Service Advice - Which Direction to Take

Hi Gang. Hope everyone had a good Christmas. I was wondering if you could give me some guidence in deciding the best course of action to take on my 99 XJ with the 4.0 (120K miles). The service work required will need to be done by a shop.

(1) Work needed now: Replace front main seal, New timing chain and gears, New water pump, New oil pump, New valve cover gasket. For those items, parts and labor will be a little south of roughly $1K.

(2) The rear main seal has a small leak will ultimately have to be replaced. I haven't gotten an estimate on that yet, but I'm certain it won't be cheap to get reparied.

(3) Now a very recent problem that just occured yesterday: I started the Jeep (Was parked several hours in the garage and cold), and for a brief few seconds after the start she studdered and blew some coolant out the overflow bottle. Help me out here if I'm on the wrong track, but I suspect a head gasket problem. (There was no coolant mixed in with the oil.) A slight loss in compression might also explain why the engine has not be idling very smoothly.

Ok, so heres the question: If I have to do all of this stuff, am I better off from a $$$ standpoint just getting the engine competely rebuilt? If so, can someone tell what's involved with a complete rebuild and roughly how much does something like that cost?

BTW, this is an adopted Jeep I recently bought (rescued) and brought into a Jeep friendly home to live with our other two Jeeps - so she needs some TLC.

Thanks much

Marty

Man, thats alot of work for a basically just broken in engine. The way you are adding up charges you are almost halfway to a Jasper rebuilt engine when you add in the rear main. How did the shop arrive at the problems, timing chain pretty much takes a visual look see. As for the rear main, any mechanic will replace it when they do the oil pump, it's a gasket.
What are the sypmptoms you are getting...

Check or replace the coolant, might have too much water in the mix in there and there might be some freezing taking place. Quick check might be to see if there is any ice forming or if the coolant is very thick in your coolant recovery tank.
Personally I would do an oil change and use a 5 or 10W synthetic like mobil-1 or Castrol syntec, K&N or Mobil-1 oil filter, flush the cooling system and refill with mopar coolant and distilled water, a new thermostat and pressure cap [dealer OEM on those] new serpentine belt and see what happens, oh and a new idler pulley while the belt is off. Water pump but only if it is leaking where you can see it, sometimes the seal/packing goes and it leaks/drips out the drain hole on the nose of the pump.

I would also have a second shop take a look at it, just does not sound right to me....

While you are doing that I would also check out your cvcc hose from the valve cover to the air cleaner box any obstruction there will make the blowby go out your main-seals expensive for a clogged hose < before My GF and I got together she paid $400 to have the mains replaced and all it was ,was the cvcc was pluged i fixed it for next to nothing , Hopefully some of this and RichP's advice will save you some green..... Happy Hollidays

The more I think about this the more I recommend a second opinion from someone you really trust, not someone working on paying off his xmas credit card bills. I build and fix alot of computers and the opportunity to find non existant problems is always there to pad the bill, I just can't do it, goes against the grain. The solution you put forward is nothing more than throwing parts, expensive parts and labor, at a problem that might or might not be there from those parts being bad. My 98XJ has over 250,000mi and NONE of the parts you are talking about have EVER been replaced. Now maybe, just maybe your new jeep came from an owner that did no maintenance on it but that 4.0 and the 2.5L are both pretty resiliant motors and can take alot of abuse.
Like I said, fluids change to start, new tstat and pressure cap, flush the cooling system and maybe the oil system too if the previous owner did not take care of it,. Then the mobil-1 or syntec route with a few filter changes based on the color of the oil on the dipstick. Change the filter when you can't read the hash marks on the dipstick and add a quart. Good luck...

this is off the top of my head but I believe it is quite close.....

to check timing chain and such..


take off the distributor cover cap and turn over motor with a wrench on the crank bolt. the crank should no more than 5-6 degrees before the rotor moves....if it is 10-12 timing chain needs replaced.

you can count degrees by using the timing marks...


Peace..................................BartG

MartyBear said:

(1) Work needed now: Replace front main seal, New timing chain and gears, New water pump, New oil pump, New valve cover gasket. For those items, parts and labor will be a little south of roughly $1K.

(2) The rear main seal has a small leak will ultimately have to be replaced. I haven't gotten an estimate on that yet, but I'm certain it won't be cheap to get reparied.

Click to expand...

Why and whom said you needed all this work done? Did you bring the Jeep into a garage after it had a problem? What problem did you have?

Timing Chain and Gears, oil pump should last over 200,000 miles. If oil pump needs replacement the rear seal can be replaced at the same time as the oil pan needs to be removed. The rear seal costs about $14.00 and is an easy 15 minute install for a good mechanic.

I think you are getting ripped off. Go to a differnet garage.

But tell us why you think you need this work done...what problems other than the coolent thing.

The short answer as to why I think it needs to be done isn't so much that it "needs" to be done more than as long as they are in there replacing the front seal why not replace the timing chain and gears at the same time? (And the water pump and the belt etc...) I'm believing that the replacement of the front seal involves the lions share of the labor that would be required to go after the timing chain while the mechanic is there???? Hey, I can be wrong, so b4 I :hang: myself if the groups collective wisdom believes I need an attitude adjustment let me have it

Unlike my other two Jeeps that I've raised from pups :laugh3: and know the entire service history of, the only thing I know for certain with this one is that it has some high mileage of 119K. It bothers me not to know how reliable my Jeep is.

Anyhow I'm very concerned about that coolant being blown out (Along with the brief engine stuttering) and I realy need to get a handle on that. Another reason I'm suspecting a gasket is that I have gotten some mild wiffs of coolant into the cabin now and again. If I have to have the head gasket replaced on her, roughy how much would the average shop charge for such a thing?

Thanks guys,

Marty

MartyBear said:

The short answer as to why I think it needs to be done isn't so much that it "needs" to be done more than as long as they are in there replacing the front seal why not replace the timing chain and gears at the same time?

Click to expand...

Simple answer on that is that the front seal is replaced externally, there's no need to pull the water pump or the timing case cover. So it isn't a case of "doing while it's open."

I replaced a timing chain in an '88 at somewhere around 200,000. I was worried, because the old AMC V8s had nylon teeth on the cam sprocket and I was afraid I was getting close to jumping time. Got it open to find all steel gears, and NO perceptable stretch in the chain. I did replace it "since it was already open," but I kept the old chain and gears and I would not hesitate to throw them into another engine.

That is very good to know. Thank you for that. This tells me something about the garage I was using

On to the coolant thing; so if it is a head gasket that needs to be replaced, is there anything else I should look to do while that's being done?

Well it took awhile to get it out of you, but you left out the most important info on why the jeep needed work in the first place 8-}

The front seal...that's a different story...kinda. As said the timing chain and gears last about 200,000 miles or more. If you are going to keep this Jeep for many years than maybe you should have it replaced. Timing set costs about $50.00 Also you should replace the harmonic balancer since it will be pulled off to get to the front seal and they start failing about 130,000 or so. The balancer costs about $50.00 If your water pump is the original than I'd say yes replace as it's due to fail with that many miles on it.

Funny...I just replaced all the above recently as I had an oil leak in my timing chain cover. My jeep has about 190,000 miles. Figured since all was off I'd go for it. I did all this work myself with the help of forums. Thanks guys again.

Regarding your head gasket. I had mine done at 125,000 miles as it was leaking badly. The mechanic suggested since the head was off to get a valve job also. I did...don't know if it helped or not as the jeep never burns oil...but never did either. How bad is the head gasket leaking? If it's just a little damp with oil then that's kinda ok with the I-6. I think the valve job and head gasket cost about $750.00


Others with more expertise I hope will chime in.

Good luck.

Find out about the headgasket first. If it is a cracked head or block then that would be a better gauge of whether or not you need a rebuild. Everything else will follow as needed. Don't bother changing the timing chain and gears until you get a complete rebuild.

I just wanted to thank everybody for taking the time to reply to my post. As always this is a great community and I hope I can contribute back to the group on those occassions when I have something worthwhie to contrribute :laugh3:

I have two exceptional mechs (Fellow Jeep Heads) that used to work on my XJ's that I would trust with my life. They moved on to a shop a bit further away from my home than I would normally drive (about 100 mi) but will be worth it to take her there to them. At least I know I won't get taken to the cleaners and my little baby will be fixed right. :repair:

Thanks again and I'll let you all know the outcome :wave:

Marty

im thinking the "rough idle" and spewing antifreeze is not so much a head gasket leak as it is a poor mixture of water/coolant.. someone mentioned this before too.. i have never dealt with a frozen engine but you being in Wisconsin i think its pretty cold there.. the over flow would only "puke" if there was a restriction "down stream" of the flow and that was the only clear route for the coolant.. and the rough idle might be the engine fighting with some slush running thru the water pump or just a flow restriction..