park and Neutral, remove the Starter Relay under the hood and identify pins 30 and 87 inside the empty relay socket. With Ignition turned ON briefly jumper these two female pins together. If Fuse #8 40 amps is OK it should turn over and fire.
This procedure overides the ignition switch, failing Actuator Pin Assembly, bad Starter Relay and bad Park or Neutral Interlocks.

Try pull codes out first and post them here. :wink:

TKB4 · **Posted:** Wed Jul 24, 2019 11:33 pm

I don't think the interlocking pin/steering column ignition switch would be affected by whether or not engine is cold or warm . Sounds like loose connection or ground or maybe battery intermittent internal short. Granted these don't get affected much by heat but vibration of running or recently running engine could affect them.
Generally the starter itself is one of the most reliable things on the CRD but of course they can and do fail too.
I doubt there will be any codes unless related to low voltage but wouldn't hurt to check. I don't believe the turning key on and off 3 times works on the USA models it doesn't on the 6 here anyway and sir sam said he had not seen one it worked on either.

Hopefully just a loose or dirty connection that happens to be easy to get to!!!!

Good Luck !!!

ebbnflow · **Posted:** Thu Jul 25, 2019 2:39 am

Sounds like ignition actuator pin fatigue to me.

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Billybob · **Posted:** Thu Jul 25, 2019 2:43 am

There may be codes related to a bad cam or crank sensor which are prone to failing when heated up....drive to a nearby store with no problem. Get back in and engine does not fire. Call for assistance and by the time it arrives the Jeep starts fine as it has cooled down enough.

The key system I believe may still work on 2005 models but not on the 2006 models.My bad!

The Export models such as I have requires 4 ON/OFF cycles to pull codes while the USA/Canada models seem to need 3 ON/OFF cycles.

So if all connections etc. seem clean and tight then codes would need be extracted by a code reader.

The starter itself is indeed pretty robust while the solenoid can have dirty contacts inside which could lead to the delay in turning the engine over.

Battery needs to be tested under load as it may be failing when warmed up.
Failing Park and Neutral sensors and a failing actuator pin assembly/ignition switch are merely factors to bear in mind if all else fails....electronic components can do weird things under heat stress!

WolverineFW · **Posted:** Fri Jul 26, 2019 1:37 am

I had another vehicle with a bad starter that would only crank when cold. The starter would crap out when it and/or the motor was hot.

Also, Optima batteries have been pretty junky since Johnson Controls bought them years back.

Test and/or replace the battery first.

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TKB4 · **Posted:** Fri Jul 26, 2019 8:40 am

My reasoning for it not being sensors is that in OP he seems to say that once it cranks normally it always starts fairly quick (in warm weather). I don't think the sensors in question would prevent the starter from rotating the engine. I would definitely start with connections and battery.

Since the ignition switch operates the solenoid once engaged by the ignition switch the starter should see normal power or no power not half power. Intermittent or total no crank or having to turn key a certain way or degree or several times would be more indicative of the pin assembly.

It would be a real PITA but OP could try starting only by jumping the relay as alluded to earlier and see if it ever acts the same way. I would suspect that it will, but it would rule out the ignition assembly. They would have to decide how many times to try this before saying it did or didn't change anything.

Of course, anything can happen and obviously something is wrong and we don't know what we don't know. I would assume an auto store nearby would not only check the codes but do a load test on the battery or check voltage while cranking .

Most of the possibilities have been explained well. Now its up to OP to follow through with supplied information and hopefully report back his findings.

BoarX · **Joined:** Sun Mar 20, 2016 12:44 pm **Posts:** 127

Guys, thanks so much for help again!
I am almost embarrassed to report that in the end it turned out, just as almost everybody suspected, a loose connection to the battery positive terminal :banghead:

! For the life of me I cannot remember disconnecting it for at least a year and when I did in the past I was always diligent about tightening it. Even more embarrassing is the fact that once I got it re-tighten I recalled, albeit vaguely, that I have already experienced exact same failure with exact same symptoms in my other life. Guess i am getting old

Interestingly though, the pattern of the problem experienced by mercdude and myself (on two counts) looks to be universal: no problem with cold cranking and intermittent delay/failure to crank when hot - check the $%$ing contacts!

Scratching my head I am wondering if battery terminals may get loose with time due to vibration or some bi-metal electrochemistry.

Peace,
Alex

WWDiesel · **Posted:** Sun Aug 04, 2019 2:59 pm

BoarX wrote:

Guys, thanks so much for help again!
I am almost embarrassed to report that in the end it turned out, just as almost everybody suspected, a loose connection to the battery positive terminal :banghead:

! For the life of me I cannot remember disconnecting it for at least a year and when I did in the past I was always diligent about tightening it. Even more embarrassing is the fact that once I got it re-tighten I recalled, albeit vaguely, that I have already experienced exact same failure with exact same symptoms in my other life. Guess i am getting old

Interestingly though, the pattern of the problem experienced by mercdude and myself (on two counts) looks to be universal: no problem with cold cranking and intermittent delay/failure to crank when hot - check the $%$ing contacts!
Scratching my head I am wondering if battery terminals may get loose with time due to vibration or some bi-metal electrochemistry.
Peace,
Alex

Glad you got it sorted out and it was not something major or expensive.
I hate clamp on battery terminals! And those side things that GM invented are a total Joke!

Whenever possible, I use a battery with studs and convert all cables to ring terminals. They hold tight and never become loose for any reason.
They also do not set up corrosion and resistance between connection surfaces.
Unfortunately, I was not able to do this on the Jeep diesel, but was able to on my Dodge diesel.

I put homemade rubber covers over both the positive + nuts is to ensure nothing ever come in contact with the terminal (5000 X 2 short circuit amps)

Troubleshooting intermittent starter problem

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