Guys,
I have been chasing the problem for 1.5 weeks. My car has white smoke at WOT and gets knock but it does not show any signs of white smoke at idle nor is my coolant level changed or has any oil in the coolant (I checked the coolant level every day since and its always the same) also the car does not overheat at all. I drained the oil and let it sit for 20 hours to see if any antifreez made it to the oil but it was fine. I have also popped off the Vavle cover beather and inspected it when the car is idleing and its NOT puffing any smoke when my car is idling. My friend had blown out some rings on his 97Z and it use to smoke like crazy out of the valve cover. Mine is completley clear (no smoke thru the valve cover). Could a head gasket leak be so minor that it does not show up in the coolant level or showing any signs of smoke out the exhaust at idle but then at Wide Open Throttle it shoots out smoke and knock or could this be another problem?


I plan to pull the plugs out this weekend and check (weather permitting) and have a compression test and leak down test done too but I was curious if anyone has had a head gasket go out without any evidience in the coolant or white smoke out the exhaust when Idling.

Thanks,
Claude

 

Hmmm.....Jim was just telling me about your problem. Sounds like a blown head gasket but if no coolant is going into you oil then I dunno. . You have the tell tell signs of it especially if its white smoke. What do your plugs look like?

 

Mean Lt1,
I am hoping the weather is nice this weekend to pull the plugs out and check em. If not, I will probably take it to a shop I go to, to have them do a leak down and compression test.

I was just curious if anyone else experienced this and did not have the normal tell tale signs Like (oil in coolant, or coolant in oil or low coolant levels or puffing from exhaust at Idle or smoke coming off the valve cover breather)....

Thx,
Claude

 

i've seen really rich cars look white.

you can change the injector constant on my car and watch it start chugging white

 

Hmmmm... I always thought and saw Black smoke when running rich. But I dont think Mine is running that rich, plus I get knock when this happens too.

thx,
Claude

 

try removing the thermostat and replace the houding.. then remove the radiator cap and start the car... if there is a very minor head gasket leak it will push air into the cooling system on the comression stroke and you should see air bubbles if very minor to coolant blowing out og the cap if major. just an old trick!

Chris

 

i knwo it sounds funny, serously though...

You can sit there and change the injector constant while the car is running and get the same effect. It looks like a light gray whiteish color.

Just don't write off the motor jsut yet you know>?

 

I did get a chance to pull the plugs out today guys. They all look normal and are pretty much the same gap. .38 to .40. One plug did look "Slightly" white in the procelin section but does not look bad at all.

I also drained the oil and will let it set overnite to see if it seperates (coolant and oil) but so far it looks good and when it was draining I was looking at it. I did not see any coolant or milky substance pour out.

Also the coolant level is still fine, I actually have a small 1/8 inch whole that I drilled into the thermostat almost a year ago to help with bleeding the system and that works great. I did leave the radiator cap off but with the thermostat in and I dont see any bubbles, nor oil and when I check the level (cold or hot) its always filled. The car idles normally, with no white smoke or coolant smell either, nor does it over heat at all.

It started to rain today after I pulled the plugs so tomorrow I will put some new plugs in it and take the blower belt off and see if that helps.

I will keep you guys informed. It would be one thing if I was just getting somewhite smoke but I am getting knock along with it. And what is really wierd is that sometimes the smoke is less and I get almost no knock other times I will see 10 degrees of knock and smoke.....I am stumped to say the least.

Rooster,
I checked my block learns when driving at highway speeds and they are both right next to each other 120/121. Also when I dynoed my car a few weeks ago my 02s were reading ~940Mv and the Widebands stated the readings were 11.6:1 at WOT. Now my 02s are still reading the same so I dont know if its a injector problem or not.

Edit, I also changed the Fuel Filter last Thursday and that did not help. Someone mentioned to me that thier might have been water in my tank or bad gas so added 3 cans of Dry Gas to it and I let the tank drain almost all the way down. Then I added another can of dry gas and filled up the tank, it took a little over 14.7 gallons of gas then after that tank was almost gone, went and replaced the fuel filter last thursday....Still No Good. I figured I would add this in just to let you guys know what all I have done so far. Also I checked my PVC valve and it was fine but I replaced it anyways and still no good.


Thanks again guys, and I will keep you informed.
Claude

 

Still sounds like a coolant thing to me. When you check the coolant level are you also checkng the overflow tank? Might be a very minor leak at head gasket that burns off all coolant at WOT. The radiator pulls the coolant back from the overflow while the car cools down before you check the level. You might go for a drive and when you see the white smoke, stop immediately and inspect the tailpipe for residue, coolant smell, etc.

Later ... Larry S.

 

Mislman,
I have actually dried that trick last week. It does not smoke when idleing or normal driving conditions only at WOT. And I went for a wide open thottle run and check the tailpipe imediately afterwards, there was only a little condensation, no evidence of coolant at all. And the overflow tank always seems to be fine, I have checked that many times, cold and hot.

Today, I installed some new plugs and pulled the blower belt off. With the blower belt off the car is MUCH quiter and I noticed that I am getting a slight rocker arm/lifter tap on the passenger side of the motor. I did not get a chance to pull off the valve cover cuz I had to wrap things up to take care of some other family stuff, but after I get back from vacation I will pull the valve cover off and see if I have a loose rocker arm or mabee a lifter going bad. Mabee a bad lifter or loose rocker arm might cause this...Who knows but I will check it when I get back from vaca.

Also, the oil has sat over night in a clear bottle and there is no evidence of coolant in it.

If anyone else has any input, please let me know as I will be checking this when I am on vacation.

Thanks again guys, The help is Much appreciated.
Claude

 

I get that to, its just unburned fuel, no biggy. I get that at wot and when i rev up and back off the gas quickly. usually once the combustion chambers get hot enough my does smoke as much.

 

Oh boy, sounds like the same thing that happened to mine. Same symptoms. WOT, smoke flowing from the car. Oil was getting past the rings and coming out through the breather onto the headers. With the incresed pressure at WOT, it was coming out everywhere. Normal driving it was fine. It got progressively worse.

I could be wrong though. What do I know.

 

It could be, Did you rings finally go or was it just excess pressure.
I also Popped my valve cover breather off at Idle and it does not puff any smoke (at all). My friend Maldo broke rings on his superchared 97Z a few years back and when you popped his breather off, it would smoke like crazy. Still not sure what this could be....cuz i am getting knock with it and the car hesitates/vibrates at WOT. I will pull the vavle cover off and see where that tapping is comming from first and if I cant do that, then its time to do a compression test and leak down test and go from there.

Thanks again guys,
Claude

 

When it first started happening there was nothing coming out of the breather, but I kept driving it anyway. The car was still running like a raped ape. Within a couple hundred miles it started smoking from the breather. I also started getting a weird idle, and a little hesitation from a start.

 

Was it a broken ring or did you just have excessive blow bye?
Also where you gettting knock at WOT?

Thx,
Claude