#1 cylinder is not firing, what are the possibilities?

[DYZ]

No idea. The car is losing a very small amount of coolant over time, wondering if it plays any role in this. The car's engine is well maintained with synthetic oil change every 5K miles. From what I read the valve shouldn't wear out in 155K miles. Here is an interesting article talking about various causes of valve failures: http://www.aa1car.com/library/ar1192.htm

[Allen]

Sounds like a factory defect.

You can look down into your cylinders with a bright flashlight and inspect the surfaces of the piston heads. Coolant has a neat way of cleaning the crap out of piston heads, so if #1 is spotless while the rest are black.......

[DYZ]

The top of the #1 piston is coated with hardened black carbon deposit. I guess I might get some clue after I pull the head. This thing happened suddenly, so it could be that the valve lost a piece of metal.

[Allen]

Now I wonder where that lost metal went.

[ericjp]

possibly a broken valve spring?

[DYZ]

Took the head off today and this is what my burnt valve looks like:

[JRL]

Oh yeah they do.
There's been a rash of engine failures lately.
Perhaps it's the Ethanol in the gas but this has been going on for a couple of years now

[DYZ]

Got the head back from my local machine shop last week and finished putting everything back today. Car runs great and feels a lot quicker getting up to speed. No leak so far. Total cost is about $1000, including the valve job ($500), head gasket kit ($280), cam locking tool ($110), torque angle meter ($10), anaerobic gasket maker ($10), and a few minor stuff (cleaners, solvent, etc).

The whole job is really not that difficult, but you do have to be patient. I took lots of pictures to help me remember where things are/go. The cam locking tool is a must. I made one myself at first, but it was destroyed when I used it to remove the cam gears. So if you make one, make sure to test it out like I did - you really don't want it to fail when you putting things together! I didn't want to take the chance seeing how tight the cam gear is bolted on, so I bought the tool from ebay.

Oh yeah, one of the test drive is a trip to the emission test center - no problem passing the test!

DYZ

[pricedm]

Got the head back from my local machine shop last week and finished putting everything back today. Car runs great and feels a lot quicker getting up to speed. No leak so far. Total cost is about $1000, including the valve job ($500), head gasket kit ($280), cam locking tool ($110), torque angle meter ($10), anaerobic gasket maker ($10), and a few minor stuff (cleaners, solvent, etc).

The whole job is really not that difficult, but you do have to be patient. I took lots of pictures to help me remember where things are/go. The cam locking tool is a must. I made one myself at first, but it was destroyed when I used it to remove the cam gears. So if you make one, make sure to test it out like I did - you really don't want it to fail when you putting things together! I didn't want to take the chance seeing how tight the cam gear is bolted on, so I bought the tool from ebay.

Oh yeah, one of the test drive is a trip to the emission test center - no problem passing the test!

DYZ

Cool you were able to fix it yourself. I have a 2001 XC70 with 180k and had same issue. Cylinder 2 and 4 failed....compression was super low. I ended up getting an engine off eBay ($750) and had an independent shop put it in. close to $3k to fix a car worth not much more. Car went thru a few coil packs in since i got it (90k) but nothing unusual. Total surprise on the engine failure as i pretty much followed the book on service.