knocking + rough idle + fuel smell=?

[hotdog71]

Hi All

On the way home from work tonight my car suddenly decided to start making a nasty knocking sound and running like crap, plus is smells of fuel so had to get her towed to the shop

Very strange no codes or any warning just failure and no I was not on the gas when it happened in fact I was slowing from about 30 mph for some traffic lights.

I didn't see any thing out of the norm when I popped the hood what would cause knocking + rough idle + smell of fuel???

 

[trinity_gt]

Did you get the sensation the car was running on 7 or fewer cylinders?

I assume the knock was mechanical in nature and not detonation "spark knock". If true, then it's possible a cylinder has died and the fuel injected is not being burned in the cylinder. The cylinder may be dead because of a spark plug blow-out (for example) or it may be related to the knock.

Any evidence of an external fuel leak?

 

[hotdog71]

Did you get the sensation the car was running on 7 or fewer cylinders?

I assume the knock was mechanical in nature and not detonation "spark knock". If true, then it's possible a cylinder has died and the fuel injected is not being burned in the cylinder. The cylinder may be dead because of a spark plug blow-out (for example) or it may be related to the knock.

Any evidence of an external fuel leak?

Hi,

Didn't see any type of leaks and it felt like it was running on half of the cylinders. When I said rough I meant it was barely holding a spark and knocking like crap.

 

[nyuk98gt]

hotdog71:

+1 for trinity gt's "spark plug popped out" possibility. That would explain a few of the symptoms. I guess your mechanic will give you the proper diagnosis so please post an update.

GL!

Chris

 

[hotdog71]

Hi,

So they pulled the valve covers off and found a broken rocker and spring on one cylinder so they are going to replace them change the oil and then see if anything else broke

 

[nyuk98gt]

hotdog71:

More info, please. How many miles? Stock valve springs? Aftermarket cams? Most aftermarket cams need beefy springs.

Chris

 

[hotdog71]

hotdog71:

More info, please. How many miles? Stock valve springs? Aftermarket cams? Most aftermarket cams need beefy springs.

Chris

Hi,

Stock internals and 97k on the clock.

thx

 

[trinity_gt]

If the "nasty" knock is a spun rod bearing, it's possible the piston on that cylinder kissed the valve and the shock broke the follower. This wouldn't really explain the broken spring though...

 

[hotdog71]

Ok, seems to me as if the spring might have failed first because I was going slow like 30MPH and was not on the gas hard, but they way the car acted.

I first I thought it was missing on 1 or 2 cylinders because it just started to idle rough as a$$ but a few seconds later I started to hear and feel the knocking while at idle. So I drove the car a few hundred feet parked it looked at it and then called a tow truck.

 

[hotdog71]

It turned out that Number 2 cylinder exhaust valve spring, rocker and follower broke and caused all the problems

The pony is up and running like to trooper now