engine work

[ready to mud]

my main bearings are starting to go a little and my lifters tick like nobodys business. i am thinking of just getting my mains done and my rod bearings if they need it and getting the crank repolished if need be. instead of a full rebuild. also putting in a mopar purple cam with new lifters and a new timing chain if i need one. i dont really want to do a full rebuild because the engine is in perfect condition with great power the only problems are the ones listed. how many hours labour should this be at a shop. also for the main bearings are they fairly easy to to yourself. i just need a bit of help as i havent done much for engine work

[XJH-007]

Unless you've driven it without oil....I'm sure your mains are fine. What leads you to believe they are bad?

The main bearings are not actually "bearings". It's simply 2 machined races that essentially ride on a pressurized layer of oil.

Anyway, you'd have to drop the pan, remove the tranny, takeoff all the piston bearing caps and drop the crank out. Parts are cheap, having the crank ground will run you around $100.00.

Just do the lifters and/or camshaft/timing chain......the labor to do just the main bearings will be 10 Times the cost of parts.

my $0.02

[ready to mud]

we were trying to diagnose engine noises and the people helping me said it sounded like the mains were going. we were using one of the stethescope things. for the cam i will probably do that myself i just didnt want to do the mains by myself unless there wasnt that much too it

[Klutch]

How many miles are on your engine? That can make all the difference. It's usually a bad idea to replace only the crank bearings. If they are worn, it's very likely your connecting rod bearings and cam bearings are also worn. If this is the case, anything short of a complete rebuild would be an expensive waste of time.

Lifters will tick if they are gummed up or if the oil pressure is low. Is your oil pressure reasonable? If so, that means your bearings are probably OK.

If your oil pressure is OK, I'd recommend changing the oil and pouring in something like Valvoline High Mileage. That stuff has some extra additives to help with things like sticky lifters.

If your engine is really gummed up, you can substitute one quart of transmission fluid for one quart of oil. In other words, drain all the old oil, then pour in five quarts of oil and one quart of tranny fluid. Run the engine awhile this way and keep an eye on the oil. When it gets really dirty, which shouldn't take too long, change the oil again. You will have effectively accomplished what you get from an expensive Bilstien oil flush (also known as the Bilstien wallet flush).

[ready to mud]

ok does this mean i should do the cam bearings when i put in a new cam? my oil pressure is good when it is cold then it goes all wonky when it is hot. i was told this could also be the mains. i would also do rod bearings at the same time. also my engine has about 130 000 miles on it. still great compression and it doesnt burn any oil through the cylinders but it goes through about half a litre every 2-3 thousand kilometers

[jipjip]

you should ALWAYS install new bearings when replacing a cam, doing a re-build, machining your cam/crank.
main bearings don't usually cause a ticking. a main bearing noise is very low pitch, more like a thud/knock. depending on mileage, i would advise removing the pan, inspecting the bearing surfaces, and crank journals, and using plasti-guage to see if your clearances are still in spec. if they are not, replace the bearings w/ new ones, and re-check your clearances.
as for the ticking noise, it's often caused by bad lifters and push rod wear. replace the lifters, push rods, and rocker arms at the same time (they all wear together), and i wouldn't worry too much about the cam, unless it looks scored, or damaged.

i would highly recommend installing a high volume oil pump while your in there, and get rid of the stock mopar piece of crap. this will increase the life of your new parts, and ensure you have enough oil at vital rotating assy's.

good luck.

[ready to mud]

i new it was the valve train ticking. i was going to put in a new cam for a bit more power.

so far the list is
mains and rod bearings if needed
cam/lifters/pushrods/rockers
timing chain if need be
oil pump if i am in the bottom end


i guess i will try an engine flush again to see if i can get rid of the ticking. i tried it once before. no harm in re-trying

[jipjip]

Originally Posted by ready to mud

i new it was the valve train ticking. i was going to put in a new cam for a bit more power.

so far the list is
mains and rod bearings if needed
cam/lifters/pushrods/rockers
timing chain if need be
oil pump if i am in the bottom end


i guess i will try an engine flush again to see if i can get rid of the ticking. i tried it once before. no harm in re-trying

a flush won't get rid of ticking, but a decent additive might. i would try a lucas oil additive or similar, and see how that goes.

good luck.

[Klutch]

Originally Posted by ready to mud

i new it was the valve train ticking. i was going to put in a new cam for a bit more power.

so far the list is
mains and rod bearings if needed
cam/lifters/pushrods/rockers
timing chain if need be
oil pump if i am in the bottom end


i guess i will try an engine flush again to see if i can get rid of the ticking. i tried it once before. no harm in re-trying

You're in the proverbial delimma of cascading replacement. IMO, none of those components are worth replacing unless you rebuild the entire engine. I also wouldn't bother installing a new cam in an engine with 130k on it.

My advice would be to keep driving it as it is until it quits. Then rebuild it properly or buy a reman. But hey, it's your Jeep and you can do what you like.