My wife's dumb husband!

[Sultan]

Yesterday my wife's dumb husband checked the coolant level on his 2.9 and drove to a pull a part. The B2 drove great all the way there but after he left the B2 would lose power going up hills. It ran great when it was level. So he thought maybe the gas gauge was wrong and he needed gas. While filling up I looked under the hood and then saw the radiator cap missing. He bought some more coolant and filled it up. The B2 drove perfectly after that.

So the question is why did it loose power when the radiator cap was off?

 

[superds]

The nut behind the wheel was loose?

 

[straycat]

Would not have lost power form that. I drove my tractor on our property for years with no coolant cap and it never lost power. Some other issue I suppose. I know pwople who drove for miles without a radiator cap to go buy a new one and they never lost power.......

 

[straycat]

OOOps....you did not mention about overheating. You said he thought it was a low gas issue. The cap will keep the coolant from spilling out. If hte temp gauge shoots way up then you can damage the motor of course.

 

[Sultan]

It wasn't gas. I watched the temp gauge the whole way which was maybe five to ten miles and it never got warm.

Still stumped....

 

[Captain Ledd]

It wasn't gas. I watched the temp gauge the whole way which was maybe five to ten miles and it never got warm.

Still stumped....

Depends if the temperature sensor was in the coolant, let alone in the hot spot at the upper cylinders and cylinder heads where there was no coolant.

The temperature gauge is merely an average temperature at that spot, and it will vary depending on it's location on the engine. It only measures the coolant temp, not the engine temp.

 

[Sultan]

So when I was going uphill the coolant would drain away from the sensor and then the sensor would tell the computer that is was overheating and kill the power? Is that what you are suggesting?

 

[jhammel85]

I did that once with the oil cap. I could not figure out why it wouldn't idle....lol

Make sure you get all the air out of it. Shutting it off without the cap on sucks in air.

 

[Captain Ledd]

Nope, the extra heat in the engine kills the power, and going up hills it was particularly noticeable.

Without any coolant in an area, and under load, those parts (upper cylinders and cylinder heads) will heat up very hot extremely quick. And if it's not pumping coolant past the sensor, it'll never know.

 

[doorgunner]

I read an article on cylinderhead heat last night....seems that a 40 degree temp increase in cylinder heads causes a 20 H.P. loss.....now that's noticeable!

 

[tbirdsps]

Nothing seems strange to me anymore. A few years ago I left the oil fill cap off and the engine pinged. I opened the hood, slapped my head and put the cap back on and it has never pinged since.

 

[Ranger Sport Honduras]

Just dont do it again, ok?