My oil guage usually indicates around "40", though when i stop to idle at a light it goes down to around "30". Last night i think i hit something under the car (i could hear it) and this morning on my way into work the needle was around 40 but would then jump all the way to 120 (nearly pegged), then jump around between 40-120 for the rest of my 30 mile commute. I checked under the hood once i was at work, but no obvious oil leaks. Oil level on dipstick was still normal. Seemed to drip a bit more oil than usual from the oilpan though. Also, there is a metal line that runs right in front of the lower engine, right next to the engine torque absorber in the front....and it looks as if that line is a bit kinked, like something hit the line and smashed it around the engine torque absorber. I should mention that this line has been a BIT kinked ever since i got the car, but it appears to be more so now that i look at it.

Anyone know what line that is?

What other explanations are there for the oil guage jumping around so much?

Thanks!

Is that line going to the radiator? You have a 3-core radiator. Coolant, engine oil, and trans.

120 is a bit high. At first thought I'd suspect the pressure sending unit, and for the low cost, that would be a first step to simply change it.

Next, I'd identify that line for sure, and replace it.

Hey will,

The line isn't hte transmission send or return, I just had those replaced about a year ago when they leaked. It is the line attached to the metal frame crossbar, further back than the transmission cooling lines.

A guy at work who used to work at a GM garage thought it might be a loose wire either in the dash or else on the pressure sending unit. But i'm not sure where the pressure sending unit is either, unless it is on the oilpan?

Here is a link to the oil pressure sending unit location.

http://www.bonnevilleclub.com/forum/...l+sending+unit

Oil LEVEL sensor is in the pan. The PRESSURE sender is in the back of the block in front of the passenger seat (that side of the motor) above the fuel filter. It'* easier to access through the fenderwell or from underneath.

If the lines you're talking about end at the radiator and they're NOT the trans lines, those are the oil cooler lines. The should originate at the filter assembly.

Ok, just brought it into the shop, as the SES light was going on a couple times in addition to the other problems.

They said they would replace the Pressure sending unit for $100, but the SES codes were relating to a bad EGR, which they will replace for $400. They also suggested replacing the transmission fluid with synthetic for $250. Does that sound about right?

The good news is that they said the engine had been dumping more fuel to correct the engine running lean, so hopefully once i have a new EGR i'll also have good gas mileage again. It used to be around 22mpg (premium) but lately has been more like 15-18mpg.

Thanks for all your help. Here'* hoping that the pressure sending unit is the problem, not the cluster in the dash.....

I'd do the work myself and save $350.00. It'* not that hard, and a Chilton manual (available at your local library if you don't care to buy one) should outline both procedures.

As to the synthetic transmission oil, it came from GM with petroleum-derived ATF, so what'* the advantage of synthetic? I think the answer is "it boosts dealership profits."

All in all, sounds like a typical dealership ream job to me.

Sounds to me like that the dealer is hard up for cash durning these slow holiday times. It takes less than 2 mins to unbolt the EGR valve. I would take the EGR valve off, and clean it and the ports running to it. The sending unit takes about an hour to replace and is only about $25.00 from autozone. Don't waste your hard earned cash on places like this that quoated you these prices.