2000 Jeep 4.0L 107k mi; coolant intrusion after rebuild

[psdtdi]

I have a 2000 Jeep 4.0 I-6 that has an engine rebuild at 107K but they used the original head not knowing that the 2000-2001heads are prone to cracking. I bought the Jeep at 117K so 10,000 miles after the rebuild, sent in a UOA which came back with high levels of coolant contamination. Found a crack in the head letting coolant into the oil. Replaced the head with a Clearwater and changed the oil. After 175 miles I sent in a sample, potassium was down from the initial 1879PPM to 139PPM. Changed the oil again and drove 700 miles, sent in a sample, potassium was down to 42PPM, changed oil, drove another 700 miles, sample came back at 26PPM. Changed the oil again, drove 1,000 miles, sample came back at 26PPM again, so no improvement this last time. I was careful to get the oil very hot before each drain, and let it drain completely even jacking up the front once it stopped draining to get everything out of the pan which resulted in another ounce or two. The filter was also replaced each time.
So I'm asking anyone who has been through this scenario is this normal to see the contamination level off like this?
Note: I did change brands of oil this last time to Quaker State All Mileage 10W-30 conventional, I had been using Valvoline Synthetic 5W-30 before that.

 

[atikovi]

What is a normal potassium count and what harm can having 26PPM cause?

 

[fantastic]

Your coolant issues have been repaired. The remaining Potassium contaminate is harder to remove but will SLOWLY reduce over the long haul. You're fine running a 5k interval & no longer need to sample every 700 miles.

 

[psdtdi]

What is a normal potassium count and what harm can having 26PPM cause?

Normal is about 4PPM and I'm not sure how harmful 26PPM is, I do know that my earlier numbers led to high wear metals as well. Iron is still slightly high on this last report.

 

[psdtdi]

Your coolant issues have been repaired. The remaining Potassium contaminate is harder to remove but will SLOWLY reduce over the long haul.

Thanks. Should I try any flushing with my next oil change, like Rislone or even kerosene?
Whoops I didn't see your edit in time : so it sounds like I don't need to worry about 26PPM in your opinion.

You're fine running a 5k interval & no longer need to sample every 700 miles.

 

[fantastic]

Thanks. Should I try any flushing with my next oil change, like Rislone or even kerosene?
Whoops I didn't see your edit in time : so it sounds like I don't need to worry about 26PPM in your opinion.

No need to worry & no need to use any additives. Your Jeep will process out the rest of the hard to remove potassium over time with oil changes. Motor on & enjoy your new used cherokee.

 

[psdtdi]

No need to worry & no need to use any additives. Your Jeep will process out the rest of the hard to remove potassium over time with oil changes. Motor on & enjoy your new used cherokee.

Thanks. It's actually a Wrangler TJ but same engine as the Cherokee.

 

[Chris142]

Ya some 0331 heads cracked just below the oil fill cap. I would not do 5k oci in this engine regardless. A uoa I sent in using a high quality synthetic oil showed the oil was done for @4400 miles on my 2002 tj.

 

[psdtdi]

Ya some 0331 heads cracked just below the oil fill cap. I would not do 5k oci in this engine regardless. A uoa I sent in using a high quality synthetic oil showed the oil was done for @4400 miles on my 2002 tj.

Ya my conventional 10W-30 also showed out of viscosity range after just 1,000 miles, SUS @ 54.6 and cST @ 8.64. I am thinking of going back to synthetic or even a 10W-40 since I live in the desert. Those 110F days with the AC running really get the oil hot.

Is your F-250 a 6.9 diesel?

 

[Chris142]

Is your F-250 a 6.9 diesel?

Yes. Gutless no turbo with a t19 and 3.55 gears. Won't pull a noodle out of a bowl lol

 

[psdtdi]

Yes. Gutless no turbo with a t19 and 3.55 gears. Won't pull a noodle out of a bowl lol

I had a 1983 N/A with a T-19 and 4:10 gears with limited slip. Drove all over the US with a big Lance camper and to the lakes with camper and boat. Then later used it for a work truck. Pretty much just kept going as long as I kept pouring oil in it. Fuel mileage was pretty good. I would always take off from a red light by popping the clutch in granny to get it rolling then hit second, it kept the smoke to a minimum.

 

[cptbarkey]

Nice. If it was blackstone, they might like to interview you on their podcast. Good stuff.

 

[himemsys]

When I had a head gasket leak fixed, it took about 5000 miles before the potassium and sodium levels returned to normal on UOAs. But iron took a lot longer to drop (from machining the head). Something like 15000 miles before iron levels started approaching normal.