Hi,
I am new to this forum and in desperate need of getting my car back up and running. I have a 1994 Volvo 940 Turbo and it has a rough idle and some white smoke at tail pipe occasionally. It makes a weird sound like marbles in a can when accelerating. I checked compression and it has 160 on 1st cylinder, 165 on 2nd cylinder and 60psi on 3rd and 4th cylinder. Any ideas what could be causing this. I am desperate. I also need to get it smogged. Is it possible for it to pass in this condition? Thanks for your help in advance.

 

Welcome to the board. So 60 psi and 40 psi on adjacent cylinders and a little white smoke out the tail pipe would seem like maybe a head gasket problem. What does your oil look like. Does the car overheat? How many miles on it. How does the bearings sound in the turbo. You most likely will not pass smog. Test the cooling system for exhaust gases . The marbles could be turbo bearings or valve noise or timing issues. You may need some help.

 

Car has about 207,000 miles. Oil looks ok. I don't notice anything weird about it. It doesn't smell like there is any coolant mixing with it and I don't see anything in there. I don't know how to test turbo bearing sound. I have never noticed a sound from the turbo. The marble sound only happens when you accelerate while driving. It doesn't happen when the car is in park and you give it gas. Just when I'm driving down the road. Also, it gets worse going up hill. The sound it makes is just like putting marbles in a tin can and shaking it around. Thanks so much for your help. I know a guy with the test equipment to check the exhaust gases so I will get back to you about that when I find out how it went. Thank you so much for your time and help.

 

Sounds like a blown head gasket. White smoke in the exhaust, low compression on two cylinders, rattling sound? All clues to a blown head gasket. I wouldn't drive it in the condition it is in. Get it addressed before more damage is done.