[TomS]

Since I will be keeping this car, I have been thinking about
getting it undercoated.

Any pro's or con's would be greatly appreciated.

 

[Donjohnk]

Do they salt the roads where you live??? DO it.. No brainer... Ive done every car/truck Ive owned. Ive never had rusted bolt issues with ones that have coating on them..

 

[Kaylee]

Undercoating works well if you don't live in the severe cold climates. Here in the frozen Canadian prairies I have had every car until this one undercoated, and within a few winters it has developed cracks or chipped off from winter road conditions.

Modern cars are very well protected, and things like suspension, exhaust and brake parts, all which typical can't be undercoated will rust out and fail long before the under carriage. Maybe if you live in the milder winter climates where it dips above and below freezing a lot you might have better luck.

If you want to protect the door seams and trunk edges, there are better protection systems that involve spraying and oily wax into the crevices and inner panels.

In most cases just keeping up with routine maintenance and regular washing will do more to prolong the vehicles life.

 

[dlm1984]

The topic has been discussed a number of times on some of 4WD / offloading forums I have been a part of. While some people swear by it, I'd say the general consensus was to to avoid it and a quality paint would offer plenty of protection. The biggest issue cited was that, given time, the undercoating would begin to crack and would (or at least could) trap water, salt, and debris between the undercoating and paint which would actually accelerate corrosion.

Perhaps some of the newer coatings are much better and are worth it, but I wouldn't spend the money.

 

[La Flama Blanca]

My 09 MKZ rear doors are rusting where the door is folded over, you can't stop rust inside the fold.
My brother worked at a GM stamping plant running a press folding the doors, he said it's bare metal under there, no
way to stop it.
04 GMC Envoy doors rusted there and my 02 Ranger

 

[WHT DVL 3%ER]

Second post! I'll throw out an opinion.

Rubberized undercoating will eventually trap liquid salt spray between the metal and the coating. I recently found a mechanic to work on my older Xterra. He does a service where he uses used motor oil, aerosals it in his compressor and sprays the underside of your vehicle. It flows because it is liquid into cracks and spaces and then dries up. Of course, oil and water do not mix so it repells water. I park my vehicle outside for a few days after the treatment while the oil dries up. The practice is fairly common in the rust belt, you just have to find someone to do it. My guy charges $80.

 

[aloyouis]

Second post! I'll throw out an opinion.

Rubberized undercoating will eventually trap liquid salt spray between the metal and the coating. I recently found a mechanic to work on my older Xterra. He does a service where he uses used motor oil, aerosals it in his compressor and sprays the underside of your vehicle. It flows because it is liquid into cracks and spaces and then dries up. Of course, oil and water do not mix so it repells water. I park my vehicle outside for a few days after the treatment while the oil dries up. The practice is fairly common in the rust belt, you just have to find someone to do it. My guy charges $80.

Yep. I have seen this done before too. Need to do it each fall though.

 

[WHT DVL 3%ER]

my guy recommends twice a year, $80? 'ell yeah I'll do it. his farm truck has 325K on the clock and still looks solid. his theory is that the metal seems to soak in the oil like water to wood and slows/prevents rust from spreading.

 

[Mubalzich69]

I did it because I figured it couldn't get any worse than normal. My 09 Ford Ranger had rust all over the place after only a few years. My bed had rusted out holes, the underside of the door was rusted out, and when I got rid of the truck there were rust bubbles under my paint in a few other locations. In the Chicago area they use an extreme amount of salt because of all the traffic. We'll see how it goes with my FFS because I'm hoping I don't get much rust on this beauty.