I doubt that as a leaking injector would continue to leak at full fuel pump pressure and show up in your fuel trims while running. You could check that though by pulling the fuel rail with all the injectors attached, reattach the fuel line and cycle the ignition on/off a few times and watch them over several minutes. What were your readings from the compression test? All of your symptoms really make me think you have a head gasket in the early stages of failure.

 

It was 125 across all cylinders.

 

Where can I find some diagrams of the back of the engine?

 

Try here:

Wiring Harness, Connector, and Component Location Diagrams

This thread contains diagrams for locating various connectors, components, and wiring through the vehicle. This info was taken from older manuals and will be more accurate for earlier years, though hopefully still helpful for later years too. There will no doubt be discrepancies over the years...

www.jeeppatriot.com

 

Smoke is coming from the areas in green.

 

What does the smoke smell like? Does it smell like fuel, or "kind of" like engine coolant, like the smoke that was in the dipstick tube?

If it smells like engine coolant then it's the head gasket, or a cracked / warped head or block, etc.; something is letting the coolant get though, regardless of the compression test.

 

The first time it happened, the first thing I thought of was that it smelled electrical.

 

Are there any wires or plastic/rubber items touching, or too close to your manifold?

 

I'm not sure, I would have to look. That wouldn't explain the rough idle though.

 

No. probably not... but the smoke and the rough idle could possibly be unrelated.

 

Every time it idles rough when I start it, it will smoke.

 

Under the exhaust manifold is a steel water pipe that feeds water from the pump to the thermostat housing and uses two o-rings on the ends. But both leaking at the same time would be a rare failure. I assume the smoke is coming from below the manifold and drifting up and around it. Does it smell like celery? That's usually what I use to describe the smell of hot evaporating coolant as.

 

I can't recall what celery smells like right now lol. Why would the smoke be happening at the same time of the rough idling? The smoke goes away when it starts running right.

 

To help diagnose a head gasket leak or oil leak around the valve stems try this

Drive on an open road with little to no traffic and accelerate to 45 MPH or faster then take you foot completely off the gas pedal and let the car slow down to 10 MPH, then hit the gas pedal hard to accelerate quickly and look in the rear view mirrors for a puff of smoke caused by a high vacuum in the engine which pulled in water or oil.

The procedure may vary depending an you transmission but the idea is to create that high vacuum for several 20 or 30 seconds and then quickly clear out and burn it off.

 

I can't find any pictures of the rear of the engine where the exhaust attaches. Other than the pics I've posted.

 

 

Have you tried running it with the radiator cap one click loose? This will keep the system from building pressure but should keep leaking to a minimum. If coolant is somehow leaking into a cylinder overnight, relieving the pressure should minimize this and you'll have less rough cold starting possibly.

 

My coolant level hasn't changed in a long time.

 

I also noticed that the two diagrams posted are different. One is 2wd with the small exhaust manifold and the other is 4wd showing the "maniverter" That confused me for some time not knowing there was a difference between the two.

 

I'm just learning this too. I had no idea my catalytic converter was located there.

 

When looking at your coolant level, are you just checking the reservoir bottle or also pulling the cap to check for fluid in the hose? Sometimes the level in the engine can get low enough to break the siphon to the bottle.

 

I had been just looking at the bottle. Should I see it under the cap when I remove it?

 

Yes, you should see coolant under the cap, in the hose. As a reminder, do not remove or loosen the cap while the engine is hot, it could be extremely painful if you do.

 

So what if I am losing coolant but nothing else points to a head gasket?

 

Coolant loss with no obvious external leaks anywhere and white smoke points to a internal coolant leak i.e head gasket, block, head, etc.

Ask your mechanic about doing a chemical test that can find combustion gas in the engine coolant, like this:

Combustion Leak Detector

Amazing deals on this Combustion Leak Detector at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Combustion Leak Detector Fluid

Amazing deals on this Combustion Leak Detector Fluid at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

 

The white smoke out of the exhaust was only one time that I've seen and I've had a compression test done that came back fine.

 

I also remember you saying you thought you might have had bubbles in the coolant.

The test I mentioned above might help find a small leak that's otherwise hard to find.

In any case, it was only a suggestion, you don't have to ask your mechanic about it if you don't want to.

 

I also remember you saying you thought you might have had bubbles in the coolant.

The test I mentioned above might help find a small leak that's otherwise hard to find.

In any case, it was only a suggestion, you don't have to ask your mechanic about it if you don't want to.

No problem. I saw bubbles but nothing like the examples I've seen online. I bought some UV dye to see what I can see.

 

I pulled my cap today on a cold engine and the coolant was right to the top of the opening. I displaced and spilled some when putting the cap back on. I assume from your previous reply the yours was low?

 

I checked my coolant this morning. It gurgled a lot when I took the cap off but I could see coolant in the tube. I added some more just in case.

Andruil, I like digging for information on the Patriot yet I'm finding very little help out there. Sounds like you have several problems which may or may not be related.

You should not see any smoke up front when starting the engine so that indicates an probably exhaust leak for either a gasket, crack, or loose connection.

The rough idle after start... Does that happen each time you start the engine whether it's hot or cold or after 20-30 minutes of resting or only when sitting overnight?

Also what year is you Patriot and what engine do you have in it?

Lastly I can't find any FSM information out there for checking the fuel pressure. Obviously it will pump up to something around 35-45psi (I'm guessing) but then does the pressure stay there or immediately release to a low residual pressure. If there's no pressure in the fuel rail then I doubt very much could leak out of an injector. My YJ holds pressure for 30+ minutes but not sure about the Patriot.

It can go days without starting rough and smoking. The smoke is definitely coming from around the exhaust manifold. I had a rough idle after starting last night when I left work. It had been sitting for about six hours. This time the smoke reminded me of a fuel smell. The electrical smell the first time was after I changed the coil packs. It could have been my mind playing tricks on me or something on the coil packs.

So what we have is a rough idle on starting (only sometimes) which always seems to coincide with smoke from the exhaust manifold. The roughness will work itself out. A compression test revealed 125 across all cylinders. The oil on the dipstick is fine and there is just condensation under the oil fill cap which doesn't really get burnt off because I live five minutes from home and don't travel with it much.

The only codes I have had are the one for the coolant temp sensor (which was replaced) and misfire on cylinder 3. The spark plugs looked fine when I had the compression test done. 2013 2.4.

 

Andruil, I like digging for information on the Patriot yet I'm finding very little help out there. Sounds like you have several problems which may or may not be related.

You should not see any smoke up front when starting the engine so that indicates an probably exhaust leak for either a gasket, crack, or loose connection.

The rough idle after start... Does that happen each time you start the engine whether it's hot or cold or after 20-30 minutes of resting or only when sitting overnight?

Also what year is you Patriot and what engine do you have in it?

Lastly I can't find any FSM information out there for checking the fuel pressure. Obviously it will pump up to something around 35-45psi (I'm guessing) but then does the pressure stay there or immediately release to a low residual pressure. If there's no pressure in the fuel rail then I doubt very much could leak out of an injector. My YJ holds pressure for 30+ minutes but not sure about the Patriot.

 

I can't find any FSM information out there for checking the fuel pressure. Obviously it will pump up to something around 35-45psi (I'm guessing) but then does the pressure stay there or immediately release to a low residual pressure. If there's no pressure in the fuel rail then I doubt very much could leak out of an injector.

Per a FSM, supposedly the pressure is maintained short term but eventually goes to zero.

 

My temp gauge has been creeping up past halfway on short trips around town. It goes back down on its own without turning the heat on. This is after driving it for about 3 miles with a slightly inclined long hill. It's always done this and I'm not sure how normal it is. It did it before on longer drives but now it's only after a short trip. I have new thermostats ordered and plan to do a coolant flush when I change them. The coolant level is fine and I added some UV dye to see what I can see.

I filled it up a couple of days ago and I haven't noticed my gas gauge changing. I also used some seafoam when I filled it up. I only drive about 10 miles a day. It seemed like it was dropping but today when the temp gauge went up, I think I noticed the gas gauge all the way full.

I have no idea what's going on.

 

Any code on the scanner?

Depending on how an injector is stuck, open or closed, it can cause smoke in the exhaust.

 

No, no codes on the scanner oddly enough. I've said this before but my gut reaction is that it's a fuel and timing issue. I give it a little gas and it will straighten out. It has started up fine the last three times I've started it today. I'm trying to find patterns in it's behavior.

 

I took this picture of the back of the engine right below the manicat. I’m not sure what these dark areas are.

 

That does look like a black powdery soot from an exhaust leak, probably the gasket on the manifold and prior to the catalytic converter. After the cat is usually clean like the end of a tailpipe. I wouldn't be surprised if some oil leaked out from the valve cover gasket. That's an easy fix if you find oil on the backside of the engine.

 

I think this is where the water pump attaches to the engine but I’m not sure.

 

This area looks like it's been wet, maybe oil or coolant?

 

I poured a small bottle of uv dye into the coolant and I haven't seen it anywhere. So what could explain the soot?

 

Check engine light came on last night. Cylinder 3 misfire. That’s been the most consistent code. I’m going to replace the coil pack for that cylinder and go from there.