Intermittent misfire on '01 Forester

subaru
engines
forester

#1

So, bought a 2001 Forester off a used car lot last summer because I was broke and in a hurry because I just wrecked my previous car. It’s had a bunch of health problems (old car with 150k miles on it when I bought it, now 169k, plus it seems at least one previous owner didn’t have the foggiest what he was doing: the Subaru dealership said the wiring harness had been frakked with).

So, a rack-and-pinion, a wiring harness, and a catalytic converter later, I finally get the Check Engine light to go away, only to suddenly develop intermittent rough starts a week later. It’s happened three times in the last week out of roughly twenty times I’ve started the car. Symptoms:

  • Sounds like the engine is struggling a bit after starting, and the headlights flicker a bit. Both of these clear up after a couple of minutes and/or if I drive 200 feet or so.
  • This afternoon it was light out (I’m usually out of the house before sunrise on weekdays) so I could see a plume of white smoke come out of the tailpipe. Dad thinks it’s incomplete combustion.
  • I’ve had one case of a blinking CEL, which cleared up, and one case of a solid CEL, which coded as a misfiring cylinder 4.
  • I know I have a head gasket on one side that is leaking to the outside, but there’s no sign of any internal leaks or coolant in the oil.

So, my first thought, run some fuel system cleaner through the engine starting on my next fill-up, and replace the spark plugs (I’m going to go ahead and replace all four since Lord knows how old they are), but I want to know if there’s anything else obvious and preferably cheap that I can do. I’d rather not sell the car because it’s paid off, it’s comfy, and the car I want is at least ten grand that I don’t have.


#2

Sounds like that external head gasket leak has gone internal.


#3

I was at junkyard yesterday and saw a complete untouched motor Subaru. I rarely see them in junkyards. Maybe I never look. I actually looked at motor for a minute. Car had 3 stock rims and 1 18" oddball alloy. Well, you know subie owners are odd.


#4

@PvtPublic: Okay, so that sounds like, I’ve got coolant intermittently leaking into one of the cylinders from around that bad gasket, but thermal expansion seals the leak once the engine heats up a bit. So much for getting out of debt to my dad sometime this year: I already know that replacing all four bad gaskets (one head, one valve cover, the oil pan, and the rear main oil seal) is going to cost almost as much as a new engine.