I just bought this 2001 Dodge Stratus w/2.4L 4-cyl engine. Unfortunately I was not able to run the engine before I purchased it, and was disappointed to find it ran very poorly once I got it. After a number of other tests and replaced parts I was still unable to locate the issue, so I decided to rent a cylinder compression tester and do a compression test.
On cylinder 1 and cylinder 4, both with and without adding oil to the cylinder, I get a reading of about 150-160. On the center two cylinders, I was getting 60-90 dry and 150-155 wet. My limited understanding is this is likely piston rings. It does not smoke out of the exhaust and none of the fluids appear to be contaminated.
Am I interpreting the test results correctly? This car was sitting for a year or two before I purchased it. Is it possible the rings are "stuck" or not seating properly? I have not changed the oil yet, but it still looks decent. Could that cause this issue?
I have read in a few forums that I might be able to improve the situation somewhat by allowing something like Seafoam or regular transmission fluid to "soak" in the cylinders for a while. I've also read I might be able to temporarily resolve the issue by using an extremely heavy weight oil.
What kind of reliability or life span should I expect out of this vehicle if I continue to run it as-is or with one of these "quick fixes"? Will it fail catastrophically or will it just begin to perform worse and worse?
It actually seems to run at least somewhat decently and I'm getting about 22mpg out of it. Pulling the engine is not an option, but I'm willing to try just about anything else. My big concern is fuel inefficiency, as I bought this car solely to replace my minivan for very long (3000-5000 mile) trips.
You are correct. Though I dont believ anything will help the rings.
Is the check engine light on?
Check wiring harness for cam and crank sensors as they are known for rotting out and causing all kinds of driving issues.
February, 10, 2013 AT 6:35 PM
There are no codes in the computer. The check engine light is faulty. Based on initial testing, assumptions and the codes that were in the computer when I received the vehicle, I tested or replaced: IAC motor, coil pack, plugs& wires, crank sensor, air filter, throttle pos. Sensor. I checked the wiring harness at all connectors that were immediately accessible. I checked the timing and the timing belt condition. I checked for contamination of the coolant or exhaust leakage into the coolant. I checked for coolant contamination in the oil. After all of these things the ECU seemed satisfied and no further codes have appeared.
I was hoping the compression test would reveal a head/valve problem as that would be consistent with what I know of the vehicle's history and would be within my skill level to repair.
I have heard whimsical stories of replacing the piston rings with the engine still installed in place. Is this possible?
February, 10, 2013 AT 6:43 PM
What were the codes? Cant believe all those parts failed at the same time.
I would also have the injectors cleaned professionally as additives have little or effect.
February, 10, 2013 AT 6:54 PM
P0505 which prompted me to replace the iac motor, which fixed the vehicle not able to start on it's own. P1495 which was a disconnected hose and another I can't remember that ended up being a cracked plastic sensor near the battery. All others were while trying to locate the misfire/rough idle problem.
I believe the previous owner, being aware of the problem but not the cause, disconnected and inadvertently damaged many of these components.
Since I've already performed a compression test and verified a problem with the rings, what would I gain from looking at the fuel system at this point?
February, 10, 2013 AT 7:06 PM
Cleaning the injectors would improve efficiency and mileage.
You were lucky as code numbers never identify bad parts, just failed systems.
Make sure you stay on top of the timing belt as it is a common failure from tensioner failures and water pump issues.
As far as the low compression, aside from rebuilding the motor, just monitor it regularly to see if it gets worse
February, 10, 2013 AT 7:21 PM
It looks like all the timing components have been recently replaced. The previous owner told me he replaced the radiator, water pump and the associated hoses. The thermostat was missing and I can tell large portions of the vehicle have been replaced (incorrectly). When I got it the entire air intake hose assembly was disconnected, and the battery was missing. This is why I was not able to start it beforehand.
Normally I would not have bought this vehicle, and I ended up paying above book value for it, but cosmetically inside and out it is nearly perfect, and I was told by a number of (usually reputable) friends who were familiar with the vehicle's history that it only needed "minor work".
Now I am forced to try to get 20-30,000 miles out of this thing as it is or try to resell it and take the loss.
Oh well, the learning experience is worth it in the end, I guess. I'll know better next time.