Coolant Loss !!!!

[joe k]

I have a 2003 H2 that has a coolant loss problem. Started to use a small amount of coolant at around 24k miles. Problem has escalated to a loss of about 1/2 gallon every 1500 miles. Have taken the H2 to the dealership several times to address this as a warranty concern, no external leaks have been found. The techs at the dealership have inspected system for gases in the coolant system (dye test / black light), along with pressure testing, ect. It also looks like the rest of the component fluids are clean (engine oil, transmission, ect). Have had 2 dealerships and 2 outside shops look at this problem and no one has a definitive response other than " the coolant is going somewhere." Also had a engine light come on at around 36k miles, turned out to have most of the ceramic insulation missing off of the #2 spark plug (rep at the dealership stated that I needed a fuel treatment before I demanded a plug inspection), have a question in the back of my mind if the 2 problems may be related.
Anyone out there have any thoughts on this? Willing to listen to any thing at this point.

[Klaus]

Well, they are right - The coolant has to be going somewhere!

It's either leaking on the ground or in the cab (heater core), leaking internally into the engine oil or the combustion chamber, or leaking into the transmission fluid. The only other possibility I can think of is that the throttle body has a coolant line running to it to keep it from freezing. If the throttle body got cracked somehow I suppose it could be leaking coolant into the intake charge.

Given you've already had a problem with the spark plug, I'd say that was your first clue. I'd pull the new spark plug out and take a look. Compare it to another plug pulled on the other side of the engine. If the plug looks bad again I'd say you either have a blown head gasket (if you're lucky) or a cracked head or block.

[Hummertech]

Why don't you give a call to Ken Batchlor up in San Antonio. They are a very good Hummer dealership and can probably fix you up.

[joe k]

Here is a pic of the #2 plug.

[KenP]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Posted by Klaus:
Given you've already had a problem with the spark plug, I'd say that was your first clue. I'd pull the new spark plug out and take a look. Compare it to another plug pulled on the other side of the engine. If the plug looks bad again I'd say you either have a blown head gasket (if you're lucky) or a cracked head or block. </div></BLOCKQUOTE>Can you say, "Bingo"? After reading the post that's exactly what I was thinking. Not good and not normal. You should be able to tell with an oil change. Another thing you can do is put the dye in the coolant, run it and blacklight the oil.

Don't let them screw around with you on this.

[joe k]

UPDATE: After 4 days at the dealership and 1 day with a hummer technician out of Detroit,,,,,
NO source of the leak could be found. I think that the area rep limited the amount of exploration to pulling the valve covers.
Problem appears to still be around but I am being told that they (GM) will offer a component warranty on the rig up to 100,000 miles, should be plenty of time to allow the problem to manifest itself in a catastrophic manner.
Once again, thanks for all of the well thought out suggestions, I know it took a lot of thought / time from multiple members of this forum. I have not ruled out any more exploration in the future at my expense, just want to forget about this problem for a few weeks.

[phenom01515]

Originally Posted by joe k

UPDATE: After 4 days at the dealership and 1 day with a hummer technician out of Detroit,,,,,
NO source of the leak could be found. I think that the area rep limited the amount of exploration to pulling the valve covers.
Problem appears to still be around but I am being told that they (GM) will offer a component warranty on the rig up to 100,000 miles, should be plenty of time to allow the problem to manifest itself in a catastrophic manner.
Once again, thanks for all of the well thought out suggestions, I know it took a lot of thought / time from multiple members of this forum. I have not ruled out any more exploration in the future at my expense, just want to forget about this problem for a few weeks.

what is a compnent warranty

[Yetti]

well as an Ex GM engine mechanic I have a couple of suggestions. one of the biggest over looked areas for consuption is through the transmission. the trans runs hot enough to boil off most water leaking into it from the radiator trans cooler. it may very well be the starting point for loss. check your trans and make sure the oil isn't murkey. if its not clear and clean its most likely the problem.
also if you suspect its a cracked head or leaking head gasket, remove the spark plugs after driving it while the engine is warm and the radiator has pressure from running. let it sit over night. in the morning use a piece of clear hose and see if you can suck any fluid out of the cylinders that has pooled on top of the pistons. something in the real small range like 1/8 dia hose works well for this. if you find fluid laying in the hole you have your culprit.
the alternative would be you use a endio scope to look in the holes for fluid.

last but not least have you checked your engine oil for coolant? this is an old trick. you climb under the truck and let it sit after loosening the drain plug just a tiny bit, just enough it doesn't seal tight. put a piece of clean white paper in a pan and put it under the truck where it can drip on it from the plug. I have seen it take days to yeild results. but once in a while you get lucky. if the spot on the paper is being made by water or coolant it will have a green or pink ring around the oil spot.

[codeman671]

I have been leakng coolant in a similar way, just found it I need a water pump (at 67k ??? ). I have a GMPP so it only cost me $100.

[NoMoGMPG]

Just FYI, if a complaint is documented under warranty and the CCC is "cannot duplicate complaint" or "NTF (no trouble found)" you do have some recourse under GM's Policy and Procedure manual. It is usually on a case by case basis and requires the Area Service Rep to approve any repairs, but it sounds like you have good documentation to back a claim up should anything happen. Just don't let it go too long.

Dave

[joe k]

Thanks for the feedback, we checked the new plug on #2 and it looks good (compared to the originals, new plug has been in for around 6000 miles) As far as it going onto the ground, I think that would have been found with the dye and black light test. Still looking.

[joe k]

Don, Thanks for the procedure, I am going to get with a third party mechanic ( I do not have the bore scope) to see how soon we can pull this off. Seems like a damn good direction to head with this as another point of verification / elimination!
I am also going to try to get a decent picture of the plug for this string. Have been told that if I can direct the GM tech to the exact source of problem (pictures, ect) I may have a leg to stand on.
Once again, thanks for the help.

[Hummie2]

Joe...

There was a post here that I don't see anymore( I guess it was deleted) and it made more sense about what is happening than anything else. It was about a cracked or porous intake port runner in the head to a water jacket. Coolant would find its way to the inlet valve then into the cylinder and out the exhaust. Compression would would not get back into the coolant because the inlet valve is closed then, so combustion gases won't be present in the coolant. Here is what you do to check:

1- get the engine hot (fully up to temp) then stop it.

2- pull #2 sparkplug, pull the valvecover for #2 cyl and turn the motor till intake and exhaust valves are in overlap (both valves partially open)then pressurise the cooling system to about 15lbs

3- wait and watch (you should see coolant in cyl with a borescope- wait long enough it will fill up and run out the plug hole!)

coolant is finding its way into #2, but compression is not going back into the cooling system. That is why the insulator broke on the origional plug (from water in the cyl) and why the new plug stays clean. The same could hold true for an exhaust runner also, but I would suspect an intlet leak because of the plug problem.

Don

[LasVegas]

Everyone here is dead on. If it's not showing up inside the cab (heater core) or outside (on the ground) and not appearing in the oil or transmission or other fluids it's just about having to be "consummed" by the engine. If it were me, I'd let it idle for about an hour in the driveway to check for external leaks. If none, it's dealer time.

[Klaus]

You might want to start researching the lemon law in your state. Depending on the state, they have so many attempts to fix the problem before the vehicle is considered a lemon.

How many times has it already been in the shop for coolant loss? Are you keeping good records?

[Hummertech]

Look real good at your trans fluid. We have seen several coolers in the radiator split. Usually you get more trans fluid in the radiator though, but check it out. Also, it's common for water pumps to leak slowly from it's gaskets. Take your front skid plates off and look very closely with a bright flashlight. It usually runs down the edge of the front cover and may be a little hard to see. This should be the first place your dealership looks, but they may be a bunch of morons. Did they pull the skid plate when they were looking for the leak? Bring it back to them. It's under warranty. It's their job to find the problem. Not yours. Good luck and let us know what the morons find.

[LasVegas]

Joe...you're being too nice at this point. It's time to take the gloves off. If this problem started during the warranty period and you have that documented you have a very strong case. It's time to pursue legal/government agency options. If it were me, I would learn all my legal options, then write them a certified letter telling them what you intend to do if they don't respond to the positive. If they don't, then do it.

[joe k]

sorry, did not clarify. I live in CC and we do not have a "hummer" dealership down here, closest one is in San Antonio. Have been using a GM dealership in town to save me the drive (350 mi rt) , to preform the actions that the hummer dealership is suggesting. Good point, will ask them if they can preform the test as well.

[PARAGON]

Ok, stupid question above. For some reason I was thinking of the outside of the plug and couldn't fathom that heat transfer through the plug could cause cracking of the insulator. Wasn't thinking.

[joe k]

Took the rig back to the dealership in SA on Tuesday morning, has been in their hands testing various components since then. Last ditch effort by all parties to make this situation right, but looks like GM is actively involved with this case at this point in time. They expected to have it for at least 4 days, so hopefully I will know something by Friday. Once again, thanks for all of the suggestions offered by the forum on this problem,,, will let all know what they find.