2001 4x4x4 with 161K miles


Few days ago, she started running rough and blowing smoke from exhaust. Limped to Advance Auto and ran checked codes. Got P0300 (explains rough running) and the code for O2 sensor on drivers side. Always thought these only had 2 sensors but learned that its actually 3...


Replaced sensor (bank 1) and the sensor before the cat. No luck...
Remembered last year when I did cap, rotor and plugs that I didn't do #3 plug. Replaced #3 plug and new wires yesterday. Running better but still rough idle and smoking from exhaust.. lots of moisture from pipe too.


planning to replace plugs again but would like advice from the gurus here first...


Some are suggesting that fuel pump may be bad...


Any help would be greatly appreciated!!!

 

Have you noticed any loss of coolant? A blown head gasket can cause the issues that you're having. A cooling system pressure test and/or emissions 'test' of the cooling system (i.e. near the opening of the coolant over-flow tank) may be in order.

 

No loss of coolant...

 

That's very good news.

What color is the exhaust smoke? Blue tends to indicate oil burning (valve guide seals, rings, etc) while white = coolant entering one of more combustion chambers due to int. man. coolant leak, bad head gasket, etc.

Meanwhile, double check the ign. rotor and cap for corrosion and that both are snugly screwed down (you've likely already checked this tho). Just keep in mind that the plastic ign. dist bodies on these vehicles are known for failure due to excessive shaft bearing play and gear wear. The rotor blade should not rotate left to right more that the width of the blade itself while pushing lightly down on the rotor. Another problem with these distributors is that the cap hold-down screw lugs are known for breaking (which will, of course, allow the cap to move out of place enough to cause rough running or worse).

 

So I installed all new plugs last night....she starts up great but there is still rough idle and smoke from exhaust. It's white smoke and lots of water from exhaust...


I'm thinking lower manifold gaskets..i pray it's not head gaskets...


Haven't really been able to drive it so I've haven't noticed any overheating nor loss of coolant...


What are some of the symptons of manifold gasket leakage?

 

One of the most common symptoms of manifold gasket leakage is coolant in the motor oil. Pull the dipstick and see if the oil looks like chocolate milkshake. If it does, then you've likely got a leaking manifold gasket.

 

The above is sound advice from Toby H.

Meanwhile, what's the current ambient humidity in your area? High humidity of 65% or greater can result in quite a bit exhaust water/vapor output (you might take note of what other vehicles are pumping out). However, I'd suspect a blown head gasket if you're seeing an unusually dense cloud of white smoke from the exhaust once the engine and exhaust system are fully warmed up (i.e. 30+ minutes of city driving or 20 of freeway use).

Note: a severe lower intake man. gasket failure will nearly always result in coolant entering the eng. oil and, in extreme cases, 1 or more cylinders as well (the chances of coolant entering the cylinders and not the eng. oil is unlikely).

Also double check the ignition cap and rotor for excessive corrosion. The distributors in these vehicles are often known to be very troublesome in high humidity conditions due to moisture build-up inside of the dist cap. Another factor with these distributors is that the body is made of plastic and, as such, they're very prone to dist cap hold-down screw lug breakage as well as excessive bushing wear (the driven gear is also known for excessive and/or uneven wear due to poor heat treating). Lug breakage will, of course, result in a loose cap and PO300 codes. Left - right rotor play, while pushing down on the rotor, shouldn't be much more than the width of the rotor terminal blade.

 

Thanx for the help guys!!


Humidity here in Va lately has been kinda high but no other car I see is blowing vapor. And once it's started, it's starts stumbling. I'll raise the RPM from the throttle lever and get the white smoke after a couple mins after startup...


But like I said before, haven't noticed any coolant loss and no milky oil....


im hoping its not a head gasket....

 

Update


Just haven't had time to try and figure out whats going on. Not sure if intake manifold gasket, head gasket or what....


Looks like I'm gonna have to limp her to a shop....

 

bad head gaskets are rare on these engines. intake manifold gasket is my guess