Failed Glow Plug Symptoms?

Rixram · **Posted:** Mon Oct 05, 2015 2:42 pm

All,

What would be the symptoms, during summer, of a failed glow plug? Would the vehicle still start? What if only intermittent starting?

papaindigo · **Posted:** Mon Oct 05, 2015 2:57 pm

A CEL and associated glow plug fault code. It would still start.

Billy M · **Posted:** Mon Oct 05, 2015 3:00 pm

What papaindigo said. Also, I would recommend changing all of them if one has failed. Especially if you still have the original ceramic tipped GPs in it. They are prone to do bad things to these engines.

Rixram · **Posted:** Mon Oct 05, 2015 3:04 pm

papaindigo wrote:

A CEL and associated glow plug fault code. It would still start.

That is what I thought. Thanks. I needed to verify with someone here about that. The shop where my CRD is at is trying to say that my no-start is from the glow plugs. I'm trying to tell them to drop the fuel tank and replace the fuel line.

papaindigo · **Posted:** Mon Oct 05, 2015 3:35 pm

My 1993 Dodge Cummins used a heat grid in lieu of glow plugs to warm the fuel just before injection which took noticeable seconds to warm up enough for the wait to start light to go out. Except in the dead of winter I never waited and it always started.

barley00 · **Posted:** Mon Oct 05, 2015 3:55 pm

Thanks for asking this, I was going to do the same given some of my starting issues lately. I went ahead and tested the plugs over the weekend though and found they're all good. Maybe you should test them? #3 is a bit of a hassle to get to but the rest aren't too bad. It's a real easy test.

Rixram · **Posted:** Mon Oct 05, 2015 4:08 pm

I finally got a chance to talk to the mechanic. he was guessing that the glow plugs may have something to do with it, or the crankshaft position sensor.

I pointed out that there is a spare crankshaft position sensor sitting on the passenger seat right already.

I have not yet had the opportunity to look to see where it actually connects though. does anyone have a quick and dirty answer for that? I would look, but I am nowhere near my vehicle at the moment.

Rixram · **Posted:** Mon Oct 05, 2015 4:11 pm

barley00 wrote:

Thanks for asking this, I was going to do the same given some of my starting issues lately. I went ahead and tested the plugs over the weekend though and found they're all good. Maybe you should test them? #3 is a bit of a hassle to get to but the rest aren't too bad. It's a real easy test.

I'd be more willing to accept it was the crankshaft position sensor before the glow plugs.

a quick question for everyone else here. does it seem like we are having a big rash of non starting CRDs lately?

barley00 · **Posted:** Tue Oct 06, 2015 6:56 am

Quote:

a quick question for everyone else here. does it seem like we are having a big rash of non starting CRDs lately?

Kinda...they ain't getting any younger...

flash7210 · **Posted:** Tue Oct 06, 2015 8:19 am

Last year, all through summer I have my GP relay unplugged. It easily started up every time.

Air in fuel will definitely make it difficult to start.
But priming and bleeding the fuel filter prior to starting should get it going.
A piece of clear tube installed at the outlet from the fuel filter can help you see if there is air in the system.
If you haven't yet, install a lift pump.
You dont have to do the in-tank pump.
You can get a Facet pump for about $60 and install it on the inlet side of the fuel filter. It can make diagnosing fuel supply problems easier.

Electronically, a bad crank sensor, bad cam sensor, or bad rail pressure solenoid can make it not want to start. All three of those things should throw a fault code if bad, but sometimes the crank sensor can go bad without throwing a code.
Also, a bad ASD fuse, ASD relay, or security key (SKIM) will make the engine not start. But usually any one of those faults will cause the red dot to appear on the instrument cluster.

So, if you have ruled out the air in fuel problem and no red dot on the instrument cluster AND no fault codes, then crank sensor is probably the most likely problem.
Its not an expensive part (about $60) but it can be a pain to get to.

papaindigo · **Posted:** Tue Oct 06, 2015 9:03 am

Crank position sensor location can be viewed at viewtopic.php?f=98&t=74594 look at images 5+. Often fails with not code/CEL; sometimes won't allow hot engine starts but will allow cold, sometimes won't allow any start, some say easier to removed/replace from under engine, common diagnosis test is hook up volt/ohm meter-apply heat with like hair dryer-if resistance goes nuts it's shot.

I'd verify fuel deliver to injectors before I started sensor checks/replacements assuming there are no code to pull. Also load test battery - weak battery=ECU won't allow start - also check battery grounds.

Rixram · **Posted:** Tue Oct 06, 2015 9:42 am

flash7210 wrote:

Last year, all through summer I have my GP relay unplugged. It easily started up every time.

Air in fuel will definitely make it difficult to start.
But priming and bleeding the fuel filter prior to starting should get it going.
A piece of clear tube installed at the outlet from the fuel filter can help you see if there is air in the system.
If you haven't yet, install a lift pump.
You dont have to do the in-tank pump.
You can get a Facet pump for about $60 and install it on the inlet side of the fuel filter. It can make diagnosing fuel supply problems easier.

Electronically, a bad crank sensor, bad cam sensor, or bad rail pressure solenoid can make it not want to start. All three of those things should throw a fault code if bad, but sometimes the crank sensor can go bad without throwing a code.
Also, a bad ASD fuse, ASD relay, or security key (SKIM) will make the engine not start. But usually any one of those faults will cause the red dot to appear on the instrument cluster.

So, if you have ruled out the air in fuel problem and no red dot on the instrument cluster AND no fault codes, then crank sensor is probably the most likely problem.
Its not an expensive part (about $60) but it can be a pain to get to.

I replaced all of the fuel lines, with the exception of the connection on the tank top. I installed an in-line pump.

There is no CEL. There is no red dot.

Load tested battery at NAPA: it tested okay.

As for the images, I cannot see them on my work computer (very restrictive network). Any link to, say, Imgur or somewhere else? Maybe just a written description?

Mountainman · **Posted:** Tue Oct 06, 2015 10:52 am

It sits on the side of the block above the oil filter, very near bell housing, about 8" below exhaust manifold, passenger side

WWDiesel · **Posted:** Tue Oct 06, 2015 12:50 pm

Note: There is a small heat shield close to the rear of the motor just below the exhaust manifold and back of the turbo you have to remove in order to see and gain access the crank sensor. It can be changed from the underside of the jeep... :wink:

Failed Glow Plug Symptoms?

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