I just bought a 99 forester with a supposed burnt valve in cylinder 4. The previous owner continued to drive the car until it stopped running. I tried to start it and it turns over, but won't catch. I didn't have enough time to do further diagnosis. I will trailer it home this Tuesday.

 

My question is this; Do I try to repair that motor or just replace it? I have a 2.5 DOHC and it has a 2.5 SOHC, can I use the DOHC? Can I put a 2.2 in there? Just throwing some ideas out.

 

Any help will be much appreciated.

 

Thanks guys

I just bought a 99 forester with a supposed burnt valve in cylinder 4. The previous owner continued to drive the car until it stopped running. I tried to start it and it turns over, but won't catch. I didn't have enough time to do further diagnosis.[...]

A bad valve in a single cylinder obviously wouldn't cause all the cylinders to not fire. Whether to repair or replace the engine will depend on what's really wrong.

 

You might want to start with compression testing. If only #4 measures low, that would suggest the original claim was probably valid, and that something else (perhaps not too serious) has occured. If more than that one cylinder is low, maybe the timing belt has jumped, etc.

Mike - find out what's wrong with it first. Should be simple to check the basics - spark at each cylinder, fuel, compression, timing.

 

DOHC and SOHC do not interchange and the intake manifold isn't interchangeable.

 

 

To make it work you'd need to swap the SOHC intake wiring harness onto the DOHC intake manifold so that you can drop the DOHC in place. It bolts in but the electronics are all off. And even then I'm not sure if you'd have a cam sprocket problem.

 

On the later model Phase II's you often need to swap cams to interchange engines (but not always). To put it simply "the cam sprocket stays with the vehicle". Simple solution for all Phase II's in that you just swap the sprockets too...but in this case I don't know how interchangeable Phase I (DOHC) and Phase II (SOHC) cam sprockets are.

You really want to stick with a phase 2 engine. You run into a wiring mess trying to put a phase 1 in, mostly with the IAC it's way different.

I'm going to check out the engine that is in it, but I want to look at all of the avenues available. The car was a great deal at 850. with 144k on the odometer.

I can see that there is going to be a learning curve now that I am moving into the phase II motors. I'm wondering if a phase I block is different than a Phase II.

I can see that there is going to be a learning curve now that I am moving into the phase II motors. I'm wondering if a phase I block is different than a Phase II.

 

It's a little different. The pistons are different and the thrust bearing is moved.