Will 2003 SOHC work as engine replacement in 1999obw (instead of head gasket repair)?

[gspoulos]

I found you guys because of a blown head gasket in my 1999 Suby Outback Wagon (limited, 30th ann, if it matters) with 95 k miles. Merry Christmas!

 

I've more-or-less committed to replacing the engine with a 2003 SOHC with about 20k miles on it ($2500), rather than the head gasket job ($1300) but could use your advice (that's a heck of alot of dough).

 

* The questions

Is this OK? What are the gotchas? If this is just a mechanical replacement will the fact that a 1999 computer and other 1999 parts from a DOHC be attached to a 2003 SOHC create other problems?

 

* The ifs

It seems as if the engine replacement would provide better performance, more lifetime, more reliability and easier servicing and thus if we're going to invest that dough to keep a car a long time, it seems reasonable. I'd be willing to go with the head gasket repair 1) if the 2003 engine insert was real risky, and/or 2) if we could be pretty sure the head gasket repair would last, say, 80-100k miles, and not create a bunch of other problems that will soon crop up (we have been warned about possible complications after the head gasket repair because of the fluids mixing). Maybe there are other reasons. Lemme know.

 

* Some details

95k miles, no previous problems, oil changes every 3k (a couple at 3500).

 

First overheat to at or near the H: Golden to Winter Park over Berthoud - noted only on the way back up Berthoud. Coasted home and dropped temp back to mid.

First repair: Thermostat, ran fine on flat, overheat (toward or at the H) on hills.

Return to mechanic: Nice recheck and head gasket suspected - used some pour-in gunk to try to hold it. Worked for a run up Floyd Hill @ 65 - seemed to be good but still did not drive it at all to be conservative.

2nd overheat: Golden to Winter Park, -5 degrees out and both ways this time. Coasted home and couldn't cool it as much but the coolant was down. It wasn't past the H much or for very long but was just below.

Now: Not driving it at all, coolant is out of sight looking in the coolant overflow - will be filling it to get to the mechanic.

 

I've smelled the oil (seems fine, nice brown, not a puke color). The coolant overflow has some gray residue (thicker in the upper part) but generally not black or very dark. I'm not sure if that is an indicator of how bad things are or not but that's where we're at.

 

I put in the coolant yesterday and it ran normal until some small hills.

[itzik93]

Why going downgrade to an SOHC engine (and pay more for it) if you'r DOHC is repairable (and even cheaper) ?

The DOHC's are better then the SOHC's (more hp's, more torque...) - I cant see any logical reason to downgrade a DOHC to SOHC.

 

Itzik.

[Gnuman]

One problem I can think of is a MAP based system (in the 2003), vs a MAF system that was original to the car. I'm guessing that this will cause you problems down the road. Several of the people that I have heard from that have had the HG repair done, and have close to or over 100K miles after the repair. The 2003 is a better engine, but the different airflow measurement system may make it a tricky install.