Espar Troubleshoot Help

Nautamaran said:

I’d still pursue the “coolant has reached temp” angle to its end...
Perhaps the temp sensor is faulty, or flow isn’t reaching the furnace properly?
Can you measure the exit hose temp with an IR thermometer, or even with a meat thermometer wrapped in a rag around the coolant line. If that gets above 180’F you’ve got a circulation issue... if it consistently cuts out at a particular temperature look closely at the temperature sensor and its wiring/connector.

Good luck with it... these things can indeed be maddening!

-dave

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That was one of my original post questions, how do you accurately test or evaluate that temp sensor? Would it need to have fluid in the water jacket to have something to measure? Sorry but electricity is not my strong point. As posted above, I'm having a similar issue whether the engine is running or not.. I feel as though the problem is not flow, but I could be wrong. I'll try to derive some sort of way to measure temp at the heater, I think my neighbor has an IR thermometer, and like anyone who actually has one, likes to use it! Stay tuned..

Ok, I'm back to pursuing the coolant 'flow' variable. The last couple times resetting and testing the heater, I seem to have better luck with the heater running for a longer period of time while actually driving the van. My next question is, does anyone have any insight on coolant flow difference between the engine at idle versus the engine at speed driving down the road?

I was assuming that with the engine running at idle, the (engine) coolant pump would be pushing enough rate for the coolant to flow constant and heater to run to high temps, but we all know what 'assume' means. So now I'm wondering if the coolant pump for the engine behaves differently while at higher rpm's. I'll be honest, I don't even know where the coolant pump is and what drives it, does it run off belts? Does the system use the auxiliary coolant pump while the engine is running at all? I'm gonna start reading up on the coolant system. Ok, thanks

The engine driven coolant pump will pump more at higher RPM. From other reports, I assume that the engine will circulate enough coolant at idle to allow the espar to run normally, but this may not be the case.

Midwestdrifter said:

The engine driven coolant pump will pump more at higher RPM. From other reports, I assume that the engine will circulate enough coolant at idle to allow the espar to run normally, but this may not be the case.

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I concur. My Espars would run engine on, but would stop engine off. I have the 7;day timer so could read the code which was inadéquat coolant flow or something....changed in a new pump, She works good now, tabernac! If f for some reason you coolantflow is restricted (pinched pipe etc....that might shut it down a low revs. I presume you have a good alternator? Low voltage will also shut down an Espar (to save battery for starting).

does anybody happen to know how to 'clear a lockout' on the D5WZ that doesnt involve use of the diagnostic tools, like the 7day timer?
(also posting here, since this thread seems to be fresher...)
have tried vic's trick to make it go (jump pins 6&7 together and add +12)
have good volts at pins 1&2 (+12 & -12), so the 25amp fuse is good, the water pump runs in REST mode, but the D5 wont go, nothing happnin.

outbound said:

does anybody happen to know how to 'clear a lockout' on the D5WZ that doesnt involve use of the diagnostic tools, like the 7day timer?
(also posting here, since this thread seems to be fresher...)
have tried vic's trick to make it go (jump pins 6&7 together and add +12)
have good volts at pins 1&2 (+12 & -12), so the 25amp fuse is good, the water pump runs in REST mode, but the D5 wont go, nothing happnin.

Click to expand...

Did this tonight to reset the control module in the espar unit:

Start the engine.
Push the heater booster button (bacon button?) so it is "on"
Pull the 25 amp and 10 amp fuses related to the heater booster
Plug them back in
Wait (mine took about 2 minutes before I noticed anything external to the vehicle and a further 3-4 minutes before I noticed a temperature change in the air from the vents)

What I noticed from the outside of the van:
I could here a clicking sound from the pulse pump (underneath the van and just behind the drivers seat).
I could smell more diesel exhaust than usual at the front of the van.
I had my headlight removed and was able to get close to hear the sound of the fan inside the espar unit.
Once I shut the engine off (key off) I could noticeably hear the fan slowing down. The sound reminded me of a jet engine powering down.

Hope this helps.

Rusty

thanks for the comeback rusty! will give it a shot - the last shot, before i replace the whole unit (given its age and unknown how long its been dead)

Patrick of M said:

I concur. My Espars would run engine on, but would stop engine off. I have the 7;day timer so could read the code which was inadéquat coolant flow or something....changed in a new pump, She works good now, tabernac! If f for some reason you coolantflow is restricted (pinched pipe etc....that might shut it down a low revs. I presume you have a good alternator? Low voltage will also shut down an Espar (to save battery for starting).

Click to expand...

Yes, battery is good and alternator are good. I'm having the same problem engine off and engine running, so I think power is not the culprit.

When the Espars gets up to temp it’s just idles it does not turn off. I do think it is likely that if is senses over temp it’s might turn off, but even then I would expect it to go into the usual cool down cycle which is a a couple of minutes of the fan running etc... a dodgy temp sensor in the Espar might prompt its ecu to start a shut down, but I would presume that multiple events like that would end up with the ecu locking up the kit and caboodle. But I’m just guessing. The thought that a dodgy sensor once warm becomes more dodgy is definitely worth investigating, and of course hard to do. Removing sensor from the Espar body can easily destroy them .

So I think I'm getting closer. I pulled the auxiliary coolant pump off and put a 9 volt batter on it and watched the propeller spin just fine. I put a hose on it and pushed some water through it and is seemed to be working.

Yesterday on a cold morning I fired up the espar without the engine running to pre-heat, it ran well until the sputtering started at which point I turned it off. The Scan Gauge read 60 degrees for coolant temp. I then started the van. While scrapping the windshield the espar fired up and ran well until the sputtering started in again, at this point it read about 80 degrees. I go in and revved the engine some and started driving the van. The epsar kept running. I was able to keep the heater running (while driving down the road) until about 160 degrees at which point I turned it off to try and keep it's positive attitude about starting again the next time it's needed.

So I'm thinking the coolant flow is either low, or the temperature evaluation by the heater is not correct.

Low flow has me a little miffed as neither of the pumps seem to push enough coolant to keep the heater happy, unless driving. It appears that either of the pumps have the ability to push enough for the heater when working correctly; the auxiliary or engine idle. How can I test or evaluate the coolant flow? What sort of thing might cause the flow to be lower than normal? I'll look for some pinched tubes and the like, but engine operation and heat build up seems normal for how I understand the van to warm up.

I'm not aware of a way to test the temperature sensor for the heater. The only thing I could try there is the overheat sensor from the other heater that I have, but the heater seems to work fine up to the 160 degree mark, after yesterday.

My neighbor has an IR Thermometer and camera and agreed to bring them by sometime. I'm not sure exactly what to look for, but getting a temperature reading right at the heater might help see what the actual temperature the heater is seeing on output. Funny enough he is a radiant heating designer for residential and commercial projects. Ok, thanks

So I ran the heater with an IR thermometer and a camera that captures heat imaging. Still waiting for the camera images, but not real sure they will show much other than neat red patterns. The thermometer showed temperatures similar to what my scan gauge reads, and with the engine running at idle it won't go past about 80 degrees F on the gauge and at the heater. If I rev the engine or drive it and keep the rpm about 2500 or higher, the heater will keep running. I have tested this now a few times. So low flow it is.

I'm now reading up on the coolant system and looking for a culprit that either might be damaged, old, not working correctly, or dirty that would restrict flow other than the water pump pushing with more force. I cannot find much for diagrams and explanations on how the system works, but still looking. I did read up on the 'cooling stack' and how it can gather gook and residue, not sure if that would be enough to restrict flow, but I'm going to dig into that next.

I don't understand the function of the 'cycle valve' in this basic sketch of the cooling system that markxengineering did, and is that 'T Joint' a valve or just a 'T'? thanks

chrismac said:

So I ran the heater with an IR thermometer and a camera that captures heat imaging. Still waiting for the camera images, but not real sure they will show much other than neat red patterns. The thermometer showed temperatures similar to what my scan gauge reads, and with the engine running at idle it won't go past about 80 degrees F on the gauge and at the heater. If I rev the engine or drive it and keep the rpm about 2500 or higher, the heater will keep running. I have tested this now a few times. So low flow it is.

I'm now reading up on the coolant system and looking for a culprit that either might be damaged, old, not working correctly, or dirty that would restrict flow other than the water pump pushing with more force. I cannot find much for diagrams and explanations on how the system works, but still looking. I did read up on the 'cooling stack' and how it can gather gook and residue, not sure if that would be enough to restrict flow, but I'm going to dig into that next.

I don't understand the function of the 'cycle valve' in this basic sketch of the cooling system that markxengineering did, and is that 'T Joint' a valve or just a 'T'? thanks

Click to expand...

I would be looking at the circulation pump

The "T" joint is a simple "T" in the rubber hose.

The "cycle valve" controls the direction of flow, normally allowing flow through the Heater Core in the cabin a/c unit, or bypassing the Heater Core when the ATC module (a/c dials on the dash) sends it power. It's on the firewall below the cabin air filter and has three hoses running into it plus an electrical connector. This usually fails in the rest position, sending coolant via the Heater Core.

The circulation pump runs full time when the engine is running to cool the EGR valve, and is a known failure risk. If you can't get HOT air from the dash vents when the engine is warmed up and idling you should look closely at the electric circulation pump. It's on the firewall with two hoses and electrical connection.

Given your symptoms I'd start with the circulation pump... brushes can be replaced, or simply replace it.
VW is said to have a similar pump, though with a different electrical harness.

-dave

Nautamaran said:

The "T" joint is a simple "T" in the rubber hose.

The "cycle valve" controls the direction of flow, normally allowing flow through the Heater Core in the cabin a/c unit, or bypassing the Heater Core when the ATC module (a/c dials on the dash) sends it power. It's on the firewall below the cabin air filter and has three hoses running into it plus an electrical connector. This usually fails in the rest position, sending coolant via the Heater Core.

The circulation pump runs full time when the engine is running to cool the EGR valve, and is a known failure risk. If you can't get HOT air from the dash vents when the engine is warmed up and idling you should look closely at the electric circulation pump. It's on the firewall with two hoses and electrical connection.

Given your symptoms I'd start with the circulation pump... brushes can be replaced, or simply replace it.
VW is said to have a similar pump, though with a different electrical harness.

-dave

Click to expand...

The circulation pump is functioning, I've pulled it and tested with a 9v battery and it spins and even pushes water when I put a tube on it. It is two years old at max. I get cabin heat just fine.

The espar heater works fine and runs with the engine on or off. Engine off it heats up to about 60 F and then shuts down. Engine on at idle it heats up to about 80 F then shuts down. The only way I can keep the heater going is to drive at 2500 rpm or better, and it will keep heating until 160 F or so. It then locks out not trying to restart (my assumption as I can reset it and do the same thing again). I can't think of anything else but low coolant flow, once I drive and the coolant flow cranks up from belt driven rpm (my assumption), heater rips along fine.

I can't quite figure out this 'cooling stack' area, but users have identified it as 'between the condenser, inter-cooler, and radiator', and is prone to collecting gook and restricting flow and sometimes causing overheating. I'm wondering if it is restricting flow causing my espar to overheat prematurely.

I've had the heater run fine at idle and without the engine running last year. Not sure what changed.

Yes, the cooling stack is the a/c, intercooler, power steering loop, and engine radiator. There’s a gap behind the a/c condenser core that can collect debris, so is worth keeping clear. It isn’t likely to be your issue though, as the boost heater is on a different coolant loop (see Dennis’ sketch) and your coolant temp is well within the normal range.

If your pump is operating I would check for restrictions. Disconnect the hose at the EGR valve and force fluid into the hose. Coolant should flow in readily and emerge at the EGR. You could also attach a short length of hose to the EGR fitting and put the two open hoses into a container of coolant, then allow the circulation pump to run and witness the flow.

-dave

Nautamaran said:

Yes, the cooling stack is the a/c, intercooler, power steering loop, and engine radiator. There’s a gap behind the a/c condenser core that can collect debris, so is worth keeping clear. It isn’t likely to be your issue though, as the boost heater is on a different coolant loop (see Dennis’ sketch) and your coolant temp is well within the normal range.

If your pump is operating I would check for restrictions. Disconnect the hose at the EGR valve and force fluid into the hose. Coolant should flow in readily and emerge at the EGR. You could also attach a short length of hose to the EGR fitting and put the two open hoses into a container of coolant, then allow the circulation pump to run and witness the flow.

-dave

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I have searched many times over and cannot find a diagram that outlines the cooling system except this one attached.

So there are two separate loops in the coolant cycle? Where do they split, or are they ever together? Does the booster heater work as a pre-heater at all really then (without the engine running)? And why would my heater keep running when the engine is at speed but not at idle then?

I will check for actual flow with the circulation pump tomorrow. I'm learning a lot about the cooling system now I guess. thanks

The coolant flowing through the engine block has two external loops.

One is an open loop that exits the block through the intake manifold and EGR valve, and circulates via the boost furnace (Espar) and has a bypass that can loop through the cab’s a/c heater core. This loop is not thermostatically controlled and flows continuously, with help from the electric circulation pump. The engine’s belt driven water pump will also flow coolant through this loop when engine speeds are sufficient (above 1200 rpm ?)

The other external loop exits out the engine thermostat into the “top pipe” hose that leads from the engine to the radiator, just below the expansion tank. Hot coolant then flows across the radiator core, and cooled fluid exits out the bottom corner.

The two external loops then join together and flow back into the engine block and circulate.

Hot fluid from the Espar first visits the cab (the bypass valve sends flow via the cab when it’s not powered), then flows back into the engine block, so there is a substantial engine warming effect. There is no flow through the radiator from the electric circulation pump.

Hope this helps clear things up,

-dave

Nautamaran said:

The coolant flowing through the engine block has two external loops.

One is an open loop that exits the block through the intake manifold and EGR valve, and circulates via the boost furnace (Espar) and has a bypass that can loop through the cab’s a/c heater core. This loop is not thermostatically controlled and flows continuously, with help from the electric circulation pump. The engine’s belt driven water pump will also flow coolant through this loop when engine speeds are sufficient (above 1200 rpm ?)

The other external loop exits out the engine thermostat into the “top pipe” hose that leads from the engine to the radiator, just below the expansion tank. Hot coolant then flows across the radiator core, and cooled fluid exits out the bottom corner.

The two external loops then join together and flow back into the engine block and circulate.

Hot fluid from the Espar first visits the cab (the bypass valve sends flow via the cab when it’s not powered), then flows back into the engine block, so there is a substantial engine warming effect. There is no flow through the radiator from the electric circulation pump.

Hope this helps clear things up,

-dave

Click to expand...

Yes, that helps to understand the system a lot. I have today to check the flow, so I'm off to give that a shot. Thank you.

I marked up the coolant flow diagram above a bit for "clarity" ...?
(so my drafting instructor continues to roll over in his grave )

The Cycle Valve is really the key component, as its position determines whether coolant flows through the cabin (unpowered default) or not (power on). It is controlled by the ATC module in the dash, and is pulsed on to interrupt the heat flowing into the cab's Heater Core.

-dave

ANyone have a picture of the cycle valve? Can it be lubed externally ? . I think mine failed in the off position for about 20 minutes today, the espar was running the engine was getting up to temp, but there was no cabin heat, eventually it kicked in. I was not impressed.