99 Yukon Head Gasket

[99Yukon4x4]

195K on her, and I believe the head gaskets are starting to fail. Noticed yesterday that I had no heat in cab, so changed thermostat, and filled coolant. Was driving around last night, and no problems. Drove around today, and noticed my temp gauge was going between 120 & 240. Checked coolant level, and was low, check oil, and oil level was above what it was a few weeks ago, and smelled coolant coming from exhaust while running.

 

[Y2KpewterZ]

Might want to investigate intake gaskets before anything else.

 

[99Yukon4x4]

That will give the same signs as a head gasket?

 

[Goodinblack]

That will give the same signs as a head gasket?

Almost. It may depending on where the gaskets start leaking.

On mine I had no issues other than coolant missing. It was leaking into the oil. On another it leaked out and not in.

 

[99Yukon4x4]

Dropped it off at a mechanic I have known for 20 years, and describing what was going on, he is almost positive it is going to be the intake gaskets. He's going to compression test it in the morning, and go from there. Hoping thats all it is. Now, my next question is, would it be worth replacing the water pump, and timing gear/chains while its in this stage? Or can those be replaced without removing the intake again?

Thanks!

 

[SunlitComet]

If you are burning coolant, read the plugs to find out where. if they are the two front plugs it could be intake or head. But if plugs 3 4 5 6 7 or 8 then almost definitely a head gasket

Sent from my SPH-L720 using Tapatalk

 

[99Yukon4x4]

Just pulled the plugs the other day, and #2 and #4 were fouled, to the point of almost no gap left. I noticed oil level was elevated, (still had an oil consistancy, and not milky) but no oil in radiator, no leaking around either head. Truck doesnt overheat, but fluctuates between 185 and 225.

 

[SunlitComet]

Replace them and run a few hundred miles longer and reinspect. Just use some plain autolite 605's for now. Got pics of them?

 

[kcb37]

I would wait on the water pump.
4 bolts, fan has to come off. Fan belt, fan/clutch, 4 bolts for water pump done.
Timing chain/cover. Oil pan has to come down, a lot more money.

Intake is not touched for either.

 

[99Yukon4x4]

I will post pictures of the plugs later, but mechanic is putting her back together now. Compression test and pressure test were done. They narrowed it down to the intake gaskets, my radiator was also shot.

They replaced both intake gaskets, upper and lower rad hoses, oil cooler lines, radiator. Will find out later today if that fixes the problem.

Oil pan is going to have to get replaced anyway this spring, showing signs of degration, as well as the valve covers. Just need it running till I get the wife another suburban.

thanks for the input guys!