[Tejas@perioimpl]

Researching for my new jeep build, i came across this topic of underbody splash guards for the engine and alternators.

Many vehicles like the XJ come with a rubber splash guard under the engine. Some DIYers have made it using sheet metal/aluminum.

I have browsed through many a forum and have accumulated the pros and cons:

Pros:

- Prevents water splash from reaching the alternator

- Some say that they are there more for air flow than water, particularly the front ones. Helps to create a vacuum in the front and pulls air through the radiator.

- That rubber splash guard could actually insulate the oil pan from airflow, therefore keeping heat in, rather than aiding in cooling.

-That splash guard is there to help prevent road splash from getting on to
and contaminating the belts, it also helps prevent stones from beating on
the lower rad hose, it also keeps debris from getting up inside the engine
compartment.

-Jeep Engineers put it on for a reason or perhaps multiple reasons. Perhaps it was to protect the alternator. Or as part of the engine cooling setup. Or to prevent belt slippage from them getting wet.

Cons

- With it out of the way, there's an escape route for all the hot air that gathers under the hood.

- Metal ones will make an annoying rattle after a few hits

- Takes time to remove and fix everytime work needs to be done under the engine


My Personal take:

I think the theory is sound. Have a rubber guard below. Atleast the engine bay will be cleaner after mudplugging and having it there won't cause any further problems.

Any other thoughts people?

OEM Rubber Guard:


Metal Custom guards:

[Jaggu]

Yup these work really well but till you do water wading. So i feel from a pure offroading perspective it will offer limited protection to engine bay. But definitely worth while.

[Tejas@perioimpl]

Another thing i came across was a water proof cover only for the alternator:

Source: MPVClub.com :: Mazda MPV TSB details

[tsk1979]

How will it help in escape of hot air. Hot air usually moves from down to up.
That said, many SUVs like the safari come with an under body plate which is pretty big and prevents the alternator etc., being splashed with water.

[Jaggu]

Alternator cover looks interesting, but must be model specific so pick up the right one. Or get the cover and accordingly pick the alternator