On a scale of 1-10, how bad is this?

[Jhnpv]

If I’ve done my research correctly, pretty sure it’s a blown head gasket no? What are your thoughts. Coolant reservoir is always low after a few weeks of driving. Truck occasionally blows white smoke when started (typically when cold, located in SD, CA)

 

[Jhnpv]

View attachment 3661490
If I’ve done my research correctly, pretty sure it’s a blown head gasket no? What are your thoughts. Coolant reservoir is always low after a few weeks of driving. Truck occasionally blows white smoke when started (typically when cold, located in SD, CA)

Correction to last, blew white smoke on a pretty hot day like today, so that gets rid of the notion that there may be moisture in exhaust system.

 

[CruiserDave]

Get one of those head gasket testers and see if it's leaking combustion gas into the coolant system. But from what you're describing it sounds like it's blown.

 

[Pascoscout]

Is the truck overheating at all? if so is it only because the coolant level drops too low?

If not, it could also be the seal on the oil cooler has failed. It's on the side of the block, just below/behind the exhaust manifold. The unit has two sets of passages, one for oil and one for coolant. They pass near each other to allow heat to transfer from the oil to the coolant. One spot is very thin and it's not unheard of for either the gasket to fail or the metal wall to get worn through and allow coolant into the oil.

I had the same issues as you, small puff of smoke, water under the fill cap, and loss of coolant after a week or more of driving. What I did not have is the consistent overheating that is common to head gasket failures. I thought my head gasket was blow but after testing determined that was not it and it turned out to be the oil cooler.

 

[robnicko]

The above.

also, have someone start the car whilst your squeezing the top radiator hose. If it pressurises very quickly is an indication of exhaust gas leaking into the coolant system.

 

[Fj80oregon]

Block Tester BT-500 Head Gasket Combustion Leak Test Kit - Made in USA Amazon.com - https://a.co/d/05HOXpYn
Do this and you will have your answer. Make sure to suck some coolant out first so there is a 1-2 inch gap between rubber and fluid level in radiator.

 

[manofthewoods]

Block Tester BT-500 Head Gasket Combustion Leak Test Kit - Made in USA Amazon.com - https://a.co/d/05HOXpYn
Do this and you will have your answer. Make sure to suck some coolant out first so there is a 1-2 inch gap between rubber and fluid level in radiator.

What's nice about the suggestion above, is that it's SO easy. Auto Zone will even lend you the kit, for free. Can't beat that with a stick