93 Dodge
W150
318/5.2

Ok so I need some help with an issue I can't quite put my finger on. I have a small engine sputter and minor vehicle shake when I am either at a stop light. or driving at low rpm's. This shake is not present when rpm's are high nor when in neutral or park. At first I read on some forums on this but could not find a distinct answer that fits my problems. I think it could be a few things correct me if I am wrong please. Possibly bad gas although I believe this to be unlikely, more than likely bad wires and or plugs. Maybe distributor cap and rotor. Also read that could be a misfire but I think that a misfire would be present no matter what rpm I was at. Last thing is that I have a small exhaust leak before my cat, can that actually cause a minor vibration and engine to be laggy??? Any help will be appreciated
Thank You

 

Sounds to me like you may have a vacuum leak.

 

yes a leaky cat could change the readings to the computer from the O2 especially if the leak was in front of the sensor. However, That being said, I think it would guess a dirty fuel injector as my first suspect. Or maybe as previously mentioned vacuum leak. A weak lifter?? Are there any other symptoms, noises??

 

Well I brought it to a mechanic and had him run some tests, he said that the rear passenger side cylinder has low compression. Said that it tested 150 for all other 7 and 45 for that one think its number 8. So now he said on the low end it would cost 900 to fix, I plan to buy a new vehicle in May of this year so I guess I am wondering if I can drive it that long. He said it is burning off the fuel and is working just very bad. Any ideas? think I can drive it and will it get worse he said it wont but I am not sure I believe that. If it is safe to drive any tips to help it maintain itself??? Thank for other advise.

 

"Is it safe?" - Probably. I doubt it will lock up or throw a rod anytime soon as long as you keep dumping oil into it before it burns it all off. There are quite a few "home remedies" that people have used over the years to limp a dying engine along a few more months. There are additives that some say will help raise low compression by sealing the piston rings. How well it works, I dont know. Some will also use a slightly heavier oil to prevent it from seeping past the piston rings. If its a dead engine anyway, I dont see any harm in trying. Good luck and keep us posted.