Jump to content
Volvospeed Forums

NA 1996 850 wagon with 5 spd manual with P0301, however...


Recommended Posts

Some history first.  Mine is not the usual easy to spot case.

My car has 404,xxx miles on it and is my daily driver.  I perform regular maintenance on it, otherwise I wouldn't be able to clock this level of mileage.  

Anyway, at the time I was driving the highway from Colorado Springs to Denver and was approaching Monument hill at about 80 mph (roughly the same as everyone else - this car is not a speed demon) and I felt a slight bump in the car after which the check engine light blinked 3 times and then stayed on stale and hasn't shut off unless I turned it off.  When I got home I pulled codes and got p0301 (misfire cyl 1). Checked the MAF, it works fine.  Checked for vaccum leaks, cannot find any- yet.  Checked plugs and only #1 looked fouled, but I replaced them.  I run 3 prong Volvo OEM plugs (my volvo mechanic told me at the higher mileage they'd burn the oil off better). I run Bogicord plug wires (replaced them about a month ago.  The rotor and cap are about a year old and look fine.  The coil is new from last year early.  The engine has never has major work except timing belt and pcv replacement or a new clutch.  I bought new fuel injectors and installed them and still p0301.  Plug wires are sending spark as I tested that arcing a screwdriver. 

It shakes at idle like a cylinder is not firing but at the exhaust I don't hear the miss at exhaust even though I can hear it in the engine compartment.  There is no metallic clanking like you would hear if you threw a bearing or something.  When I start from a stop there is noticeable shake from that cyl 1 misfire- it feels like but then once the rpms get higher it smooths out a lot but still very slightly noticeable.  There is a definite power loss.  I have not tried a compression test because i don't have the equipment.

I am completely baffled.  Any ideas?  Stuck valve I'm thinking which is big $$$, but really no idea how much.  Starting far left is 1 then 2, 3, 4, 5

plug.jpg.6084bd2144316f5e13e4fdf881d5e902.jpg

Thank you in advance,

Rick

Link to comment
Share on other sites

Compression test is the next thing you need to do.  Cylinder 1 is obviously the issue. If the compression is low, then the head has to come off regardless of the issue.  Could be a valve or it could just be a head gasket. It could be a damaged piston.  Head gasket is probably the likely cause, and the cheapest.

What does the oil look like?

 

 

Link to comment
Share on other sites

  • 3 weeks later...

This sounds like a classic burnt valve. High load while driving uphill are the typical conditions at the time of failure. What octane fuel do you run?

It's not TOO bad of a repair, but it's a little more involved. Assuming you burned a valve, the most cost effective solution would probably be to source a used cylinder head, bring it to the machine shop to be resurfaced, and drop it on. Or, you could bring yours in and get the valve replaced, along with all the machine work. That shouldn't cost too much more. Of course, replace the valve stem seals while it's apart, as those leaking over time have shown to be a possible cause for burning valves.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...