1998 Cadillac Eldorado werid cooling system issue HELP

GCP4 · #1 (**permalink**) 07-25-08, 11:51 PM

I Just bought a super clean 98 Eldorado ETC. I put new antifreeze and a thermostat in in right away. The car runs great but everyonce in a while at a light the temp gauge will go to the next line after the half way point. I Know these northstars pretty well. I've owned a ton of them. Im 98% sure it's not a headgasket issue. Im think radiator. Any Ideas??

kdsevillle · #2 (**permalink**) 07-25-08, 11:57 PM

Idk but what ever your problem is I'm having the SAME THING. When I idle it gets hot. Put in new coolant tank, coolant, and thermostat also. Still gets hot when idle.

**Ranger** · #3 (**permalink**) 07-26-08, 12:19 AM

Check the belt tensioner & the purge line.

GCP4 · #4 (**permalink**) 07-26-08, 02:21 AM

You mean the belt tensioner on the water pump and the purge line for flow?

BIG ERN · #5 (**permalink**) 07-26-08, 08:16 AM

thats what he means

submariner409 · #6 (**permalink**) 07-26-08, 10:24 AM

Don't forget that with the A/C off the fan(s) don't start in low until 224 degrees, near the "1 o'clock" line.

The gauge is sort of tailored to fool you (average owner) in that the 12 o'clock line covers from 190 degrees to 210+: Modern vehicle owners are scared silly when a gauge actually moves in time to engine functions, so the makers damp the movement to practically zero. Imagine the warranty screams if Maggie Jane could see her oil pressure actually vary from (hot) 16 psi at idle to ~50 psi on the road.

Click on the pic and scroll in. The approximate temps were done by one of our members a couple of years ago and were created by allowing the car to heat up with the radiator covered. It's a good guide, though. If you want the dead-nuts truth, go to www.scangauge.com. (Backordered 2 weeks.)

**Ranger** · #7 (**permalink**) 07-26-08, 05:19 PM

Quote:

Imagine the warranty screams if Maggie Jane could see her oil pressure actually vary from (hot) 16 psi at idle to ~50 psi on the road.

Sub, I think it is more like 5 psi at idle. That would REALLY panic them.

submariner409 · #8 (**permalink**) 07-26-08, 08:26 PM

Yep, The 2002 FSM minimum pressure specs are 5 psi/idle, 35 psi/2,000. There were a couple of threads, one a few weeks back, another last year about this time, wondering about flickering oil pressure warning lights. The first time around I dug into my gauges and copper tube box and jury-rigged a SW 0-80 psi 270 degree mechanical gauge with a T for the sending unit. Ran the gauge to the air intake grille dent area in front of the driver's side and left it there for a week. Lowest I saw, hot idle, was 15 psi, and around 47 psi, hot, highway (60 mph/2000 rpm cruise.). Someday I fully intend to permanently install a mechanical oil gauge, maybe in the flip-up ashtray puka, because I hate and distrust idiot lights.