hit 320K, p0300 back... with a broken rod?

[mightybeet]

p0300 came back, brought it to firestone(right across the street from apartment) and after a day and half trying to figure out the random misfire they found a broken rod.

so now i have to make a tough decision, new/reman engine or say goodbye.... anyone recommend a good engine replacement with transmission?

 

[dude1116]

I mean...the thing doesn't owe you anything.

That being said...everyone always says, it's cheaper to fix up then buy new. (Or used!)

 

[TwoBobsKJ]

p0300 came back, brought it to firestone(right across the street from apartment) and after a day and half trying to figure out the random misfire they found a broken rod.

so now i have to make a tough decision, new/reman engine or say goodbye.... anyone recommend a good engine replacement with transmission?

Wait a minute...

A misfire and a broken rod do go together (sorta) but a broken rod would almost certainly blow the engine - either out the side of the block or other noticeably nasty ways. A broken VALVE stem would create a misfire and as long as the valve stayed in the head and didn't drop in the cylinder you'd have a dead cylinder but you'd be able to drive it...

Now, if the engine is shot then it depends on how much you enjoy your KJ. 320K on the clock is a lot of miles but if the body is in decent shape and other mechanicals have been maintained then a new/reman engine is a decent investment. In my opinion, replacing the engine is a reasonable expense if you like the Jeep. Because by the time you put a down payment on a new/used vehicle, consider the increased insurance rates of a newer vehicle, monthly payments, etc, then $3000 (on the high side) for a replacement engine is a good deal.

Personally, until the body falls off my KJ I will drive it till I'm not allowed to drive anymore. I've put in a new engine and the $1500 it cost me is less than 6 months worth of payments on a cheap new car - and it wouldn't have near the fun or capability of the Jeep. I'd do it again in a heartbeat :waytogo:

Bob

 

[mightybeet]

Wait a minute...

A misfire and a broken rod do go together (sorta) but a broken rod would almost certainly blow the engine - either out the side of the block or other noticeably nasty ways. A broken VALVE stem would create a misfire and as long as the valve stayed in the head and didn't drop in the cylinder you'd have a dead cylinder but you'd be able to drive it...

Now, if the engine is shot then it depends on how much you enjoy your KJ. 320K on the clock is a lot of miles but if the body is in decent shape and other mechanicals have been maintained then a new/reman engine is a decent investment. In my opinion, replacing the engine is a reasonable expense if you like the Jeep. Because by the time you put a down payment on a new/used vehicle, consider the increased insurance rates of a newer vehicle, monthly payments, etc, then $3000 (on the high side) for a replacement engine is a good deal.

Personally, until the body falls off my KJ I will drive it till I'm not allowed to drive anymore. I've put in a new engine and the $1500 it cost me is less than 6 months worth of payments on a cheap new car - and it wouldn't have near the fun or capability of the Jeep. I'd do it again in a heartbeat :waytogo:

Bob

they said rod but going to talk a little bit more on how they figured that out other than noise and not finding anything else. there is a click but nothing like a knock and that click has been going for sometime now.

it idles fine under 2800 rpm. once it hits 2800+ rpm is when the CEL starts flashing and engine sputters. stops sputtering when i let off the gas.

 

[LibertyTC]

Pull the valve cover off on the tick/clicking side and have a peak in there, if may have just thrown a rocker.

 

[ltd02]

Pull the valve cover off on the tick/clicking side and have a peak in there, if may have just thrown a rocker.

I'd second this! That's similar to what mine did the three times I dropped the #2 exhaust rocker. BUT, I did get a code for a misfire on #2, not just a p0300. Last time I put in a new lash adjuster and no issues since. Of course now I just jinxed myself :gr_grin:

 

[renegade 04]

If the CEL ever flashes that means you have a major problem.

 

[mightybeet]

talked with them and didnt really get any additional info other than they heard a knocking and they concluded it was a rod but not sure which. of course the engineer part of me wont accept this.

cel is on constant with new codes all pointing to plugs, coils, and sensors (see list below). they were not there before i dropped it off and must of come up while they were diagnosticing. i ll also check the rockers as all have pointed out.

new codes:
p0300 stupid code
p0301 cylinder 1 misfire
p0303 cylinder 3 misfire
p2302 ignition coil "A" secondary circuit
p2308 ignition coil "C" secondary circuit
p2317 ignition coil "F" secondary circuit
p0138 O2 sensor circuit hight voltage bank 1 sensor 2
p0032 HO2S heater control circuit high bank 1 sensor 1
p0052 HO2S heater control circuit high bank 2 sensor 1

 

[dude1116]

If the CEL ever flashes that means you have a major problem.

That just means the engine is missing and you are possibly adding additional wear and tear to your Cats.

 

[mightybeet]

regular mechanic looked and found the knocking coming from the drivers side catalytic converter. he unbolted it and the knocking went away. he ran a camera thru and found it all clogged up with 320K miles of crap(still on the original exhaust). explains the driver side related misfires.

...those walker cats any good?

 

[TwoBobsKJ]

regular mechanic looked and found the knocking coming from the drivers side catalytic converter. he unbolted it and the knocking went away. he ran a camera thru and found it all clogged up with 320K miles of crap(still on the original exhaust). explains the driver side related misfires.

...those walker cats any good?

I thought the broken rod diagnosis was - shall we say - dubious :mexsmoke:

You'll get all kinds of opinions on aftermarket vs Mopar cats, but I installed two Walker cats 2 years and about 90,000 miles ago and they're perfect. Never had any codes and they were installed on the original engine and the one I swapped in about 60,000 miles back.

They worked for me, your mileage may vary.


Bob

 

[JeepJeepster]

Isnt that something? Went from a broken rod and needing a new engine to a clogged cat... Mechanics are.... Well, scary.

Think of all the people that had a new engine put in, or scraped the vehicle and bought a new one. Pitiful.

 

[JasonJ]

Any time we thought there was a a damaged con-rod when I worked at the dealership, we pulled the damn oil pan to look. You can see if a rod is bent or broken very easily by putting your EYES ON IT.

A broken connecting rod in a running engine doesn't just make a "knock" sound. It sounds instead like Thor's hammer smashing about inside a cast iron pot after a bad night with the Hulk.

 

[southernwake]

I mean they were firestone mechanics. Not all of them are bad but I have dealt with some that were not very good at the whole mechanic thing. There are some people out there that are just not good at diagnosis and then again there are some places that just like to prey upon people without mechanical knowledge. Its unfortunate.

 

[turblediesel]

My Alfa Romeo's bad rod made this sound:
bbbbbbrrrrrrrRRRRRRR POW! RRRRRRRrrrrrrb.

The hole was hiding behind the starter.

 

[mightybeet]

got the walker cats installed, kind of... (bring on the "see? ya should of gone with the OEM cats") the combo of v clamps and cat flanges diameter maybe 1/16th in less that the manifold makes centering the best excuse to verbally express yourself in new found ways. i got the passenger side done without leaks but keep getting a leak on the driver side. anyone ever use copper rtv or a thin gasket on the flange?

if you decide to get walker cats, go to walker exhaust site first and get the part numbers before buying online. i see a lot of sites stating you need addition gaskets that dont apply to your jeep.