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Guest · Posted: Mon Jun 04, 2001 8:49 am Post subject:

From: wayne d
Email: wdeblaker@hot.rr.com
Date: 04 Jun 2001
Time: 08:49:25

The Mystery of the Oil Gauge
..... This is definitely a rude and crude tip, but it can save time and headaches. One of our member shops (a lube shop) called up. His people had just changed the oil on a Ranger, 2.31. Seems the customer got some distance down the road when the lifters started chattering and the oil gauge read very, very low. After he had checked it over, replaced the oil and filer, again, it still had the problem. Of course the customer blamed the shop, and the shop was wondering how just changing the oil and filter could cause low oil pressure.
..... I helped the shop check the engine oil pressure using a master gauge and determined the Ranger did have an oil pressure problem. The gauge would surge to a normal reading upon start up, then steadily drop to almost zero pressure within a few seconds. I told the shop it was probably a pressure relief valve problem, and to explain to the customer that the oil pan would have to come off for inspection. Tell the customer the shop would repair it for no charge. If it was the shop's problem (and it may not be), then it would be customer pay. We have all been there. The "it didn't do that before you people..." headache. The customer agreed to this.
..... Here is where the crudeness comes in. This also falls under you NEVER want the customer around when this is attempted. Let the vehicle sit over night, preferably outside, where the oil can get good and cold. Start the engine, and almost immediately floor the throttle and hold it for a second (a second seems like a looong time at WOT), release the throttle and open it again. If there is junk in the pressure relief valve, the cold oil hitting the valve suddenly will force the valve wide open, and often flush out whatever was holding the valve open. If it doesn't flush it, you were no further behind than before. In this case, it worked, and saved time and dollars for both shop and customer.

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