4.7L HO Grand Cherokee with combustion leak - what to do?

fasteddy47

Adventurer
Not sure of the .00002 micron rating on the Mopar filter, everything I read was 20-30 micron. Particles in smoke are about 1 micron ( like carbon) for comparison so .00002 would let nothing pass through, including the oil. Mopar are made by Champion Labs in West Salem, Illinois. ).

00002 is 20 microns.....

I have cut about 20 oil filters down in recent months to do a comparison. The best bang for the buck...and the heaviest filter....thicker base plate and more pleats is the Mopar from what I have cut thru so far. After seeing at least 10 or so 4.7 Grand Cherokee's , Durango's and 4.7 Pick Up's loose the bottom end in the last year at our Dealership......all of the Tech's agree..... it is a dirt or grit problem with 4.7's.

Any 4.7's that have come apart and been well maintained have no babbitt issues on the rod or main bearings... any that have come in knocking seem to have lots of tarnish and black sludge throughout the oil galleries..... and the babbitt is gone off the rod bearings. This isn't an oil pressure issue with this engine... it is a service issue.

I told One customer complaining about having his 4.7 go out in his Ram 1500 after 45,000 km's that he changed the oil too much.... His reply..... "I've only changed it like 3 or 4 times"......
 

fasteddy47

Adventurer
interested in part number for that special filter, the only one i have is 5281090... and the local parts counter guy would look for a piston return spring in the computer for an hour if i let him, so he's no help.

You can use 5281090 or 5281090AB

Both same the AB is less $$$'s..... by some change.....
 

fasteddy47

Adventurer
awhat do you guys think of the filters with "anti-drain back valves"? marketing hype, or useful technology?

If you could somehow build a prelube system that primed the engine to 20psi before it started.... you would probably get about a million km's out of an engine. The startup is what kills it...the first few "Microseconds" without Oil Pressure. But if manufacturers did that.... they wouldn't sell any parts.... or new cars...
 

BlaZeJeep

New member
Ah my mistake, read one thing...thinking another...HA HA. Hope you get your WJ going soon. I have followed your build over on Jeep Forum as well. Keep up the good work!
 

OverlandZJ

Expedition Leader
Hope the Promar engine works well for you.

FWIW i had a great experience with Jasper after one of their engines failed after 2 years and 20K miles. That was better than a decade ago however.

I just swapped in a rebuilt 4.0L to the wife's WJ, another victim of the piston skirt breakage.

Look fwd to seeing this back up and running.
 

fasteddy47

Adventurer
hey fasteddy - how do i prime it? do i need this: http://www.hawkinsspeedshop.com/mop...ing-shafts-oil-pump-primer-mopar-v8-each.html

and where does it go, i don't have a distributor hole do i?

thanks for the help!

No distributor hole. Pull the fuel pump relay or mega fuse..... put a charger on the battery..... Spin it over until the Oil gauge bumps up.... Plug the relay back in and fire it up. Make sure you have a second pair of hands... One to burp and top off the rad...and one to keep the RPM about 1800 for the first 20 minutes . After an hour when it's good and hot drop the oil and filter and refill it with fresh oil. Let it heat soak until it's cool again, then fire it up and run it as long as you want.

The expansion contraction ....cooling off period seems to help the rings seat better. I have noticed this on both cast and moly rings. The 4.7 is such a great little engine...it's too bad about the sludge and bearing problems.

I use straight synthetic now as it leaves no visible varnish or residue....or at least takes longer to build up. Pricey oil changes every 3000 mile or 5000 km's but cheaper than a rebuild!!!!

I think I am going to stuff one of those Griffin triple core aluminum radiators in mine... Pull the hydraulic fan and revert back to some Taurus electrics on 190 degree sensors. I keep hearing how these motors need to run hot to be efficient.... I think that running them hot makes for some gasket related failures in the long run. I would rather run it cool and worry about setting off O2 codes than worry about puking a head gasket.

Like you I want to go on some extended trips with my Jeep.... But I keep my eye's glued to the temp gauge... Makes me to nervous to drive it in the middle of no-where without another vehicle along....

Maybe that comes from working in a dealership and watching the Tow trucks come in day after day :ylsmoke:

Cheers
Eddy
 

Bodo

Adventurer
Following your engine swap on the other site. Why are you removing all of the accessories before removal from the truck and before the replacement gets there? I find it easier to pull the old one, put it on the engine stand and swap everything over when the new one arrives. That way you can't forget where anything goes or lose that odd bolt...
 

theksmith

Explorer
Following your engine swap on the other site. Why are you removing all of the accessories before removal from the truck and before the replacement gets there? I find it easier to pull the old one, put it on the engine stand and swap everything over when the new one arrives. That way you can't forget where anything goes or lose that odd bolt...

cuz the vehicle is the only engine stand i have! ;)

and i'm doing everything i possibly can up till the last minute when the new engine comes, then i'll borrow a cherry picker and do the actual swap in one day. then i'll put everything back together over the next day or so.

also, it's very hard to get to a few of the wires and connectors and remove the harness without removing some of the accessories.

i put every accessory's bolts in a labeled baggie, so that's not a concern. and i wrote down the order i removed everything and will just reverse it to put it back together.
 

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