White smoke from tailpipe. Always coolant/water?

[DonkRado]

'90 Renix 4.0. 36K on reman.

Ok, so I picked the car up and drove it home 300 miles. The person riding behind me claimed I had puffs of black smoke when getting down on the gas, but only black. It also dropped several quarts of oil so I have recently gone through and replaced the following:
Front & Rear Main Seals
Valve Cover Gasket
Oil Pump
Oil Pan Gasket
CCV Hoses
New plugs, wires, dizzy cap, rotor button

I had a little bit of an issue getting it to start after I initially reindexed the distributor. So, I cranked on it for several days with timing off a few teeth before I finally reset it at TDC and it fired right up. I always notice a small splattering of black 'soot' on the ground behind the tailpipe after it has first started, and it just continuously pours steady white smoke out of the tailpipe. I haven't even put a full mile on it since I put it all back together, so I haven't ruled out residual condensation in the exhaust system, but the smoke definitely worsens when blipping the throttle from idle. At no point during the drive home did it overheat, nor has it had any high temperatures since I have put it back together.
One thing I noticed when I had the valve cover off and was removing the old CCV hoses was that the old grommets were really hardened and almost crystalized... totally full of gunk. For some reason, I didn't dissassemble the actual CCV parts inside of the valve cover, and now I'm wondering if they are stopped up. There was definitely oil in the old air filter, so there was some blowby present. Could the CCV filters being clogged cause white smoke at the tailpipe? Any other ideas? I'm not quite ready to accept a blown HG due to the consistently low temps, and I don't want to pull the head off if it could potentially be something easier.
The car has officially emptied my bank account, and I'm now nickel and diming my credit cards. I know that someone will suggest a leakdown, but does anyone have an idea what that would roughly cost me?
Lastly, I've seen mention of reading the spark plugs for symptoms, but I wasn't able to find any specific symptom of coolant or water in the chamber. Anyone know? New plugs, so it should be fairly easy to read. Thank you.

 

[87manche]

pull the plugs, if one of them looks totally clean then that's a sign of coolant in the cylinder.
you may just want to take it to a garage with a hydrocarbon tester.
They can sniff the radiator and tell you if you're getting CC gases in there. Certainly cheaper to spend $50 on a diag than throw parts at it.
look here for spark plug diag.
http://www.ngkspark.com.au/tech_index.htm?http://www.ngkspark.com.au/pages/spark_plug_analysis.htm

 

[5-90]

Black Smoke - usually fuel (running excessively rich)
Blue "Smoke" - usually oil (actually, steam...)
White "Smoke" - usually water/coolant (actually, also steam.)

As mentioned, check plugs - if one is MUCH cleaner than the rest, it's got coolant in there, and it's been "steam cleaned." A small flexible light can also help - while you've got the plugs out, you can stick the light in there and see the tops of the pistons for much the same symptoms.

Oil fouling of a plug (an oily coating on the porcelain and ground strap, usually black) is a sign of oil getting into the cylinder - could be past the oil control rin, or it could be past a valve seal. Easier to deal with the valve guide seals first.

Black is a fuel trim issue (and you'll see a black sooty coating on the plugs for the cylinder(s) affected,) and could be a fuel injector sticking open, a spark plug that isn't putting full spark out, or a failing plug wire or distributor cap terminal - check all of them. Plug wires can be checked with an ohmmeter (I don't recall the spec, and I should post it in my Tech Archive,) and dizzy terminals can be checked visually - look for soot on the terminals proper, and "carbon tracks" (looks like irregular pencil lines) on the inside and outside of the dizzy cap, tracking from a terminal to the bottom of the cap (grounding out on the dizzy casting.)

Anything else?

5-90

 

[XJING]

Make sure your line from your MAP to your TB is good and on tight with no little cracks in it. That is a line that gets knocked off or rotton and overlooked causing smoke. Good Luck

 

[DonkRado]

Ok.. I'll check that stuff. Also, there's a crack in the belly of the muffler that runs widthwise across it. It's pushing smoke out too. Could be a condensation source? I haven't even run the thing for a full 30 minutes since I put it all back together. I'll have to replace that thing before I can pass the visual inspection, but I should wait until I've got the smoking problem cleared first, right? No need to gum up a new muffler.

 

[Ecomike]

'90 Renix 4.0. 36K on reman.

Ok, so I picked the car up and drove it home 300 miles. The person riding behind me claimed I had puffs of black smoke when getting down on the gas, but only black. It also dropped several quarts of oil so I have recently gone through and replaced the following:
Front & Rear Main Seals
Valve Cover Gasket
Oil Pump
Oil Pan Gasket
CCV Hoses
New plugs, wires, dizzy cap, rotor button

I had a little bit of an issue getting it to start after I initially reindexed the distributor. So, I cranked on it for several days with timing off a few teeth before I finally reset it at TDC and it fired right up. I always notice a small splattering of black 'soot' on the ground behind the tailpipe after it has first started, and it just continuously pours steady white smoke out of the tailpipe. I haven't even put a full mile on it since I put it all back together, so I haven't ruled out residual condensation in the exhaust system, but the smoke definitely worsens when blipping the throttle from idle. At no point during the drive home did it overheat, nor has it had any high temperatures since I have put it back together.
One thing I noticed when I had the valve cover off and was removing the old CCV hoses was that the old grommets were really hardened and almost crystalized... totally full of gunk. For some reason, I didn't dissassemble the actual CCV parts inside of the valve cover, and now I'm wondering if they are stopped up. There was definitely oil in the old air filter, so there was some blowby present. Could the CCV filters being clogged cause white smoke at the tailpipe?

I really doubt it. I suggest looking elsewhere.

Any other ideas? I'm not quite ready to accept a blown HG due to the consistently low temps, and I don't want to pull the head off if it could potentially be something easier.
The car has officially emptied my bank account, and I'm now nickel and diming my credit cards. I know that someone will suggest a leakdown, but does anyone have an idea what that would roughly cost me?
Lastly, I've seen mention of reading the spark plugs for symptoms, but I wasn't able to find any specific symptom of coolant or water in the chamber. Anyone know? New plugs, so it should be fairly easy to read. Thank you.

I recently had a similar problem with my deisel. It turned out to be too much fuel. The white smoke was unburned deisel. Do you smell gas in the white exhaust? If so it could be a bad injector stuck open or leaking, or an injector Control problem.

Good luck.

 

[5-90]

I recently had a similar problem with my deisel. It turned out to be too much fuel. The white smoke was unburned deisel. Do you smell gas in the white exhaust? If so it could be a bad injector stuck open or leaking, or an injector Control problem.

Good luck.

A Diesel works on a different principle, and there are significant differences in the two fuels.

Unburned Diesel, in small quantities, will present as black particulate smoke. In large quantities, it will present as a white-grey steam with the smell of the fuel This requires checking (use you noses!) the steam for unburned fuel.

Also, the operating AFR of a Diesel is MUCH wider than that for a gasoline engine - you won't "flood out" a Diesel until you have enough liquid fuel in the chamber to pop out a glow plug, or just damage something serious. Not so with a gasoline engine.

A gasoline engine runs on a combination of paraffinoids and aromatic esters. The Diesel cycle was originally conceived to run on peanut oil (true story!) Also, while a gasoline engine is throttled by controlling airflow and maintaining a fairly consistent AFR (12:1 to 17:1, usually a Diesel maintains constant airflow, and is throttled by varying fuel delivery...

Not trying to say you're wrong, but the two cycles are different enough that you can't always readily apply principles from the one to the other...

5-90

 

[Ecomike]

Nice feed back, but what if just one of the fuel injectors hangs open on the gasser? Will that make white smoke in the exhaust on a gasser?

 

[5-90]

Nice feed back, but what if just one of the fuel injectors hangs open on the gasser? Will that make white smoke in the exhaust on a gasser?

Shouldn't. Gasoline has a rather lower "flash point" than Diesel oil, and will partially combust when it runs that rich. You should still get black smoke (read: particulate carbon.)

5-90

 

[Fish'nCarz]

My dad told me black was carboration, but generally, what he said.
I figure I can adjust or replace minor stuff to fix black smoke, but Blue or white smoke usually means some serious mula!

Black Smoke - usually fuel (running excessively rich)
Blue "Smoke" - usually oil (actually, steam...)
White "Smoke" - usually water/coolant (actually, also steam.)

As mentioned, check plugs - if one is MUCH cleaner than the rest, it's got coolant in there, and it's been "steam cleaned." A small flexible light can also help - while you've got the plugs out, you can stick the light in there and see the tops of the pistons for much the same symptoms.

Oil fouling of a plug (an oily coating on the porcelain and ground strap, usually black) is a sign of oil getting into the cylinder - could be past the oil control rin, or it could be past a valve seal. Easier to deal with the valve guide seals first.

Black is a fuel trim issue (and you'll see a black sooty coating on the plugs for the cylinder(s) affected,) and could be a fuel injector sticking open, a spark plug that isn't putting full spark out, or a failing plug wire or distributor cap terminal - check all of them. Plug wires can be checked with an ohmmeter (I don't recall the spec, and I should post it in my Tech Archive,) and dizzy terminals can be checked visually - look for soot on the terminals proper, and "carbon tracks" (looks like irregular pencil lines) on the inside and outside of the dizzy cap, tracking from a terminal to the bottom of the cap (grounding out on the dizzy casting.)

Anything else?

5-90

 

[DonkRado]

Well, after letting it run for a bit, it stopped blowing the white smoke. There's still a little bit at first startup, but I suspect it's condensation. I'm under the car replacing the muffler right now (Dynomax Super Turbo), and I see a bit of coolant hanging out on the chassis. I guess I'll be looking for that coolant bottle leak next. Thanks for the tips, lots of good info here.

 

[DonkRado]

Ok. The heavy white exhaust smoke kind of comes and goes. It really seems to be primarily at startup, but it's certainly more than the usual 'condensation steam'. I definitely have a coolant leak somewhere as I can see it dripping down right behind the front passenger wheel well. I wish I could remember the name of the part that the leak seems to be first appearing at, I guess I've been away from solid beam axles for too long. Regardless, it's a suspension part, not anything cooling related. I don't see any leaks at the coolant reservoir or the hoses, but I do notice a puff of white smoke coming from the back of the engine when I blip the throttle. I'm kind of suspecting the heater core (as the car blows practically no heat), but I can't find any smell or dampness in the passenger cabin.

 

[87manche]

from the sound of it you seem to be describing one of the control arms.
I'd take a good look at the heater core and it's hoses at the firewall.
A coolant leak external to the motor should not create white smoke in the exhaust however. It's also likely that if you do have a head/headgasket problem that it may be presurizing the coolant system and the coolant is finding the weakest spot to leak out at.
I still recomend that you have the coolant tested for hydrocarbons and then go from there.

 

[DonkRado]

Yep. It's the backside of the lower control arm. I've already replaced most of the hoses in the bay, so I may as well complete the job. I'll also flush out the heater core this weekend, and if it's leaking or on its' way out, I'm sure that'll finish it off. So far I've been replacing hose strictly by diameter, but I suspect that tight bends like those connecting to the heater core should be purchased pre-formed, right? Don't want anything to get hot and develop a kink.
I have begun to wonder if I put in too light weight of an oil when I did the change the other day. It's already pretty dark (no froth or milkshake), and it's turned up a quart low in ~100 miles. I am suspecting a pretty fair degree of neglect in this engine's short reman'ed life (36K). I think it might be allowing some blowby and sending the burnt oil out in the exhaust. I don't see any of the same external oil leaks that it had before, and the white smoke started as soon as I changed the oil, so I'll have to try something a bit heavier than 10W30.
I'm still going through the car to get it passable for inspection, so I'm not quite to the hydrocarbon sniffing stage yet. If I don't cure it along the way, I'll probably get it tested whenever I do take it in for inspection. Next, I need to get the e-brake working, and fix the super soft brake pedal.
Thanks.