Volvo 850 Question

paradigmcubed · Post by **paradigmcubed** » 05 Mar 2005, 23:01

Hey, I have a 1994 Volvo 850 Station Wagon. Whenever I start it right up without having driven it for at least four hours or more, the engine knocks really really loud and the car sorta shudders, but it still drives. After driving awhile the knocking goes away. And if I drive the car again within that 4 hour span of just driving it, the engine does not knock at all. Any ideas?

Thanks

White850Turbo · Post by **White850Turbo** » 06 Mar 2005, 04:57

paradigmcubed wrote:Hey, I have a 1994 Volvo 850 Station Wagon. Whenever I start it right up without having driven it for at least four hours or more, the engine knocks really really loud and the car sorta shudders, but it still drives. After driving awhile the knocking goes away. And if I drive the car again within that 4 hour span of just driving it, the engine does not knock at all. Any ideas?

Thanks

http://www.volvospeed.com/CheckEngine.htm

See if your car is throwing any codes. Tell us what you get and I'll tell you how to fix it. The shuddering thing sounds like 1 or more bad motor mounts. It sounds like there could be other problems as well though.

paradigmcubed · Post by **paradigmcubed** » 06 Mar 2005, 22:31

I am getting no codes that alert me to anything. The mechanic is replacing the exhaust manifold because it had a leak, could that have anything do with it?

Thanks for the reply!

White850Turbo · Post by **White850Turbo** » 07 Mar 2005, 05:54

paradigmcubed wrote:I am getting no codes that alert me to anything. The mechanic is replacing the exhaust manifold because it had a leak, could that have anything do with it?

Thanks for the reply!

Leaky manifold might cause some more noise, but shouldn't cause any shudders. Misfiring can also cause shuddering sensation, but more likely than not, one or more of the motor mounts need to be replaced.

turbotim2 · Post by **turbotim2** » 07 Mar 2005, 06:51

Sounds to me like you have some lifters going bad. Has it been doing this for awhile?

kenk · Post by **kenk** » 07 Mar 2005, 09:44

it could be the manifold, if the leak was big enough, what happens is that you loose enough exhaust to fool the 02 sensor, and it makes the car run crappy. It could also make the car sound really strange, see what it sounds like after the manifold is done.

Especially dont mention the knocking the mech, and see if he says anytihng, if its knocking he should mention that, pretty hard to miss that when you work on a car.

kenk · Post by **kenk** » 07 Mar 2005, 09:52

it could be the manifold, if the leak was big enough, what happens is that you loose enough exhaust to fool the 02 sensor, and it makes the car run crappy. It could also make the car sound really strange if its got a hole that close to the engine, see what it sounds like after the manifold is done.

dont mention the knocking the mech, and see if he says anytihng, if its knocking he should mention that, pretty hard to miss that when you work on a car.

paradigmcubed · Post by **paradigmcubed** » 09 Mar 2005, 15:56

It's been doing this for about a year. If I let the car warm up for a minute or more, it won't knock or shudder. When I don't it shudders and makes a rumble that goes in and out. I'll be getting it to the mechanic really soon. So, I'll see how it sounds after that.

paradigmcubed · Post by **paradigmcubed** » 09 Mar 2005, 15:57

Thanks for the replies!