[Diogenes1]

hey guys, have a 2006 MDX that's done 245000 kilometers. A while ago there was a coolant leak and eventually the cylinders have to be replaced. That was recently and soon after that happened started noticing white smoke from the exhaust whenever the car was started or the car started moving from a stop. It also smells bad, not sweet, but foul. Oil light soon comes on after a bit of driving and oil levels drop low really fast and have to be filled frequently so I'm assuming it's burning oil.

We think it's related to something that happened when the cylinders were changed but the mechanic disagrees. The PVC is fine. Mechanic doesn't want to open up the cylinders again. Before the cylinders were changed and the vibrations were happening from the coolant leak, we never had the oil light turn on not even once, nor had white smoke from exhaust or foul smell. All this started happening right after the cylinders were changed. Mechanic claims it's because after cylinders were changed the seal was "tightened" or something and now the oil is burning.

Mechanic doesn't believe he made a mistake or anything and is looking for an engine to replace it with. We're not sure how to proceed. :frown2:

Thanks for taking the time to read and any help would be appreciated guys!

 

[Diogenes1]

bump

 

[Artbuc1]

How do you change cylinders?

 

[Bluepill]

Really impossible to make any reasonable response without much more information.

1. Why was the work performed? What symptoms did you have?

2. Exactly what work was performed? (Cylinders do not get changed on this engine).

3. Can you post a copy of the Repair Order and/or invoice for the work?

 

[Diogenes1]

well it's a long story, first symptoms were vibrations when starting up the car...then it would vibrate while driving and get worse sometimes....finally the spark plugs were changed by another mechanic even though the stealership said they were fine at first...then timing belt was changed...

vibrations came back and then the coolant we noticed was draining really fast and it appeared to be a coolant leak, perhaps as result of overheating from the misfiring happening earlier...and could smell the sweet coolant smell from the exhaust...

so valves were replaced I think? and coolant leak was stopped...I will post the invoice later when I find it...

then after that was done, the vibrations stopped, but there would be smelly odor from the exhaust when engine was started or when accelerating from 0 to around 40km/h, and could see the greyish smoke from the rearview...at highway speeds we don't really see much smoke or smell it...

and so it's burning oil because the oil indicator light would come on and the tank would be heavily drained...

my dad's technician friend said it's possible the oil was still burning with the coolant previously but we didn't notice because it was burning with the oil...but the oil light never came on that time...is the oil indicator sensor measuring the oil tank itself or is it somewhere else?

 

[Artbuc1]

Hard to know about original vibrations but sounds like you have a blown head gasket. I'm guessing valves were adjusted, not replaced, unless you broke a timing belt and bent valves.

 

[Diogenes1]

the head gasket was changed, and yeah I'm pretty sure it was the valves that were adjusted...they were warped or something....and timing belt didn't break but was replaced I believe...

 

[Artbuc1]

the head gasket was changed, and yeah I'm pretty sure it was the valves that were adjusted...they were warped or something....and timing belt didn't break but was replaced I believe...

Sorry but you do not know enough about the car's history for me to be helpful.

 

[Bluepill]

Here is the deal: If the engine was burning coolant as you suggest, there may have been damage to the piston rings and/or cylinder walls. The procedure recommended by Honda and Acura is this: If any piston crown shows signs of coolant "wash", the piston rings and rod bearings should be replaced, as well as a light honing of the cylinders. "Wash" is removal of some or all of the normal carbon coating on the piston crown. This is caused by what is essentially "Steam Cleaning" as the coolant turns to steam during combustion. It was established by Honda R & D that enough coolant leakage to cause wash can also cause oil burning problems after the repair.

This condition can be confirmed without removing the heads. Using a fiber optic borescope through the spark plug holes will give a good visualization of the piston crowns.

See this video:

https://youtu.be/JpozuZakEoE

 

[Diogenes1]

Here is the deal: If the engine was burning coolant as you suggest, there may have been damage to the piston rings and/or cylinder walls. The procedure recommended by Honda and Acura is this: If any piston crown shows signs of coolant "wash", the piston rings and rod bearings should be replaced, as well as a light honing of the cylinders. "Wash" is removal of some or all of the normal carbon coating on the piston crown. This is caused by what is essentially "Steam Cleaning" as the coolant turns to steam during combustion. It was established by Honda R & D that enough coolant leakage to cause wash can also cause oil burning problems after the repair.

This condition can be confirmed without removing the heads. Using a fiber optic borescope through the spark plug holes will give a good visualization of the piston crowns.

So I've confirmed the cylinder heads were replaced, and spark plugs were also changed. Bolts were also changed.

Bluepill, I don't believe steam cleaning was done and neither were the piston rings or cylinder walls.

The coolant leak has been fixed though as coolant has stopped leaking.

Bluepill, when you say, "It was established by Honda R & D that enough coolant leakage to cause wash can also cause oil burning problems after the repair."

can you explain why the oil burning didn't start during the coolant leak and when the problem started? Why does the oil burning start AFTER the repair exactly?

Thank you all.

 

[Joe Average]

Sorry but it sounds as if you need an engine rebuild or an engine replacement.

You can either pay to have that done or sell the vehicle as-is (or trade it in) and buy a different vehicle.