The community here has been so helpful to me in the past - I come once again seeking wisdom.

 

My daughter's '96 Subie Impreza (210k miles) I was trying to do a couple things to help get it ready for a road trip from Colorado to the Northwest. So a several thousand mile trip. It had been having a (I think) P0304 code for "Cylinder 4 misfire" for at least a year, and that didn't change when we replaced plugs and wires. So I decided to replace the coil pack and the cylinder 4 fuel injector with some junkyard parts. The good news is that now, the CEL and the P0304 are gone, but the bad news is that when I swapped the injector and then tried to start the engine, it acted "blocked". I judged that it was probably liquid locked from fuel having gotten into cylinder 4 when I was messing with the injector. So I loosened that spark plug a bit and was then able to crank and get the engine to run. Tightened the plug and now it runs pretty well.

 

But, I think the "liquid lock" thing may have compromised the head gasket because we get bubbling up through the coolant overflow tank, and my daughter thinks it is doing it pretty regularly.

 

I have not done a head gasket job before, but I normally would go ahead and take on the job as I'm a pretty advanced do-it-yourselfer. I had the engine out of this Subie when we first got it so I could replace the badly leaking oil separator plate with the steel version.

 

But time is pretty short (a week) until her trip. So I'm wondering whether I need to have her take a different car on the trip, or else maybe someone here with experience wants to take on the job for pay. I think only the driver's side would need to be done pre-trip. I wouldn't leave it long term without doing the other side too. Or maybe as long as she keeps after the coolant level on the trip, it would be OK. I'd hate to damage the engine since in other respects it's a pretty strong runner. Also, maybe there's a shop with a good reputation who charges a fair price and could do it on pretty short notice. I don't really know what a fair price would be for that, though.

 

Thanks for any advice!

 

Bryan

I posted this to a non-local group while kinda thinking in local terms. Anyway I'm in the "Denver and north" area of Colorado. Advice from Colorado people and otherwise is still appreciated!

In a past similar situation, I elected to rent a car for that long a trip. It was worth the peace of mind, that the rental would get me there and back without a break down, my car not so sure. Car rentals charge for number of days rented with unlimited millage. Rental deals rates available, when you check rental prices on line. With 210K miles on your daughter's Impreza, IMO, a rental seems like a better option. It is far better to have your own car insurance cover a rental, as it is expensive to buy then the insurance from a rental company.

Rent a car.

You don't know for sure which head is compromised. The gasket could have been bad before the incident and you're only now noticing the symptoms.

 

You've figured it out the hard way now, but for future reference, you can't pull the injectors out of these willy-nilly. The injectors are side feed type, so the lower o-ring on the injector seals the fuel rail around the injector. When you pull the injector out, all the fuel in the rail dumps out into the intake port, and when the valves open (if they aren't already) all that fuel dumps into the cylinder. This can cause hydro-lock of the cylinder when you attempt to start the engine, which can bend the connecting rod.

 

If you let it sit for long enough all that fuel will run past the piston rings and drain into the oil pan, leaving you with highly fuel-diluted oil. Fuel thins the oil which can cause bearing damage. It leaves varnish in the engine which leads to the formation of sludge and "coke", which is a thick black tar-like coating left behind by evaporated petroleum based liquids.

 

Its best to change the oil before starting the engine if a large amount of fuel goes directly into the cylinders. Fuel has low surface tension, so it quickly runs through small areas and can cause dilution of the oil.

Take note - that head is so easy to remove, you can't get an easier headgasket to replace.  The headbolts are external and it's easily done in the vehicle without pulling the engine.

 

Pull head

resurface

install with Subaru headgasket.