#5 cylinder reads ZERO during compression test & leaking

93volvo850 · Post by **93volvo850** » 26 Nov 2006, 17:16

Ok, so bare with me. My dad just bought a 93 850. He said he did a compression test and #5 cylinder reads ZERO. The other cylinders are good.

What would be causing this? He also said that after taking the car for a drive around the block and was idling on the driveway, it was leaking a lot of gas from under the car.

Any ideas?

Post by **MadeInJapan** » 26 Nov 2006, 17:25

Sounds like 2 problems...one seems to be a broken gas line. The other is a bad cylinder sleeve or ring. How was the compression test done?

mrscullini · Post by **mrscullini** » 26 Nov 2006, 17:35

with regard to the low comp reading, there are a number of issues that could produce low readings;

stuck ring
broken ring
scored cylinder
stuck valve
damaged valve seat

the first thing i would do is pour about 1/2 ounce of high viscosity oil into the cylinder. if the cylinder is scored this will fill the scores and produce a comp reading. if that produces no results, i would next pull the valve cover and look at the valves. try to determine if one is stuck. you may have to turn the motor by hand to cycle the valves. without pulling the head it will be tough to diagnose a stuck/broken ring or damage valve seat. you can try an additive such as restore, this product claims to remedy stuck rings.

another thought, if it were a stuck or broken ring there would probably be raw gas in the oil. change the oil and give it the "sniff" test. if it were a stuck valve, you would probably have raw gas in the exhaust stream. again, give it the "sniff" test.

93volvo850 · Post by **93volvo850** » 26 Nov 2006, 19:59

i was thinking the cracked sleeve too.. but i will have him put some oil in and see what happens.

He says when he drives is smells of gas..

If the gas line was ok, would the gas be able to leak out of the block or head?

93volvo850 · Post by **93volvo850** » 26 Nov 2006, 20:02

MadeInJapan -> Im from Nashville. Do you know any places where I can get an Engine and Transmission with low miles for a good price?

I heard about some place called Jim Long's Volvo's, ever heard of it?

Post by **MadeInJapan** » 26 Nov 2006, 20:27

Hey, 93volvo850. Sorry I've never heard of them. There's supposedly a pretty good place in Nashville, but other than that erievovo.com I know that they warranty their engines. What's up with yours?

CarVolvo · Post by **CarVolvo** » 26 Nov 2006, 20:49

if its leaking gas from the block.. i wonder if you checked the number five fuel injector. Perhaps one of the "o" rings are loose or the injector unit itself is not installed properly.

Then again if no compression is on the 5th cylinder then i would imagine you will be smelling a lot of unburnt fuel.

93volvo850 · Post by **93volvo850** » 27 Nov 2006, 05:04

well my dad likes to jump the gun on a lot of things.

He bought this 93 or 94 850 non turbo for $800. It runs, but rough because of whatever is going on with cylinder 5. And he is an old timer and isnt all high tech so he cant diagnose problems very easy, so he just figures if he can buy an engine, that would just solve the problem and still be cheaper and then he'd have a really nice car. I havent seen it since im here in Nashville at school, but apparently the body is MINT!

So ill have to see in a few weeks when i go home for the holidays and check this 850 out.