Hippo misfires!

Well, it started again. As some of you recall, I had the coolant boiling on wife's 2002 V6, and the stat, recovery bottle with cap, and intake manifold gaskets were replaced. All was good for about a week, and the wife was happy (happy wife=happy me!).

Last night she came from work in panic. Hippo runs like "crap", she smells gas, and at idle there is a cloud of black smoke behind her! Me thinks NOT good.

Pulled the scanner out this morning, and got crapload of codes:

P0300 (multiple cyl misfire)
P0302 (#2 cyl misfire)
P0303 (#3 cyl misfire)
P0304 (#4 cyl misfire)
P0305 (#5 cyl misfire)
P0270 (#4 injector low circuit)
P1472 (that I was not able to identify)

All electrical seems to be OK, with the exception of the inop windshield wipers!! (they worked fine before all this)

I erased the codes, started it (starts fine), and it idles rough, with the strong gasoline smell around. Turned it off, and pulled the codes again. Hippo reported two this time:

P0304 (#4 cyl misfire)
P0270 (#4 injector low circuit)

So,.....I would appreciate if someone with the specific knowledge chimes in, and explains this to me. Without inop wipers, I'd suspect cracked head (inop coil, bad plug, dead cylinder, etc.), but even the coolant is NOT overpressurizing, and it's at the same level where it was after bleeding last week.

So what do you say Hippo wranglers? Where should I start on this, or should I step up the efforts to rebuild the other engine I have, and forget about this one? Inop wipers are pointing me to the electrical issue, but I am not sure at this point. I've been working on cars, bikes, and airplanes since the 60s, and I NEVER saw misfires in connection with windshield wipers.

Thank you all in advance.

First thing I'd do is whip out all the plugs and give the engine a compression test. While the cover/ filter housing is off, check for pinched wiring to the coils and injectors.
If the compression pressure is over 180psi and all cylinders are within 10% of each other, all is well.
It's well worth checking fuel pressure too. I've just replaced my fuel pump as it was shot at 42K miles.
The injector out of spec could be a wiring issue. Failed injectors are not common, but do happen on occasion.
Edit: The wipers could be a red herring but it is curious why they would fail at the same time.

The odor of the unburned gas, is telling me that #4 is not firing, and it's dumping the fuel into the exhaust manifold (hence the smell and the smoke). This (in my mind) eliminates fuel pump. Wife says there was no warnings of any kind, except "service engine soon", and the whole thing happened a week after the stat replacement, which would eliminate broken wires. If something was broken on install, it would show immediately.
Pinched wire might be a possibility. Pinched on reassembly, and after a week, it rubbed through.

As soon as the weather lets up a little, I'll dig into it. Thanks for your help.

Nodge68 said:

First thing I'd do is whip out all the plugs and give the engine a compression test. While the cover/ filter housing is off, check for pinched wiring to the coils and injectors.
If the compression pressure is over 180psi and all cylinders are within 10% of each other, all is well.
It's well worth checking fuel pressure too. I've just replaced my fuel pump as it was shot at 42K miles.
The injector out of spec could be a wiring issue. Failed injectors are not common, but do happen on occasion.
Edit: The wipers could be a red herring but it is curious why they would fail at the same time.

Click to expand...

If the compression test comes out good, check fuel pressure. Your 2002 Freelander may be covered under a factory recall LR put out (check dealer).

I would also do a leak down test and a combustion gas test before taking anything apart. Since you are in the USA the testing equipment is dirt cheap at rockauto amazon or harborfreight.

That many misfire is strange. Were you very careful with the knock sensor wire when you replaced the thermostat sensor ? I basically wrapped every wire in silicon tape (from home depot ) when I did mine.

zefrench said:

I would also do a leak down test and a combustion gas test before taking anything apart. Since you are in the USA the testing equipment is dirt cheap at rockauto amazon or harborfreight.

That many misfire is strange. Were you very careful with the knock sensor wire when you replaced the thermostat sensor ? I basically wrapped every wire in silicon tape (from home depot ) when I did mine.

Click to expand...

I guess I'm lucky that I have more than few vehicles, and no repair/diagnostic is ever urgent. I've spent few days thinking about it, and devising the plan of attack. That said,...all of us in this post were right! Nodge68,.....yes, the wipers are a "red herring" (no connection to the rest). Zefrench,....yup, I was not carefull with the wires. And my deduction about the pinched wire was right on the spot too!

Took everything apart, and found out I've made a beginner's mistake. Injection cable on #4 I routed ABOVE the fuel rail, instead of UNDER! I had phone calls, dogs, and horses interrupting me while I was reassembling everything last time, and somehow I overlooked this! (that's my excuse anyway ). Intake was sitting on the cable, and all worked fine for a week. After a week of driving (rubbing, and pinching), the intake went through the insulation, and shorted the cable. Injector stayed open, and sprayed the fuel out of control. That explains P0304, and P0270 (codes that reappeared after the reset). Why she was misfiring on multiple cyls, I have no idea. Maybe the old Hippo just wanted to stress out the urgency of the pinched wire, and how much it hurts him to have a pinched nerve?

Anyway,......all done, Hippo purring, wife happy, and I have no clue about the wipers! Now I need to work on wipers, and I would appreciate if someone could tell me exactly which fuse, and which relay control the wipers?

Thank you all.