Replace head gasket?

I have an '05 with 180k miles. My understanding is that I'm at high risk for head gasket failure.

I'm about to pull the intake manifold to track down a P0333 knock sensor code (suspected rodent damage to wire harness), and also, I'm about to swap out the steering rack, which is starting to leak a lot. And, since I have to drain the coolant anyway, I'm also going to flush, replace all the hoses, and put in a new radiator.

So, it will never be easier for me to replace the head gaskets. Should I replace them preemptively?

Positive symptoms:
- "swoosh" sound from dash when revving engine, especially after starting

Negative symptoms:
- Never stumbles or blows smoke on startup
- Oil looks great, no oil consumption.
- Coolant looks OK (but old) -- no coolant loss

I was thinking about having a shop test for combustion gasses in the coolant. Any other ideas?

 

Replacing the head gaskets are not easy to do,bascally the whole top end and front half needs to be taken apart,do you have a v6 or 4cyl ?

 

Sorry, it's the 6cyl 4.0

 

Major job!
If it were me,I would replace them,but like I said it's a major job.

 

Yeah, I haven't ever done head gaskets before. But I appreciate your feedback, it sounds like something I should probably do. I recently got the truck and plan to keep it for a long time.

Maybe I'll have a shop test for combustion gasses in the coolant. Any hint of impending failure would make this a very easy decision!

 

Swoosh sound started on mine about 6-8 months before I started getting misfire error code on cyl 6. Another couple months later, bubbles started in coolant jug.

Problem is most likely cyl 6, but pull spark plugs and put a scope in the hole. If one of the cylinders looks alot cleaner than the others, good chance coolant is leaking in there.

I never had coolant in the oil.

 

You could also try burping the system to get air out. With truck cold, take radiator cap off, start the truck, put heater on high, let it warm up, watch radiator fill hole, see if air bubbles get burped out. Once air comes out, turn truck off, put radiator cap back on. On next cold start, you shouldn't have swoosh sound. See how long it takes to come back.

 

If you do end up replacing the head gaskets, have a machine shop do a valve job on the heads, DO NOT mill the surface of the heads!