- This topic has 3 replies, 3 voices, and was last updated 10 years, 9 months ago by
.
-
Topic
-
To satisfy my own curiosity and get a sense of the general health of the 5.9L V8 in my new-to-me 2001 Ram, I decided to do a “relative compression test”. I turned the key on, put the gas pedal to the floor, and cranked the engine. Apparently this model doesn’t have clear flood mode because the starter gave a half turn and then the engine roared to life and bounced off the redline before I could react and lift my foot.
My only guess is that somehow a combustible substance (oil?) was in the intake already? These engines are known to leak oil into the intake by way of a defective plenum pan gasket, but this engine shows no other symptoms of that pattern failure.
-
Replies
-
Don’t forget when using clear flood mode. The vehicle usually is flooded
and won’t start. It may take the computer a little bit to respond.Sometimes that does happen. In fact, in a video that ScannerDanner and I did about a year ago he had the same issue.
Just to be safe you could also pull the fuel pump fuse. There are actually 2 things you’re looking to accomplish when putting the vehicle in ‘clear flood’ when doing a compression test. One to shut the fuel off, but also to make sure the throttle is open when you do the test. If the throttle isn’t open when you do the test you will not get accurate compression readings.
The video with ScannerDanner immediately jumped to my mind and since they are both Chrysler vehicles of similar generation, I think it is a reasonable conclusion to make that the system just doesn’t respond quickly. I know that early Chrysler OBD-II is very crude and not the most observant. For example I have audible spark knock at idle in this truck, but no misfire codes? Like, how does it miss that? Thanks for the help guys.
- You must be logged in to reply to this topic.