Intake Leak?

[Tobs99Ranger]

So my Ranger (99 with the 4.0, automatic 4wd) was running like crap the other day. So I changed the plugs, the ones on the pass side looked fine but I had new ones so I changed them, then I went to the drivers side and the looked horrible I cant believe it was still running. I put the new ones in and it runs great. I showed the plugs to one of my buddies, and he said I have an intake leak and that antifreeze is leaking in the intake. Is this an easy fix that I could do? Or am I better off bringing it to a garage? Any help would be great, thanks.

 

[Sour Grapes]

im not 100% on the 4.0L, as i am having a few issues myself. however, if there is in fact coolant on your plugs (im not sure how one would tell, seeing as it would burn up through ignition, im pretty sure), i would believe it is something head related. I would assume the head gaskets if it is in fact a coolant leak.
I would smell the exhaust. if it smells sweet, like the smell of coolant, i would be suspicious. Also, check your oil dipstick and the underside of the filler cap for ANYTHING other than the normal look of oil. If it looks milky or smells really weird, the only thing to do is get down and dirty!

as for if you can handle it, that depends upon your mechanical ability and how comfortable you are tearing things and putting things back together. I am replacing the valve cover gaskets on my truck currently, and personally i find it easy. Patience is key; and maybe a few beers lol.

good luck! I found that working on my truck is sometimes the most rewarding and aggrevating thing at the same time.

 

[Sour Grapes]

any updates?

 

[Tobs99Ranger]

Thanks for the help, Im gonna take a look at the dipstick and that other small stuff. I feel pretty confident in doing my own work on the truck. I will let you know what I find

 

[Sour Grapes]

what colour were the plugs when you pulled them? grey? black? were they dry or wet? maybe you have the same issue as i do; a leaky valve cover gasket.

 

[Tobs99Ranger]

The plugs were white and dry.

 

[Bird]

It's a known issue with the 4.0 OHV that the intake bolts eventually loosen off and cause a leak of oil / water into the intake ports. Easy enough job to replace the gasket and fix the problem. You can check for this condition by just checking the 10 intake bolts for tightness.

Bird

 

[Tobs99Ranger]

It's a known issue with the 4.0 OHV that the intake bolts eventually loosen off and cause a leak of oil / water into the intake ports. Easy enough job to replace the gasket and fix the problem. You can check for this condition by just checking the 10 intake bolts for tightness.

Bird

Thanks Bird, I will check that out.

 

[skyway0018746]

some of the 4.0l had a problem with craching heads (not as common as the jeep 4.0l) min i believe was cracked and replaced before i bought it..
like said the intake gaskets are known to leak.

 

[bigrockets]

The tech library has the proceedure for tightening the lower intake manifold bolts. Most times you don't have to replace the gaskets. Try the wrench first.

 

[bilzy7]

Ya I'm about to undertake replacing valve cover gaskets. Mine leak oil into socket #whatever the **** is on drivers side closest to cab. That socket gets soaked. It has leaked enough that every 4-5k miles I lose 2 quarts. Never did a valve cover before but it's so easy to reach I'm not worried. I just gotta make sure not to drip crap on anything once cover is off. I hope that fixes both our problems.

 

[bhawk]

If the plugs are burning white, and not golden brown or tan colored, I would suspect an air leak at the intake manifold gasket. The design is poor and they leak there often. I would change the lower and upper intake gaskets, and do the valve covers while you have them off. No hard job, just need patience as you have to move or take off lots of parts to get the valve covers off. Check out rock auto for gaskets, not expensive. Second best would be to retorque the lower intake bolts according to the service manual. They have a special sequence for torquing down the lower intake and it must be followed to have success. The ranger 4.0 used a poor design to hold the lower intake to the heads. All bolts go straight down into the block instead of bolts going right into the head to ensure a good seal.