Gabe's FSJ Diary (formally Grand Wagoneer build thread)

[Nikkormat]

More bad news on the Jeep front. My PO didn't like oil changes.

Changed the oil yesterday and the last quarter of what came out was nasty nasty thick sludge, keep in mind it had an oil change 3k miles and 3 months ago. I'd say about as thick as 90 weight. Stuck to my drain pan so bad I used a whole can of carb clean getting it clean. And the stuff that didn't come out like sludge had very fine magnetic material in it.

Threw in a new filter and some cheap 10w30 for a flush and the motor has gotten very noisy. My knock is now very obviously one or more failing lifters. With the thinner oil it's much noisier on startup as the lifters pump up, and if held at a consistent RPM they bleed down and the motor starts to knock and misfire.

I screwed in a mechanical gauge from the hardware store and have verified I still have good oil pressure. So I'm considering throwing a cam and lifters at it just for fun. Do you think that's worth my time if the motor has been filled with nasty sludge? I've got 20 psi hot idle with 10w30, and the cylinder walls look fine on camera.

If not I'll probably end up buying a parts Jeep with a good motor to try and recoop some costs. Ugh. It's never easy.

Also discovered it needs a water pump.

[Cheap Hobby]

Drop the pan and look at your bearings, also you can clean the sludge out as well. How's the sludge build up under the valve covers? Swap the 401 over.

[Nikkormat]

Drop the pan and look at your bearings, also you can clean the sludge out as well. How's the sludge build up under the valve covers? Swap the 401 over.

Haven't pulled the valve covers yet, waiting to pull the pan until I hear back on a parts car with a rebuilt motor.

Swapping the 401 isn't a bad idea. I'm planning to put a transmission in the Cherokee this summer though, if it runs and drives my parents will store it while I'm gone.

[AwesomeJ10]

Swapping the 401 isn't a bad idea. I'm planning to put a transmission in the Cherokee this summer though, if it runs and drives my parents will store it while I'm gone.

You are more than welcome to store some junk here at my place.

[tedlovesjeeps71]

Isn't there an old codger method of cleaning out sludge? I thought there was something about running atf through for a bit... or something like that.?.


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[Cheap Hobby]

Yep at. No more than 2 qts bring it up to temp and shut it off. Drain it while it's hot. Change filter fill with new oil . Some of our old mechanics that would do it would keep a close eye on the new oil and drive the car overnight or weekend and change it again to see how it looks and make sure there were no chunks floating around. If the customer has been using Havolin we passed on trying to clean. If it was cheap high paraffin oil (you could smell birthday cancels with the leaked oil got hot) they would try it once.

[Cheap Hobby]

Yep atf. No more than 2 qts bring it up to temp and shut it off. Drain it while it's hot. Change filter fill with new oil . Some of our old mechanics that would do it would keep a close eye on the new oil and drive the car overnight or weekend and change it again to see how it looks and make sure there were no chunks floating around. If the customer has been using Havolin we passed on trying to clean. If it was cheap high paraffin oil (you could smell birthday cancels with the leaked oil got hot) they would try it once.

[ShagWagon]

Marvel mystery oil breaks up oil sludge.

Put a quart in and drive for a few hundred miles before you change out the oil.

[Greenmachine]

Seafoam. Put it in 100-300 miles before an oil change about half a can for our engines. I don't trust ATF anymore. There is lots of stuff in ATF that wasn't in it when the old timers were doing it.

[Charles Kline]

Replace that water pump and see what it really sounds like. The bad water pump on mine made a super weird sound.

[Nikkormat]

Replace that water pump and see what it really sounds like. The bad water pump on mine made a super weird sound.

The noise is present without the belts and the water pump pulley removed.

But the pulley was bent!

[Nikkormat]

Today, was a long day.

First I researched every redneck shoe string collapsed lifter fix I could find.

Then I pulled the valve covers and rockers, spraying carb cleaner down the pushrod oil passages into the lifters. Under the valve covers there was quite a bit of carbon, but less sludge than expected.

Then I put the whole mess partially back together. Left off the fan, more on that in a second.

Next I added some motor flush, the can of acetone kind, to the crankcase and started her up. Let it idle warm and then ran it like I was breaking in a cam until I got her good and hot. 230° on the gauge.

Then I drained the boiling hot oil. It was disgusting, but came out as one consistency. Let that drain for half an hour while I changed the filter and re installed the fan.

Put in some 15w30 (no that's not a typo) Chevron diesel oil, and two bottles of some marvel mystery oil knock off.

Then I took it for a drive. And shockingly there was a very noticeable difference! The lifters would stay pumped up until you gained RPM too fast. And they'd pump back up after running at a consistent RPM for a while. Woooooo! So there is hope!

So I've ordered a k8600 cam, lifters, and nessecary install parts and I'll tear into the motor hoping for the best. I'll be able to see the cam bearings (which are what concerns me the most) and the front most crank bearing. If they are damaged then I've got a previously running 73' 360 up in Conifer I can dingle ball hone and throw bearings and rings into IF my crank is to rough to just throw bearings at.

[Nikkormat]

Cam, lifters, timing set, water pump, and intake gasket have arrived. The rest should be here soon. Assuming the snow holds off I'll be digging in tomorrow.

[tedlovesjeeps71]

Cam, lifters, timing set, water pump, and intake gasket have arrived. The rest should be here soon. Assuming the snow holds off I'll be digging in tomorrow.

Good luck! I added some sea foam to the wife's waggy hoping it cleans out some gunk and helps it run better. I'm sure I'll be following in your shoes soon with timing chain and water pump.
What cam did you end up going with? How aggressive is it compared to stock?


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[Nikkormat]

I wouldn't call it aggressive, I would call it a good "RV" grind for anyone that likes to shift up around 5500 rpm.

Summit K8600, cam blank is made by CWC Textron in Michigan. Same people made the factory camshafts.

https://m.summitracing.com/parts/sum-k8600

And just btw... These are the ONLY AMC timing sets worth a damn anymore. Cloyes 1118 and 3118. Made in the USA, true roller, and they have the correct placement and number of oil passages.

https://m.summitracing.com/parts/clo-9-1118

https://m.summitracing.com/parts/clo-9-3118

I have the 3118 in my 401. It lined up perfectly with the oil hole in my speedpro/melling mta1 cam the rebuilder insisted I run and after 15k miles of daily driving and shifting as high as 6000 rpm driving like a jackass in low range it showed very little slack when I poked at it through the fuel pump hole.

The 1118 is the same crank gear and chain, with a weaker casting cam gear. Still way overkill for any motor I could build though. It lined up perfectly with the summit cam and is just as high of quality as the 3118. Almost half the price, too.

[tedlovesjeeps71]

Good info^^ thank you!


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[Nikkormat]

Good info^^ thank you!


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No problem! I'm glad my research could help someone.

[Nikkormat]

Blake runs a K8600... You can see it's tourqe demonstrated till 2:30, and it's top end power (admittedly breathing through a 380 CFM throttle body) after that.

https://youtu.be/589tcFg043o

[Nikkormat]

Have to wait to tear into it, again. We finally got some snow!

[Charles Kline]

Yeah we are!!