Glow plug issue engine hot

[taskunitbruiser]

After replacing the glow plugs (4 were bad) the engine starts amazingly easy when cold. The "wait" light stays on about 10 seconds when cold, everytime. If the engine is not fully cooled down (say I drove it an hour prior) the wait light stays on about 1/4 of a second (i.e. a quick flash) and the vehicle is quite hard to start.

I show a current draw when this happens and also when I unplug the main temp sensor connection near the TPS. When I did transmission diagnostics, I would always unplug this per the TM, but always wondered why the dash gauge showed it drawing current. Where does current go?

For the warm engine start problem I suspect the temp sensor is faulty and telling the ECM/Smartbox to not activate the glow plugs. I was told this engine may have two temp sensors, one for the dash gauge and one for the ECM/Smartbox/computer. Is this correct? My dash gauge temp sensor seems to function normally. Does anyone know the location of the second one?

Again, only ever have issues when the engine is still a little warm; wait light flashes once and it just sucks starting it. Anyone had this problem?

 

[mgFray]

Two temp sensors. One for the start box, in the water jacket top passenger side of engine with a big harness…. The other affects the injection pump/fuel delivery. It’s near the rear of the engine on passenger side, on the side. Accessible via the dog house.

 

[Barrman]

Anything below 158° is considered cold for an indirect injection diesel engine. I agree with your diagnosis of something not letting it glow when the engine is above overnight cold but below normal operating temperature.

By the way. Just about every 6.2 glow plug system has trouble with the 1-3 hour after shut down restart glow cycle to some degree.

 

[Retiredwarhorses]

What start box Do you have?
I’ve had hundreds of trucks….yes, I’ve seen this issue, but generally from the early EESS boxes, not so on the S3…
The issue is not common…

 

[taskunitbruiser]

Anything below 158° is considered cold for an indirect injection diesel engine. I agree with your diagnosis of something not letting it glow when the engine is above overnight cold but below normal operating temperature.

By the way. Just about every 6.2 glow plug system has trouble with the 1-3 hour after shut down restart glow cycle to some degree.

I got the 6.5 L turbo

 

[taskunitbruiser]

What start box Do you have?
I’ve had hundreds of trucks….yes, I’ve seen this issue, but generally from the early EESS boxes, not so on the S3…
The issue is not common…

 

[taskunitbruiser]

Two temp sensors. One for the start box, in the water jacket top passenger side of engine with a big harness…. The other affects the injection pump/fuel delivery. It’s near the rear of the engine on passenger side, on the side. Accessible via the dog house.

Do you know which one the dash gauge reads from?

 

[Retiredwarhorses]

install a new TSU and go from there

 

[taskunitbruiser]

install a new TSU and go from there

Just find one for Nartron, correct? I heard these have to match the start box.

This is something I must get from hummerpartsguy or Mac Motors correct? MME, Federal, and Eastern Surplus have some cheaper; but some even look unlabled/unbranded. Not sure if those are for the EESS boxes or just pure junk?

Do you think I can swap these out quickly and have minimal coolant loss or should I buy fluid too? I heard not to use parts store green coolant, but maybe go to a "big rig" shop and get some quality coolant with high electrolysis protection?

 

[FlameRed]

Do you think I can swap these out quickly and have minimal coolant loss or should I buy fluid too?

I recently changed my TSU and I think about a cup of coolant came out with the engine totally cold, so I just added a bit of water to the jug.

 

[Mogman]

Do you know which one the dash gauge reads from?

The gauge reads from the sending unit in the front part of the left head under the exhaust manifold. The one on the back of the head is for the cold advance as stated above

 

[Mogman]

There is a sticky near the top of this forum that will tell you what TSU to use with what box.

 

[taskunitbruiser]

I recently changed my TSU and I think about a cup of coolant came out with the engine totally cold, so I just added a bit of water to the jug.

Probably just fine for naturally aspirated, but I am worried with a turbo, plus mine is a tad low already.

 

[Mogman]

Probably just fine for naturally aspirated, but I am worried with a turbo, plus mine is a tad low already.

If it is the original coolant you should change it anyway, get plain old green inorganic coolant, that is all that setup needs

 

[Retiredwarhorses]

Just find one for Nartron, correct? I heard these have to match the start box.

This is something I must get from hummerpartsguy or Mac Motors correct? MME, Federal, and Eastern Surplus have some cheaper; but some even look unlabled/unbranded. Not sure if those are for the EESS boxes or just pure junk?

Do you think I can swap these out quickly and have minimal coolant loss or should I buy fluid too? I heard not to use parts store green coolant, but maybe go to a "big rig" shop and get some quality coolant with high electrolysis protection?

Either KDS or Narton TSU work with either mfg S3…does not make a difference.
Stay away from anything from MME,FMP or ES, buy only from MAC or HPG to guarantee you get an OEM part backed by a good return policy.
No idea who says not to use auto store sourced green coolant, it’s made specifically for cast iron blocks, more experts spouting nonsense I suspect.

 

[Barrman]

A 6.5 center mount turbo, a 6.5 NA and a 6.2 all have the same basic engine design, cold starting assistance needs and engine architecture. So, if someone offers help and happens to write something besides 6.5 center mount turbo. Unless it is about the turbo itself, the help being offered is probably relevant.

The TM’s read the same way. 6.2 and 6.5NA based with 6.5 center mount turbo differences pointed out when needed.

 

[taskunitbruiser]

Either KDS or Narton TSU work with either mfg S3…does not make a difference.
Stay away from anything from MME,FMP or ES, buy only from MAC or HPG to guarantee you get an OEM part backed by a good return policy.
No idea who says not to use auto store sourced green coolant, it’s made specifically for cast iron blocks, more experts spouting nonsense I suspect.

Some crap about HOAT coolant and they are selling OAT. I always thought any green was for cast and other stuff (like orange GM Dexcool) for aluminum. Not sure how well green Prestone holds up with turbocharger static over time?

 

[taskunitbruiser]

A 6.5 center mount turbo, a 6.5 NA and a 6.2 all have the same basic engine design, cold starting assistance needs and engine architecture. So, if someone offers help and happens to write something besides 6.5 center mount turbo. Unless it is about the turbo itself, the help being offered is probably relevant.

The TM’s read the same way. 6.2 and 6.5NA based with 6.5 center mount turbo differences pointed out when needed.

I was referring to static electrical buildup from the turbocharger effecting coolant. Same engine, yea.

 

[Mogman]

Some crap about HOAT coolant and they are selling OAT. I always thought any green was for cast and other stuff (like orange GM Dexcool) for aluminum. Not sure how well green Prestone holds up with turbocharger static over time?

That turbocharger is not water cooled, just read the label and make sure it is IAT
EDIT, you are correct that some manufactures are selling green HOAT and OAT coolant

 

[Mogman]

This is what I use.

Zerex ZX001 Zerex Origninal Green Antifreeze and Coolant | Summit Racing

Free Shipping - Zerex Origninal Green Antifreeze and Coolant with qualifying orders of $109. Shop Antifreeze and Coolant at Summit Racing.

www.summitracing.com

My local NAPA store carries it