91 Metro 3 cylinder Possible sticking valve. Options and advice needed.

[doug2060]

It's me again. I was hoping to have all my major metro issues behind me then an old one pops up again. I believe I have a sticking valve. I'll be going down the road and lose power and get a backfiring sound until I let off the gas. The car doesn't cut off and sometimes it only lasts a couple minutes and other times I have to deal with it until it cools down and it's usually fine. It hasn't done it in a couple months but just started again today and lasted about 30 minutes. What should I do here? The head gasket was just replaced (head shaved too) in December or January. I also wanted to know if a can of sea foam would be a good idea if anyone here is familiar with it. I know it works great in larger engines and would I have to adjust the amount used for this smaller engine?

[91Caprice9c1]

What weight oil are you using? If you're getting too thick, say in the 10w40-20w50 region, your lifters may not be deflating properly, causing a valve or two to stay open.

You can try changing to a thinner oil, and run a seafoam treatment on the motor, it's good stuff. Follow the directions on the can.

-MechanicMatt

[doug2060]

I use 5w30. I have never used seafoam before but I got a can because I've heard its real good. Should I use less than 1/3 portions of it since the engine size is much smaller than typical engines?

[older'n'dirt]

MechanicMatt - not doubting your background or advice here, just curious. I have never heard of lifters deflating. What is that?

It's OK. I think I figured it out. Just a terminology thing. Sorry.