Water temps all over the place...?
Discussion
Just got back from an epic trip to the Ring and Spa with my R400 D (dry sump). Covered over 1,000 miles in 4 days and made it back to base camp in one piece. So far so good.
However, I encountered a strange situation that has me confused. The ambient temperatures during the first 3 days were very high - in some cases nearly 37 C. On track, water temps stayed in the 90s most of the time, with the odd foray to 102 C after a few laps. Oil also got into the 90s. Then strange stuff started to happen. During an hour long ferry drive from Spa to the Ring, I was just cruising along a country road at constant speed (about 60 mph - no more) when there was a sudden blow out blast of white stuff from the union between the manifold pipes and the cat pipe. The blow out happened almost instantly and never repeated. There was no noticeable change in engine response, and oil/water temps stayed consistent, so I carried on. At the Ring, I checked all fluids, and all was correct, so I headed out for a couple of laps. On the second lap, I noticed the water temp dropping off bizarrely under hard acceleration - for instance, it would drop from circa 90 C to 60 C (or less) when I was accelerating, then recover back to 90 within a few seconds. I eased off, and went back to the hotel to let things cool off. I checked oil and water for signs of emulsion, but nothing was evident. The water level seemed a little low, so I topped up with about 400ml of water. Next morning, the car started up fine and drover fine. After a few miles, I stopped to check fluids, and found that the water level had increased significantly (where did that come from!). After a few more miles driving, the erratic water temp situation had returned - again, only under hard acceleration. Also, when I drive above 60 mph, the water temp level suddently (instantly) drops by about 10 - 15 C, and as soon as I slow back to 60, it goes back up again instantly.
Anybody got any ideas about what might be up? Head Gasket? Water Temp sensor? Something else?
However, I encountered a strange situation that has me confused. The ambient temperatures during the first 3 days were very high - in some cases nearly 37 C. On track, water temps stayed in the 90s most of the time, with the odd foray to 102 C after a few laps. Oil also got into the 90s. Then strange stuff started to happen. During an hour long ferry drive from Spa to the Ring, I was just cruising along a country road at constant speed (about 60 mph - no more) when there was a sudden blow out blast of white stuff from the union between the manifold pipes and the cat pipe. The blow out happened almost instantly and never repeated. There was no noticeable change in engine response, and oil/water temps stayed consistent, so I carried on. At the Ring, I checked all fluids, and all was correct, so I headed out for a couple of laps. On the second lap, I noticed the water temp dropping off bizarrely under hard acceleration - for instance, it would drop from circa 90 C to 60 C (or less) when I was accelerating, then recover back to 90 within a few seconds. I eased off, and went back to the hotel to let things cool off. I checked oil and water for signs of emulsion, but nothing was evident. The water level seemed a little low, so I topped up with about 400ml of water. Next morning, the car started up fine and drover fine. After a few miles, I stopped to check fluids, and found that the water level had increased significantly (where did that come from!). After a few more miles driving, the erratic water temp situation had returned - again, only under hard acceleration. Also, when I drive above 60 mph, the water temp level suddently (instantly) drops by about 10 - 15 C, and as soon as I slow back to 60, it goes back up again instantly.
Anybody got any ideas about what might be up? Head Gasket? Water Temp sensor? Something else?
It all seems a bit strange! I would start looking beyond the cooling system - it could be an electrical issue with voltage regulation (causing instruments to miss-read). Is it a stack dash? Does the aux belt look OK? Either way, I think a serious cooling/engine problem would soon make itself known and not go away.
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