Car blowing white smoke after servicing

My 1999 Ford Explorer went to the dealer to diagnosis a smell coming around the radiator. They checked all seals and found no leaks - no problems. I told them to change the oil and I"d pick up the car.

They called after the oil change and said the car was smoking badly out the tail pipe. They kept the car overnight. I came in the next morning and the car was running in the shop with huge billowing white clouds of smoke coming from the tailpipe. The service guy said I needed new seals in the head casket at a cost of $2400. This car had not shown signs of this kind of exhaust smoke prior to the oil change. In fact it has run with no problems up to this time. Wondered if changing the oil for some reason enhanced the seal problem or could they have done something to the engine (added too much oil) causing excessive smoking. Since the car has 150k miles I think it could need new seals but since it wasn’t showing signs of billowing white clouds of smoke before I took it in - - I’m skeptical of this dealership repair shop.

They did repair a small leak around the thermostat of the car after I came in and after the oil change.



I Think You Were Low On Coolant From The Thermostat Housing Leak Before You Took It In.

That could have caused head gasket(s) failure. When they fixed the leak and filled it with coolant, the now full, pressurized cooling system injected coolant through the leaking gasket(s).

You had no other symptoms of a coolant leak besides the smell, like a too high or too low temperature reading or no passenger compartment heat?

I think the damage was done before it went in. It’s possible that catching that leak sooner could have prevented the damage, but like you say its got age and miles on old gaskets.

The car went to the shop for a smell around the radiator,I conclude the smell was coolant but you recieved a “alls good” verdict, then they went on to repair a leak,the time line is out of wack.

Did they say “we looked at your cooling system and the coolant level was very low we had to add 1.5 gallons (for example)of coolant,you have been driving your car with the coolant level very low”

So did you ever check the coolant level in the system at any time up to this repair?

A tiny leak anywhere can creep up on you fast. This leads to overheating, which may not always be shown on the gauge, and once the leak is repaired the cooling system will pressure up to what it should be.
In turn, a weakened head gasket may then give up its life due to the now normal system pressure.

Thanks for the reply. The car was blowing white billowing smoke AFTER they changed the oil and BEFORE they fixed the small thermostat water leak. That’s what is odd to me.

I stood over the hood of the car with the mechanics and they did a pressure check on the water system. Then they found the small water leak but that was a day after the oil change and the smoking began. FInally they drove the car and the smoke cleared. I don’t see signs of smoke now. They also jammed the hood release so when I got home I couldn’t open the hood. Have to go back in for a cable.

Thanks again.

Thanks for your reply.

I had been checking the radiator water level regularly and it would be down a bit (1/3 of a cup) occassionally so when I stood over the car with the mechanics and saw water leaking from the hose (after a pressure check) in the Thermostat area I was not surprised. But the unusual aspect of this is that immmediately AFTER the oil change the car started billowing white smoke - - - the water leak was not found until a day after the smoking started. Then they drove the car and the smoke cleared. Now I see maybe a small - very small amount of white smoke but not nearly what it was after the oil change. The engine runs fine - I still smell some water vapor.

Thanks for your reply.

Yes I would check it occassionally and it would be down just a bit. Maybe a 1/3 cup. So when I stood with the mechanics and asked them to pressurize the sytem and we saw a leak right by the thermostat area I was not surprised. But the smoke started a day before they did the test for the leaking water and a day AFTER the oil change which is when the car began to smoke badly in the shop. The drove the car after servicing all of this and cleared the oil. It did not show signs of blowing smoke. The engine runs fine - I still smell a trace of water vapor.



Well as stated in my other entries. The water level in the radiator would drop slightly every week or so. So when I saw the leak with the mechanics (by the Thermostat) I was not surprised. But , , , the smoking started a day BEFORE the pressure check and the water leak repair. - - - right after they changed the oil. They stated I need new seals - that oil was seeping thorugh the seals. It had not smoked before - and the smoke was so intense they had to open the doors of the shop for a bit. They drove the car after servicr and repairs and the smoke cleared. It seems to run fine - some vapor odor still exists but no major smoking issues. Thanks

THey drove the car and the smoke cleared. I don’t see signs of smoking now and the engine seems to run fine . . . although I still smell water vapor. THanks

A 1/3 of a cup is not enough to worry about.
No idea what the problem is at this point and a simple oil change should not cause this problem.
However, maybe the lube tech who performed the oil change overfilled the engine oil.
When this occurs it’s quite possible for engine oil to get forced into the combustion chambers. On startup it can smoke like a grass fire and in some extreme cases may even hydrolock the engine.

If an oil overfill is the case what are the chances they caught this on the return and drained some out while of course not owning up to it?
Just a theory anyway and hope it helps.

I ask why did you withold the information that the condition currently does not exist? Be fair and tell us all information in your inital post. Its hard enough filtering out peoples bias.

Did you think if you told us that you currently do not have a engine smoking problem you would not get any attention?

RIght on, glad it worked out.


That helps. If The engine could as you say “Smoke like a grass fire” if overfilled with oil then my hunch is they drained some out after discovering they overfilled with oil. I asked the service attendant if they had overfilled it. He simply said no that can’t happen - it’s premeasured. I asked him what could account for such a massive cloud of white smoke after an oil change . He said he didn’t know and that it was bizzare.

The smoke wasn’t coming through the exhaust so they fixed the problem instead of causing it.

I don’t know exactly what they mean by pre-measured, but it is certainly possible to overfill an engine due to carelessness. I’ve seen it a few times; most caused by a lube tech using an overhead oiler that dispenses oil from a drum in the back room.
Get careless by letting the mind wander for a few seconds and it’s quite possible this can happen.

In a few cases the engines suffered hydrolock; meaning so much oil was forced into the combustion chamber the rotating assembly (crankshaft, rods, pistons) would instantly lock up as the oil could not be displaced past the valves fast enough. Since the oil is not compressible the engine would come to a screeching halt.

While a shop foreman at a large dealer a fairly new tech approached me as I was going to lunch and stated that he had just finished a head gasket job on a VW and it was making some funny noises. I told him to leave the car alone and I would take a look after lunch.
When I came back after lunch (the tech never came back, ever) I discovered the engine was overfilled with oil and had locked up solid. Luckily there was no engine damage and since it was a diesel I simply removed the injectors, hit the starter, and blew the oil out of the cylinders. Reinstalled the injectors and it ran fine afterwards once the smoke cleared out. It happens.

Glad the engine didn’t lock up. I’m hoping no damage was done to the engine and clearing the oil out of the cylinders by driving the car was ok. Should I consider adding any additives? Hard to tell if I"ll need head casket work. Guess I’ll watch to see if the smoking comes back and or the water runs low in the radiator.

Thanks again for all your replies. This is a great format for the public. Thanks also to Click and Clack and Car Talk for the radio show, the web page and all the helpful links. I’m a long time fan. Best Ted