Bought a 88 comanche... Guy said he over heated it... It runs but is knocking like crazy... Whats my best bet here? What normaly goes wrong when this happens? Bent valves? Rods? Springs? Rockers? What is it normally on a I6? Also whats the best way to troubleshoot which it may be?

Theres no milky crap under the cap so i dont think it was from a blown head gasket... Either lack of oil change or just was out of water...

I know how to fix any of these just not the best on troubleshooting internal problems... Looking to at the most ordering a head and stock parts... ill sell it as is before i go buy motor though... Dont have time for all that right now... Lol thanks guys

 

Check your oil see if there is antifreeze in it. If there is antifreeze in the oil chances are you have bearing issues.

 

With the bottom end yeah... Ill check it when i drain it but no signs of a blown head gasket yet

 

Understood it was overheated, might check those bolts into the torque converter anyway. (if it has one). Not a bad idea anyway on GP since that seems to be a common problem. Good luck!

Also once my top starter bolt was hitting the toque plate.

 

Its most deffinately the motor knocking... Fo sho! Thanks though...

 

Pull plug wires one at a time. If the knock stops, it's a rod bearing on that cylinder. I still wouldn't dismiss torque converter bolts to flexplate if it's an auto. What's the oil pressure gauge show?

 

weelllll let me hold onto my last statement now... pulled the valve cover and started her up... didnt sound like it was coming from the head... all the rockers seem tight like they should be... when running the rods were spinning around and around which to me if one was bent bad enough it wouldnt do that... plus i was kinda watching them spin around and none looked warped...

so i need to look at these just incase since they really are pretty common... oil looks a bit old but not horrible... no signs of milky residue or muddy oil...

i turned it off then thought i should get under it running and listed... well it wont start back up now... go figure... tried hitting it with starting fluid and nothing... so its something electrical... sucks because the last thing i wanna do is put money in getting something running that may never be running right for me... lol..

 

oil is pumping to the top i saw with the cover off... its got the cluster with all the lights... oil pressure light... overheating light... yatta yatta...

 

i hope that ill come home from dinner and itll just start right up again... lol

 

nope... bolts are tight... it really doesnt sound that horrible of a knock... oil looks good... full... i dunno... right now i got another problem i need to get right... may play a part i dont know...

also i tried pulling a couple plug wires to see what it would do... i pulled two different wires before it shut off... it actually didnt do a thing different? just kept running like it was... lol... frickin weird...

heres what ive found with the new problem that i gotta get right first...

https://www.cherokeeforum.com/f2/new...0/#post1253347

 

I think he meant to pull them one at a time. (then put it back). If it' a rod bearing the knock will be gone or allot quieter while it's not firing. Also with a tack. you can take notes and call it a "dynamic compression" test. The stronger cils will cause a higher RPM drop, the weaker ones, less. Glad you got her goen again. Mine knocks a bit on multy grade, but is OK on straight WT Castrol 30 W. (over 260K). It doesn't get that cold here and I make sure to give it a minute when it is.

If pulling two wires didn't change it you might check your firing order?

 

i didnt mean i did them at the same time... i know how to check for a misfire... same way... i meant in doing each of the two wires the RPM's never changed... it never did anything... stayed like i never pulled a wire... its not running again and wont till tomorrow... gonna swap the CPS out... it may be knocking all kinds of funny because its firing all kinds of funny... possible...

 

Oh! Gotch'ya. When you said you pulled two before it quit I misunderstood. I should but out and leave you with cruiser and these other capable folk. Two together can be a head gasket or two anywhere could be the wires are switched.(153624) Good luck! D.

 

say what? 2 together? and naw your good man... i may have typed that where it could have been read two ways... happens alot... any help is good help...

 

Yea, well Ive seen more than a few, mostly 4 bangers myself, where the gasket went between two cylinders taking them both out. (usually in the middle). Sounds like your busy getting your electrics straight but a compression test gives that one up easy.

Hate when I have spark and fuel and it wont run. I think I've flooded it more when I was flooded!