Why all the smoke?!?

[blacklake]

1993 Explorer Eddie Bauer
K&N air filter
A/C delete
230,000 mi.
Automatic Transmission
Stock

I will try not to make this too long/wordy, but I am really stumped her folks, need a little help.

I wanted to get my explorer ready for a long hard winter here in NY, so I figured a few replacement parts would be a good thing. This all started because my radiator had a small leak in the top and never really held pressure that well.

First steps:
Drain old coolant and run a prestone radiator flush. I drove it around the block a few times despite the label saying to idle the engine. I left the cleaner in for a day or two while it was in the driveway. Drained and flushed with plain water a few times. I ran then explorer with plain water for a day because I was skeptical that it would leak else where. Seemed fine, so I added new coolant and distilled water. the next day there is a leak from the timing chain cover... a bad leak. Here is a picture of the gasket.

Fixed that. I drive the explorer to the gas station and fill it up. I get back and the intake gasket is leaking freely it looks like this.

you may have noticed that in both cases the gasket looks fine (great I might add for being 20 years old) BUT the gasket is severly degraded around the coolant ports. I feel like I must have done something wrong to cause these two gaskets to fail back to back. time for a new intake gasket, I figure while I am in there why not clean the fuel injectors by following this method.
Reassemble.
I am getting smoke out of the tail pipe. It smells strongly of raw fuel!!! I realize I messed up an injector. So the injectors come back out, the offending one replaced.
Reassemble.
The engine sounds awesome! But wait, after 5 min of idling I am starting to see smoke again! I check all engine codes. Sure enough I have a lean oxygen sensor. Ah Ha that is causing the smoking after the computer goes into closed loop it reads a lean O2 and adds too much fuel.
Replace O2 sensor and Reassemble.
I idle it again runs even better, but there is still smoke after 5 mins. So I go on a mass diagnostics frenzy because I suspect a blown head gasket (after seeing the other gaskets.

• No KOEO or KOER or continuous error codes I get all 111 pass codes
• Compression tests all cylinders fall in range of 173-185 psi
• Spark plugs are not wet or oily (but they are black from the o2 sensor failure)
• Dipstick not milky (brand new oil <20 mi)
• Pressure test coolant system @ 10.5 psi reads 10 psi after 20 min.
• Pressure test coolant system with warm engine slightly faster drop maybe 1psi per 20 min.
• hold pressure on coolant system for 1 hr. then check for a wet cylinder. no cylinders are wet...
• Test fuel pressure regulator. 35psi running 40 psi once you unplug vac line. holds fuel pressure indefinably once you shut engine off.
• No air bubbles in radiator cap when idling/smoking.
• disconnected PCV... still smokes
• Checked auto trans vac modulator (new 2 yrs ago) does not appear to be bad
• I am having a difficult time identifying the smell of the smoke. It is white/greyish. It doesn't smell sweet, but it is certainly not foul like oil smoke. It doesn't burn my eyes at all. I thought that burning coolant (actually mostly steam) dissipates quickly. This smoke does not dissipate quickly (a few times the neighbors thought they needed to call the fire department!!!)

After all that I thought the head gasket was blown. So I bought new gaskets and head bolts. This is the most suspect region I could find. Notice the brownish color were the steel ring seats. (don't worry I cleaned that carbon out of the cylinder)

This is both head gaskets. Over all nothing seemed horrible about them to me.

So I did a major cleaning. Against everything I have read from this forum I reused my old heads! I did an inspection for cracks in the usual locations (between valves, between coolant ports) I didn't see any with the naked eye, but I am imperfect and there very well could have been a crack.

I installed the new head gasket and bolts
Reassemble
Now I still have the exact same smoking problem as before. Are my heads cracked? Can any one think of a diagnostic test I should run?

My justification for using the old heads was that they worked for 230,000 miles (most of the time with the radiator half empty) they should work through the winter. Since I have had these problems I have not over heated the engine, nor has it ever over heated in the past. By my estimation I have invested >$800 in maintenance items in the last 6 months that includes brand new tires. So I would like to get it running so I don't have to swallow that expense. At the same time investing $400 for new heads doesn't sound appealing considering how rusty my body is getting and the 230,000 miles on the transmission and engine...

 

[Anime]

White/grey smoke is the color of burning coolant, but that's only for sure when the engine is at operating temp, since engines also burn white/grey smoke on startup until the engine reaches operating temp and the catalytic converters get hot to function correctly.

If it's no longer smelling like fuel then the injectors might be fine, if you get white/grey smoke when running normally otherwise, there's a coolant leak. Could be one of the gaskets you replaced.

Also, in my experience the newer Prestone and similar coolants are all the same as Dex-Cool, OAT organic acids, which eat gaskets, and may be responsible for the damage on yours. Switching to HOAT hybrid organic acid coolant, either something like Zerex original green or Zerex G-05 (yellow, used in all newer Fords) works great and doesn't eat gaskets. You can get Zerex at Napa if you can't find it anywhere else.

 

[Roadrunner777]

I would not have left the flush in overnight. I would do a leakdown test to confirm the cylinder integrity. I might also do a hydrocarbon test on the coolant.

 

[blacklake]

Anime,

Thanks for the tip on Zerex coolant, I did not know about the gasket eating thing.
Also I can confirm that the exhaust no longer smells like raw fuel. I also have done a fuel pressure holding test. The pressure remains at 40 psi after the engine is shut off. So I too beleive the injectors are no longer a problem.

I also thought suspected I replaced the intake gasket wrong the first time. But it looked good when I took it out. After buying a the head gasket kit I replaced the intake gasket with a new one a second time.

Roadrunner777,

How would I do a hydrocarbon test on the coolant?
I will look into doing a leak down test. (though I dont have a leakdown tester or compressor in my garage)

Thanks for the replies guys

 

[Roadrunner777]

http://www.amazon.com/Lisle-75500-C...51119496&sr=8-1&keywords=head+gasket+test+kit

http://www.amazon.com/OTC-5609-Cyli...id=1351119594&sr=1-1&keywords=leakdown+tester

 

[blacklake]

I am sceptical about spending money on both tools, and the local autoparts store doesn't loan these tools.

If I use a leak down tester and I see some leaking. How will I know if it is a crack or just a leak from 20 year old piston rings and valves?

I am sceptical about the hydrocarbon test because, I know some oil got into the cooland at some point during the 2 or 3 times I have had to drain it and replace it. I usually catch the coolant in a clean oil pan (not surgically clean, but good enough).

I ran compression tests again last night. the lowest reading was 180psi with some readings up to 190psi!! Seems really high to me. The interesting thing was that 4 of the spark plugs were soot black but two plugs were a nice golden brown. Here is a schematic of the plug conditions

X=black with soot
0= Looks good

Back of engine

0 X
0 X
X X

Front of engine.
* note that these plugs were not brand new, but i did have then cleaned with a propane touch so they were not previously sooted.

I cannot think of any thing that would cause burning like this except possibly warped heads or maybe a fuel injector issue. I would suspect that a cracked head would only effect 1 or 2 cylinders at the most.

Thanks