Hello all, I’ve searched threads, poked around a good bit, looked through the rave manual, and replaced parts referring to relevant posts, and my problem is slightly better, but not fixed. My 98 D1 is slowly cooking itself. Never overheated, but runs hotter than “normal”. Using an UltraGauge, at idle and slow speeds under 10mph it runs fine - 188 to 195 degrees or so. On the highway, or consistent speeds above say 40mph, the temp bumps up to 210-212. Highway, at 65-70mph I’ll see 215 degrees, uphill pushing hard - 219 degrees (ac on or off doesn’t matter).
History – a month ago I drove it to VT from NJ on a cool night - first time using the UltraGauge. It hit 225 going up hill at 65mph, ac off, I backed off and it came down a bit to 219. That was the hottest I’ve ever seen - of course the dash temp needle stays a little below 9 o'clock at all times. After reading posts and logically trying to decipher the issue, I replaced the thermostat (did nothing), then the radiator – a RockAuto Nissen (ran a little cooler), because my stock radiator did have some scaling when I looked into the cap, then I finally replaced the water pump. The old water pump had a little notching when turned by hand when I removed it, no leaks, fins were okay, so this probably wasn’t it. After the water pump replacement and no change in highway temp driving, I thought maybe I got a bad thermostat, so I purchased a new thermostat and tried again. No change – still at 212-215 on the highway, perfect at idle. I thought maybe it was a bad temp sensor, but it is hot after a highway stint - the hood latch and prop rod are very uncomfortable to touch without gloves or a rag. The electric fan does come on with the a/c and stays on when hot - key out of the ignition. The fan clutch is still stiff when cold. The system does not lose coolant, coolant is clean, no bubbles in the coolant when on, the engine oil is still clean after 500 miles, I burped the system twice between every parts change (and no loss of coolant), the flow of coolant at the upper radiator plug is consistent when when burping the system, will even overflow quickly when giving a little gas when burping. I feel the disco is slowly cooking and I’m slowly getting more grey hairs trying to figure it out.
This isn’t a daily, so I’m not driving it consistently, especially since we’re in a heat wave right now in the 90’s. The disco has 76,000 miles, I am not the original owner.
Could I have received a bad new Nissen radiator? I ordered a temperature gun and will run it across the new, installed radiator when I get it tomorrow. Should there be a difference from top to bottom, left to right? I have the old radiator still and was planning on having it flushed/rodded and kept as a spare – should I have that done and try the old radiator again? Are blockages elsewhere in the cooling system common? Thanks for any advice!
History – a month ago I drove it to VT from NJ on a cool night - first time using the UltraGauge. It hit 225 going up hill at 65mph, ac off, I backed off and it came down a bit to 219. That was the hottest I’ve ever seen - of course the dash temp needle stays a little below 9 o'clock at all times. After reading posts and logically trying to decipher the issue, I replaced the thermostat (did nothing), then the radiator – a RockAuto Nissen (ran a little cooler), because my stock radiator did have some scaling when I looked into the cap, then I finally replaced the water pump. The old water pump had a little notching when turned by hand when I removed it, no leaks, fins were okay, so this probably wasn’t it. After the water pump replacement and no change in highway temp driving, I thought maybe I got a bad thermostat, so I purchased a new thermostat and tried again. No change – still at 212-215 on the highway, perfect at idle. I thought maybe it was a bad temp sensor, but it is hot after a highway stint - the hood latch and prop rod are very uncomfortable to touch without gloves or a rag. The electric fan does come on with the a/c and stays on when hot - key out of the ignition. The fan clutch is still stiff when cold. The system does not lose coolant, coolant is clean, no bubbles in the coolant when on, the engine oil is still clean after 500 miles, I burped the system twice between every parts change (and no loss of coolant), the flow of coolant at the upper radiator plug is consistent when when burping the system, will even overflow quickly when giving a little gas when burping. I feel the disco is slowly cooking and I’m slowly getting more grey hairs trying to figure it out.
This isn’t a daily, so I’m not driving it consistently, especially since we’re in a heat wave right now in the 90’s. The disco has 76,000 miles, I am not the original owner.
Could I have received a bad new Nissen radiator? I ordered a temperature gun and will run it across the new, installed radiator when I get it tomorrow. Should there be a difference from top to bottom, left to right? I have the old radiator still and was planning on having it flushed/rodded and kept as a spare – should I have that done and try the old radiator again? Are blockages elsewhere in the cooling system common? Thanks for any advice!
