heywood05 Posted February 10, 2014 Share Posted February 10, 2014 I have a 10 f250 that came in on a hook, high pressure fuel was bouncing around between 50-100 psi during cranking. Both exhaust manifolds were dripping fuel/oil mix between the manifold and inlet pipe gaskets. when I removed glow plugs and cleared all the excess liquid, performed a relative comp test and it passed, however a manual comp test showed all cylinders compression between 190 to 250. I dont see alot of 6.4s at my dealership we are fairly small. My question being shouldnt the compression be upwards of 350 psi? Any advise appreciated....btw # 8 injector was way overfueling. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted February 11, 2014 Share Posted February 11, 2014 check your fuel for metal contamination Quote Link to comment Share on other sites More sharing options...
heywood05 Posted February 11, 2014 Author Share Posted February 11, 2014 I did that found none, I replaced injector and fuel psi is well above 4000 psi, just the compression that im concerned with Quote Link to comment Share on other sites More sharing options...
mchan68 Posted February 11, 2014 Share Posted February 11, 2014 Did you change the oil after replacing the injector? Fuel diluted oil can definitely affect compression readings. Quote Link to comment Share on other sites More sharing options...
Aaron Posted February 12, 2014 Share Posted February 12, 2014 Depending on your elevation, I'd say that motor is likely bitched. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted February 13, 2014 Share Posted February 13, 2014 We're about 1000 ft above sea level here and I typically see 340-360 on a dry engine. I've had fuel and coolant washed down cylinders affect compression readings. A little squirt of oil into the adapter seems to help Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted February 13, 2014 Share Posted February 13, 2014 350 PSI in Vermont = bent rod Quote Link to comment Share on other sites More sharing options...
heywood05 Posted February 14, 2014 Author Share Posted February 14, 2014 thanks , finally got a borescope small enough to fit down the cylinder the walls are scored Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.