2000 Intrepid, 78k miles, engine light goes on for a while, then off for a while and gives 0172 and 0175 codes. Engine runs smoothly 95% of the time. When the car has been sitting for a while (6+ hours), but in hot weather, it may idle roughly for a minute or two. The mechanic says this is due to leaky or worn injectors and that the computer is trying to lean it up.He says the O2 sensors are within specs. Has anyone heard of leaky injector problems like this? Is there something else that I should look for or try first?

 

Well, for want of any responses or other ideas, I ran a couple of bottles of injector cleaner through the tank and the problem seems to have gone away.

 

Well, the 0172 and 0175 codes have stayed away. I did notice, however, that the fuel gauge started acting wacky. Around sharp corners, the needle would drop to E and the warning tone would go off. Then it would shoot back up to where it should be reading. This happened for a week or so until I got a fresh fill-up without the injector cleaner.

 

So, another update on the Intrepid. A few weeks ago, I had a dead battery. Got a jump and drove home. Took a look at the battery terminals and found that the terminals were so corroded that they ate away quite a bit of the cable connector and the post on the the battery. On every other car I've ever owned, when I'd change the oil, I'd look around the engine compartment and underneath to see if there was anything that needed attention. Well, because the engineers at Dodge saw fit to hide the battery under the air filter housing, it's conveniently out of sight, and therefore, out of mind. Well, I replaced the battery and cable and gooped it up with that red battery terminal sealant. We'll see how well that does. But I will certainly add "Check the stupid battery connections" to my list of maintenance checks.

 

Oh yeah. A week after the battery incident, the car crapped out again. Turned over great, but just wouldn't start. After it was towed home, I sprayed some starting fluid in the intake and it ran on the starting fluid. This is important because it led me into a trap. I got out the Haynes and the PDF of the shop manual that I downloaded and proceeded to troubleshoot. I cracked the fuel line and found no fuel coming out while cranking. Stupid me figured it was the fuel pump and replaced it for $170 and several hours on my back in the driveway. Still didn't run. Who didn't see THAT coming? Read a little more in the books and found that the fuel pump is told to run only when the computer sees input from the crankshaft position sensor and the camshaft position sensor. Well, the crankshaft sensor also tells the computer to energize the spark plugs, and because it ran on the starting fluid, I figured that sensor was ok. So I looked at the camshaft sensor. The book said there should be 8 volts at the sensor when the ignition is on. I read 0 volts. Hmmm.... the 8 volts come from the computer, so obviously, the computer was bad, right? Nope. I picked up a PCM from a junkyard ($65) and installed it only to have the same results. No voltage. Hmmm... Then I disconnected the crankshaft sensor and measured 8 volts at the camshaft sensor. The crankshaft sensor was shorted and brought the voltage down to zero. Replaced the sensor ($40) and all is well.

So, a 5 minute, $40 repair turned into a 2-week, $275 fiasco. On the upside, I probably would have ended up paying that much if I had taken it to a garage for diagnosis and repair, plus I have a brand new fuel filter/pump/sending unit on a car with 90,000 miles, so I'll probably never have to replace it again. I also have a spare computer on the shelf just in case the original one does indeed crap out.

 

So, how do you like my car blog? Feel free to submit comments or questions.

 

Well, the Intrepid has been running ok for a while. Still not happy about the mileage. The best I've been able to get is 24 mpg on the highway. And that's driving at 55 mph and being a bit of a road hazard, so it's back to 65 mph and 21 mpg for me.

It also has this annoying squeak in the steering wheel when I go over bumps in the road. It's more pronounced when it's cold. It started after I had the A/C evaporator replaced. I think the mechanics didn't tighten all the bolts. I'll look into that this summer.

I got the 0172 code again yesterday. I reset it with the OBDII code reader to see if it would come back. Nope. I think I'll get another bottle of fuel line cleaner and run that through. Perhaps I have an injector that is leaking. The fuel additive seemed to get rid of it last time.

I'm also wondering about the O2 sensors. The car now has 94k on it and the O2 sensors have never been replaced. They check ok with the scantool, but I suspect that new sensors would make things a little better. Problem is, there are 4 on the car. Only the upstream sensors will throw a code. The downstream sensors merely monitor the function of the catalytic converters. Well, the fuel additive is a cheap thing to try. I'll do that first.

 

Well, the Intrepid now has 122K on it! I was going to do some PM on it this past summer and replace the water pump, timing chain, etc. that I was supposed to do at 80k. Didn't get around to it. Then in October, the car quit. It would run for a little bit, then crap out. Really strange. Good compression, other diagnostics indicated that all should be well. It just wouldn't run. No sludge in the oil, either. So in an act of desperation, I disconnected all of the sensors. I reconnected the crank position sensor and it started! Then I would reconnect another sensor and start it. Shut it off. Reconnect another sensor, and start it. I kept doing that until the only sensor that wasn't connected was the camshaft position sensor. When I connected that, the car wouldn't start. And both sensors were new. That told me that there was a timing disparity between the cam and crank position sensors. Reading up on it, one possibility could be a broken flex plate. The enjuneers designed the flex plate so the place where it flexes the most is where the bolt holes are. So it cracks there, then shifts until it binds up. But at that point, the timing is off and the car won't run. I made some calls and a dealer and a mechanic both said to tear into the timing chain cover first. Glad I did. The water pump had failed so dramatically that the timing was off enough that the engine wouldn't run. The catastrophic failure actually saved the engine! I did find bits of bearings in the oil pan. So I ended up repairing the car during the school year when I don't have time instead of doing all that work in the summer when I DO have the time. Oh well. Live and learn, I guess. Didn't want to throw the car away after installing $1,000 in suspension parts in the last two years and replacing all the brake lines. The car should be around for a while! Unfortunately, it's starting to show its age. Just today, the CEL came on again and I searched for 0175 and found this old thread I started. I still wonder if anyone has read it. Well, it reminded me that I should get a can of injector cleaner and run that through the tank. Well, I guess that's about it for now. Happy New Year!