So first time poster,

I'm fixing my sisters car for her and ran into a bit of a mystery here's some backround, sort of a long storey.

A couple years ago the car overheated a couple times and started steadily buring some collant, I advized them that it's likely the head gasket and it'll need to be changed, after that they went to a local mechanic that proceeded to tell them the same thing and charge them what I thought was way to much for a gasket change but they got it back running fine and then I belive not long after it started to burn ALOT of white smoke, so much that they coudln't drive it without getting pulled over by police. This smoke would start out reletivly light then increase dramaticly.

It was otherwise running fine, not overheating and I don't belvie there was any transfer of fluid between the oil and coolant at all. At this point rather then dump more money into it I told them I would try and sort it out, a few months later they towed it into my driveway where I proceeded to mess around.

I started by stripping of the intake punum and found those gaskets were toast, what confidence I may have had in the mechanic was now completely gone and replaced with contempt, I logicly concluded collant was migrating here into the intake manifold and being burnt rapidly, this would explain why it woudlnt overheat aslong as there was coolant in the system and why there was no polluting of the oil or coolant.

I changed these and put it back together, no noticable change in smoke. then I got it into my head that this must still be a head gasket issue perhaps the mechanic didn't use new head bolts or did'nt inspect the heads etc. so rather then spend hundreds of dollars on gaskets and such I decided to grab an engine from the local parts yard on engine sale day (150$ for a long block). replacing these engines are alot simpler and easier then the head gaskets so I did that with a fine looking engine from what apeared to be a theft recovery car, the heads looked brand new and all the sensetive bits were weather protected.

I poped that thing in and it runs great but to my dispare it started burning ALOT of white smoke ... again, runs fine idles and revs nicely, no overheating no migration of fluids so far, I ran the thing for a good 20 minutes thingking maybe the CAT was fluded with coolant or water and no change and since I din't quite torque up the manifolds to the Y ipe fully soem smoke was coming out there too sort of eliminating that CAT as a culprit.

I find it incredibly unlikely that 2 different engines have the exact same head issue, I didn't reuse and parts the new engien was complet from the air filter to the exhast manifolds. Niether engine created smoke with a noticbly sweet or oily smell, I'm stumped.

Since I simply hooked everything up as it was already hooked up I thought maybe coolant hose was hooked up wrong or a vacum line maybe but I have nothing to compare it too, and theonyl lines I'm not pretty sure of is the heater core loop and the 2 vacume lines into that cylinder at the firewall I think it's part of the EGR system, any help is apreciated.

 

I read that it's possible for a brake master to break down and allow fluid into the brake booster which can then migrate up thoe booster vacuum line into the intake, anyone ever heard of this on a 3VZFE? I tihnk hydrolic fluid burns white. Is there anything on the ATF side of things that can migrate into the intake?

 

Good find on the $150 engine!

Aside for smoking how does the engine run and idle?

Anything change between before and after the smoke starts coming out the tail pipe such as engine problems?

Any link between smoke starting and engine coolant temperature?

Have you smelled the smoke, coolant smells sweat?

Would examine each vacuum hose large or small connected to the engine for oily residue, signs of gasoline or anything else inside.

Plug the front plugs and check for signs of excess, gas, oil, etc.

Has happened master brake cylinder fails and brake fluid can be drawn into the engine. You can disconnect the hose to booster and plug to close off as would be an air leak, then check for smoke.

The gas tank EVAP can have a problem the result being gasoline is drawn in through a vacuum hose into engine but car may run rough from excess gas.

Some makes of cars had a vacuum line running to the trans for the modulator but the car should not.

The trans and engine both have seals at shafts, if the trans was leaking the fluid would be showing up under the bell housing cover.

Check PCV valve system, hoses, etc if valve stuck open engine can burn more oil.

 

It startes and idles perfectly as it did before, this makes me think it's not an air/fuel mixture problem or an excessive gas problem, there is no gas smell present.

NO aparent problems or changes to the performance before or after the smoking starts.

The heavy smoke starts fairly quickly before the coolant reaches normal temp, less then 30 seconds anyway, it starts at a light smoke, a typical cold weather looking kind.

No aparent sweet smell but that may be becuase the coolant is pretty diluted, maybe 1/4 ratio or less.

I'm hesitant to think it's a problem with the PCV valves since those are also new with this engine, but thats an easy check

The trans is also new, no noticible fluid leekage anywhere, there is a hydrolic pump for the fan that uses the trans fluid somehow, I don't see how that could migrate to the engine in any case.

I've heard the ecu can mes with the fuel delivery but that would produce a gas smell and make it run poorly so probly not that.

I'm going to start checking lines maybe switch the EGR ones around a bit this weekend, I'll look at the plugs too I know that can give you hints but it's never a definate indicator, the days are short and I work till dark.

I found one other fella on another forum with a similar problem but they kept harping on him that it's the head gasket so I tihnk he gave up.

Given the head gasket was changed by a mechanic (be it a ****y one) and a different engine produces the exact same results there has to be a factor out side of the engine it's self cuasing this.

 

Did you check the brake booster vacuum hose?

Something called a block test will check coolant at radiator fill point for exhaust gas. Coolant gas bubbles up through a chemical in a tube then changes cooler if exhaust gas is present.

You can also do a pressure test but block test is more accurate.

An open EGR valve is going to cause excess exhaust gas ingestion and cause the engine to idle rough or die.

 

Won't be checking anything till the weekend, I wont be loosing sleep over it. I can usually figure these things out but this ones got me, I mainly want to see if there's some angle I've missed I'm not super familiar with these engiens.

First thing saturday I'll be going through all the hoses and vacuum lines to see if anythings fishy and I'll try switching a couple lines I took an edjucated guess on.