Engine Sputtering, Lacking Acceleration and Power... Can it be the Exhaust?

[mudwisr]

Hello,

This is kind of related to my previous post. I am trying to get my 99 TJ back to good health after a rough mudding trip. I had hydrolocked my engine and managed to turn it over and get it running again. Mud was definitely in the engine and in the oil. So far I had changed the oil, oil filter, and air filter. I also put fuel injection and intake cleaner with 3/4 tank of gas fill up.

As if things couldn't be any worse, the pipe between the catalytic converter and the muffler broke. I removed everything from the catalytic converter down to the tailpipe. Right now I just have a rusted catalytic converter.

My symptoms are engine tempereture rising faster than normal, engine temperature redlines after idling for about 30 min, engine sputtering and hesitation which only seems to happen after several minutes of driving, when the engine temp is right around 210. At this point the sputtering is intermittent, more sputtering than not. Check Engine light is not on.

My question is could it be just my exhaust system thats causing my engine to be sluggish, hesitation and sputtering, and lack of acceleration? Could it be because I dont have a muffler connected to the catalytic converter? Could it be a bad catalytic converter? I am just hoping that nothing is wrong with my engine, although it did suck in some mud through the air intake. I hear no knocking, engine seems to sound ok on idle. Today I am planning to put engine cleaner with my oil and replace the oil and oil filter again. I already ordered a dynomax cat back, should I be thinking about ordering a catalytic converter too?

Thanks in advance for your suggestions and comments.

 

[jay79cj7]

Your temperature problems might be due to the radiator being plugged up with mud.

 

[mud4feet]

Might check the downstream O2 sensor while you're at it. A bad sensor will cause some REALLY bad engine performance.......though it would trip the check engine light. Just a thought.

 

[Saurian]

Hate to be the bearer of bad tidings, but the O2 will not *always* throw a check engine light, so it's hit or miss on that one, but I totally agree, that would cause very poor performance.

I second the thought on the radiator... It took me three months of nearly daily hosing out to get the darned thing working properly again, just when I thought that my overheating problems were over, it would blast off to the nether-regions of the gauge. If you hit a mudpit at any good speed, that radiator is probably a solid block of stucco...

Best of luck in the repairs... You're not hearing a knocking, that's very good. Have you listened against the block with a broomhandle or something like that, it's a very good way to hear what you might not otherwise be able to. Is there coolant in the oil, or oil in the coolant, thick white smoke pouring out while driving, that sort of thing, if not, I'd say you got good and lucky

Oh yeah, and did you change the plugs and/or distributor cap and rotor? If mud made it into the intake, and got into the engine, the plugs are probably fouled up pretty bad. Just a thought, again, best of luck to you.

Oh yeah, and the exhaust missing can't be helping... I don't know specifically how much that affects things, but I know that every vehicle I have ever driven has run *much* better after an exhaust leak was fixed than before.

 

[mudwisr]

Thanks a lot guys. I'm gonna go ahead and clean up under the hood, everything is brown in there. No smoke or anything like that. O2 sensors are probably the thing to check after getting the muffler installed. Thanks again.

 

[jfrabat]

Mudwisr,

I had similar problems with sputtering in my 94 2.5L some time back, and it turned out to be mud in the fuel system. It ONLY acted up when the weather was hot and the engine warmed up (still dont know why!), but when I took doen the fuel tank, there was some mud there (nut much, but some), and in the fuel rail and the injectors, it was REALLY bad (so the injectors were clogged up). Just to be on the safe side, I replaced the fuel pump, fuel filter, injector rail (it had broken anyway), fuel pressure regulator and injectors all at the same time... And there has been no sputtering since. By the way, the mud had gotten into the fuel system by means of one of the two hoses that are on the top of the tank which was unplugged (I think they call them "roll-over hoses" or something like that, but not sure).

But I would DEFENETELY go the cheap way first and check:
1. For mud in the radiator and fluid level
2. That the fan is working properly (the cluth, that is)
3. Changle plugs and distributor cap and rotor
4. The O2 sensor (I thik in the TJ there is two, but not sure; only 1 in the YJ)

You could take the injector rail out and check for any signs of mud, as it is really easy to take out and check... Then you dont change it if you do not need to. Anyway, hope everything comes out fine AND CHEAP!

Just the 2 cents of a rookie Jeeper!

Felipe

 

[redrooster]

Sounds like the catalytic converter to me. Is it possible that your broken exhaust let mud into the catalytic converter?
Unbolt what is remaining of your exhaust and see if you can determine if it is clogged. Might be able to test it with a hair dryer to see if it flows well.

 

[mudwisr]

I wouldn't be surprised if mud got in the catalytic converter. As soon as I got pulled out of the mud pit, the pipe between the catalytic converter and the muffler was already cracked.

Also, A question regarding O2 sensors. I looked up the topic a bit and can't seem to find where the upstream and downstream O2 sensors are located on a 99 TJ. I saw some pictures and I'm guessing it would be that wire connected to the catalytic converter? Is that the downstream or upstream? Which one should I be replacing in my situation?

Thanks again.

 

[mud4feet]

On my '03 4banger, the upstream is in the engine compartment (in the exhaust manifold), the downstream is in the exhaust pipe between the catalytic converter and the muffler (if memory serves). If there's a wire coming out of your converter, I would guess that would be it.

 

[mudwisr]

Just wanna say thanks again to all of you for your replies.

To be on the safe side, and assuming my engine is fine, I'm moving forward to replace the entire exhaust system starting from the cat converter and the o2 sensors. Ive been driving it 10 mi a day for the past week and the only problems I have noticed are the lack of power on acceleration accompanied by occasionaly sputtering, and engine temp rising too fast. Hopefully the new exhaust system will restore the power. Almost everyone I talked to says a bad cat converter can cause poor engine performance. I still have to get all the gunk out of the radiator, which probably is causing the engine temp to go up so fast. After all that is done, I'll go with replacing the distributor cap, rotor and plugs.

Wish me luck.

 

[mud4feet]

Good luck!!! And keep us posted!p0p

 

[LauraBoston]

Could be anything. If you got a IR thermometer check the bottom of the radiator see if it's getting hot..if it's not probably got a clogged radiator.

On the other hand, I disagree, an o2 will always set a CEL, it's emissions related.

A cat will mostly cause poor engine performance during acceleration, and it could smell bad. I hope cat and exhaust fix your problem.

One more thing h20 and engine don't mix.

 

[mud4feet]

..........an o2 will always set a CEL, it's emissions related.......

That's what I thought. And, yes, H2O and engines don't mix very well..........probably why they went away from internal combustion submarines.:lol: :lol: :lol: :lol:

 

[redrooster]

I still have to get all the gunk out of the radiator, which probably is causing the engine temp to go up so fast. After all that is done, I'll go with replacing the distributor cap, rotor and plugs.

Wish me luck.

Replace the exhaust sytem, but try to reuse your O2's. They are expensive and may be fine. You will get a check engine light if they are not.
Driving 10 miles a day when you know that you have engine issues isn't good. Take 10 minutes to hose out your radiator and another 10 to knock a few holes in your catalytic converter until such time as you can get it replaced. If you are going to replace it anyway, then it won't be a loss, but will free up some air flow and possibly save your engine.

 

[mudwisr]

Ok here's an update.

Totally new exhaust system.. new cat converter, o2 sensor, and muffler.

Finally got the mud off the radiator so my engine temp is somewhat closer to normal now, although the temp still rises a bit too fast in my opinion (10 minutes of driving and its up to 200 already)..

One problem remaining.. When the engine warms up close to 210, everything sounds ok if I just press the gas pedal less than half way to the floor, but when I press it down a bit more it sputters and loses acceleration. It's still a bit sluggish.. the exhaust smells terrible but maybe it could be the fuel injection cleaner I mixed with the gas.Last night there was some smoke coming out of the exhaust when the temp was around 210.. it was grayish transparent.. not thick and white, though its clearly visible.. Today I started it when I got home from work and no smoke out of the exhaust..

My buddy told me I could have a couple bad cylinders. My question is am I showing signs and symptoms of having a bad cylinder(s) and if so, how do you get them working again? He told me I can just take the valve cover off the engine and clean the cylinders. Another buddy told me to get my engine flushed.. I'm just a bit confused.

Thanks in advance for any suggestions.