Coolant Leak â€“ The ongoing saga

racertracer · **Posted:** Sun Jun 05, 2011 9:29 pm

Recap –
-12 weeks ago, thermostat failed open.
Replaced thermostat with a new OEM thermostat.
Note: No coolant leak at this time.

-11 weeks ago, coolant low level light comes on.
Added small amount of coolant. Coolant light goes off.

- 8 weeks ago, coolant low level light comes on. Coolant residue around radiator cap, indicating high pressure and possible radiator cap malfunction
Replaced original 16 lbs. rated radiator cap with a new revised OEM 17 lbs. one.

-7 weeks ago, small drip around 3/8” hose near spring clamp on top of plastic coolant bottle.
Replaced 3/8” spring clamp with new 3/8” screw clamps on both the top and bottom of plastic coolant tank.

-6 weeks ago, low level coolant light returns, no leaks visible.
Added antifreeze to coolant bottle, replaced spring clamps on 5/8” heater hoses leading to heater core.

-5 weeks ago, low level coolant light returns. Small puddle of antifreeze on garage floor leading from passenger side frame rail and catalytic converter, unable to locate source.

-4 weeks ago, low level coolant light returns. Drip around heater hoses nearest firewall, replace hose and new clamps.
Pressure tested system, loss of pressure exists, nowhere to be found.
Coolant dripping from passenger side frame rail and also around flexible braided exhaust pipe while overnight. Unable to locate source.
Checked motor oil for coolant… none present.

-3 weeks ago, low level coolant light returns, puddle under car at same area as before.
Filled the bottle and this time it took more coolant than usual, can’t drive the car but a few miles before the low level light comes on.

-2 weeks ago, small leak around heater hose.
Replaced original heater hose.

-1 week ago, low level light on.
Drank a tall glass of Johnny Walker, sat on the porch and pondered about purchasing a big gun.

_Today.
The Heck with it.

Anyone else experience this? Any Ideas.

HELP

SmokinJoe · **Posted:** Sun Jun 05, 2011 10:22 pm

I feel for ya Racer...and I've got the same problem. Trouble with mine is, I have not found one drop yet! I'm thinking serousily of having an oil analysis done, then decide what to do from there. My coolant loss is slightly more frequent than yours, but still slow. It seems to be a little worse if I'm on the highway for an extended period.
I don't have any white smoke, oil in the coolant, bubbles in the reservoir, ect., but who knows....
Mine actually started before I had my thermostat replaced....
I wonder if it could be the egr cooler.....what would be the symptoms???

HELP X 2 !!

yakers · **Posted:** Mon Jun 06, 2011 12:25 am

My story is similar: I am trying to figure out the slow loss of coolant. I have posted before and received several suggestions but they don't seem to be the issue in my case. This included checking for a leaky thermostat, leaking lines to/from the coolant recovery tank and staring at the EGR tubes to try to spot a leak. I had the thermostat replaced about a month ago, no visible leaks on it before or after replacement (although the gauge shows the right temp now).
The loss is not too significant and seems to be more related to the starting cycle than based on how long the engine is running. I think if I didn't shut the engine off it would make a cross country run successfully without coolant loss. There are no drips under the vehicle. There appears to be no coolant in the oil. I am not totally sure about combustion in the coolant. There seems to have been some event that sent some blackish residue at the top of the coolant overflow tank but it looks like maybe a single event, nothing of a recurrent nature. The dealer did an 'engine block test' and said it is fine.
I have looked at every hose I can see, I know there are a lot of hidden places on this rig and I am not sure I have checked them all. I tried taping some paper towel around the ends of hoses and no moisture showed.
I have 90K miles on the Jeep now, the 10k service will be another opportunity to explore possible leak points but nothing obvious right now. Maybe try the UV test if I keep leaking coolant.

racertracer · **Posted:** Mon Jun 06, 2011 5:09 am

Furthermore, I am thinking that it may be coming from a leaky heater core but I don't see water leaking in the cabin, the carpet is dry and the external drain on the fire wall is dry.

The places I can see and feel coolant is on the top of the metal shroud covering the turbo below the plastic coolant reservoir and then on the garage floor under the passenger side, so I do feel and see coolant. I don’t believe it is being burnt in the combustion chamber no white smoke visible, and none in the oil.

I pressure tested the coolant reservoir by itself for leaks and couldn’t find any.

I am thinking that maybe the coolant could be coming from the overflow escape hole on the reservoir, not sure why this would happen but one of my thoughts was that I might have improperly installed the coolant hoses after the thermostat swap, possibly causing a buildup of pressure that is escaping from the hole on the rear of the bottle.

I checked for the possibility of hoses being improperly installed by asking members if they could look at their set up and report back. The set up looked good but just to reconfirm, here is the way mine is set up.

1. Top 3/8” hose barb on the thermostat goes to top of reservoir bottle. Is this correct?

2. Top 5/8” hose barb on the thermostat goes to hose barb on the left side of the viscous heater (left side of viscous heater while looking at the engine and not left side of viscous heater while sitting in the car). Is this correct?

3. The bottom 5/8” hose barb on the thermostat connects to some other? I would appreciate some help.

I know there has to be more CRD owners out there experiencing undetectable coolant loss not just the 3 of us, so let's hear your experience becasue more data may help decipher the problem.

S.O.S.

DOC4444 · **Posted:** Mon Jun 06, 2011 7:08 am

To see if there are hydrocarbons in the coolant, find someone with an emissionstesting unit. Open the radiator cap and remove an inch or so of coolant with like a turkey baster, etc. Insert the tail pipe sniffer probe into the neck, just above the coolant and rev the engine. The meter will show if combusfion gas is getting in. If positive, that is why your coolant is disappearing.

DOC

papaindigo · **Posted:** Mon Jun 06, 2011 9:58 am

racertracer - hose routing 1) yes but the top side not the barb right under the radiator cap; 2) yes; 3) I cannot follow all of the routing but I'm 95 percent sure it goes to the same manifold as the water line from the bottom left (viewed from front) of the plastic reservoir. Look down toward the turbo along the water line from the plastic tank with the silver heat shield wrap and you will see the manifold.

All - a leaky heater core will generally produce water vapor out of the heater vents and a distinct antifreeze smell and often an antifreeze tinged drip from the AC drip vent in the firewall (where water condensate drips when the AC is running). If you are hunting a potential external leak (not inside the engine) I wouldn't waste my time looking for drips as water can take strange paths (same as with a roof leak). Run by any decent parts store and get a vial of leak detector (stuff that glows under UV light); add to coolant per instructions; lightly rinse off the engine with clean water and let dry; drive per instructions; look for leak with UV light. That's how I found a leak that was in a location where there was no visible drip because the drip hit a hot surface and immediately evaporated leaving no residue.

I recall some forum chat about leaks in the coolant lines to/from the EGR valve on the back of the engine.

SmokinJoe · **Posted:** Mon Jun 06, 2011 1:26 pm

DOC4444 wrote:

To see if there are hydrocarbons in the coolant, find someone with an emissionstesting unit. Open the radiator cap and remove an inch or so of coolant with like a turkey baster, etc. Insert the tail pipe sniffer probe into the neck, just above the coolant and rev the engine. The meter will show if combusfion gas is getting in. If positive, that is why your coolant is disappearing.

DOC

Would bubbles of any sort be present in the reservoir if combustion gasses were getting in, or would the gasses be taking a different entry path and not visible?
I've suspected something of that sort, but never noticed any visible evidence of it, if visible evidence is possible. :?:

I haven't tried the dye either, so think I will try that also, but will have to come up with a uv light to check it with.

Thanks for the suggestions

papaindigo · **Posted:** Mon Jun 06, 2011 2:40 pm

Don't know about bubbles but suspect they would be present if you have a water to combustion chamber leak but not water to oil passage leak. UV flashlights, if not available at a parts store, are less then $10 at Amazon and eligible for their free shipping if you order $25 worth of stuff total.

Squeeto · **Posted:** Mon Jun 06, 2011 3:12 pm

Problems started with the thermostat change.
What gasket did you use for thermostat to block?
If you have a leak here, the coolant is going to burn up pretty quickly.
Did you torque the bolts to 20 ft-lbs?

I used blue silicone to make sure that I had a good seal.

racertracer · **Posted:** Mon Jun 06, 2011 8:21 pm

Squeeto wrote:

Problems started with the thermostat change.
What gasket did you use for thermostat to block?
If you have a leak here, the coolant is going to burn up pretty quickly.
Did you torque the bolts to 20 ft-lbs?

I used blue silicone to make sure that I had a good seal.

Sqeeto, good point, I will remove and reattach the themrostat with blue silicone sealant. I used the OEM gasket supplied with the thermostat.

But why would I see coolant puddle under the passenger side and dripping from the rail.

I'll try the UV test and hydrocarbon test next

mdalien · **Joined:** Tue Jun 22, 2010 10:22 pm **Posts:** 41

Mine started losing coolant, turned out to be the water pump.
Never saw any coolant on ground or anywhere else.

SmokinJoe · **Posted:** Mon Jun 06, 2011 10:23 pm

mdalien wrote:

Mine started losing coolant, turned out to be the water pump.
Never saw any coolant on ground or anywhere else.

How did you find out it was the water pump if there was never a sign of leakage?

It would be great if it was the water pump, as I've got some warranty left. :SOMBRERO:

My upcoming timing belt issue would be solved.

WolverineFW · **Posted:** Mon Jun 06, 2011 10:29 pm

mdalien wrote:

Mine started losing coolant, turned out to be the water pump.
Never saw any coolant on ground or anywhere else.

Since the waterpump is buried so deep, that is a definite possiblity as coolant would probably burn off before it would hit the ground on a slow leak.

Squeeto · **Posted:** Tue Jun 07, 2011 11:11 am

racertracer wrote:

But why would I see coolant puddle under the passenger side and dripping from the rail.

Not sure about the rail.
But pressure remains after the engine is shut off for a while. With exhaust no longer hot enough to evaporate the coolant, the puddle appears.

mattybombatty · **Posted:** Tue Jun 07, 2011 5:20 pm

Same prob. I did my thermo and TB, now every 500 or so miles I need to add coolant. It crossed my mind that it's the WP, since I didn't replace it when I did the TB, which may not have been the best move.

SmokinJoe · **Posted:** Tue Jun 07, 2011 6:38 pm

mattybombatty wrote:

Same prob. I did my thermo and TB, now every 500 or so miles I need to add coolant. It crossed my mind that it's the WP, since I didn't replace it when I did the TB, which may not have been the best move.

matty, hate to hear your a member of the "Grim Leakers" club now. :grim:

Hopefully we'll find a reasonable solution to this coolant loss prob.

We've got some good guys here trying to help us out.

You haven't noticed any drips or anything since your loss started?

Yours could be the thermostat gasket too like Squeeto pointed out.

Drewd · **Joined:** Mon Feb 06, 2006 12:24 pm **Posts:** 902

Isn't the EGR valve water cooled? If so, coolant may be leaking into the exhaust and boiling off without any visible exhaust signs especially if it is a small leak.

camo · **Posted:** Tue Jun 07, 2011 10:56 pm

The other day I took the EGR and EGR cooler off for cleaning and rutine hose replacement and wander myself thingking how though it would be to find a small leake inside the EGR cooler, as it would go back to the combustion cycle and it will cause no performance issues, no smells, no white smoke.... just enough to turn the coolant light on

also the egr hoses thoug they were no leaking they were all crack and wornout......
anyway, thnx God im not having that issue but I would definetly suspect of the EGR cooler if I had it.

SmokinJoe · **Posted:** Tue Jun 07, 2011 11:50 pm

I think my plan will be to put in some leak detect stuff tomorrow and run it for several days, then check with UV. If that doesn't produce anything, I'll get a rig from Harbor Freight or some place and pressure up the cooling system and let it sit for a few days cold. If that doesn't produce anything, then I think I'm headed to the EGR Cooler next.

Does anyone have any suggestions on how to check out an EGR cooler for leaks? I know I'm not blowing any smoke out the tailpipe, but don't know if theres another way to confirm a cooler leak.

I don't guess a leaky EGR Cooler would produce any visible signs of it while under a cold pressure test, other than maybe a pressure drop, would it??

Hopefully it won't get to that point, but.........

camo · **Posted:** Wed Jun 08, 2011 1:08 am

I think it would be easy to test the EGR and cooler for leaks, they both have inlet and outlet for the coolant hoses, so what I would do would be to take them out and test one at the time by plugging them with rubber plugs and securing the plugs with clamps, then put the cooler or egr in a place that you can see the water coming out in case they are in fact leaking, then connect a hand pump to the other hole so you can pump some coolant in and keep it pressurized, then just wait some few minutes to see if anything comes out of them.
:5SHOTS:

Coolant Leak â€“ The ongoing saga

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