I am stumped ---- Coolant Leak

geordi · **Posted:** Mon Apr 23, 2012 5:10 pm

Sorry, but if your coolant had jelled, someone put the wrong coolant in at one time or another. Proper ELC HOAT coolants should not do that ever.

racertracer · **Posted:** Mon Apr 23, 2012 7:09 pm

grywlfbg wrote:

Jeep's running like a top now so finger's crossed. Wife is happy and saved me from buying her a $53k Toureg TDi.

I would replace the fan cluth as assurance and check to see that the electric fan comes on when it should.

At one time my electric fan didn't come on when it should have and there was no warning signs that it failed.

grywlfbg · **Posted:** Tue Apr 24, 2012 1:46 am

geordi wrote:

Sorry, but if your coolant had jelled, someone put the wrong coolant in at one time or another. Proper ELC HOAT coolants should not do that ever.

It was the original factory coolant - never changed. I would be inclined to blame the KSeal but the heater started acting up before the whole warped head episode - Jeep would alternate between hot and cold air even w/ heater on full hot. It doesn't get that cold around here so wasn't bad enough to take it in. I recall someone else on this board having jelled coolant in their heater core.

racertracer · **Posted:** Tue Apr 24, 2012 5:18 am

grywlfbg wrote:

the heater started acting up before the whole warped head episode - Jeep would alternate between hot and cold air even w/ heater on full hot.

Mine did the same thing after I replaced the thermostat. I couldn't figure out why it did that. It might have been trapped air becasue i just continually kept purging air out of the radiator by slightly twisting open the black twist valve on top when the engine cooled down. It was a continous process.

grywlfbg wrote:

I recall someone else on this board having jelled coolant in their heater core.

The Hoat coolant that came out of my heater core was heavy and sluggish compared to the water stream that eventually came out.

For instance, when I applied a high stream of water pressure from a garden hose nozzle into the top heater core orifice, at first it slowly moved the coolant out. The coolant was very sluggish coming out, traveling a mere 1" past the orifice on the other end before dropping, but when the Hoat coolant had been totally pushed thru the core and a clear water began coming out, that is when the steam reached went approx. 8" past the orifice. It was a very noticeable difference.

Something was definitely wrong and it wasn't the K-seal that caused the coolant to become thick, because at that time there wasn’t any K-seal in the system.

The coolant was just too heavy and I believe that the water pump didn't have enough strength to push the heavy coolant thru the system, not fast enough to cool down the engine.

The coolant had been recently changed and had approx. 5000 miles on it.

I believe that the hoat coolant may able to keep the system rust free but it is not able to maintain a low viscocity to allow the water pump to keep up with the high flow the system requires to keep the engine cool.

Some of you may want to clean your heater cores after reading this and I would ask that you report back with your findings.

Your thoughts?

Randy B · **Posted:** Tue Apr 24, 2012 9:07 pm

My thought,
With both ractracker and grywlfbg both finding gelling coolant in the heater core, and it being the correct hoat coolant installed could the hoat coolant when being at its end of life cycle, ie 5 years or 100,000 mile start to gel? I know when other types of coolant start's to break down the ph will also change. Just my two cents, for what's it worth.

geordi · **Posted:** Tue Apr 24, 2012 9:33 pm

Randy B wrote:

My thought,
With both ractracker and grywlfbg both finding gelling coolant in the heater core, and it being the correct hoat coolant installed could the hoat coolant when being at its end of life cycle, ie 5 years or 100,000 mile start to gel? I know when other types of coolant start's to break down the ph will also change. Just my two cents, for what's it worth.

If that is the case... Can we test from the coolant bottle to see whether it is time, and take care of it without tearing out the entire system? I don't really want to create or deal with any air pockets, is there anywhere on the heater system that is a confirmed spot for 100% of the coolant flow? Maybe one of the two lines into the heater core, where we could tap in a hose connection and run fresh water through the whole system to force everything out?

Then you would just need to drain out enough clear water to fill it with HOAT from the coolant bottle at the top and maybe have the right mix without air pockets?

I know on my engine, I have maybe 65k on the current fill b/c that was when the engine was replaced. I haven't opened the coolant system since, and it seems to be running beautifully. I really don't want to violate the "if it ain't broke" laws and annoy Lord Murphy.

racertracer · **Posted:** Tue Apr 24, 2012 9:50 pm

geordi wrote:

Randy B wrote:

My thought,
With both ractracker and grywlfbg both finding gelling coolant in the heater core, and it being the correct hoat coolant installed could the hoat coolant when being at its end of life cycle, ie 5 years or 100,000 mile start to gel? I know when other types of coolant start's to break down the ph will also change. Just my two cents, for what's it worth.

If that is the case... Can we test from the coolant bottle to see whether it is time, and take care of it without tearing out the entire system? I don't really want to create or deal with any air pockets, is there anywhere on the heater system that is a confirmed spot for 100% of the coolant flow? Maybe one of the two lines into the heater core, where we could tap in a hose connection and run fresh water through the whole system to force everything out?

Then you would just need to drain out enough clear water to fill it with HOAT from the coolant bottle at the top and maybe have the right mix without air pockets?

I know on my engine, I have maybe 65k on the current fill b/c that was when the engine was replaced. I haven't opened the coolant system since, and it seems to be running beautifully. I really don't want to violate the "if it ain't broke" laws and annoy Lord Murphy.

Great idea.

We have to get the flushing process down correctly though and it would be good to hear from the experts on how it's done on this engine.

What is the proper way to flush this system without getting air in it?

Randy B · **Posted:** Tue Apr 24, 2012 10:07 pm

geordi wrote:

Randy B wrote:

My thought,
With both ractracker and grywlfbg both finding gelling coolant in the heater core, and it being the correct hoat coolant installed could the hoat coolant when being at its end of life cycle, ie 5 years or 100,000 mile start to gel? I know when other types of coolant start's to break down the ph will also change. Just my two cents, for what's it worth.

If that is the case... Can we test from the coolant bottle to see whether it is time, and take care of it without tearing out the entire system? I don't really want to create or deal with any air pockets, is there anywhere on the heater system that is a confirmed spot for 100% of the coolant flow? Maybe one of the two lines into the heater core, where we could tap in a hose connection and run fresh water through the whole system to force everything out?

Then you would just need to drain out enough clear water to fill it with HOAT from the coolant bottle at the top and maybe have the right mix without air pockets?

I know on my engine, I have maybe 65k on the current fill b/c that was when the engine was replaced. I haven't opened the coolant system since, and it seems to be running beautifully. I really don't want to violate the "if it ain't broke" laws and annoy Lord Murphy.

It was just a thought, I really do not know a thing about the hoat coolant. Do not know what the ph is when new. Or how it breaks down with age.

Randy B · **Posted:** Tue Apr 24, 2012 11:05 pm

I am going to look in the fsm and see what/ how they recommend on flushing and refilling the system. I cringe when it come's to doing a drain and fill on a car with aluminum heads. Back in 1990 I cracked a aluminum head by not getting all the air out of the system. Was on a Chevy and dummy me did not open or drilled a hole in the stat to let the air out, before starting.

j_humph · **Posted:** Tue Dec 18, 2012 6:47 pm

Where is the EGR cooler located? And what is the best way to access it to isolate it for ruling out any issues?

I have the Gde hot tune, after isolating it can I then just plug it closed?

Thanks

papaindigo · **Posted:** Wed Dec 19, 2012 7:44 am

There is a metal coolant line running across the top of the engine in front of the oil filler cap; follow that line down the driver's side to behind the FCV/intake elbow to the EGR cooler. Keith at GDE told me that the EGR cooler can be capped off so no coolant flows to it with the EcoTune and the turbo tune. I assume the same holds for the hot tune but you might want to send him a direct email to confirm.

geordi · **Posted:** Wed Dec 19, 2012 9:54 pm

papaindigo wrote:

There is a metal coolant line running across the top of the engine in front of the oil filler cap; follow that line down the driver's side to behind the FCV/intake elbow to the EGR cooler. Keith at GDE told me that the EGR cooler can be capped off so no coolant flows to it with the EcoTune and the turbo tune. I assume the same holds for the hot tune but you might want to send him a direct email to confirm.

That line that runs across the top of the engine -IS- the correct one to follow to find the EGR... However, I must caution everyone after reading Papaindigo's post:

DO NOT CAP THAT LINE OFF!!!!!

That hose is VERY VERY important. Not for the EGR - feel free to pull the rubber section off and ignore the EGR cooler, if you have the GDE tunes or an SEGR device, or both. Your EGR exhaust pipes might also 'accidentally' fall off too, and not hurt anything if you have those remedies.

No, that coolant line is super important because it is the sole source of coolant to the aluminum head. The EGR cooler and EGR have a small knot of metal coolant lines on them, then the 1" hose leaves the EGR area and connects directly to the side of the head between cylinders 2 and 3, right up under the valve cover where it is REALLY hard to get at the snap ring. Unless you have removed the valve cover / intake... Then it is only a pain in the arse to get to that snap ring.

Simply redirecting that coolant line straight into the head (I cut the metal hose part a few inches shorter to make it fit nicer and not kink the hose) and the head will be protected and your EGR valve can be forgotten.

papaindigo · **Posted:** Thu Dec 20, 2012 1:22 pm

geordi's caution is spot on. I cheerfully assumed anyone disabbling the EGR cooler would simply reroute flow from the metal line into the obvious port back into the engine as to do otherwise would leave that port vented to atmosphere. Perhaps not a great assumption so I'm glad geordi made it crystal clear what NOT to do.

Goglio704 · **Posted:** Fri Dec 21, 2012 10:24 am

viewtopic.php?f=5&t=71859

GreenDieselEngineering wrote:

fatweasel,

You could just plug the EGR coolant circuit since you are running a GDE tune. Cap the supply end from tstat and then the return to the block near EGR. Much cheaper and it will increase coolant flow to the cabin heater at the same time for better winter heating.

I am stumped ---- Coolant Leak

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