Topic

Well this weekend was meant to be my MG meet in devon. I know a few of you guys on here wanted to come and im sorry that it was called off. On the other hand i did email every MG club in cornwall, devon and most of them in the bristol/somerset areas and they wernt aware that it had been canceled. No body from any of these clubs came.

Still, i would like to express my thanks to Jamie and his son and my dad who did come anyway. Gave a few of us time to have a chat about bits and bobs.

While i was out nosing at the cars a lady friend of mine asked to be taken out for a spin, while i was out i hit the straight and floored it. The engine temp gauge dropped to noting within a couple of seconds and then gently climbed back to where it was suppose to be and remained there. Checked fluid levels and all seems well. What could of caused this drop as im now a bit worried. its never done it before.

Any advice would be appreciated and heres a few pics from yesterday...

Well done, anyway.


As for the sudden drop in temperature, I have two thoughts.

One,
an electrical fault in the sensor wiring. Possibly a temporary short when acceleration moves a wire. You may have to get in there and wiggle the wiring loom around. Try the plug to the sensor first.

Two,
an air bubble in the coolant. I had a similar problem once, although in my case the temp was suddenly rising and then dropping back slowly. This was after the car had run up to temp for a good while. Every time I floored it the temp would shoot up then drop back slowly. I eventually found that a bubble of air was sitting in the coolant around the engine. The increased flow due to acceleration was pushing the bubble to the site of the sensor at the engine coolant outlet. Suddenly the sensor was measuring hot air instead of coolant.
I suspect you may be having this (opposite) effect if the engine was relatively cold when it happened. Try bleeding the coolant at the engine bay bleed.

Just to add that a rapid change in temperature reading is almost always not due to overheating if the system has sufficient coolant.