Engine replacement yes/no

tommudd · **Posted:** Thu Aug 16, 2012 9:28 am

So why are you saying you would not of bought it two years back if you would of known..........?

ihatemybike · **Posted:** Thu Aug 16, 2012 9:31 am

Here's the code to make the pics show.

Code:

[img]http://i1155.photobucket.com/albums/p557/MALiberty/pistonwithchunkout2.jpg[/img]

Wow, your piston really got tore up! Sounds like you have a good plan going to get it back on the road.

MALiberty · **Posted:** Thu Aug 16, 2012 11:30 am

Tom.... if I had known about the 2002 3.7 L issues with oil and lube problems, dropping valve seats from running hot/overheating I prob would have not let my then 19 year old daughter talk me into it and bought something else.... btw, thanks for the code for pics to show, but pardon my ignorance, how do I get the code in the reply/message?

and Aaron, yes it got really tore up... he says he thinks it was the valve seat that got sent around the cyl, damaging the cyl sides and them wrecking the piston itself then disintegrated, prob out the exhaust port.

Anyway, I was glad it got sent to the machine shop and he weighed in that it needs a sleeve and that while the piston is being replaced all the cyls will be honed and all new rings put on and well.... more to follow.

John

ihatemybike · **Posted:** Thu Aug 16, 2012 12:16 pm

Despite the issues we've had, I'm still relatively happy with the 3.7L.

Granted I'd rather have another GM 4.3L/4L60E combo.

Chrysler PowerTech 3.7L
210 hp @ 5200 rpm / 235 lb·ft @ 4000 rpm

GM Pushrod V6 4.3L
200 hp @ 4,600 rpm / 260 lb·ft @ 2,800 rpm

tommudd · **Posted:** Thu Aug 16, 2012 12:20 pm

Ok just wondering,
I see nothing wrong with the 3.7s
Sure you run any engine hot there will be issues, 3.7s are no different
I'm expecting mine to run up into the 300,000 with no issues

TAHOE · **Posted:** Thu Aug 16, 2012 12:25 pm

MALiberty wrote:

Update: So another option surfaced. I called a good friend who is very practical to run things by him. The outcome is he has a couple of friends who are ASE mechanics and have been working on cars since hey were 14 (now in 40"s) professionally they work for a big outfit. They work on motors for fun and a few bucks to keep them in their dirt track race car hobby. We talked and one of them had a class recently where the jeep 3.7L motor was discussed. He said they have had sludging and bad lubrication issues... esp the 2002.... and when they run low on oil they are prone to jump timing as there is a hydrolic tensioner on the timing chain... when it jumps timing the piston will hit the value and bend it often causing the symptoms my jeep has.

They agreed to take it apart and see if it's this simple as maybe only the heads have to come off..... good price and parts at cost....

Anyone else heard of the jumping timing issue? Make sense?

Tx

I was just in my BIL's shop the other day, he had a 4.7 Durango in there replacing valves. They drove with low oil, the hydro tensioner did not pump up and caused the chain to jump therefore bending all the valves on one side. He said the 3.7's are basically a 4.7 with 2 cyls chopped off and the 3.7's can have same issues. He replaced the head on my neighbors 3.7 in his Ram 1500 last summer due to dropped valve seats. I have read, the valves were changed slightly in '05 which made issue even worse. Like you, if I had known that, the wife would not be driving a Libby, especially her '05.
At least you wil be getting a fresh motor now.
Aaron, they may be around the same Hp/torque, but my 4.3L in my astro would out pull our 3.7 Libby any day of the week, plus I think it would last longer. I only hope the wife's libby lasts to 120K, but not going to hold my breath.

ihatemybike · **Posted:** Thu Aug 16, 2012 12:43 pm

Tahoe, that's why I'd rather have the 4.3L. Stupidly robust, low tech engine with its torque on the low end of the RPM band.

Pretty sure your wife's Jeep will make it past 120k. You already know what to watch for and she doesn't wheel it. Eugene had been overheated a couple times before the valve seat dropped, think it has somewhere around 190k now.

TAHOE · **Posted:** Fri Aug 17, 2012 9:20 am

ihatemybike wrote:

Tahoe, that's why I'd rather have the 4.3L. Stupidly robust, low tech engine with its torque on the low end of the RPM band.

Pretty sure your wife's Jeep will make it past 120k. You already know what to watch for and she doesn't wheel it. Eugene had been overheated a couple times before the valve seat dropped, think it has somewhere around 190k now.

I won't hold my breath. If I pull a trailer and go up a hill, it will lose power, have to manually downshift to get RPM's back up. Maybe nees good tranny flush/filters too. It runs pretty rough too even with new plugs and I run in tank FI cleaner regularly. Hopefully it will last long enough to get paid off and she can get something else, but she wants another Jeep, ugh!!!

Sorry MALib, don't mean to hijack.

tommudd · **Posted:** Fri Aug 17, 2012 9:36 am

But all goes back to one fact
maintenance
ANY motor that is run hot or run low on oil will have issues
even the junky 4.3s, which I hate
Not that more powerful nor that much better than any other engine
trust me been through so much BS with my Step fathers 4.3 in the 94 Blazer, carbon built up/ EGR issues, blown gaskets etc , it hasn't been half the engine that my 3.7 has been and its got less miles .

MALiberty · **Posted:** Fri Aug 17, 2012 10:01 am

tommudd wrote:

But all goes back to one fact
maintenance
ANY motor that is run hot or run low on oil will have issues
even the junky 4.3s, which I hate
Not that more powerful nor that much better than any other engine
trust me been through so much BS with my Step fathers 4.3 in the 94 Blazer, carbon built up/ EGR issues, blown gaskets etc , it hasn't been half the engine that my 3.7 has been and its got less miles .

No disrespect intended, you do have a 2004 model 3.7 L. The first model year was 2002 and Aaron's and mine are 2002's.... and that's when the issues we're talking about were "built in"... then corrected, at least to some extent, in future years. You can find a lot of write ups about the 2002 3.7 motors and overheating (aluminium on steel) dropped valve seats, jumping timing, oil and sludging issues, and bending valves. In the end I would prefer a later year motor but I am getting a pretty much rebuilt 2002 for a very reasonable cost to me.

TAHOE · **Posted:** Fri Aug 17, 2012 11:04 am

I think they are all steel seats in aluminum heads, maybe they just changed seats design a little. I had read the '05's got valve design changed too and they are real bad for carbon build up and dropping seats too, I dunno, i can only hope not. I know our 3.7 is one of the loudest and roughest running motors in any vehicle we've had.

Tom, guess we have to agree to disagree, glad you and Chirs too have gotten good mileage out of yours. I've had 3- 4.3L's and all but one were still going after 160K when sold with little care other than injectors and basics. I know they had their intake gaskets issues due to DexClog, but I only had 1 motor fail and it was because of a blown oil line while driving which was my fault for not changing it when I knew it was leaking. The 4.3's are just a 350 with 2 cyls hacked off and usually last forever, far from "junky". Got a buddy has 400K on his Astro with no rebuild and still uses it in his company van everyday.

ihatemybike · **Posted:** Fri Aug 17, 2012 11:26 am

tommudd wrote:

the junky 4.3s

Both the 3.7L and 4.3L are good engines when all is well and things are maintained, but when things go wrong the 4.3L seems to weather it better.

Grumpy was much abused before me. PO put 123k miles on it in 19 month. First tune up ever done at 300k miles. Someone mixed green coolant in with the orange creating brown sludge that took over 15 minutes of flushing to clear out.

When Grumpy's tensioner pulley seized and shredded the serpentine belt I not only finished driving to work, I drove it home after and then on to the parts store for a total of over 40 miles. Things didn't turn out so well when Eugene's tensioner seized and belt shredded.

Green overheated late at night on a trip to my parent's house miles from the next town. Stopped, let it cool, checked everything, then drive till hot/let cool a couple times into town, under some lights and a water source to find a water pump gasket leaking. Engine runs just at good now as it did before overheating.

I've only had one 4.3L "die", my 1986, back before I did all my own work. Van overheated, so I pulled over let it cool and checked everything. Looked good, so I started the engine to hear top end tapping. The next day a garage told me that the oil pump died, restarting damaged the top end and that an engine replacement was recommended. That was the only Astro I've owned not equipped with an oil pressure gauge. Had it had one, I wouldn't have restarted the engine. Knowing what I know now, I would have swapped in a new oil pump and let the engine tap into oblivian. Instead it was traded in on a 1994 Astro that I totally abused, which had an oil pressure gauge that saved the engine when it developed an oil pan leak due to driving where I shouldn't have been.

tommudd · **Posted:** Fri Aug 17, 2012 11:27 am

I have had 3 small block GMs that went up into the 250,000 plus range before trading them off with no issues
The 4.3s that I was forced to work on for extended time periods ( one my Step fathers, 2 of my sisters, and one of my Uncles ) all had issues though. Maybe just plain bad luck . Dealership finally refused to work on my Sisters anymore and why I got the privledge :ROTFL:

Give me a 289 Ford/ 283 Chev, slant 6 or 318 Mopar , and I'll be one happy camper :BANANA:

Oh and all 3.7s have aluminum heads etc so no difference there
some changes in design of valves
But whatever I have a set of heads already ready and under the work bench if needed
and know where I can pull an engine from real quick :-)r

ihatemybike · **Posted:** Fri Aug 17, 2012 11:41 am

tommudd wrote:

Give me a 289 Ford/ 283 Chev, slant 6 or 318 Mopar , and I'll be one happy camper :BANANA:

Tom's having engine nostalgia.

TAHOE · **Posted:** Fri Aug 17, 2012 12:13 pm

"I got the privelage" ...now that's funny. Been there, done that.

I could be sour at my SBC's, I'm pulling the 350 out of Tahoe know due to lifter/cam/oil pressure issues for another motor, it only has 131K.
I've had to do valve job on a 304 in our old CJ at under 100K, the 4.0L in a Cherokee started rod knock at 65K, and the 3.7 in Libby is just rough, IMO. I'm just gun shy of the Chrysler motors.
Now talk about the GM 2.8L in the S10 blazers, what a boat anchor that was. :furious:

tommudd · **Posted:** Fri Aug 17, 2012 1:26 pm

Don't even go to the 2.8s :banghead:

what a waste
Well now that I have the discussion rolling along I need to find somewhere else to shake things up :ROTFL:

dieselenthusiast · **Posted:** Fri Aug 17, 2012 9:28 pm

If you love your vehicle, then you don’t mind rebuilding a motor or installing a crate motor for that matter. It’s when you lose passion for your vehicle is when you hate spending money on it. I really enjoy owning all my vehicles therefore I don’t mind spending the extra money if I need to. I do go overboard on maintenance to ensure longevity, efficiency, and reliability. And I think that’s what Tom was trying to point out. If we use the highest quality filters, lubricants and fuel accompanied with adequate change intervals, then those best practices alone might be enough to detour some of these premature breakdowns etc.

I pull a UOA (used oil analysis) at every oil change interval to ensure that the engine and lubricant is doing its job. The UOA also helps me detect other problems such as a head gasket leak, injector failure, etc. These are problems that you can’t see happening unless you are taking oil samples. For example, I realized that my Jeep Cherokee wasn’t getting up to operating temperature during the winter months. My UOA showed higher levels of gasoline in the oil causing oil dilution and a loss of viscosity. If I didn’t notice this potential problem, it’s very possible that I would have developed premature engine wear.

I strive for reliability, efficiency, and durability. Owning a vehicle is either a chore or a passion. For me, it’s a passion, and something that allows me to feel good about owning it, driving it, and most of all, depending on it.

4THEFAM · **Posted:** Fri Aug 24, 2012 8:12 pm

Got 160,000 on our 05 Liberty and am having the first issues EVER with this motor. Its been rock solid and I'm real happy with it. Just replaced the radiator and think I may have a head gasket leak into teh coolant system and the old radiator looks like it blew due to pressure. Not sure but I'll see if a leak down test will answer. If it s , I'll open her up. Heck, a complete rebuild would be fun on this engine. You heard they just stopped making the 3.7? Closed the plant this month I think!

Boomerang · **Joined:** Tue Jul 26, 2011 7:46 pm **Posts:** 184

My heads are being replaced and the vavle system rebuilt. $3k
47k on the mileage.

dieselenthusiast · **Posted:** Mon Aug 27, 2012 11:15 pm

Boomerang wrote:

My heads are being replaced and the vavle system rebuilt. $3k
47k on the mileage.

What year is your KJ? What brand and weight of motor oil were you using?

Engine replacement yes/no

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