Thursday, November 22, 2012

Are you Cavitating?


Having a conscience in the automotive service industry, and making a living can be like mixing oil and water. I find myself in a constant battle the Ying and Yang of making a living or just simply telling a customer the ramifications of all that I have found. Although it's not my money or car; should a person throw good money after potentially bad?
As a customer, client or guest you need to rely on my honesty. I voice my opinion at times to inform you of repairs I feel might be opening up a proverbial 5 pound can of worms.

All this is simply put on the table as a reference before I begin my story. Currently I have such a vehicle in for repairs and it’s been leaking engine oil much like a severed artery would leak blood.

The car has nearly 275,000 miles on the odometer. Should I be thankful for the work or should I be giving of my observations and opinions. What if my customer cannot afford expensive repairs or ultimately the replacement of this vehicle? 

A decision must be made by an intelligent mature automobile owner. My job is to diagnose, estimate and inform them of what I’ve found. I must then turn the information and observations over to the owner for a final decision.

Restoration Observations

I haven’t seen this car for well over 30,000 miles. Although it had one of my lube reminders in its windshield it was thousands of miles overdue. The oil leak was so profuse it didn't justify a standard LOF. The habit of topping off the oil, but not changing the oil filter was being followed.

That sewing machine sound

Yesterday morning before repairs began I started the car to position it onto a hoist. As the motor sprang to life I was instantly reminded of my childhood and the sounds that a Singer sewing machine would generate.

I quickly turned the key off to check the oil level; it showed oil was a quart low. I again started the engine and although the noise was still there, it wasn't as loud as before and began to finally disappear as volumes of oil began coursing throughout the engine.

My diagnosis and comments
The sound is like valve lash adjuster clatter. For the moment I will assume that the rapid loss of oil can only be from the oil pump, which on this car is driven by the timing belt.

Was it Cavitation?
Yes because air pockets had formed in the oil pump. Have you ever heard that term cavitation, if not you should look it up or even Google it!
This was a very successful repair. The oil pump seals were the cause as I'd  thought they might be and engine damage was not obvious. I will put the car on a 3K interval and watch as well as listen for the next year. I have a good feeling about the car now.