[racng69]

hello guys, ive read all the posts here about blown head gaskets. my truck started showing the "low coolant" message. I added coolant, and it came back within a week.

Also the truck wont get up to temp unless i am on the highway.

So i went to the dealership this morning, thinking the worst, head gaskets. They told me it was a hose underneath the turbo that had to be replaced, and the gaskets were fine.

They did a compression test, and it checked out. No other leaks anywhere they said.

So i pick it up this afternoon, everything looks fine, start driving it home, drive 5-7 miles temp guage still says 160. Stays at 160, until i get on my street i open it up, and bam she jumps to 210, and then back down to 180ish. Then the :low coolant" message pops back up. So im back at square one, and 400 dollars in the hole.

Any suggestions? They say for sure its not the head gaskets. Im guessing next step is thermostats?

 

[621Ranger]

The dealer needs to clarify what they did... A compression test will not tell you if you have a head gasket problem. A cylinder leak test will.

 

[621Ranger]

Suspect Head Gasket Problem?

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The common symtoms it seems is loss of coolant, loss of heat and temp very slow to rise if it does at all without taking out on a highway run to force T-stats open... Has to do with reduced bypass flow on cold motor. While cooling system is in bypass mode the combustion chamber leakage disturbs coolant flow...No heat / no warmed coolant to temp sender... when the motor is worked @ Hwy speed enough heat is generated to open T-stats... with the increased flow with T-stats open the engine temp stabilizes and heater ops goes back to normal. Don't keep driving like this.

Quick check you can do... Just fill the coolant reservior to the top...leave the cap off and look for bubbles while the engine is running. Continious bubbles strongly indicates cylinder breach to cooling system.

Next you can look for signs of external leakage from base of head... look all around visable parts of heads including behind starter. Use a light and a mirror... If leaking you will see a wet engine block or stains on the engine block from a previous leak that has dried. The block is black and stains look somewhat like a dried tanish leak path.

The next test is (you likely will want a garage to do this) apply regulated air to cylinder through the glow plug hole with adapter. Use cylinder leak tester or just run air pressure at 25-35psi. With cylinder on compression stroke; coolant bottle full to neck... Apply air and watch for bubbles or fluid level rise in the coolant bottle... Any reaction means leak. No reaction means no leak is evedent on that cylinder. Air test helps pinpoint cylinder(s) with problem just in case you pull heads and don't see a blown gasket. Then you need to focus on the problem cylinder castings... Crack check heads & check cylinder walls carefully. Finding nothing more than slight gasket leakage would make me want better fastners for the heads.

Root cause for head gasket failure... Who knows... Overheating is a big issue via high exhaust gas temps or running low on coolant. Head bolts are suspect too; stretchable torque to yield factory head bolts to be specific. Theory... Increased cylinder pressure with performance tuning can cause the head to lift and lose seal prematurely. ARP head studs will likely remedy the problem... There are people who run twin turbos and 60lbs of boost on factory gaskets and bolts without a problem too.

 

[racng69]

no continous bubbles when doing the first test, but i noticed that the fan is going on and off....Maybe fan clutch??

 

[621Ranger]

It's possible the dealer didn't get all the air out of the cooling system and it burped out some air and the coolant went down... top off coolant and just drive it. The temp on a diesel usually is on the low side untill worked. If it will run between 160 and 210 and not burp coolant your ok. If it keeps blowing coolant your air locked, over heating or the head gaskets are leaking. Check the radiator for proper air flow too. Sometimes cotton wood seeds or leaves and pollen build up on the core and blanket it so the core gets restricted. You will need to look between the radiator and the intercooler. Talk to the dealer and let them know what happened and ask if they did a actual cylinder leak test. How many miles do you have on it; and are you under warranty?

 

[racng69]

it has 150k on it...so no warranty on it. Was thinking about getting extended warranty but i doubt it covers head gaskets

 

[Maine Silverado]

Any updates for us?

 

[victorbrad]

i was looking for my chevy head casting numbers in order to find some faults which have come up recently. had to take it to the dealer to get the problem fixed.

 

[racng69]

Mine was headgaskets.

 

[jlb444]

^^How much did the dealer charge you and did you go ahead and replace the head bolts with studs??
Just curious.

 

[racng69]

I paid 2500 for headgaskets (both sides) and ARP headstuds. Not from a dealer though. Harley @ Georgia Diesel hooked me up!