I was driving to get a trailer yesterday doin about 65 and all of a sudden the wotor started to shake real bad, lost some power,and it sounded like the motor was exhausing through the intake! So I pulled off to the side for a minute it sounded normal when idling, so I tried to take off easy and when I got to about 1800 rpm it did it again. Not good cause I was about 150 miles from home. I knew it was time for an oil change and thinking that maybe the combo of dirty oil high rpm might be causing the valves to float so I limped it to a oil change place and had it changed I put in 3 quarts of lucas oil treatment, and 7 of oil. I drove back home with no problems whatso ever. and the last 50 miles i was hard on it floored it and held it there with no problems. But today after about 275 miles with no problem it did it when I was going up a hill towing a 4000 lb trailer on the highway I was doin 62 and didn't give any skinny pedal when I was goin up I was just letting the truck slow down it was about to down shift. and it did it so I pulled to the side and sat for about 30 seconds and then it was fine (it idles normal still) I drove another 40 miles and it did it again under load,but lower rpms. and I was able to drive home normal after that. There no real hills by me just overpasses and small hills i'm in illinois remember. What do u guys think? weak valve springs, or bad guides? help I will lose about $250 a day if it goes down. Im pricing new truck now just in case.

 

Do you have excess smoke from the exhuast?

 

a fuel filter thats just starting to stop up could give this problem. Any telltale smoke signs?What about a temp reading?

 

a fuel filter could cause this? really? maybe a bit more black smoke when it did it , but not much. Temps are normal. I'll change my filter tomorrow it's got maybe 5,000 onit.

 

You have air leak in the system someplace would be my bet..wont let it pump enough fuel at high speed system gets bubbles will do strange things

 

thanks guys for the info. I would like to know what do the big hitters think as well

 

It almost sounds like a gasser with a plugged catalytic converter. But since it doesn't have a cat....

It sounds like a fuel problem all right. Possibly air in the fuel system? Possibly an IP problem? Possibly a lift pump issue?

Were you running on the same fuel tank each time it did this? How much fuel was in the tank you were running on when it happened?

 

It might be a fuel thing like you say, but it hasn't done it since I changed the oil and added all 3 qts. of lucas. It was doing it on both tanks full and half. I'm not gonna address it anymore if the deal on the new truck goes right. I would fix and keep it till next fall, but it is under powered for what I do, and gets 6 to 8 mpg towing. the 15.5 empty is cool, but I can make $40 more a delivery with a psd I do about 3 deliverys a week on average. I planned on paying off my car in 6 more months, and knocking the trailer down some to but I don't have the credit to have two car notes, and my travel trailer note, So my Vw has to go now I guess.