The check engine light (CEL) came on in my 2002 Subaru Legacy as I was exiting the highway. As I slowed to merge with traffic, my car then began bucking. I took the car to a local repair shop (no independent Subaru mechanics in my area and I’ve head bad things about the dealership) today and the CEL code indicated a misfire, so the shop mechanic ended up replacing the spark plugs, wires, ignition coils and battery. The car is running on 2 cylinders, so now the mechanic is considering replacing the timing belt. If it were timing-related, I would think that all 4 cylinders would be impacted. Besides, I had the timing belt, spark plugs and head gasket replaced less than 2 yrs ago. Any thoughts on what else it could be? Thanks for your advice!
The timing belt would be the last thing to consider.
You don’t say which two cylinders are misfiring, but if they’re adjacent to each other I’d first do a cylinder leak-down test to determine if there’s a leak in the head gasket between the cylinders.
+1 to Tester’s comments.
I strongly suggest that the OP remove his vehicle from the shop of his current mechanic, who is playing very expensive guessing games with the OP’s car and the OP’s wallet.
I agree that the timing belt is not the issue. Any codes present, which 2 are missing, and so on need to be known because without some basics the guessing can get out of hand.
Just my opinion, but it sounds like the shop your car is at has been doing some guessing.
You state the head gasket (singular) was replaced 2 years ago. There are 2 head gaskets and also the issue of whether the head gasket job was done properly.
The dealership shop will be cheaper than this guy who has no clue what to do, and has already replaced parts that weren’t bad in the 1st place.
Apparently, it WAS the timing belt. I just received a call this morning and the mechanic told me that whoever replaced the timing belt when I had the head gaskets replaced put it on backwards. It was actually replaced by a Subaru-certified mechanic at an independent shop about two years ago. I’ve put 20,000 miles on the car since that time and never had a problem until now.
“whoever replaced the timing belt when I had the head gaskets replaced put it on backwards”
Installed incorrectly, i.e.–“off” by one or two cogs–possible.
However, if that had been the case, there would have been major symptoms right after the belt was installed, not 20k miles later.
In this case, I think that none of us (including the OP) will ever know what the problem really was, nor will any of us ever know exactly what the OP’s mechanic did in order to remedy the situation, but I have confidence that it was not the timing belt.
Shells–How much did you pay this mechanic?
I’m not buying that backwards belt story for one nano-second. The details behind this would be quite interesting to hear.