I went to look at a used CX-5 today. Overall, the vehicle is in good shape inside and out with a Carfax that shows 1 owner and oil changes done every 5k miles. However, when I pulled the engine cover I found a large amount of foam and what appeared to be some type of nut shells. I shined my flashlight around and found a rodent nest in the outer portion of the intake manifold. The void is filled with shredded foam that the critter(s) pulled from the intake manifold void, peanut shells, other bits of nuts, etc. I don't think the foam itself is particularly important, but I'm concerned about other potential issues. The dealership GM just shrugged at me when I mentioned it to him, so whatever lies ahead would be on me. Thoughts based on your experiences? Thanks.

 

Likely just cleaning out all the crap should be enough, but….
Rodents often like the taste and chewiness of wire insulation. That could easily lead to problems down the road.
My concern would be more with the dealer. Poo pooing away your concerns does not give me confidence in how service down the road would be if you have problems. Also, stuff like this should get spotted by them when the car comes in. Did they not do a presale check and cleanup, or do they just not care?

 

If you purchase the vehicle, it is something you need to watch out for is rodents.
Especially chipmunks, as they love the underside of a CX-5 hood and the exhausts of BMW K1200GT motorcycles.
In two days, chipmunks render a new Chevy Corsica I had completely useless by chewing most of the ignition wiring (cost me $1000 way back when).
As Gozo said, I would be concerned with the dealer's ho-hum attitude.
He/she should at a minimum verify, in writing, he/she has inspected the wiring and found it has not been affected.
Otherwise, I'd look elsewhere.

 

Thank you both for your replies.

I don't typically visit the dealer for service, but they're not actually a Mazda dealer anyway (Ford dealer).

Re the presale check, the salesman told me they only do what is necessary - so they do very little. On this particular vehicle they checked for codes, changed the oil (done for every vehicle that comes in), replaced the wiper blades, replaced the battery, did a state inspection and washed it (inside, outside and engine bay). Front brakes look new, but they didn't do it so I guess the previous owner did. I will need to replace spark plugs, do rear brakes (pads and rotors), coolant change and probably trans fluid/filter since I'm sure that was never done. Belts are likely original, but still look good. FWIW, dealer is asking $15.5k.

GM offered to let me take it to my mechanic, but doubt I will get anything in writing from him.

 

Remove the foam clean it and carefully inspect the wire harness. There is relatively nothing that could be really harmed except the wire harness. But chances are because the rubberized foam would serve the rodents desire to nipple and make a mess you should be ok. It the wire harness had been compromised you would have surely by now had a DTC engine check light. As for the foam I am not 100% sure why it is there. Best guess is noise reduction. I removed mine about a year ago and did careful observation of IATs. Nothing changed. I am not sure if I even herd any increase in engine noise either?

 

 

You can easily wash the complete engine bay with a simple garden hose. Use only car wash soap sparingly and don't concentrate the spray nozzle on any one area to long. Let the engine air dry for about 2-3 hours before starting if you can.

 

I am not taking sides but ..................................................
Pulling engine covers is not really part of inspecting an engine in the used car lots? For any make! And...
It is not really an area that would be looked at with a used car and in that area if you go look at a Skyactiv engine can easily be overlooked from veiwing. .

 

I can't say for sure re the DTC as the dealer could have cleared it and I only drove it very briefly around the lot. I'll have to go back and more carefully inspect the wiring.

No one seems to know why that foam is there, but it certainly seems to be unimportant.

The dealer already washed the engine down and used some type of car wash, as the residue is still on the plastic, etc. They left the engine cover on though so they didn't even see the rodent nest. :/

 

Sorry to say but it is also very doubtful that the engine cover was removed. Its just not typically done!

AS I said examine the wire harness on the top area. I am sure that because of the easy access to chewing and building the nest the rodent confined to the foam in the intake and other nine auto related materiel's brought to the nest?