weak 4.0 engine

[tonyjklh]

ok so im trying to figure if this is my engine or if it's my tires. ive got a 90 ex cab ranger 4" lift with 31 tires and 3.73 gears. my truck has sat for 6 months with a bad trans, so i finally rebuilt my trans and at the same time did my lift/tires, so after that long i really dont remember how much power my truck had. but ive noticed that acceleration is poor, and when i go up a 5% grade hill i need full throttle to maintain 40 mph(now think how that will be when i pull my wheeler). also fuel econemy is about 10 mpg.

so does it sound like i just need to re gear, or does it sound like something is wrong with my engine? im trying to decide weather to just swap in a V8 to fix this problem. and if this helps at all my engine has about 175,000 miles, never any smoke from exhaust, i add about a quart of oil every 1000 miles(probably from leaks), and ive just noticed my intake seems to always be full of oil.

any help would be great.

 

[bilzy7]

ohh god intake full of oil? i mean my 208k mile engine is somewhat losing power but thats because ive some some suction somewhere draining my power. it cant be just the gears if your wot and barely keeping 40 on a small hill. my weak engine takes the hill to my mothers house which is like 80 feet high at like a 70 degree incline at half throttle. sounds like your engine hates you... i would of said whens last time you changed your spark/wires other stuff but oil in intake... idk just sounds F*cked.

 

[tonyjklh]

well all the plugs/wires etc was the first i had checked/replaced. as for the oil in the intake my word choice may have been overstated, but there is definitally a fair amount in there, and actually last time i had the upper intake off i could hold it with the tb pointing down and it would be dripping.

so i guess it looks like time for a rebuild or a v8 swap.

 

[bilzy7]

ya sounds like somethings cracked.... im no expert... when it involves internals, im kinda useless. I always hope problems on my truck can be solved by nuts n bolts and cutting.

 

[RavoHimself]

Definitely not the gears and tires. 3.73s and 31s with the 4.0 is great. I would say take it apart and look for anything cracked or broken. If not then idk how you're getting oil in there. I just put new heads on mine and it runs great. I would say just rebuild

 

[tonyjklh]

ok, i guess i will go for a rebuild. doese anyone have any sugestions for the internals, any modifications for more power?

 

[Larry's shee]

Maybe try a little diagnostic/maintenance work first. Check compression, cat, pcv valve, o2 sensors, clean MAF with proper stuff, clean throttle body making sure everything opperates smoothly, run some sea foam, injector cleaner. Milage could be dirty/leaking injectors ($ )
JMHO, your results may, and will, vary.

 

[RavoHimself]

Maybe try a little diagnostic/maintenance work first. Check compression, cat, pcv valve, o2 sensors, clean MAF with proper stuff, clean throttle body making sure everything opperates smoothly, run some sea foam, injector cleaner. Milage could be dirty/leaking injectors ($ )
JMHO, your results may, and will, vary.

i second the motion.

but with that mileage any new parts will help. almost all of my valve seats were shot on my old heads so i had lost a lot of power. so new heads could go on the list. also if you want more power go for a new cam shaft and lifters/rockers

 

[bilzy7]

Cylinder heads for 4.0, idk how this site is but what'd you guys pay for new heads? 349.99 with gaskets and other stuff

 

[bilzy7]

I could get an engine for that lol.

 

[RavoHimself]

I paid about 350 for both complete heads. I got them on ebay. You just had to ship your old ones back so they had parts to make refurbished ones with. I think it was worth the money

 

[tonyjklh]

ok so I'm going to do a compression check today. What is the normal for this engine?

 

[tonyjklh]

ok so here are the results of the compression test #1=125, #2=110, #3=120, #4=100, #5=120, #6=120.
what do you think, good or bad? i have no idea what the compression is supposed to be.

 

[brian1116]

That sounds great for that many miles

 

[maxwell.hunt]

i know it has nothing to do with the oil but you could try a fuel pressure regulator. my 92 blew through one it was causing huge loss in fuel ecomomy and power, also somehting as small as a fuel filter makes a world of differnce, my friends 77 camaro would just die around 90 km's/h and the fuel filter made her purr