Hi folks,

Please bear with me I'm new here. I realize this thread is million mile away!
I had this MDX 2004 five years ago. Is now sitting in my garage for a month.
This engine has been rebuild about two years ago. It a long story but I need new engine and again! I was told by mechanic who rebuild my engine and was surprise this 2004 model has a HEMI .... ummm wondering?
So I was told this alum block engine has been over cook that cause thread in block strips out to hold cylinder heads to the block. For that reason head gasket leaks pushing the anti-freeze out. They follow spec from Acura Service Manual for proper torque. Before this happening the mechanic calls every where to get over size piston but at that time was not available. It has new piston standard OEM size but already over bore each cylinder in less than .15 inch. So any way I was so piss about it. I spend 7 grand total to removed, rebuild, and install. Now new mechanic wanted 8 grand to rebuild again. The first mechanic retired he is 75 year old and was best mechanic in racing engine.
Due to this problems this block thread was strip out or broken thread on each head bolt would not able to torque it. I once removed front head and drill out each bolt hole and add Heli coil to each. The rear head near body wall was good but there no way to have room to work on. The rear head has no leak which was good and torque was okay. It ran well after one year till it started to leak from over heat was due to loss of anti-freeze.
Now I'm worried about those alum block design has made from manufacture has not check rockwell hardness spec. What should I do? RIP my loving MDX? Possibly, not want to buy another Acura/Honda again?
Man...I love this ride and performance. Now I'm broke!!

 

Hemi is short for Hemispherical heads, which the J32-J35 engine has. So, technically it is a Hemi.

 

Sorry for all the trouble you're having man. You definitely need to get the overheating problem addressed no matter what you do to the engine.

I would think if it's only an overheat condition, which can warp the heads (and possibly the block deck) causing the leaks, that you could possibly have the head (and deck if needed) milled flat, have a valve job done with new springs, new head gasket, etc. Not sure why you need an overbore with new pistons? The cylinder bores of the aluminum block are fitted with cast iron liners so, I may be wrong here but, I would think that they could be refitted with standard bore liners? But on the other hand I don't know all the details either. Seems like you could have a good used engine sourced and installed for a big time savings. I mean a warranty, if you had one before, obviously didn't help you're pocketbook after the last rebuild. Good luck, and if it was me I'd save the MDX with a good used engine (thoroughly inspected of course).

 

Wow, did I read that right: this engine has standard pistons in an oversized bore?

Wtf!