Hello All,

I have a 1999 V70 AWD XC with just over 160,000 miles on it. I purchased this car used in 1999 with just under 12,000 miles on it. Since that time, I have used nothing but synthetic oil and have changed the oil every 5,000 miles.

Yesterday when my wife went to drive the car on the highway, as soon as she got on, the engine began to run rough and the check engine light came on. She was afraid the engine would stall, so she drove home immediately. The engine seemed to be running on 4 versus 5 cylinders. I assumed an ignition coil had gone bad. I dropped the car off at my private mechanic. He cal me today and said there was no compression in cylinder #3. He suspects one of not both of the exhaust valves in that cylinder are bad. He won’t know for sure until he takes it apart. He told me that he has seen a couple of XC’s of my cars vintage suffer from failed exhaust valves. He believes the metal that Volvo used in making these exhaust valves was defective or not manufactured properly.

Has any one else personally or in the alternative knows of anyone who has experienced failed exhaust valves on ’99 XC with approximately 160,000. I’m shocked and disappointed. I take really good care of this car, and expected that with the maintenance I provided, I would never experience an failed valve. Thank you in advance to all who respond.

Hugh

Hi Hugh,

I wonder if that's a result of using Low octane gas?

Bill

Bill,

Based upon Jim’s comments and Klaus’ my consistent use of 87 Octane for the last 16 years may be the reason why I’m having a problem now. If so, I engaged in a “poor economy” of trying to save money by purchasing a less expensive gasoline.

Hugh

Hi Hugh,

I'm having trouble with "No-compression in cyl #3".
Does that mean 0 compression? did he add oil to the cylinder and try again?
I would think the valves wouldn't crap out so badly and so suddenly.
It might be a head gasket? Did you check for that?

Bill

Bill,

I will confirm if oil was injected into the cylinder to see if it affected the compression. The head gasket was replaced on this car at I think just over 100,000 miles. I have to check. It was done at the same shop that is presently fixing my car. I complained to Volvo about the head gasket failing in my opinion prematurely. Volvo agreed to pay for the parts only and not the labor to replace the head gasket.

Based upon the comments above, I hope I did not sabotage my car by using 87 Octane all these years. I put a call into Volvo’s corporate office and asked if I would damage my Volvo. The representative basically read the owner’s manual back to me. She said Volvo recommends 91 Octane and when the car was tested when new, Volvo used 91 Octane. However, 87 Octane can be used. She did not say that it would adversely affect my car.

My two ’96 850s are non-turbos and I have run them on 87 Octane without incident. I guess I have to trade up for my ’99 XC.

Hugh

Bill,

I will confirm if oil was injected into the cylinder to see if it affected the compression. The head gasket was replaced on this car at I think just over 100,000 miles. I have to check. It was done at the same shop that is presently fixing my car. I complained to Volvo about the head gasket failing in my opinion prematurely. Volvo agreed to pay for the parts only and not the labor to replace the head gasket.

Based upon the comments above, I hope I did not sabotage my car by using 87 Octane all these years. I put a call into Volvo’s corporate office and asked if I would damage my Volvo. The representative basically read the owner’s manual back to me. She said Volvo recommends 91 Octane and when the car was tested when new, Volvo used 91 Octane. However, 87 Octane can be used. She did not say that it would adversely affect my car.

My two ’96 850s are non-turbos and I have run them on 87 Octane without incident. I guess I have to trade up for my ’99 XC.

Hugh

Hugh,

Bill is correct. Klaus and others have said here that using regular gas can burn valves in the 5 cylinder engines. Do you know what octane the turbo engine requires? My NA engine requires 91 octane. Hope your mechanic's diagnosis is wrong.

Jim

Jim,

I don’t have the owner’s manual in front of me, but I suspect the engine requires 91 Octane. If using regular (87 Octane) is the cause of my problem, then I am the “villain”. Since I purchased this car back in 1999 with 12,000 miles, I have run it on 87 Octane. Sometime in 1998 or 1999 I attended an Open House of Volvo’s headquarters in Rockleigh, NJ. At that time there was a Volvo engineer present who said that although the owner’s manual recommended 91 Octane for Volvo 850s and the then new XC (I think), you could use 87 Octane without damaging the engine. Knock sensors in the engine would compensate for the lower octane, and you might get fewer miles per gallon and your car might be less peppy.

Since that time I’ve run my two ’96 850s (non-turbo) and my ’99 XC on 87 Octane without incident, until now. If 91 Octane is required for the XC to avoid burned valves, then this problem may have been caused by me.


Hugh