1998 Volvo S70- Engine Misfire P0300, P0302 & P0304

[aartzer]

I need some help troubleshooting what's going on with my car. I had the P0300, P0302 and P0304 codes come up on my car after I moved across the country. I replaced the distributor cap, rotor and spark plug wires. When I initially replaced them, there was a little bit of oil in the distributor cap. The car ran great for a couple of days and then my car threw the same codes a couple days later. When I took off the distributor cap to see if there was any oil in it, there was a little bit of oil and condensation. I cleaned up the cap and did some research on what could be causing condensation and oil to get into the distributor cap. Again, it ran fine until oil and condensation got back in. Could it be the rear cam seal? I don't know what else could be causing oil to get into the distributor cap. There is a little bit of oil on the top of the cylinder head and I have a slight oil leak, but I don't know if that has anything at all to do with the problem. Should I try to replace the rear cam seal first (Is this a hard job?) Any ideas of what else could be causing oil and condensation in the distributor cap? Any help would be much appreciated. Thanks!

[kahl]

Good job on your research and faulting the rear cam seal. Extremely easy job to complete. Make sure to use Volvo seals or SKF from NAPA. Ensure your rotor is reinstalled in the same position you took it out. The item you need to address is how this seal got unseated. You should do the glove test to evaluate if you have positive crankcase pressure. If you do then it is time to do your PCV system. The seal job, glove test and PCV service are in the repair data base.

[aartzer]

I did do the glove test on the PCV system, it was fine. I will look to see how to replace the cam seal. I haven't ever done it before. If it wasn't anything with the PCV system, what else could cause the cam seal to become unseated? I also had someone tell me that the cause of the oil leak may be below from bad piston rings. Is that a possibility?
As far as replacing the cam seal, I'm assuming I can do it by just removing the rotor from the end of the cam shaft? I haven't found too much information on how to do this. If you have any info to help me out, it'd be greatly appreciated. Thanks again!

[kahl]

pretty straight foreword, remove dist cap, remove rotor then the rotor plate. Pull out old seal and install new seal.

[erikv11]

Oops, hold on there: you must do the glove test with the cam seals installed and sealing. Otherwise, any crankcase pressure could just escape out through the blown cam seal, making everything look OK at the glove even when it isn't.

Worn piston rings ("blowby") is a possibility but it is a distant second place behind PCV, test that properly with all the seals installed then go from there. You should check the rear cam seal behind the cam position sensor (on the other cam) as well, it could be popped.

Rear cam seals is an easy and common repair, so it gets beat like a dead horse here, there are several quality DIY guides with pictures, a new one comes out every couple of years, and there are lots of comments. This is probably the most recent thread, all the info you need will be there: https://www.matthewsvolvosite.com/forums ... hp?t=50752

Get Volvo or SKF or Corteco seals, that is a must.

If the PCV is blocked then you have to fix it soon or the cam seals will just blow again.

[aartzer]

After I posted this I found that guide on how to replace the cam seal! Thanks for the help. I ordered the part and will do the glove test again after I've finished the job.

[abscate]

If you do have crankcase pressure, the next in line to go is the rear main seal, which is a 10 USD part and 1000 USD of labour.....

[Vancethevolvo]

So did this work for you? This is the exact issue that I have with the same car.

[aartzer]

It did work for me it stopped the misfire

[E Showell]

Looks like we need another "MVSolved" in the title on this one.