Why You Should Stop Spraying Oil Under Your Car

When it comes to automotive maintenance, Pakistan is probably a country that lies at the very bottom of the awareness index. That is if such an index even exists. In a pre-internet era Pakistan of two decades ago, it was understandable to some extent why the ignorance prevailed, even among the educated class. Today, however, things are much different from the yesteryears. We have modern cars, better training programs sponsored by the manufacturers, more access to informative online content such as service manuals, etc. Despite all that has changed over the years around the world one thing that hasn’t changed much in our country is how we service our metal bodied soul mates.

The problem I’m about to highlight here is one of the most common automotive scams / myths / pandemics that exists in our country. When we take our car for its periodic servicing, be it at a dealership or a petrol pump, one of the most common practices, is to apply motor oil or diesel at critical suspension joints, bushings and the undercarriage. All under the claim that it “lubricates” the joints, prevents rust from forming on the undercarriage, helps reduce noise and in some cases also as a selling point to make the entire engine bay shine like it just went through a glitter factory.

This oily scam in a tin can is sold in a very persuasive and convincing manner and most gas stations even charge a few hundred rupees for the undercarriage spray. Some of those claims might actually be true if your vehicle in question was a Bedford truck, using metal bushings, leaf spring suspension and a host of different technological hallmarks of Alexander’s era. However, if you happen to drive a modern vehicle and by modern I mean most cars that were designed after the mid ’80s, which are inherently based on front-wheel drive platforms, then I’m afraid, applying motor oil or diesel to the undercarriage is about as healthy as surviving on carcinogenic asbestos crackers as a means of food.

Applying oil or diesel to the undercarriage causes the critical suspension parts, specially the bushings to fail prematurely as the solvent based oil/ diesel mixture eats away the rubber components quite rapidly. This is especially true for areas with warmer climate. Secondly but more importantly, oil attracts dust particles on the critical suspension parts, including the moving components. This dirt then accumulates and forms a sticky mixture of high friction particles, which can potentially wear out the metal components prematurely as well. But the problems don’t end here, this mixture of oil and dirt also traps in moisture and metal eating salts, specially in humid environments, thus in-turn spreading the rust far more rapidly, even on galvanized chassis components.

On more modern high-end cars not only does it damage the O2 sensors when applied repeatedly, but also damages or causes suspension sensors (used in most air-suspension equipped cars which have self-leveling feature) to transmit faulty readings, which can be a pain to fix. Moreover, oil exposure to wiring inside the engine bay can cause the plastic wire coatings to become brittle and develop a short-circuit when they start rupturing. This happens because once oil is applied, the engine heat starts affecting the plastic coatings by raising the temperature of the surface beyond its designed performance envelope.

This could have been forgiven and forgotten had this practice only been observed at the low-cost spectrum service gas stations. But to my horror, most of our dealerships (more commonly referred to as Stealerships in Pakistan) are involved in such practices too, despite strict guidelines from manufacturers to only use water as a means to cleanse the chassis and suspension components.

Whether it’s a practice to protect their own interests, in order to keep the inventory rolling or simply a case of ignorance and lack of knowledge, is anyone’s guess, but its ultimately the dealership’s responsibility to follow the correct guidelines supplied by the manufacturer while servicing the vehicle. Isn’t this the reason why we pay them exorbitant service charges? It’s their job to know.

Educating the masses is another way to prevent our hard earned money being washed down the drain and that’s exactly what the purpose of this article is. Next time you take your ride for a service, ask the gas station or your respective dealership to wash the car with water or high-pressure steam only. Spraying oil under your car might give a temporary relief from those annoying creaks and rattles, but in the long run, it’s surely going to cause you hell of a of trouble.

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Umer J Saleem

Umer J Saleem is a Mechanical Engineer with a minor in Automotive Engineering from Michigan State University. Since an early age he has been extremely fond of cars and it's this very love for cars that made him follow his dream and go all the way to Motown. He loves Nihari Paye and sleeps at night with his camera by his side.

  • rashid

    Amazing “carcinogenic asbestos crackers”!

  • Ahmed

    This is probably the first time that I have read an article on PW blog written in such proper English. I have thus really enjoyed the article which is quite informative as well. Thanks Umer J.

  • Tausif | توصیف

    Good piece of writing. Keep them comming.

  • Naveed

    What about spraying WD40 on bushes etc?

  • Zee

    Does this also apply to petrol?

  • MasroorGilani

    Very nice and well written article. I have seen the warnings about oil spray on under carriage at service stations in Islamabad, but both customers and servicemen only feel accomplished after doing this job.

  • FSY

    Interesting… I’ll make sure that next time, I won’t let the guy apply diesel to my car and bike!

  • Sabeeh Ur Rehman Tariq

    I don’t think so, I have used petrol with a mixture of car shampoo……… The petrol helped in taking care of stains and other hard codded godforsaken mud thingies and after a while it just turned into vapor and it was gone. :_

  • Sabeeh Ur Rehman Tariq

    WD40 is more like for rusty parts. It attracts dust too so, I don’t think so. I use it on door hinges and stuff but not under the body

  • Sabeeh Ur Rehman Tariq

    I knew it…………….. there was always something fishy about that shinny engine bay. -_-

  • Ahsan

    Very useful piece of information.

  • Is this true for bikes as well?

  • Amir

    I guess you are not completely correct. The petrol will affect the rubber parts too. The problem is not specific with diesel, it’s associated with any petroleum derivative product. Though, petrol may evaporate readily, so, may be it won’t damage that much and won’t attract dust. But, I guess it will still cause harm. A proper car shampoo is enough to wash your car followed by a proper polish/ wax. Just my 2 cents.

  • Yes.

  • Petrol/Diesel/Oil all have the same effect on rubber parts. It is best to use water only.

  • Arshad

    There is also a practice of spraying the whole engine itself with jet water. A part (I don’t remember exactly which one is that) is covered with plastic bag as according to them, it should not get wet. Is this action also recommendable?

  • Shaqx

    Always WD-40 it bro!

  • Ayub Khan

    Lol, Pakistani people usually follow the moto “Ignorance is a bliss”….

  • Mohsin

    I have a question here. Then what measures we should take to avoid rust on our cars if the oil is not applied?

    Secondly do we have to stop getting diesel on the engines?

  • Faisal Javeed

    I have kept mehran, Honda city and civic, have been driving my own cars for more than a decade and never got oil sprayed, never had any issue of rust.

  • Faisal Javeed

    Special care to be taken not to get water in ECU (if yr car has one). Also Toyota’s ECU is exposed and has no cover, get water in it and it will can cost you a good 60K to 80K.

  • Farhan

    Very useful info, keep it up bro.

  • Sabeeh Ur Rehman Tariq

    oh, thx for the info 🙂

  • tjnapster555

    is ka matlab kay car ko sirf water say he dohain??

  • Fahd Raza

    Wow! I didn’t know this. Now I’ll take care.

  • 509 Cars

    Interesting article. Had no idea that dealerships did this in other countries. Thanks for the post and awareness.

  • Service Master 24 Hour

    Good article, and thanks for bringing awareness. Didn’t know this was a standard procedure there.

  • Abdus Sami

    what then I use in my car after cleaning with water for lubrication?

  • Engr Wasim

    i enjoyed writing style and thanks for valuable information

  • Hamid

    There is no concept of using oil for cleaning or lubing after service , i use to service my car weekly in London they never had use any oil…

  • Hassan Ayaz

    But how to wash the cars engine, when company’s stick sticker on the chassis that do not use high pressure water for engine cleaning? for example: Santro in pakistan.

  • hamaad

    What thoughts do you haave for a 80 rolla , rear whelly !! Should we use oil / diesel or no ???

  • Use fresh Diesel, buy youself and use on under body and avoid the suspension area… enough said.

  • Bilal Ahmed

    Due to the classy roads in Pakistan, its quiet common in every car there might be some lose suspension or something else creating unwanted sound which needs to be stopped. If you say that sparing oil isn’t good then what should a common man do who is already fed up of paying other bills? He will never pay mechanic thousands, if he thinks its OK with spraying oil for 50 or 100 rupees. May be roads need more attention then vehicles, still i will appreciate for such a valuable info. Thanks man.

  • Wasf Wasif

    Very informative article.i didn’t know about it,yesterday got my car serviced & guy asked me to spray oil I didn’t know for what so I told him to spray it,he told it is diesel & after spraying the noises are gone.As you wrote oil leads to eating of bushes that lead to expensive repair works later that are time consuming too.

  • Bitter Truth

    Informative written article and written in professional manner this is the 1st post which is very sound not like local post which are junk like post 🙂 Thumbs up Umer J Saleem.

  • Dr. Taimoor

    The only English mistake I’ve come across in that whole brilliant-written article was that of a spelling for ‘especially’ that he mistakenly wrote ‘specially’. Sorry Umer Jaan. But you are great. May I have your phone number please? 😛

  • Arif Noor Mahsood

    Then how to get rid of Oily Koily Stains on Engine Bay Etc….Should i use only water,Water alone cant work….

  • وجاہت علی

    finally someone raised a real issue!!!

  • Mushtaq

    Very informative article, also stress on what to do.

  • Abdur Rauf

    I have since stopped spraying my car and washing engine.

  • Afzaal M. Khan

    Waxoil chassis coating can be self –made for vintage vehicles .
    Basically it’s wax, turpentine and machine oil blended at medium high tempersture.
    Coat or spray on , stays flexible and gives good protection against corrosion.

  • Hashim Zuberi

    Finally, an automotive engineer seconded what I’ve been telling anyone who’ll listen for the past 15 years.

    carcinogenic asbestos crackers equals LOL

  • AB

    could Diesel spray an alternative to used oil ? Please advise

  • Muhammad Saqib Siddiqui

    Well said Umer, but you mentioned that oil exposure to wiring inside the engine can cause plastic wire coating become brittle. Can you please tell me while applying oil, how can oil expose inside the engine?

  • Muhammad Saqib Siddiqui

    Brother, we shouldn’t wash our car frequently because water and moist air are the sources of rusting. imagine rather to prevent from water we intentionally apply water to the whole body. only use the steam technology.

  • Shoukat Ali Sajidi

    there was a noise from backside of my car (Prius C) i went to toyota dealership they advised me to spry oil while getting wash/clean, believe me, as soon as i got oil sprayed, there was no noise. under such circumstance what to do then if oil spray is not recommended.

  • Ahmed Shahir Usmani

    “Pakistan is probably a country that lies at the very bottom of the awareness index”

    For some reason I wouldn’t agree with this phrase because many uneducated mechanics advised me to not use oil spray two decades ago. May be you were fooled by some.

  • Zaeem Ahmed Chaudry

    Wash with high pressure steam

  • Muhammad Mansoor

    Pakwheels getting low on articles posting something from two years ago. That’s desperate. Informative, but desperate.

  • Zoeb Ali

    If the mechanics were “uneducated”, then how they advised you to not to us oil……please define “educated” and “uneducated” for the masses.

  • Ali Hafeez Azmat

    How come most of the articles on pakwheels don’t show the date of publication

    2nd please share more information on car bike bicycle maintenance