INTRODUCTION
You hurriedly got in to your car, ready to drive to work, and suddenly you kinda notice that warning lights have kit up on your instrument cluster, and you're like, "thus wasn't there yesterday, so, how on hell did all these lights lit up in the cluster today"?

You got the car scanned with your Bluetooth scan tool, and discovered, you've got a P0302 code logged in the ECU (car's computer).

What should you do next?

Well, helping you answer that question, would be ....But do realised that machines, even human beings, are bound to fail some day. They're frail.

So, that shouldn't be surprising to you.
But if you've being up and doing as regards your car's scheduled maintenance, some of those failures car's experience Daiky, and the attendant financial drains that cone with fixing them, would have being abated.

Today, I'd be tackling a rare instance where engine oil spills having its way through the spark plugs ports have caused issues like the scenario enumerated in the introductory paragraph.

It should be noted that asides, engine oil intrusions into the spark plug ports, other known causes of such code (P03002), are ignition, mechanical, fuel, and even electrical systems related.

For instance, fouled spark plugs, or a clogged injector system, would definitely set up such codes.

WHAT ARE THE SOURCE(S) OF SUCH OIL SPILLS?
Most engine oil spills into the spark plugs ports, are as a result of a failed top cylinder head valve cover gasket (seal).

These gaskets, are susceptible to heat, and aging. So, if your car's mileage is in the hundreds of thousands, and its having problems with oil shortages, you've got to suspect the valve cover gasket is brittle already. This would fail to provide the sealing capability it was intended.


SYMPTOMS OF A FAILED VALVE COVER GASKET

1.Engine oil spills are everywhere in the engine's compartment, especially the top cylinder area.

2. Engine performance and driveability us affected. In some severe cases we've seen, you lose some kind if power, when you drive the car. It bugs down, as you try to accelerate.

3. Various warning lights get lit up on the instrument cluster.
Engine oil getting into the spark plugs ports, would hamper one of the combustion strokes(spark)on a particular or all cylinders.

This, would shortened the lifespan of the spark plug coils, if your car is equipped with a coil on pack (COP) system.

The reason for the potential ignition system coil reduced lifespan is that the ECU ignition system drive, tries as much as possible, innumerable times to provide the sparks needed for the completion of the combustion cycles, but it's just unable to cope with the load. So, it then fails.


HOW TO PREVENT THIS FROM HAPPENING
Replace the top cylinder head valve cover gasket (seals), when there's sign of a leak, around the top cylinder.
Do not attempt to reuse the valve cover seal, by applying RTV gasket sealer. That would only be a short term fix.

PS: Do not use old gasket seal.
Use only OEM specified gasket seals


CONCLUSION
There isn't a one peg fits all instance in situations like these.

Oil leaks, especially around the top cylinder head area, shouldn't be taken for granted. They could wreck havoc, and may have you stranded somewhere, you've never expected.

Always have the engine compartment of your car, detailed. Thus would unmask any oil leaks, that you might not be seeing at the moment.

Replacing the valve cover seals, especially on V engine configurations, isn't that easy, as their I4 cylinder counterpart, but it's a worthwhile investment.




CASE STUDY

Vehicle model/year: Rav4; 2008
Mileage on "her"!: 156,940mi
Transmission system: Automatic
Engine configuration: 4cylinder, with VVTi; 2AZ-FE


Complaints from customer:

¶Excess fuel consumption
¶Warning lights on the dashboard (Check engine, Slip indicator, ABS)
¶Loss of power. The engine doesn't just give a proportional response to the throttle.


The FIX!

¶Get the car scanned first before doing anything.
Retrieve the codes, and read through the freeze frame data, to give you a clue, when the fault occurred, and under what parameters(You could look at the engine temperature, intake air temperature, and trim fuel values), to come to some sort of conclusions.

¶We already got a P0302 code retrieved from the car's ECU (computer system).
Here, we already know that the problem was coming from only a particular cylinder (and that was cylinder number 2).

A P0302 code, sets when a car's ECU (or computer) system, detects engine misfires, as a result of any of the following reasons mentioned below:

a) faulty injector system
b) faulty ignition system
c)faulty mechanical related problems vis-à-vis an above normal cylinder bore diameter.

But how do you know the actual problem the code was indicating was?

This was what we did. Prior to this time, we've worked on the car's suspension system (all engine mounts and front and rear shocks have being replaced), and there wasn't such problems, when the customer brought in the car.

¶Started the engine, and unplugged all the fuel injectors and ignition system coils, one after the other, to test how the engine reacts under such conditions, and even interchanged the ignition coils. There wasn't any improvement.

¶Decided to remove the spark plugs one after the other, to inspect them visually.

To our surprised, the spark plug on number 2cylibder, was submerged in engine oil, probably coming from the valve cover gasket.

That was where the problem was coming from.
It would behoove you to note that all the other spark plugs, had little spills on their threaded extensions. But that wasn't a problem, for the engine as at the time.

¶Cleaned the spark plugs, and tightened then back.

Please be absolute careful when tightening the spark plugs back in. If done wrongly, the ceramic insulator (that whitish long rod), could get broken in the cylinder head plug port. That would be hell to remove.

¶Replaced the old, brittle valve cover gasket, with an OEM one.
In some instances, I don't apply RTV seals on the purchased gasket. If you aren't comfortable with that, you lightly apply on the sides of the gasket(s), before covering em up.

¶Allowed it to set for say, 5-10min, before starting the car.

¶Erase all stored codes, and do a drive cycle test, to simulate the parameters under which the code(or fault) was indicated earlier on by the customer.

¶Hand over the car to the customer after confirmation of job done, and you're DONE fixing it!

DISCLAIMER
If you aren't comfortable working on systems like these, please do visit your dealer for consultations.
Failure to follow the procedures as enumerated above, is at your own risk. I am not responsible for any eventualities, if not done well.






Regards,
Igono Joseph Okeme
DW Nig Ltd
oigonojoseph@yahoo.com/info@dxta.net.ng
08066643532(calls/WhatsApp)
Twitter: @dw_Nig
Facebook page:
https://www.facebook.com/Dexterwise-DW-Nig-Ltd-767933589982123/

You did not remember to define P0302.

Tried this supposedly simple task on my car one time. And i tell ya all it is hell on earth. Will try it again as part of service soon.

Also bought an identical spare engine for #25 on its way down now. Fun fun

@timifakay: Thanks for the reminder. That's being done now.
@ricki: You saying you bought that valve cover seal gasket for #25k, or ?
Well, not that an easy tasks, if you own a V configured engine.

TRYGO:
@timifakay: Thanks for the reminder. That's being done now.

@ricki: You saying you bought that valve cover seal gasket for #25k, or ?

Well, not that an easy tasks, if you own a V configured engine.

Entire engine
Can somebodi spell awoof for us...

Mine is just 4 cylinder but coolant temperature sensor is inside the cover and it become undone one time then broke eventually.

ricki:


Entire engine
Can somebodi spell awoof for us...

Mine is just 4 cylinder but coolant temperature sensor is inside the cover and it become undone one time then broke eventually.

What car is this?

TRYGO:
@timifakay: Thanks for the reminder. That's being done now.

@ricki: You saying you bought that valve cover seal gasket for #25k, or ?

Well, not that an easy tasks, if you own a V configured engine.

can a vehicle with bad shock front and rear trigger a code?

Yes, it depends on the kind of vehicle, and how the suspension system is designed.

For instance, vehicles with air/hydraulic system operated suspension systems, would trigger a or some codes, if there are problems with the system.

Example of vehicles you could find this applications are some variants of Lexus (like LX570); range rovers, etc.

Cars like the one in question on this article has got no air hydraulically operated suspension systems. So there isn't any information that's being sent to the car's ECU, as regards various checks that's being run on air hydraulically operated ones.

You determine such checks, basically by experiential knowledge.


Hope this clarified your questions.




Regards,
Joseph
08066643532(call/WhatsApp)
DW Nig Ltd
Lagos
www.dxta.net.ng