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Long story short, the engine and transmission have again been removed in search of a repair to a coolant leak causing smoke at the rear side of the engine bay once the car gets to operating temperature/the thermostat opens.
Unfortunately, I didn't do the easy thing of adding dye into the radiator before I removed the engine.
The only thing I have to go on at this point is seeing what I assume to be coolant bubbling out of one of the lower exhaust manifold stems/nut when I had it running.
So now I'm at a total loss where this leak is coming from. I've removed the "wet" stem and find no leaking. I'm not sure I have a puncture of the head. I doubt it.
I've read somewhere that a failing/failed EGR cooler can be a coolant leak source. I've already removed the EGR pipe and applied pressure to the coolant pipes there, with no pressure loss after a significant period of time...overnight I think I did. There's a pipe that runs from the EGR system down into the exhaust manifold...wondering if as the car gets up to temp, the thermostat opens, sending coolant through the EGR cooler and, perhaps, there is a very small crack where, once at temp, allows the coolant to enter this pipe. But, again, it held pressure with no drops?
So......questions:
1. Is it possible there is some failure I am not seeing in the EGR system that is allowing coolant to drop into this pipe and thus be smoked off?
2. Is there some issue with the (rear facing) exhaust manifold gasket that is allowing coolant in/burned off? What would be the source of coolant getting into the exhaust manifold?
3. I have already tested the system for a blown head gasket. It tests fine.....no exhaust gases in the radiator...no change in color. Stays blue. Ran for over an hour like this.
4. Being this only occurs once the car gets to temp, what other areas should I be looking at. Would the water pump - located on the perpendicular side of the engine - cause any issues? I am not seeing any path (without opening that area up) where coolant can reach around to the rear side of the engine and bubble out of this lower manifold stem/nut.
5. Anything I'm not thinking of?
Any help would be very appreciated to help me find the source of this leak/smoke.
It would have been much easier if you used a cooling system pressure tester when the engine was still in the car. How do you know the smoke is caused by coolant?
It would have been much easier if you used a cooling system pressure tester when the engine was still in the car. How do you know the smoke is caused by coolant?
Right! I agree. But we're beyond that now.
I believe it's coolant because the overflow container empties.
Yes. Through the throttle body and then through the EGR cooler. By the way, I remembered I actually DID do the pressure test of the system - bought a kit for that. The one that hooks up to the radiator cap - right - and you send air into the system??? Yes, I did do that. No drop of pressure/coolant at all. Again, this issue arises once the car gets to operating temperature and the thermostat opens, which led me to believe at the time I did the pressure test that, because the thermostat would have been closed at the time - because I did it when the engine was off/cool, the pressure couldn't get to the back. I suppose I know enough about this to be dangerous. Perhaps, the test needed to be done when the engine was still warm, or on??? Anyway, I did do some sort of pressure test there, yes.
Here are a couple of pictures: The EGR system and the Exhaust outlets. The marked area is where the stem and nut were bubbling liquid (assumed coolant).
At this point, if it has to do with the EGR system, I'd just as soon as bypass/delete
it. I can't seem to find a replacement part.
If you don't have California emissions (which has an EGR temp sensor) then yes remove the EGR valve completely. Cap all the ports and done. EGR valve on this engine is enormous and overly complex.
Can't explain your leak have not seen anything like it.
If you don't have California emissions (which has an EGR temp sensor) then yes remove the EGR valve completely. Cap all the ports and done. EGR valve on this engine is enormous and overly complex.
Can't explain your leak have not seen anything like it.
Vehicle DOES have CA emissions. Any issues, therefore, in removing the EGR valve??? Other than I assume a check engine light for???
07-19-24, 11:22 AM
ES250 Smoking Issue (Continued)
