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Hey all,
I’ve had a noticeable drop in oil level in my van, and replaced the valve cover gaskets and the oil pan gasket after I noticed visible signs of leakage. All mating surfaces were cleaned, sealant added at parting lines of crank case per service manual, and bolts torqued to specs and I used Felpro gaskets. I also went ahead and changed the spark plugs and wires. I accidentally did two stupid things however. I switched spark plugs wires on cylinders 1 and 3. I drove the vehicle about 1/4 mile before I realized the mistake and switched the wires. Mistake two is that I overfilled the engine oil by a quart, this however I did not realize until a few days after. I test drove the vehicle, with no issues, then took it out the next day for a normal day of driving (street/highway) and had no issues or leaks. The next day the vehicle turns over and starts but immediately stalls upon which the oil pressure lamp appears.
Pulled the dipstick and realized the oil was overfilled. It also smelled like gas, and was relatively dirty for the short amount of driving. Drained all the oil, held it to sunlight, no metal flakes. Pulled the plugs, which were dirty, and seemed to be covered in oil. Cleaned all plugs and replaced, added only 3 quarts of oil to a 5 qt system and tried again. Cranks, starts, stalls. CEL did appear P0107 and P0108 which is low and high voltage MAP sensor error (I believe).
My next step will be to test the MAP sensor (once I replace a failing DVOM) and possibly remove and clean. Am I on the right path, or am I missing something obvious? Did switching the wires exacerbate the issue? I know I wrote a novel, but just trying to be thorough. Thanks!
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here is a link to help.
http://troubleshootmyvehicle.com/chryslers/six-and-eight-cylinder/40-how-to-test-the-map-sensor
I don’t think the MAP sensor is the issue and I know cleaning it won’t do any good, that’s not the way they work. I think it’s a symptom rather than the cause. You may have an issue with the mechanical timing of the engine, if that was the case it may not start and would likely set a MAP sensor code. I think it’s worth looking into if nothing else.
Alright, so I got a new DVOM and set out to test the MAP sensor per the link provided by college man. MAP is getting 4.7V from PCM (wire 1). Without vacuum the 2nd wire (signal back to PCM) was .05V and when I applied vacuum there was absolutely no change in the voltage. According to the service manual this wire with MAP with no vacuum pressure should read at .5V. I checked the ground wire (#3) to positive battery terminal, my reading was just over 6V, not 12V as indicated in the link. Is it safe to say that I need to replace the MAP sensor?
Eric, should I start looking into timing issues like you suggested as well to be safe? I’m not very familiar with this territory, any suggestions on where to start?
Thanks guys.
Well as I said in the last post if the mechanical timing is off it’s likely to set a MAP sensor code. You can chase down sensors all day but if the engine has a mechanical problem you wont’ know till you check. Nothing works right if the engine isn’t right mechanically.
Eric, can you point me in the right direction as to how to get started diagnosing mechanical timing issues? Thanks!
I’m not familiar with the set up on that engine but if it’s an OHC engine then it’s either driven by a belt or a chain in which case you can remove front covers or valve covers to check the mechanical timing marks of both the cam and the crank. If the cam is in the engine this is a bit more difficult I’m afraid. Check the service manual for specifics on how to set up engine timing.
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