coolant lly

[bluepittsrace]

im loosing coolant but not while it sits but coolant light comes on while driving add 1/2 gal or so and good for another 300 miles but cant seem to see where its leaking got no smoke and oil is clean but when I raise hood the top hose is collapsed not solid like head gasket problem so any ideas to check or previous encounters with same would be helpful thanks

 

[NC-smokinlmm]

Either your egr cooler is leaking or your HG's are blown. Your problem is not unique, there are literally hundreds of threads addressing this topic. Every LLY owner tends to think mine couldn't be blown it's got to be something else. It's not, more than likely the HG's are shot, your not alone. Every LLY I've ever dealt with eventually needed HG's...

 

[bluepittsrace]

I always thought with head gaskets the top hose would stay solid though at least that's the way it done when they blowed the last time I replaced and studded them in march of this year

 

[mike diesel]

If the hose is collapsed then I would buy a new overflow bottle cap.

 

[bluepittsrace]

just got back from doing that going to see if that corrects it but would it cause to loose coolant with bad cap

 

[POWDR]

If the coolant cap doesn't fix it, I would grab a pressure test kit and pressurize the system. I lost tons of coolant from a small leak in a hose to the turbo.

 

[pizza pig]

With an LLY all the "it could be" symptoms are usually the worst case. Ive seen so many people replace water pumps, caps etc when the gaskets are bad. Just properly diagnose it and dont throw parts at it. I dont suggest asking the internet what is wrong with your truck either, but there are some smart dudes on here. Take it for what its worth :hug::thumb:

 

[NC-smokinlmm]

I always thought with head gaskets the top hose would stay solid though at least that's the way it done when they blowed the last time I replaced and studded them in march of this year

Ive seen them collasped and have bad HG's. I would start with an egr delete, the cooler can rupture and feed your engine the coolant thru the intake, ive tested coolers once removed before and seen leaks. I have always wondered if a failed egr cooler is what causes some lly gaskets to go early, gm changed the design on the lbz...

 

[bluepittsrace]

oh I will properly diagnose im just looking for suggestions on some items to be checking this being first diesel not as familiar but always open to ideas new cap helped the hose but still loosing fluid I see it dripping on pass side of truck but cannot seem to locate the cause only drips when running

 

[02greysixer]

Check the stupid plastic quick connects at the heater core. It can be tough to spot a leak there.

 

[NC-smokinlmm]

First you state there are no visble leaks now you say it drips? Which is it? You do know the ac compressor drain is on the passenger side right? Is that what you are seeing drip? Is it coolant? Ive seen the gasket blown at the rear passengers side before so bad that it was blowing bubbles. You need to shoot us straight info otherwise your wasting yours and our time. A leaking truck and one with no leaks will have a very diffrent diagnosis...

 

[bluepittsrace]

at first sitting in driveway no leaks I took it on drive testing new cap and as I pulled over to check things in parking lot seen couple drips on pass side and yes I know a/c is on that side its not water it is dex cool I was updating as I find something it doesn't pour out just small drip mabee the size of quarter in 10 min but dripping off of the a- arm and cant seem to see the area coming from and that is why I asked if there was any ideas of something I figured someone might know of a line or something that's tucked under somewhere I cant see and as to the plastic fittings ill be checking them here in a few thanks to all that is trying to help

 

[NC-smokinlmm]

I second that you check the lines going into heater core but I thought they were spring clamped. You coud also have a bad heater core, any wetness inside the cab on the passenger side?

 

[bluepittsrace]

okay ive narrowed down to coolant is coming from around the first injector hold down right under the ficm

 

[bluepittsrace]

im thinking cracked head if this would be correct any good places to buy them used

 

[NC-smokinlmm]

I highly doubt it's a cracked head. HG could have let go there...

 

[bluepittsrace]

im just as dumb founded by it myself trying to figure out how it would be coming out the injector hole its running right past the injector hold down bolt can watch it with bore scope camera that's why I was doubting a gasket how could h/g leak up through injector bore and 1 not smoke because lly is machined bore it has no cup with O-rings so I ask has anyone seen this before

 

[NC-smokinlmm]

You sure its coolant? Could have a leaking injector seal as well...

 

[bluepittsrace]

its coolant looking for set of heads

 

[Bustedknuckles]

im just as dumb founded by it myself trying to figure out how it would be coming out the injector hole its running right past the injector hold down bolt can watch it with bore scope camera that's why I was doubting a gasket how could h/g leak up through injector bore and 1 not smoke because lly is machined bore it has no cup with O-rings so I ask has anyone seen this before

Had a friend with the same issue. He used blue devil block sealer on it and its been fine for over 2 years.