flashing CEL code p0302

Post by **benweekes** » 30 Aug 2010, 09:59

I have a 1999 v70xc with 165,000 miles on it.I was driving the car on the highway yesterday when I suddenly lost power.The CEL began blinking engine sputtering but never stalled.Had the car towed to my house and ran the codes.I got the code p0302 cylinder 2 miss fire detected.I figured probally blew a plug.I replaced all the plugs with NGK gapped at .028 but no change.Same code came up the coil pack looked a bit worn so I replaced it and two others that looked worn.Cleared the code and started the car same problem running very rough and within two min the p0302 code was back.When I changed the old plug it was covered with oil mix,I pulled the new one and it is fine looking not sure what to do next anyone with some guidance would love to hear from you only car in family need it back fast.

Post by **Ozark Lee** » 30 Aug 2010, 14:12

Do a compression check on cylinder 2.

...Lee

Post by **benweekes** » 31 Aug 2010, 12:12

I ran a compression test today.Cylinders 1,3,4,5 were all between 180 and 185 psi and cylinder 2 had nothing.I ran the test twice to verify the results and they were the same both times.Any thoughts as to what it could be and what should my next move be.

Post by **Ozark Lee** » 31 Aug 2010, 18:58

Most likely you have a burned exhaust valve. You have a couple of options but none are really fun. My choice would be to remove the head and replace the valve (if that is what it is). The valves are only something like $30.00 each and you will need to lap them in but at that point you are looking at a full head-gasket / head bolt replacement and you can often find a used engine for about the same money.

Removing the head will tell you everything and you can make a more informed decision and most of the stuff that you do to remove the head will need to be done to remove and replace the engine so it won't, for the most part, be lost labor.

Much of your decision should be based on what history you have with the car and if you have service records.

...Lee

jlrsn · Post by **jlrsn** » 01 Sep 2010, 11:20

benweekes wrote:I ran a compression test today.Cylinders 1,3,4,5 were all between 180 and 185 psi and cylinder 2 had nothing.I ran the test twice to verify the results and they were the same both times.Any thoughts as to what it could be and what should my next move be.

The fact that you have no compression can be caused by a few things. First off if you had a burnt valve you should have had a little compression showing unless the head of the valve was partially or fully broken off. Did you check to see if you had blue exhaust smoke. The fact that the spark plug was oily can be caused by many things but the worst is that you have a holed piston or seized/broken piston ring. A quick cheap test before you disable the engine is to remove the oil filler cap while the engine is idling. If you have a bad piston it will be pumping air into the crankcase which will be evident when you remove the oil filler cap. You’ll usually have a small amount of blow-by but if you have a bad piston or seized/broken piston ring there will be quite a mount of blow-by.

If you have an air compressor and can jury rig an adapter to where you can pressurize your combustion chamber you will be able to tell quickly where the problem is. If, with the engine NOT running with the piston at TDC (Top Dead Center) during the compression stroke and with combustion chamber pressurized you hear escaping air from the oil filler cap, you have a holed piston or seized/broken piston ring. If you hear air escaping from the intake with the intake filter removed you have a bad intake valve. If you hear air escaping from the exhaust pipe you have a bad exhaust valve.

Bear in mind that if you have a burnt exhaust valve you also probably have a burnt exhaust valve seat which will need to be ground/lapped as required. I have worked on thousands of engines over the last 55+ years, some with as many as 28 cylinders (P&W R4360) , and I will usually do a combustion chamber leak test with the engine “OFF” before I tear into a possible repair.

Good luck,
Jim

Post by **benweekes** » 01 Sep 2010, 17:10

So I made a few calls today looking at prices with the various options I'm stuck with.To repair a burnt valve I was qouted $1,750 to start and that is if there are no surprises.I called around and can get a remanned head with all the fixings for $675 and then 20 hours of shop time to install (that seems like a lot of time but I dont know).I have not found a junk yard with a compatible engine yet in my area.I would llike to do the work myself but have not pulled the head off a volvo before only a honda civic and I'm more than a bit certain this going to be more complicated.If I am not able to it myself available time is also a problem I work two full time jobs which option seems the best to you guys?

Post by **Ozark Lee** » 01 Sep 2010, 19:54

Tough call.

The Volvo head replacement should really be no more difficult than the Honda - they are both overhead cam engines so the same stuff applies. Setting the cams to a proper setting for the #1 cylinder being timed to TDC seems to bee the biggest source of grief.

For around $18.00 you should be able to at least order a Haynes 850 manual from a local parts store - they rarely actually stock it. It will describe the cam holders (and how to make them yourself out of scrap metal) and the procedure to R&R the head.

Clearwater Cylinder Heads in Clearwater, Florida ( http://www.cylinder-heads.com ) can provide you with a new, re-manufactured, and tested head for about the same money as you describe and many members have been quite pleased with their product. They do offer a generous veterans discount if that applies. As I recall the discount covers the return freight for the core which is not insignificant.

If you have swapped out the head on a Honda this should pose no huge problem for you other that the time involved and I understand that your time is tight.

Other things to budget are a new timing belt and perhaps the rollers and tensioner depending on your mileage but that will apply in any choice you make.

I understand your time problem but I also hate to pay the shop for something I can do myself.

I guess the best I can do is say that I feel your pain - I was down to 2 operating cars with 4 drivers earlier this year and it caused friction in the household since I was 200 miles away from home with one of the two operating cars on a job. At the end of the day I got everyone fixed myself in the driveway (no labor charges) but the family had to be patient with me.

Best of luck and let us know how we can help you out no matter which path you choose.

...Lee