Hit a deer - related problem?

[Danh]

An apparently suicidal deer surprised me last week. He was waiting for a semi that I was overtaking on a 4 lane road to pass and found me in the next lane. Poor thing was courteous enough to trip and fall just before we hit him, so he went under our Mercury Mariner instead of hitting us head-on. Certainly not a good day for the deer, but we were able to keep driving.

The obvious damage is pretty minimal, with a cracked bumper and damaged assorted underneath plastic pieces. No leaking fluids or other obvious damage. Had the alignment checked and adjusted.

Now here's the strange bit. A couple days after this occurred, I checked the engine oil and found it was just slightly low, so I added about 6 ounces. The next morning and every cold start since things start out normally, but after about 15 or 20 seconds of running there is a pretty loud rapping sound coming from the engine, which goes away entirely after a minute or so. The car otherwise behaves normally.

Maybe this is all a coincidence. On the other hand, if the deer banging around under the car pushed a component like the air conditioning compressor into the dipstick tube, could I be getting a false reading on it? The tube looks OK, but is a curvy thing and it's hard to tell if all the curves are original. Coulld overfilling the crankcase by that amount result in these symptoms?

I know this seems unlikely, but one could sure concoct a cause and effect scenario. The car has the 3.0 liter V6.

Guess the simplest thing to do would be to drain 6 ounces of oil and see if the problem goes away.

Thanks for any thoughts you may have.

 

[FL_Rob]

Coulld overfilling the crankcase by that amount result in these symptoms?

No,but a hoof(hoove?) breaking a line loose or bending the fan shroud could.You might need to get under there and pull and shake things to find a loose bracket, etc.

 

[ahoier]

I'd say get the car up on a lift of some sort, so you can inspect the whole under carriage....

If you go to Walmart TLE and say you need a "state inspection" they may be able to put the car up on their lift for you....just make sure they put it on the large "truck lift" that you can walk underneath and not the little lift that they typically put passenger cars on, and sits low to the ground.

 

[olddognewtrks]

Check the flat bottom of your oil pan. If it was pushed up/caved in even slightly, you could be starving your engine for oil flow. There might now be only minimal clearance between the bottom of the pan and the oil pickup; the rattle might be a near-dry start condition.
Keep us posted. Inquiring minds want to know.

 

[Nyquist]

A bent oil filter can also cause a loss of oil pressure and flow.

 

[Danh]

Originally Posted By: olddognewtrks
Check the flat bottom of your oil pan. If it was pushed up/caved in even slightly, you could be starving your engine for oil flow. There might now be only minimal clearance between the bottom of the pan and the oil pickup; the rattle might be a near-dry start condition.
Keep us posted. Inquiring minds want to know.


Happily, this problem has been easily resolved. The oil pan and all visible engine bits were apparently untouched. However, the studs on an exhaust clamp were badly bent as the unfortunate animal passed underneath.

I reasoned that maybe what I was hearing was an exhaust leak rather than an internal engine noise - which kind of made sense as the noise went away after a minute or two and heat made the exhaust components expand.

The truly excellent service department at my Lincoln Mercury dealer took a look and found loose bolts on the exhaust manifold at the number 6 cylinder. Simply retorquing them solved the problem. The force of hitting the deer evidently puuled the entire exhaust system backwards, with loose bolts the result. Interestingly, smell is one of the things that led the service guys to the problem - what I thought was the smell of, well, deer bits was actually exhaust gases before they hit the catalytic converter.

Anyway, a good outcome compared to some of the internal engine issues I thought could have occurred.