2005 K3500 LLY Low Coolant message

[Mynyrd1]

I have a 2005 K3500 it has 75098 miles on it last fall I got a low coolant message stopped and topped it off. No problems until last weekend drove about 150 miles stopped for dinner came out restarted teh truck and had the lowcoolant message. stopped at a station got some dexcool opened the cap and coolant started to come out of the overflow. Let the truck cool down refilled the tank. seemed ok. Ran the 150 miles home the temp was 210 like always good heat no temp spikes.

Started the truck to move it over to the garage went to check the level it was a little low went to open the cap and the tank was pressurized.

First thought head gaskets then heard about the EGR cooler any way to easily test the cooler?

Thanks for your help.

[Kennedy]

If it holds pressure when cool it's pretty much undoubtedly a head gasket issue. I have seen claims of EGR coolers failing, but have never seen proof. This to me is just wishful thinking. If the EGR cooler was leaking the cooling system would not hold pressure and the coolant would be in the exhaust.

Head gaskets have a way of leaking in one direction-combustion chamber to coolant as this pressure is quite high whereas cooling system pressure is more like 16 psi max

[Mynyrd1]

Thanks John for the reply I will get it checked out.

[CoyleJR]

Mynyrd1,
Look at the DP Information resource page (the list under the picture of the white truck when you are logging onto the DP). One of the subjects is Duramax head gasket failure. In that article Jim talks about problems with the coolant filler cap causing symptoms much like you described. My truck runs great but uses about a quart of coolant each year. It also likes the coolant level to be just above the low mark on the coolant tank when it is hot. Additionally, it holds pressure in the coolant system over night, even with a new pressure cap. ?????

John

[Kennedy]

Cooling system pressure is normal and is caused by expansion of coolant as it warms up. When it contracts it should come back to normal.

If there is pressure remaining when cooled then you are adding something from somewhere.

If there is a vacuum the upper hose will collapse and that just tells you that something escaped plus the cap did not vent inward properly.

[Mynyrd1]

Well it was Blown head gaskets. both were blonw on #2 and & cylinders. I took it to the dealer due to it being a stock truck and low miles. The dealer ship was pretty good to work with.

I am disappointed with Chevrolet customer service.

I know my warranty is expired (5years/100000 miles powertrain) due to time but I do not feel that a truck like this should have blown head gaskets at 75000 miles, I brought up the TSB that called out for a design change in the head gaskets.

The people in customer service take down the information and pass it up the chain. When I asked to speak to some one further up the chain I was told that there was no one else I could talk to.

I was trying to get reimbursement for the repair. I was offered a 1500 voucher for my next new car purchase cost of the repair was in the 5500 range.

[More Power]

No matter the brand of diesel pickup, they are so expensive to repair that owners should think about future maintenance for any out of warranty truck.

Those owning an out of warranty diesel should consider one of the following strategies for future maintenance.

1- Those who are willing and able to perform most service work will save at least half, maybe more, of any future service. Buy the tools and maintenance manuals you'll need ahead of time. Invest the time in learning more about your truck.

2- If self-service isn't possible, consider an extended vehicle service policy that covers injectors, injection system, engine mechanical, transmission and the rest of the drivetrain.

3- Lastly, while an extended warranty policy can be a great nerve calmer for a future problem, it's money that you'll never see again if your truck doesn't have a problem during the time you own it. So, why not consider becoming your own extended warranty company. Put $100 into a vehicle service account each and every month you own this truck. If you have a big problem, the account will take the bite out of the bill. If the truck doesn't need service work during the time you own it, you'll still have the money for the next truck... Unless you live in Cyprus... ;)

Jim

[Mynyrd1]

It is very true that repairs on these trucks are expensive and your idea about extended warranty and the account are very good advice.

Thanks Jim

Arnie

[gary_lucas]

Sorry to revive an old thread, but I'm getting similiar symptoms.

Upper hose collapsed, mechanic told me about it awhile back.

Also, just starting to get 'low coolant' messages on the console.

I'm going to get a new cap this evening, the hose has been replaced a time or two.

If there's coolant escaping (and I'm not sure there is) where would it be escaping too?

I put some fresh dexcool / water in a few days ago and the message came back today.

[Kennedy]

I don't get too concerned about the hose flattening, but to catch the coolant loss I would put a bottle to trap the overflow from the surge tank. You will probably find it is getting out here when the system over pressures.

Aside from that try a simple pressure test on the entire system and see if it holds.

[chessy56]

Interesting posts on pressurized coolant system. I just had my head gaskets replaced by the dealership a couple of months back. I've learned that even after the engine cools down (over night), my system is still under pressure. Until all of the air was worked out of the system, my coolant level always seemed a bit low upon cool-down (release the pressure cap and the coolant level jumped up above the full/cold mark). My upper rad hose never collapses. Dealership tells me all is good, so not knowing any better and having the heads serviced/gaskets replaced by a "trained tech", I'll have to assume their word is OK. My bottle level remains consistent now.

[Kennedy]

In theory (and typically in practice) if you open the cap to normalize pressure when cold, then start the engine and cycle to operating temp and back down to ambient there will be no pressure in the system as it will normalize back to the same pressure.

Nothing added=nothing gained, nothing leaked=nothing lost as the coolant expands then contracts back to the same volume.

[rapidoxidationman]

Chessy,
Is the cooling system properly bled? Seems like I remember reading here that running the engine at 3K rpm for 10 seconds is necessary to really purge the air from all of the coolant lines. Easy to do this going downhill if you don't like to run the engine that high without a load on it...

[gary_lucas]

I don't get too concerned about the hose flattening, but to catch the coolant loss I would put a bottle to trap the overflow from the surge tank. You will probably find it is getting out here when the system over pressures.

Aside from that try a simple pressure test on the entire system and see if it holds.

WIll do, thanks Kennedy :)

G

[chessy56]

I caught the 3K rpm for 10 sec as well. Was the system properly bled? Can't say for sure; I assumed the work was done properly being that the dealership's trained tech did the work (and he does a bunch of DMax engines). Then again, I can't speak to what GM is training their techs to do. I experienced the same draw down of coolant after a water pump change and an injector swap. Add more coolant after the system has cooled down, and eventually it holds a consistent level and doesn't seem to lose any.

I heard that cracking open the plug on the thermostat cover was supposed to help bleed the air from the system. Live and learn I guess....

[gary_lucas]

So had a scare this morning.

WHen I got to the truck this morning there was a small puddle of pink liquid under the front of the truck.

Definitely coolant, near the midline of the engine, possibly a little towards the drivers side.

Brought it to the mechanic and he confirmed there is definitly some coolant loss at 15PSI. He said it wasn't substantial and that he wasn't sure he would want to do the job as he doesn't have some of the required tools.

He's going to ask around the community to find / borrow the tools or find someone who he trusts to do the work at a reasonable price.

I'm going to re-read the main articles on coolant / head gaskets. Anything I should check? We're pretty sure it's not a hose as far as we can tell.

Gary

[DmaxMaverick]

There are other possible leaks that will show in that area. Most common is the turbo coolant line that runs right behind the fan pulley. It's a short hose section between two hard lines. The hose can crack, or the clamps get tired. If it's leaking, it will have coolant residue on the lines and in the area below it. I've replaced a few of these. The thermostat housing and other plumbing can also leak there. Most are O-ring sealed.

[gary_lucas]

There are other possible leaks that will show in that area. Most common is the turbo coolant line that runs right behind the fan pulley. It's a short hose section between two hard lines. The hose can crack, or the clamps get tired. If it's leaking, it will have coolant residue on the lines and in the area below it. I've replaced a few of these. The thermostat housing and other plumbing can also leak there. Most are O-ring sealed.

Thanks, I'm camping this weekend... Do I need to pull the shroud off in order to see those lines? Or can I only see them from underneath?

That would be a whole heck of alot cheaper.

G

[DmaxMaverick]

Thanks, I'm camping this weekend... Do I need to pull the shroud off in order to see those lines? Or can I only see them from underneath?

That would be a whole heck of alot cheaper.

G

No. It's on the top, immediately behind the fan pulley. If you get your eyes over it with a flashlight, you can see it. The hose section is about 3/8" x about 2.5" long, with GM squeeze clamps at each end (I posted a pic of it some time ago, but can't find it now). Also look for coolant residue along the sides of the pulley boss, and beneath the water pump. The water pump has a weep hole, which should show residue if the seal is leaking (it's on the bottom, so you'll have to look up at it).

[gary_lucas]

https://plus.google.com/u/0/103645652808911426825/posts/j7gMPgAxjiH

There's definitely something going on there.

The block is kind of dirty, but when I zoom in there seems to be a red sheen and it's definitely wet.

I'll do some more investigation, but I think that's the problem. If it were entirely the water pump that area should be dry and it wouldn't surprise me if it had been leaking for awhile and suddenly got worse.

I may bring it back to my mechanic tomorrow, I don't think he got eyes right on the pump, but if he has time I'll get it on the hoist and we can check both ends.

That google post should be public and allow everyone to see it, if it's not let me know.

[Kennedy]

Not sure where the red sheen comes from I don't see it. What I do see is typical oil weep from the intake due to the closed PCV system. Perfectly normal and perfectly harmless if that is what it is.

Water pump is one of the most common leaks and unfortunately often a symptom of a head gasket issue and over pressurization of the system.


On the bleeding:

The bleeder on the stat housing is there as a quick air purge for filling. I fill the tank and wait for discharge here then plug it. I then fill the tank a couple of inches above the midline and go for a drive. Stats open, system burps, and air travels to the tank lowering the level to final level. Let the system cool and top off to just above the midline.

[gary_lucas]

Not sure where the red sheen comes from I don't see it. What I do see is typical oil weep from the intake due to the closed PCV system. Perfectly normal and perfectly harmless if that is what it is.

Water pump is one of the most common leaks and unfortunately often a symptom of a head gasket issue and over pressurization of the system.


On the bleeding:

The bleeder on the stat housing is there as a quick air purge for filling. I fill the tank and wait for discharge here then plug it. I then fill the tank a couple of inches above the midline and go for a drive. Stats open, system burps, and air travels to the tank lowering the level to final level. Let the system cool and top off to just above the midline.

Yup, showed it to my mechanic and he said the same thing regarding the oil. He's not sure if can do the job (not a diesel tech...) He's going to ask around and either find someone who can for a recommendation or study up / borrow tools from someone who's done it before, it's an open question but neither of us think it's something that needs to be done immediately.

I may pull the shroud this weekend and see what I can see with that thing out of the way. Rick (mechanic) said he put it on a hoist and had a look from underneath and he's fairly sure it's coming from the weep hole on the water pump but couldn't get a good look at it. He's 90% sure, we'll have to do a little more investigation to get to 100%.

In terms of pressure in the cooling system, he said he can't detect anything abnormal... How do you detect / measure pressure in the cooling system while the engine is running?

[Kennedy]

The problem is that now it will not make a lot of pressure because it leaks. They do make a tracer dye that works in coolant. You could add some and then use a black light to trace back to the source.

It could be that the pump just leaks and that is that. Then again it could be related to a head gasket issue. About the only way is to add a psi gauge somewhere. You could pull the bleeder out and tap in there for simplest, but again it will just push past the water pump if that is what is leaking.

[gary_lucas]

ongoing frustration.

So, water pump is still leaking, but it's no more than a tablespoon or two on any given day, and then only when I've had it out long enough to warm up.

We've take the trailer out twice since then, I just make sure to top up the coolant first.

However today was a disaster.

I was on a 2 hour high way drive, and the engine coolant temperature (as measured on my Insight) started spiking, it hit 250 and set off the DIC alarm... I immediatly pulled over... Then let it cool down.

The highway I was on wasn't very hilly, there were a couple of slightly steep grades but nothing substantial. I should have learned my lesson then... howver I thought: "Well, if I go slower, put my hazards on and keep it to 80kph or less I should be fine."

Previously whenever my truck started getting hot, I just let off on the fuel and it's fine within 10 minutes, however doing 60kph in a much, much hillier stretch and the coolant spiked to 260 very quickly. I had to pull over again, I ended having the trailer towed back and driving back home.

Truck was running fine if it's not pulling up a grade.

Time to do some research, my trailer is 9500lbs and the grade really isn't substantial... I've pulled up much steeper without issues before...

Edits:
=================
1 The actual hilly section where the 2nd overheat happened was really not that steep, it was fairly long... I was doing about 70kph.
2 When I pulled over It just happened to be on the same pullout where a tow truck driver was waiting for a tow truck... To tow him, so he used hsi radio to get us help.
3 the Tow truck that eventually hauled my trailer back to storage was the same goddamn truck that I Have (2004.5 lly) except it was a DRW.
Gary

[gary_lucas]

Previous owner had this thing on it:

http://www.etrailer.com/Custom-Grilles/GMC/Sierra/2004/P64312.html?vehicleid=2004634805

Pulled that this morning, should improve airflow a little. Spoke to a few people and most people assume it's a thermostat issue. Truck seems fine to drive normally, it's just highway pulling and moderate grades that cause the issue. I also saw a p0046 on the insight yesterday. But that is probably unrelated.

G

[cstephens93]

DId you ever figure out what the issue is?

My truck has been every now and then blowing coolant out the overflow into a bottle I have attached. However, I never have the hard upper radiator hose issue

[Kennedy]

If it's pushing past the cap it's really hard for it to be anything other than a head gasket issue.

[DmaxMaverick]

DId you ever figure out what the issue is?

My truck has been every now and then blowing coolant out the overflow into a bottle I have attached. However, I never have the hard upper radiator hose issue

A broken pressure cap can cause it. They're cheap. Otherwise, like John said, head gasket(s).